Ketan Jhunjhunwala | NIMHANS - Academia.edu (original) (raw)

Papers by Ketan Jhunjhunwala

Research paper thumbnail of Repetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp

European Journal of Neurology, Jan 26, 2015

Background and purpose: Writer's cramp (WC) is a focal task-specific dystonia of the hand which i... more Background and purpose: Writer's cramp (WC) is a focal task-specific dystonia of the hand which is increasingly being accepted as a network disorder. Non-invasive cortical stimulation using repetitive transcranial magnetic stimulation (rTMS) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsfMRI). Methods: Nineteen patients with right-sided WC and 20 matched healthy controls (HCs) were prospectively evaluated. All patients underwent a single session of rTMS and rsfMRI was acquired before (R1) and after (R2) rTMS. Seed-based functional connectivity analysis of several regions in the motor network was performed for HCs, R1 and R2 using SPM8 software. Thresholded (P < 0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Results: Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After rTMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamusÀright globus pallidusÀright thalamusÀright prefrontal lobe network loop. Conclusions: It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by rTMS probably act through subcortical and trans-hemispheric unaffected connections. Longitudinal studies with therapeutic rTMS will be required to ascertain whether such information could be used to select patients prior to rTMS therapy.

Research paper thumbnail of Can yoga lead to maladaptive plasticity resulting in disorder of motor control?

Annals of Movement Disorders, 2020

The practice of yoga is based on the traditional Indian philosophy. Children during their develop... more The practice of yoga is based on the traditional Indian philosophy. Children during their development show adaptive neuroplasticity which is due to long-term potentiation that causes changes in the synaptic transmission. Excessive plasticity in the developing brain can lead to maladaptive neuronal circuits which can cause hyperkinetic movement disorders. It is not clear at what age yoga should be started and whether certain yogas or yogas done improperly can lead to maladaptive plasticity. We report here an unusual case of tic disorder which was precipitated by yoga.

Research paper thumbnail of Shaky and unsteady: Dynamic posturography in essential tremor

Journal of the neurological sciences, Jan 15, 2018

The spectrum of symptoms exhibited by patients with essential tremor (ET) extends far beyond the ... more The spectrum of symptoms exhibited by patients with essential tremor (ET) extends far beyond the classical tremor. This study aims to explore and establish the presence of subtle balance abnormalities in ET using dynamic posturography (DP). DP was performed on 18 patients with ET and 26 controls. Diagnosis of ET was based on the Consensus Statement of the Movement Disorder Society on Tremor. Dynamic stability which included the overall balance index, anterior-posterior index and mediolateral index, and limits of stability were measured. Patients with ET had significantly impaired balance indices. Impairment of dynamic stability revealed poor static balance control in all directions. Lower limits of stability scores indicated a smaller range of motion prior to which patients have to shift foot balance. No correlations were observed between age at evaluation, age at onset, duration of illness and the balance indices. Dynamic posturography reveals significant balance impairment in pati...

Research paper thumbnail of Imaging biomarker correlates with oxidative stress in Parkinson's disease

Neurology India, 2017

While oxidative stress (OS) may be one of the crucial factors determining the initiation and prog... more While oxidative stress (OS) may be one of the crucial factors determining the initiation and progression of Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease (PD), its correlation with gray matter (GM) atrophy is not known. To determine the GM volume (GMV) changes using voxel-based morphometry (VBM) and correlation with OS marker serum malondialdehyde (MDA) in PD. Seventy-two patients with PD were clinically evaluated and underwent magnetic resonance imaging (MRI) on a 3T MRI scanner using a 32-channel head coil. Lipid peroxidation product MDA levels were measured by spectrophotometry. MDA levels and regional GM differences using VBM were compared with 72 healthy controls. The mean age of the patients was 51.3 ± 10.6 years and that of controls was 50.8 ± 10.4 years. The mean age of onset of symptoms in PD was 45.2 ± 11.3 years. In PD, serum MDA level was significantly higher than that in controls (0.592 ± 0.89 μmol/l vs. 0.427 ± 0.055 μmol/l; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). Compared to controls, patients had greater regional GM atrophy in all the brain lobes (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, uncorrected). A significant positive correlation was found between GMV and MDA in the caudate nucleus (CN) and posterior cingulate gyrus (PC) in the patient group (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, uncorrected). We observed GM atrophy in all major brain lobes of patients when compared to controls. Only in the patient group, a significant positive correlation was observed in CN and PC with MDA. These findings suggest that, even though the whole brain is affected in PD, some of the non-substantia nigra regions of the brain, such as CN, may have some differential compensatory mechanism, which are preserved from oxidative damage.

Research paper thumbnail of Research in Parkinson′s disease in India: A review

Annals of Indian Academy of Neurology, 2016

treatment). The reference lists of included publications were also searched. Studies were eligibl... more treatment). The reference lists of included publications were also searched. Studies were eligible for inclusion if: i) PD was evaluated in India. The exclusion criteria were: 1. Parkinsonism apart from PD such as atypical Parkinsonism and secondary causes, 2. Animal studies, 3. Case reports, and 4. Pharmaceutical trials. The search results have been given in Table 1. A total of 95 articles were according to the search criteria. The first published article from India on PD in indexed journals could be traced to 1988. In later years, the number of publications has steadily increased [Figure 1]. There are more publications in international journals (n = 76) than in national journals (n = 19). We attempted to categorize the articles on various aspects, such as clinical, epidemiology, genetics, pathogenesis, investigations, pathology, treatment, social issues, and physical rehabilitation. Of these, clinical aspects, nonmotor involvement

Research paper thumbnail of Movement disorders of probable infectious origin

Annals of Indian Academy of Neurology, 2014

as HIV [4] have been reported causing whole range of MDs. Kalita and Misra [8] in their study on ... more as HIV [4] have been reported causing whole range of MDs. Kalita and Misra [8] in their study on Japanese encephalitis had reported predominant post-encephalitic dystonia. Isolated case reports of infl uenza virus encephalitis causing chorea and paroxysmal dyskinesias have also been reported. [6,9] Bacterial infections such as streptococcal group causing Sydenham's chorea have been most widely proven. Though the incidence of Sydenham's chorea has reduced it is still prevalent in developing countries. Parasitic infections such as toxoplasma abscesses in the subthalamic nucleus, thalamus, caudate nucleus, or globus pallidus have been reported to be associated with contralateral limb ballism, choreoathetosis, and dystonia. [3] Several studies have a empted to explain the MDs secondary to specifi c infectious agent. Apart from a large study on SMD [2] conducted at our center, most of the reports are limited to a single patient or a series of patients defi ning a particular infectious agent. The conclusions from these studies are varied and diffi cult to generalize. The objectives of our study were to 1. Characterize the pattern (phenomenology) of MD temporarily related to infection 2. Characterize the probable nature of infection causing SMD, and

Research paper thumbnail of Posttraumatic movement disorders: A clinical and imaging profile of 30 patients

Neurology India, 2019

Background: Posttraumatic movement disorders (PTMDs) are frequently associated with severe head i... more Background: Posttraumatic movement disorders (PTMDs) are frequently associated with severe head injury. There are very few studies on the clinical phenomenology and radiological correlation of PTMD. Aims: To study the clinical phenomenology of patients with PTMD and correlate it with the site of lesion on brain imaging. Materials and Methods: This was a prospective study of patients with suspected PTMD. All of these patients underwent neurological evaluation to characterize the phenomenology and imaging, such as computed tomography/magnetic resonance imaging (CT/MRI), to localize the site of lesion. Results: The age of the patients was 32.6 ± 16.4 years and the age at onset was 29.1 ± 16.0 years. Right upper limb was the initial body part affected in 36.7% patients. Tremor (alone or with dystonia) was the most common movement disorder (MD; 44.7%) followed by parkinsonism (17.2%), dystonia (13.8%), dystonia plus (dystonia associated with choreoathetosis: 10.3%), mixed MD (more than o...

Research paper thumbnail of Neuroinvasiveness of West Nile Virus: A Case Report (P6.013)

Neurology, 2018

Objective: To highlight the neurological manifestations of West Nile Virus Background: We present... more Objective: To highlight the neurological manifestations of West Nile Virus Background: We present a case of serologically proved West Nile virus with involvement of cervical motor neuron cell, brainstem and cerebellum suggestive of neuro invasiveness of the virus. Design/Methods: Twenty-eight right-handed African-American female presented with fever and headache for 8 days. Patient reported she was apparently in perfect health about 8 days back when she had sudden onset bi-frontal headache which was not associated with nausea, vomiting and photophobia. Three days following the headache patient started complaining of high-grade fever with nausea and vomiting. After starting antibiotics next day patient’s aunt noticed that patient was not able to use her bilateral upper limbs to text from her cell phone. On initial evaluation patient had symmetric bilateral upper limb proximal weakness with absent reflexes in upper limb. Bilateral lower limb power was normal with normal reflexes. Pati...

Research paper thumbnail of Basal ganglia contributions during the learning of a visuomotor rotation: effect of dopamine, deep brain stimulation and reinforcement

It is commonly thought that visuomotor adaptation is mediated by the cerebellum while reinforceme... more It is commonly thought that visuomotor adaptation is mediated by the cerebellum while reinforcement learning is mediated by the basal ganglia. In contrast to this strict dichotomy, we demonstrate a role for the basal ganglia in visuomotor adaptation (error-based motor learning) in patients with Parkinsons disease (PD) by comparing the degree of motor learning in the presence and absence of dopamine medication. We further show similar modulation of learning rates in the presence and absence of subthalamic deep brain stimulation. We also report that reinforcement is an essential component of visuomotor adaptation by demonstrating the lack of motor learning in patients with PD during the ON-dopamine state relative to the OFF-dopamine state in the absence of a reinforcement signal. Taken together, these results suggest that the basal ganglia modulate the gain of visuomotor adaptation based on the reinforcement received at the end of the trial.

Research paper thumbnail of Phenotypic Variability of Essential Tremor Based on the Age at Onset

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 2019

ABSTRACT:Background: Essential tremor (ET) is reported to have a bimodal distribution of age at o... more ABSTRACT:Background: Essential tremor (ET) is reported to have a bimodal distribution of age at onset (AAO) with phenotypic variability based on the AAO. This study aims to explore the distribution of AAO based on mathematical modeling and ascertain the differences, if any, in the clinical features of groups. Methods: A chart review was conducted for 252 patients with ET diagnosed based on the Consensus statement of the Movement Disorder Society on Tremor. Finite mixture modeling was performed to identify groups of the cohort based on the AAO. Results: Three groups were defined: early onset (EO): AAO ≤ 22 years, n = 63, intermediate onset (IO): 23 ≤ AAO ≤ 35 years, n = 43, and late onset (LO): AAO ≥ 36 years, n = 146. There were no significant differences related to family history or responsiveness to alcohol. The EO group had significantly higher prevalence of upper limb and lower limb tremor. Head tremor and voice tremor was more prevalent in the IO and LO groups. Cerebellar signs...

Research paper thumbnail of Clinical Utility of Longitudinal Measurement of Motor Threshold in Wilson’s Disease

Canadian Journal of Neurological Sciences/Journal Canadien des Sciences Neurologiques, 2019

This study describes the longitudinal changes of resting motor threshold (RMT) and central motor ... more This study describes the longitudinal changes of resting motor threshold (RMT) and central motor conduction time (CMCT) in 18 patients with Wilson's disease (WD). The RMT, CMCT, and Global Assessment Scale for Wilson Disease (GAS-WD) were measured at baseline and at follow-up after 12.94 ± 7.23 months. There was a significant decrease in the RMT (72.11 ± 18.62 vs. 63.7 ± 15.52%; p-value = 0.002) and GAS-WD scores (14.38 ± 5.35 vs. 9.77 ± 6.47 ms; p-value = 0.04). CMCT did not improve despite chelation therapy. Hence, RMT may serve as a marker of chelation efficacy in WD. RÉSUMÉ: Utilité clinique des mesures longitudinales du seuil moteur au repos dans le cas de la maladie de Wilson. Cette étude entend décrire les changements longitudinaux affectant le seuil moteur au repos (SMR) et la vitesse de conduction nerveuse motrice (VCNM) chez 18 patients atteints de la maladie de Wilson. Tant le SMR et la VCNM que la Global Assessment Scale for Wilson Disease (GAS-WD) ont été mesurés au départ de l'étude et au moment d'un suivi après 12,94 ± 7,23 mois. Une diminution notable du SMR (72,11 ± 18,62 contre 63,7 ± 15,52 % ; p = 0,002) et de la GAS-WD (14,38 ± 5,35 contre 9,77 ± 6,47 ms ; p = 0,04) a pu être observée. En revanche, aucune amélioration sensible de la VCNM n'a été notée en dépit d'une thérapie par chélation. Par conséquent, il se pourrait que le SMR, dans le cas de la maladie de Wilson, puisse être utilisé comme marqueur de l'efficacité de la thérapie par chélation.

Research paper thumbnail of Implications of secondary unresponsiveness to dopaminergic drugs with preserved response to subthalamic nucleus stimulation in Parkinson's disease

Neurology India

Improvement in motor symptoms with levodopa is one of the hallmark features of Parkinson's di... more Improvement in motor symptoms with levodopa is one of the hallmark features of Parkinson's disease (PD). The response to levodopa may reduce during the course of the illness. Few studies have also reported reduced response to levodopa in patients with PD several years after deep brain stimulation (DBS) of the subthalamic nucleus (STN) on both the sides. In this study, we report an extreme unresponsiveness to levodopa in the presence of a good response to STN stimulation in a patient 5 years after the DBS proceudre had been carried out. The implications of this phenomenon are also discussed.

Research paper thumbnail of Abnormalities of Eye-Hand Coordination in Patients with Writer's Cramp: Possible Role of the Cerebellum

Tremor and other hyperkinetic movements (New York, N.Y.), 2017

Writer's cramp (WC) is one of the commonly observed focal dystonias. The pathophysiology of W... more Writer's cramp (WC) is one of the commonly observed focal dystonias. The pathophysiology of WC has not been fully understood. The role of the cerebellum has been increasingly recognized in the pathogenesis of dystonia. As the cerebellum is crucial for maintaining accurate eye-hand coordination (EHC), its role in the pathogenesis of WC can be investigated by studying the EHC in patients with WC. Fifteen patients with WC (women:men, 3:12) and 15 age- and gender-matched controls performed oculomotor and EHC tasks. A visually guided stimulus (VGS) task was first performed with eye-only condition (EOC) and then with EHC. A significant interaction between the groups (controls and patients) and tasks (EOC and EHC) with age as a covariate confirmed that the two groups reacted differently to the tasks in saccadic latency (F(1,27) = 4.8; p = 0.039) and average saccade acceleration (F(1,27) = 10.6; p = 0.003). The curvature index of acceleration of the hand was significantly more in patien...

Research paper thumbnail of Experience of pallidal deep brain stimulation in dystonia at a tertiary care centre in India: An initial experience

Neurology India

Dystonia is one of the most prevalent forms of movement disorders and is characterized by sustain... more Dystonia is one of the most prevalent forms of movement disorders and is characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonia causes significant morbidity with an adverse impact on the quality of life. When dystonia is medically refractory, causing severe pain and impairment in activities of daily living, deep brain stimulation (DBS) of the globus pallidus interna (GPi) is a potential option to reduce disability. This is a chart review of patients who underwent DBS for dystonia (from 2009 to 2015) at our tertiary referral centre. A total of ten patients (7 males, 3 females) underwent DBS for non-parkinsonian conditions. The patients were selected after failure of adequate medical management. All the patients had a severe disability with normal cognitive (Mini-Mental State Examination) and psychiatric profile. They also had to have a suitable GPi for DBS based on magnetic resonance imaging. The mean ...

Research paper thumbnail of Contents Vol. 73, 2015

European Neurology, 2015

Access to full text and tables of contents, including tentative ones for forthcoming issues: www.... more Access to full text and tables of contents, including tentative ones for forthcoming issues: www.karger.com/ene_issues

Research paper thumbnail of Altered brain network measures in patients with primary writing tremor

Neuroradiology, 2017

Purpose Primary writing tremor (PWT) is a rare task-specific tremor, which occurs only while writ... more Purpose Primary writing tremor (PWT) is a rare task-specific tremor, which occurs only while writing or while adopting the hand in the writing position. The basic pathophysiology of PWT has not been fully understood. The objective of this study is to explore the alterations in the resting state functional brain connectivity, if any, in patients with PWT using graph theory-based analysis. Methods This prospective case-control study included 10 patients with PWT and 10 age and gender matched healthy controls. All subjects underwent MRI in a 3-Tesla scanner. Several parameters of small-world functional connectivity were compared between patients and healthy controls by using graph theory-based analysis. Results There were no significant differences in age, handedness (all right handed), gender distribution (all were males), and MMSE scores between the patients and controls. The mean age at presentation of tremor in the patient group was 51.7 ± 8.6 years, and the mean duration of tremor was 3.5 ± 1.9 years. Graph theory-based analysis revealed that patients with PWT had significantly lower clustering coefficient and higher path length compared to healthy controls suggesting alterations in small-world architecture of the brain. The clustering coefficients were lower in PWT patients in left and right medial cerebellum, right dorsolateral prefrontal cortex (DLPFC), and left posterior parietal cortex (PPC). Conclusion Patients with PWT have significantly altered small-world brain connectivity in bilateral medial cerebellum, right DLPFC, and left PPC. Further studies with larger sample size are required to confirm our results.

Research paper thumbnail of Role of Corpus Callosum Volumetry in Differentiating the Subtypes of Progressive Supranuclear Palsy and Early Parkinson's Disease

Movement Disorders Clinical Practice, 2017

Background and Objective: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative... more Background and Objective: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disorder. Classic PSP or Richardson-Steele phenotype (PSP-RS) and parkinsonian phenotype (PSP-P) are the common subtypes of PSP. At the early stage, differentiating the subtypes of PSP as well as differentiating PSP from other parkinsonian disorders, especially Parkinson's disease (PD) is challenging. Microstructural abnormalities of corpus callosum (CC) have been reported both in PSP and PD. The objective of this study was to compare the volumes of various segments of CC between patients with PSP-P, PSP-RS, and early PD. Methodology: This study included 32 patients with PSP (RS: 18, P: 14), 20 patients with early PD, and 25 controls. All subjects underwent 3-Tesla MRI. An automated surface-based analysis package (FreeSurfer) was used to divide CC into five segments: anterior (CC1), midanterior (CC2), central (CC3), midposterior (CC4), and posterior (CC5). Volumes of these segments were compared among the four groups. Results: The PSP-RS group had significantly lower CC volume in all segments except in CC1 and CC5, whereas the volumes of the five segments of CC were comparable among PSP-P, PD and controls. The PSP-RS group had lower CC3 volume compared to the PSP-P group, and the PSP-RS group had lower volume of both CC2 and CC3 compared to the PD group. Conclusions: The lower volume of the central segment of CC (CC3) might help in differentiating PSP-RS from PSP-P. There is no significant difference in the pattern of CC atrophy in PSP-P and early PD. Studies with higher sample sizes are warranted to confirm the results of our study. Progressive supranuclear palsy (PSP) is a chronic progressive neurodegenerative disorder characterized by postural instability, falls, parkinsonism, supranuclear vertical gaze palsy, behavioral disturbances, and dementia. 1,2 PSP belongs to the class of tauopathies, which include diseases characterized by hyperphosphorylation of the microtubule-associated protein tau (MAPT). Aggregation of tau leads to neurodegeneration in multiple regions of the brain. 3 There is heterogeneity in the clinical presentation of PSP, which has led to the categorization of PSP into two major pathologically and clinically distinct subtypes: classical Richardson-Steele-Olszewski variant (PSP-RS) and parkinsonian variant (PSP-P). 4 Later identification of other uncommon subtypes of PSP, such as PSP-CBS (corticobasal syndrome), PSP-PAGF (pure akinesia with gait freezing), and PSP-PNFA (progressive nonfluent aphasia), has compounded the clinical heterogeneity of PSP. 2 During the early stage of the

Research paper thumbnail of Advanced structural neuroimaging in progressive supranuclear palsy: Where do we stand?

Parkinsonism & Related Disorders, 2017

No. of references: 107 No. of tables: 4 No. of Supplementary figures: 1 No. of Supplementary tabl... more No. of references: 107 No. of tables: 4 No. of Supplementary figures: 1 No. of Supplementary tables: 2

Research paper thumbnail of Role of altered cerebello-thalamo-cortical network in the neurobiology of essential tremor

Neuroradiology, 2017

Introduction Essential tremor (ET) is the most common movement disorder among adults. Although ET... more Introduction Essential tremor (ET) is the most common movement disorder among adults. Although ET has been recognized as a mono-symptomatic benign illness, reports of non-motor symptoms and non-tremor motor symptoms have increased its clinical heterogeneity. The neural correlates of ET are not clearly understood. The aim of this study was to understand the neurobiology of ET using resting state fMRI. Methods Resting state functional MR images of 30 patients with ET and 30 age-and gender-matched healthy controls were obtained. The functional connectivity of the two groups was compared using whole-brain seed-to-voxel-based analysis. Results The ET group had decreased connectivity of several cortical regions especially of the primary motor cortex and the primary somatosensory cortex with several right cerebellar lobules compared to the controls. The thalamus on both hemispheres had increased connectivity with multiple posterior cerebellar lobules and vermis. Connectivity of several right cerebellar seeds with the cortical and thalamic seeds had significant correlation with an overall score of Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) as well as the subscores for head tremor and limb tremor. Conclusion Seed-to-voxel resting state connectivity analysis revealed significant alterations in the cerebello-thalamocortical network in patients with ET. These alterations correlated with the overall FTM scores as well as the subscores for limb tremor and head tremor in patients with ET. These results further support the previous evidence of cerebellar pathology in ET.

Research paper thumbnail of Exploring cortical atrophy and its clinical and biochemical correlates in Wilson’s disease using voxel based morphometry

Parkinsonism & Related Disorders, 2016

To determine cortical grey matter (GM) changes and their clinical and biochemical correlates in p... more To determine cortical grey matter (GM) changes and their clinical and biochemical correlates in patients with Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease using voxel based morphometry (VBM). Clinical and imaging data of 10 patients (all male, mean age 16.0 ± 6.3years) with Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s Disease were analyzed. T1W volumetric MRI data of patients without obvious cortical atrophy or signal changes on conventional MRI was compared with MRI of 11 matched control subjects using VBM analysis with Statistical Parametric Mapping 8. Results were expressed at statistical threshold of p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 (FWE corrected) and p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001 (uncorrected). Multiple regression analysis was done to analyze possible relation between GM atrophy, duration of disease and biochemical abnormalities. Compared to controls, patients showed scattered areas of reduced GM volume in bilateral caudate head, medial part of right globus pallidus and body of right caudate (FWE corrected p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). At p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001(uncorrected) widespread areas of cortical atrophy were also noted involving the frontal and temporal lobes, lentiform nuclei, cerebellum and thalamus. Significant positive correlation (uncorrected p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) were noted between (i) duration of disease and cortical GM volume of frontal, parietal and temporal lobes and cerebellum (ii) serum copper levels and GM volume of right medial frontal gyrus and paracentral lobule. To the best of our knowledge, this is the first VBM study in patients with Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease. In spite of apparently normal cortex on visual inspection of MRI, decreased cortical GM volume was detected using VBM. In addition, serum copper may act as surrogate marker of cortical abnormalities in Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease.

Research paper thumbnail of Repetitive transcranial magnetic stimulation induced modulations of resting state motor connectivity in writer's cramp

European Journal of Neurology, Jan 26, 2015

Background and purpose: Writer's cramp (WC) is a focal task-specific dystonia of the hand which i... more Background and purpose: Writer's cramp (WC) is a focal task-specific dystonia of the hand which is increasingly being accepted as a network disorder. Non-invasive cortical stimulation using repetitive transcranial magnetic stimulation (rTMS) has produced therapeutic benefits in some of these patients. This study aimed to visualize the motor network abnormalities in WC and also its rTMS induced modulations using resting state functional magnetic resonance imaging (rsfMRI). Methods: Nineteen patients with right-sided WC and 20 matched healthy controls (HCs) were prospectively evaluated. All patients underwent a single session of rTMS and rsfMRI was acquired before (R1) and after (R2) rTMS. Seed-based functional connectivity analysis of several regions in the motor network was performed for HCs, R1 and R2 using SPM8 software. Thresholded (P < 0.05, false discovery rate corrected) group level mean correlation maps were used to derive significantly connected region of interest pairs. Results: Writer's cramp showed a significant reduction in resting state functional connectivity in comparison with HCs involving the left cerebellum, thalamus, globus pallidus, putamen, bilateral supplementary motor area, right medial prefrontal lobe and right post central gyrus. After rTMS there was a significant increase in the contralateral resting state functional connectivity through the left thalamusÀright globus pallidusÀright thalamusÀright prefrontal lobe network loop. Conclusions: It is concluded that WC is a network disorder with widespread dysfunction much larger than clinically evident and changes induced by rTMS probably act through subcortical and trans-hemispheric unaffected connections. Longitudinal studies with therapeutic rTMS will be required to ascertain whether such information could be used to select patients prior to rTMS therapy.

Research paper thumbnail of Can yoga lead to maladaptive plasticity resulting in disorder of motor control?

Annals of Movement Disorders, 2020

The practice of yoga is based on the traditional Indian philosophy. Children during their develop... more The practice of yoga is based on the traditional Indian philosophy. Children during their development show adaptive neuroplasticity which is due to long-term potentiation that causes changes in the synaptic transmission. Excessive plasticity in the developing brain can lead to maladaptive neuronal circuits which can cause hyperkinetic movement disorders. It is not clear at what age yoga should be started and whether certain yogas or yogas done improperly can lead to maladaptive plasticity. We report here an unusual case of tic disorder which was precipitated by yoga.

Research paper thumbnail of Shaky and unsteady: Dynamic posturography in essential tremor

Journal of the neurological sciences, Jan 15, 2018

The spectrum of symptoms exhibited by patients with essential tremor (ET) extends far beyond the ... more The spectrum of symptoms exhibited by patients with essential tremor (ET) extends far beyond the classical tremor. This study aims to explore and establish the presence of subtle balance abnormalities in ET using dynamic posturography (DP). DP was performed on 18 patients with ET and 26 controls. Diagnosis of ET was based on the Consensus Statement of the Movement Disorder Society on Tremor. Dynamic stability which included the overall balance index, anterior-posterior index and mediolateral index, and limits of stability were measured. Patients with ET had significantly impaired balance indices. Impairment of dynamic stability revealed poor static balance control in all directions. Lower limits of stability scores indicated a smaller range of motion prior to which patients have to shift foot balance. No correlations were observed between age at evaluation, age at onset, duration of illness and the balance indices. Dynamic posturography reveals significant balance impairment in pati...

Research paper thumbnail of Imaging biomarker correlates with oxidative stress in Parkinson's disease

Neurology India, 2017

While oxidative stress (OS) may be one of the crucial factors determining the initiation and prog... more While oxidative stress (OS) may be one of the crucial factors determining the initiation and progression of Parkinson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease (PD), its correlation with gray matter (GM) atrophy is not known. To determine the GM volume (GMV) changes using voxel-based morphometry (VBM) and correlation with OS marker serum malondialdehyde (MDA) in PD. Seventy-two patients with PD were clinically evaluated and underwent magnetic resonance imaging (MRI) on a 3T MRI scanner using a 32-channel head coil. Lipid peroxidation product MDA levels were measured by spectrophotometry. MDA levels and regional GM differences using VBM were compared with 72 healthy controls. The mean age of the patients was 51.3 ± 10.6 years and that of controls was 50.8 ± 10.4 years. The mean age of onset of symptoms in PD was 45.2 ± 11.3 years. In PD, serum MDA level was significantly higher than that in controls (0.592 ± 0.89 μmol/l vs. 0.427 ± 0.055 μmol/l; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.0001). Compared to controls, patients had greater regional GM atrophy in all the brain lobes (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, uncorrected). A significant positive correlation was found between GMV and MDA in the caudate nucleus (CN) and posterior cingulate gyrus (PC) in the patient group (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001, uncorrected). We observed GM atrophy in all major brain lobes of patients when compared to controls. Only in the patient group, a significant positive correlation was observed in CN and PC with MDA. These findings suggest that, even though the whole brain is affected in PD, some of the non-substantia nigra regions of the brain, such as CN, may have some differential compensatory mechanism, which are preserved from oxidative damage.

Research paper thumbnail of Research in Parkinson′s disease in India: A review

Annals of Indian Academy of Neurology, 2016

treatment). The reference lists of included publications were also searched. Studies were eligibl... more treatment). The reference lists of included publications were also searched. Studies were eligible for inclusion if: i) PD was evaluated in India. The exclusion criteria were: 1. Parkinsonism apart from PD such as atypical Parkinsonism and secondary causes, 2. Animal studies, 3. Case reports, and 4. Pharmaceutical trials. The search results have been given in Table 1. A total of 95 articles were according to the search criteria. The first published article from India on PD in indexed journals could be traced to 1988. In later years, the number of publications has steadily increased [Figure 1]. There are more publications in international journals (n = 76) than in national journals (n = 19). We attempted to categorize the articles on various aspects, such as clinical, epidemiology, genetics, pathogenesis, investigations, pathology, treatment, social issues, and physical rehabilitation. Of these, clinical aspects, nonmotor involvement

Research paper thumbnail of Movement disorders of probable infectious origin

Annals of Indian Academy of Neurology, 2014

as HIV [4] have been reported causing whole range of MDs. Kalita and Misra [8] in their study on ... more as HIV [4] have been reported causing whole range of MDs. Kalita and Misra [8] in their study on Japanese encephalitis had reported predominant post-encephalitic dystonia. Isolated case reports of infl uenza virus encephalitis causing chorea and paroxysmal dyskinesias have also been reported. [6,9] Bacterial infections such as streptococcal group causing Sydenham's chorea have been most widely proven. Though the incidence of Sydenham's chorea has reduced it is still prevalent in developing countries. Parasitic infections such as toxoplasma abscesses in the subthalamic nucleus, thalamus, caudate nucleus, or globus pallidus have been reported to be associated with contralateral limb ballism, choreoathetosis, and dystonia. [3] Several studies have a empted to explain the MDs secondary to specifi c infectious agent. Apart from a large study on SMD [2] conducted at our center, most of the reports are limited to a single patient or a series of patients defi ning a particular infectious agent. The conclusions from these studies are varied and diffi cult to generalize. The objectives of our study were to 1. Characterize the pattern (phenomenology) of MD temporarily related to infection 2. Characterize the probable nature of infection causing SMD, and

Research paper thumbnail of Posttraumatic movement disorders: A clinical and imaging profile of 30 patients

Neurology India, 2019

Background: Posttraumatic movement disorders (PTMDs) are frequently associated with severe head i... more Background: Posttraumatic movement disorders (PTMDs) are frequently associated with severe head injury. There are very few studies on the clinical phenomenology and radiological correlation of PTMD. Aims: To study the clinical phenomenology of patients with PTMD and correlate it with the site of lesion on brain imaging. Materials and Methods: This was a prospective study of patients with suspected PTMD. All of these patients underwent neurological evaluation to characterize the phenomenology and imaging, such as computed tomography/magnetic resonance imaging (CT/MRI), to localize the site of lesion. Results: The age of the patients was 32.6 ± 16.4 years and the age at onset was 29.1 ± 16.0 years. Right upper limb was the initial body part affected in 36.7% patients. Tremor (alone or with dystonia) was the most common movement disorder (MD; 44.7%) followed by parkinsonism (17.2%), dystonia (13.8%), dystonia plus (dystonia associated with choreoathetosis: 10.3%), mixed MD (more than o...

Research paper thumbnail of Neuroinvasiveness of West Nile Virus: A Case Report (P6.013)

Neurology, 2018

Objective: To highlight the neurological manifestations of West Nile Virus Background: We present... more Objective: To highlight the neurological manifestations of West Nile Virus Background: We present a case of serologically proved West Nile virus with involvement of cervical motor neuron cell, brainstem and cerebellum suggestive of neuro invasiveness of the virus. Design/Methods: Twenty-eight right-handed African-American female presented with fever and headache for 8 days. Patient reported she was apparently in perfect health about 8 days back when she had sudden onset bi-frontal headache which was not associated with nausea, vomiting and photophobia. Three days following the headache patient started complaining of high-grade fever with nausea and vomiting. After starting antibiotics next day patient’s aunt noticed that patient was not able to use her bilateral upper limbs to text from her cell phone. On initial evaluation patient had symmetric bilateral upper limb proximal weakness with absent reflexes in upper limb. Bilateral lower limb power was normal with normal reflexes. Pati...

Research paper thumbnail of Basal ganglia contributions during the learning of a visuomotor rotation: effect of dopamine, deep brain stimulation and reinforcement

It is commonly thought that visuomotor adaptation is mediated by the cerebellum while reinforceme... more It is commonly thought that visuomotor adaptation is mediated by the cerebellum while reinforcement learning is mediated by the basal ganglia. In contrast to this strict dichotomy, we demonstrate a role for the basal ganglia in visuomotor adaptation (error-based motor learning) in patients with Parkinsons disease (PD) by comparing the degree of motor learning in the presence and absence of dopamine medication. We further show similar modulation of learning rates in the presence and absence of subthalamic deep brain stimulation. We also report that reinforcement is an essential component of visuomotor adaptation by demonstrating the lack of motor learning in patients with PD during the ON-dopamine state relative to the OFF-dopamine state in the absence of a reinforcement signal. Taken together, these results suggest that the basal ganglia modulate the gain of visuomotor adaptation based on the reinforcement received at the end of the trial.

Research paper thumbnail of Phenotypic Variability of Essential Tremor Based on the Age at Onset

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 2019

ABSTRACT:Background: Essential tremor (ET) is reported to have a bimodal distribution of age at o... more ABSTRACT:Background: Essential tremor (ET) is reported to have a bimodal distribution of age at onset (AAO) with phenotypic variability based on the AAO. This study aims to explore the distribution of AAO based on mathematical modeling and ascertain the differences, if any, in the clinical features of groups. Methods: A chart review was conducted for 252 patients with ET diagnosed based on the Consensus statement of the Movement Disorder Society on Tremor. Finite mixture modeling was performed to identify groups of the cohort based on the AAO. Results: Three groups were defined: early onset (EO): AAO ≤ 22 years, n = 63, intermediate onset (IO): 23 ≤ AAO ≤ 35 years, n = 43, and late onset (LO): AAO ≥ 36 years, n = 146. There were no significant differences related to family history or responsiveness to alcohol. The EO group had significantly higher prevalence of upper limb and lower limb tremor. Head tremor and voice tremor was more prevalent in the IO and LO groups. Cerebellar signs...

Research paper thumbnail of Clinical Utility of Longitudinal Measurement of Motor Threshold in Wilson’s Disease

Canadian Journal of Neurological Sciences/Journal Canadien des Sciences Neurologiques, 2019

This study describes the longitudinal changes of resting motor threshold (RMT) and central motor ... more This study describes the longitudinal changes of resting motor threshold (RMT) and central motor conduction time (CMCT) in 18 patients with Wilson's disease (WD). The RMT, CMCT, and Global Assessment Scale for Wilson Disease (GAS-WD) were measured at baseline and at follow-up after 12.94 ± 7.23 months. There was a significant decrease in the RMT (72.11 ± 18.62 vs. 63.7 ± 15.52%; p-value = 0.002) and GAS-WD scores (14.38 ± 5.35 vs. 9.77 ± 6.47 ms; p-value = 0.04). CMCT did not improve despite chelation therapy. Hence, RMT may serve as a marker of chelation efficacy in WD. RÉSUMÉ: Utilité clinique des mesures longitudinales du seuil moteur au repos dans le cas de la maladie de Wilson. Cette étude entend décrire les changements longitudinaux affectant le seuil moteur au repos (SMR) et la vitesse de conduction nerveuse motrice (VCNM) chez 18 patients atteints de la maladie de Wilson. Tant le SMR et la VCNM que la Global Assessment Scale for Wilson Disease (GAS-WD) ont été mesurés au départ de l'étude et au moment d'un suivi après 12,94 ± 7,23 mois. Une diminution notable du SMR (72,11 ± 18,62 contre 63,7 ± 15,52 % ; p = 0,002) et de la GAS-WD (14,38 ± 5,35 contre 9,77 ± 6,47 ms ; p = 0,04) a pu être observée. En revanche, aucune amélioration sensible de la VCNM n'a été notée en dépit d'une thérapie par chélation. Par conséquent, il se pourrait que le SMR, dans le cas de la maladie de Wilson, puisse être utilisé comme marqueur de l'efficacité de la thérapie par chélation.

Research paper thumbnail of Implications of secondary unresponsiveness to dopaminergic drugs with preserved response to subthalamic nucleus stimulation in Parkinson's disease

Neurology India

Improvement in motor symptoms with levodopa is one of the hallmark features of Parkinson's di... more Improvement in motor symptoms with levodopa is one of the hallmark features of Parkinson's disease (PD). The response to levodopa may reduce during the course of the illness. Few studies have also reported reduced response to levodopa in patients with PD several years after deep brain stimulation (DBS) of the subthalamic nucleus (STN) on both the sides. In this study, we report an extreme unresponsiveness to levodopa in the presence of a good response to STN stimulation in a patient 5 years after the DBS proceudre had been carried out. The implications of this phenomenon are also discussed.

Research paper thumbnail of Abnormalities of Eye-Hand Coordination in Patients with Writer's Cramp: Possible Role of the Cerebellum

Tremor and other hyperkinetic movements (New York, N.Y.), 2017

Writer's cramp (WC) is one of the commonly observed focal dystonias. The pathophysiology of W... more Writer's cramp (WC) is one of the commonly observed focal dystonias. The pathophysiology of WC has not been fully understood. The role of the cerebellum has been increasingly recognized in the pathogenesis of dystonia. As the cerebellum is crucial for maintaining accurate eye-hand coordination (EHC), its role in the pathogenesis of WC can be investigated by studying the EHC in patients with WC. Fifteen patients with WC (women:men, 3:12) and 15 age- and gender-matched controls performed oculomotor and EHC tasks. A visually guided stimulus (VGS) task was first performed with eye-only condition (EOC) and then with EHC. A significant interaction between the groups (controls and patients) and tasks (EOC and EHC) with age as a covariate confirmed that the two groups reacted differently to the tasks in saccadic latency (F(1,27) = 4.8; p = 0.039) and average saccade acceleration (F(1,27) = 10.6; p = 0.003). The curvature index of acceleration of the hand was significantly more in patien...

Research paper thumbnail of Experience of pallidal deep brain stimulation in dystonia at a tertiary care centre in India: An initial experience

Neurology India

Dystonia is one of the most prevalent forms of movement disorders and is characterized by sustain... more Dystonia is one of the most prevalent forms of movement disorders and is characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonia causes significant morbidity with an adverse impact on the quality of life. When dystonia is medically refractory, causing severe pain and impairment in activities of daily living, deep brain stimulation (DBS) of the globus pallidus interna (GPi) is a potential option to reduce disability. This is a chart review of patients who underwent DBS for dystonia (from 2009 to 2015) at our tertiary referral centre. A total of ten patients (7 males, 3 females) underwent DBS for non-parkinsonian conditions. The patients were selected after failure of adequate medical management. All the patients had a severe disability with normal cognitive (Mini-Mental State Examination) and psychiatric profile. They also had to have a suitable GPi for DBS based on magnetic resonance imaging. The mean ...

Research paper thumbnail of Contents Vol. 73, 2015

European Neurology, 2015

Access to full text and tables of contents, including tentative ones for forthcoming issues: www.... more Access to full text and tables of contents, including tentative ones for forthcoming issues: www.karger.com/ene_issues

Research paper thumbnail of Altered brain network measures in patients with primary writing tremor

Neuroradiology, 2017

Purpose Primary writing tremor (PWT) is a rare task-specific tremor, which occurs only while writ... more Purpose Primary writing tremor (PWT) is a rare task-specific tremor, which occurs only while writing or while adopting the hand in the writing position. The basic pathophysiology of PWT has not been fully understood. The objective of this study is to explore the alterations in the resting state functional brain connectivity, if any, in patients with PWT using graph theory-based analysis. Methods This prospective case-control study included 10 patients with PWT and 10 age and gender matched healthy controls. All subjects underwent MRI in a 3-Tesla scanner. Several parameters of small-world functional connectivity were compared between patients and healthy controls by using graph theory-based analysis. Results There were no significant differences in age, handedness (all right handed), gender distribution (all were males), and MMSE scores between the patients and controls. The mean age at presentation of tremor in the patient group was 51.7 ± 8.6 years, and the mean duration of tremor was 3.5 ± 1.9 years. Graph theory-based analysis revealed that patients with PWT had significantly lower clustering coefficient and higher path length compared to healthy controls suggesting alterations in small-world architecture of the brain. The clustering coefficients were lower in PWT patients in left and right medial cerebellum, right dorsolateral prefrontal cortex (DLPFC), and left posterior parietal cortex (PPC). Conclusion Patients with PWT have significantly altered small-world brain connectivity in bilateral medial cerebellum, right DLPFC, and left PPC. Further studies with larger sample size are required to confirm our results.

Research paper thumbnail of Role of Corpus Callosum Volumetry in Differentiating the Subtypes of Progressive Supranuclear Palsy and Early Parkinson's Disease

Movement Disorders Clinical Practice, 2017

Background and Objective: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative... more Background and Objective: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disorder. Classic PSP or Richardson-Steele phenotype (PSP-RS) and parkinsonian phenotype (PSP-P) are the common subtypes of PSP. At the early stage, differentiating the subtypes of PSP as well as differentiating PSP from other parkinsonian disorders, especially Parkinson's disease (PD) is challenging. Microstructural abnormalities of corpus callosum (CC) have been reported both in PSP and PD. The objective of this study was to compare the volumes of various segments of CC between patients with PSP-P, PSP-RS, and early PD. Methodology: This study included 32 patients with PSP (RS: 18, P: 14), 20 patients with early PD, and 25 controls. All subjects underwent 3-Tesla MRI. An automated surface-based analysis package (FreeSurfer) was used to divide CC into five segments: anterior (CC1), midanterior (CC2), central (CC3), midposterior (CC4), and posterior (CC5). Volumes of these segments were compared among the four groups. Results: The PSP-RS group had significantly lower CC volume in all segments except in CC1 and CC5, whereas the volumes of the five segments of CC were comparable among PSP-P, PD and controls. The PSP-RS group had lower CC3 volume compared to the PSP-P group, and the PSP-RS group had lower volume of both CC2 and CC3 compared to the PD group. Conclusions: The lower volume of the central segment of CC (CC3) might help in differentiating PSP-RS from PSP-P. There is no significant difference in the pattern of CC atrophy in PSP-P and early PD. Studies with higher sample sizes are warranted to confirm the results of our study. Progressive supranuclear palsy (PSP) is a chronic progressive neurodegenerative disorder characterized by postural instability, falls, parkinsonism, supranuclear vertical gaze palsy, behavioral disturbances, and dementia. 1,2 PSP belongs to the class of tauopathies, which include diseases characterized by hyperphosphorylation of the microtubule-associated protein tau (MAPT). Aggregation of tau leads to neurodegeneration in multiple regions of the brain. 3 There is heterogeneity in the clinical presentation of PSP, which has led to the categorization of PSP into two major pathologically and clinically distinct subtypes: classical Richardson-Steele-Olszewski variant (PSP-RS) and parkinsonian variant (PSP-P). 4 Later identification of other uncommon subtypes of PSP, such as PSP-CBS (corticobasal syndrome), PSP-PAGF (pure akinesia with gait freezing), and PSP-PNFA (progressive nonfluent aphasia), has compounded the clinical heterogeneity of PSP. 2 During the early stage of the

Research paper thumbnail of Advanced structural neuroimaging in progressive supranuclear palsy: Where do we stand?

Parkinsonism & Related Disorders, 2017

No. of references: 107 No. of tables: 4 No. of Supplementary figures: 1 No. of Supplementary tabl... more No. of references: 107 No. of tables: 4 No. of Supplementary figures: 1 No. of Supplementary tables: 2

Research paper thumbnail of Role of altered cerebello-thalamo-cortical network in the neurobiology of essential tremor

Neuroradiology, 2017

Introduction Essential tremor (ET) is the most common movement disorder among adults. Although ET... more Introduction Essential tremor (ET) is the most common movement disorder among adults. Although ET has been recognized as a mono-symptomatic benign illness, reports of non-motor symptoms and non-tremor motor symptoms have increased its clinical heterogeneity. The neural correlates of ET are not clearly understood. The aim of this study was to understand the neurobiology of ET using resting state fMRI. Methods Resting state functional MR images of 30 patients with ET and 30 age-and gender-matched healthy controls were obtained. The functional connectivity of the two groups was compared using whole-brain seed-to-voxel-based analysis. Results The ET group had decreased connectivity of several cortical regions especially of the primary motor cortex and the primary somatosensory cortex with several right cerebellar lobules compared to the controls. The thalamus on both hemispheres had increased connectivity with multiple posterior cerebellar lobules and vermis. Connectivity of several right cerebellar seeds with the cortical and thalamic seeds had significant correlation with an overall score of Fahn-Tolosa-Marin tremor rating scale (FTM-TRS) as well as the subscores for head tremor and limb tremor. Conclusion Seed-to-voxel resting state connectivity analysis revealed significant alterations in the cerebello-thalamocortical network in patients with ET. These alterations correlated with the overall FTM scores as well as the subscores for limb tremor and head tremor in patients with ET. These results further support the previous evidence of cerebellar pathology in ET.

Research paper thumbnail of Exploring cortical atrophy and its clinical and biochemical correlates in Wilson’s disease using voxel based morphometry

Parkinsonism & Related Disorders, 2016

To determine cortical grey matter (GM) changes and their clinical and biochemical correlates in p... more To determine cortical grey matter (GM) changes and their clinical and biochemical correlates in patients with Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease using voxel based morphometry (VBM). Clinical and imaging data of 10 patients (all male, mean age 16.0 ± 6.3years) with Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s Disease were analyzed. T1W volumetric MRI data of patients without obvious cortical atrophy or signal changes on conventional MRI was compared with MRI of 11 matched control subjects using VBM analysis with Statistical Parametric Mapping 8. Results were expressed at statistical threshold of p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05 (FWE corrected) and p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001 (uncorrected). Multiple regression analysis was done to analyze possible relation between GM atrophy, duration of disease and biochemical abnormalities. Compared to controls, patients showed scattered areas of reduced GM volume in bilateral caudate head, medial part of right globus pallidus and body of right caudate (FWE corrected p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). At p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001(uncorrected) widespread areas of cortical atrophy were also noted involving the frontal and temporal lobes, lentiform nuclei, cerebellum and thalamus. Significant positive correlation (uncorrected p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) were noted between (i) duration of disease and cortical GM volume of frontal, parietal and temporal lobes and cerebellum (ii) serum copper levels and GM volume of right medial frontal gyrus and paracentral lobule. To the best of our knowledge, this is the first VBM study in patients with Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease. In spite of apparently normal cortex on visual inspection of MRI, decreased cortical GM volume was detected using VBM. In addition, serum copper may act as surrogate marker of cortical abnormalities in Wilson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s disease.