N. Hoggard - Academia.edu (original) (raw)

Papers by N. Hoggard

Clinical Radiology

To investigate whether imaging is associated with early detection of the organic causes of the fi... more To investigate whether imaging is associated with early detection of the organic causes of the first episode of psychosis (FEP). Individuals with FEP but no neurological signs referred to a tertiary centre for cerebral magnetic resonance imaging (MRI) or computed tomography (CT) were reviewed retrospectively. Two groups were evaluated with either CT or MRI; the two groups were independent and no individual underwent both CT and MRI. One hundred and twelve consecutive cerebral MRI and 204 consecutive CT examinations were identified. Three (2.7%) individuals had brain lesions [brain tumour and human immunodeficiency virus (HIV) encephalopathy] potentially accountable for the psychosis at MRI. Seventy patients (62.5%) had incidental brain lesions, such as cerebral atrophy, small vessel ischaemic changes, unruptured Circle of Willis aneurysm, cavernoma, and arachnoid cysts at MRI. Three patients (1.5%) had focal brain lesions (primary or secondary tumours) potentially accountable for the psychosis at CT. One hundred and thirty-three patients (65.2%) had incidental brain lesions unrelated to the psychosis on CT scan. There was no significant difference between MRI and CT imaging in detecting organic disease potentially responsible for FEP (p < 0.001). Routine MRI or CT imaging of the brain is unlikely to reveal disease leading to a significant change in management. MRI was comparable with CT in terms of diagnosis of both pathological and incidental cerebral lesions. Therefore, routine brain structural imaging of FEP in patients without focal neurology may not be routinely required and if imaging is requested then CT may function equally as well as MRI as the first-line investigation.

Journal of Neurology, 2020

Lupus, 2018

We describe a man presenting with unusual neurological manifestations of systemic lupus erythemat... more We describe a man presenting with unusual neurological manifestations of systemic lupus erythematosus (SLE) including pachymeningitis, aseptic meningitis and encephalitis with grossly elevated cerebrospinal fluid protein, responding to immunosuppression. Initially he had intermittent dysarthria, dysphasia and unilateral upper limb weakness. One month later he experienced dysphasia, right-sided hemiparesis and confusion. Cerebrospinal fluid (CSF) analysis showed a white cell count of 70 x 106/litre and an unusually elevated protein level of 5.39 g/litre. An MRI brain showed dural and leptomeningeal enhancement compatible with a meningitic process. He improved with cefotaxime and aciclovir. On day seven of antimicrobials he developed left-sided weakness, sensory inattention and a left homonymous hemianopia. He responded well to intravenous methylprednisolone. On switching to oral prednisolone he developed expressive dysphasia, a right inferior quadrantanopia and seizures. His bloods w...

Neurology Genetics, 2018

ObjectiveTo clinically, genetically, and radiologically characterize a large cohort of SPG7 patie... more ObjectiveTo clinically, genetically, and radiologically characterize a large cohort of SPG7 patients.MethodsWe used data from next-generation sequencing panels for ataxias and hereditary spastic paraplegia to identify a characteristic phenotype that helped direct genetic testing for variations in SPG7. We analyzed MRI. We reviewed all published SPG7 mutations for correlations.ResultsWe identified 42 cases with biallelic SPG7 mutations, including 7 novel mutations, including a large multi-exon deletion, representing one of the largest cohorts so far described. We identified a characteristic phenotype comprising cerebellar ataxia with prominent cerebellar dysarthria, mild lower limb spasticity, and a waddling gait, predominantly from a cohort of idiopathic ataxia. We report a rare brain MRI finding of dentate nucleus hyperintensity on T2 sequences with SPG7 mutations. We confirm that the c.1529C>T allele is frequently present in patients with long-standing British ancestry. Based o...

Cerebellum & ataxias, 2017

Cerebellar ataxia with sensory ganglionopathy (SG) is a disabling combination of neurological dys... more Cerebellar ataxia with sensory ganglionopathy (SG) is a disabling combination of neurological dysfunction usually seen as part of some hereditary ataxias. However, patients may present with this combination without a genetic cause. We reviewed records of all patients that have been referred to the Sheffield Ataxia Centre who had neurophysiological and imaging data suggestive of SG and cerebellar ataxia respectively. We excluded patients with Friedreich's ataxia, a common cause of this combination. All patients were screened for genetic causes and underwent extensive investigations. We identified 40 patients (45% males, mean age at symptom onset 53.7 ± 14.7 years) with combined cerebellar ataxia and SG. The majority of patients (40%) were initially diagnosed with cerebellar dysfunction and 30% were initially diagnosed with SG. For 30% the two diagnoses were made at the same time. The mean latency between the two diagnoses was 6.5 ± 8.9 years (range 0-44). The commonest initial ma...

Pediatric radiology, Jan 24, 2015

Birth-related acute profound hypoxic-ischaemic brain injury has specific patterns of damage inclu... more Birth-related acute profound hypoxic-ischaemic brain injury has specific patterns of damage including the paracentral lobules. To test the hypothesis that there is anatomically coherent regional volume loss of the corpus callosum as a result of this hemispheric abnormality. Study subjects included 13 children with proven acute profound hypoxic-ischaemic brain injury and 13 children with developmental delay but no brain abnormalities. A computerised system divided the corpus callosum into 100 segments, measuring each width. Principal component analysis grouped the widths into contiguous anatomical regions. We conducted analysis of variance of corpus callosum widths as well as support vector machine stratification into patient groups. There was statistically significant narrowing of the mid-posterior body and genu of the corpus callosum in children with hypoxic-ischaemic brain injury. Support vector machine analysis yielded over 95% accuracy in patient group stratification using the c...

AJNR. American journal of neuroradiology

Conventional catheter angiography (CCA) is the current reference standard for the diagnosis, asse... more Conventional catheter angiography (CCA) is the current reference standard for the diagnosis, assessment, and management of pial brain arteriovenous malformations (AVMs). The purpose of this study was to develop an MR angiographic technique that produces dynamic images comparable to those provided by CCA and to apply the technique to the investigation of pial brain AVMs. Twenty patients with brain AVMs referred for stereotactic radiosurgery were recruited. All patients had CCA performed on a 1.5-T superconducting system. Sixty images were obtained at a rate of one image per second. Slices were orientated to produce Towne, lateral, and anteroposterior projections. A set of mask images was taken and then a series during the passage of a bolus of contrast material. MR examinations were assessed independently by neuroradiologists blinded to the conventional catheter angiographic findings. The nidus of the AVMs was depicted in 19 of the 20 patients, and correlation with CCA was excellent ...

Practical Neurology, 2013

A 51-year-old man presented to the neurology clinic with numbness affecting the left side of his ... more A 51-year-old man presented to the neurology clinic with numbness affecting the left side of his chin, which had developed over a few days. Three weeks later, he reported pain affecting the left side of his face, locking of the jaw on chewing and numbness of the left side of the tongue. He worked as a maintenance fitter in a sewage works and had suffered exposure to raw sewage 2 months before his clinic visit, followed by diarrhoea and vomiting. Serological testing for leptospirosis was negative. These symptoms had settled before the numbness developed. He had no headaches or visual symptoms. His swallowing and speech were normal. He had lost 10 kg in weight over the previous 3 months. He had a strong family history of bowel carcinoma but a recent screening colonoscopy with biopsies was negative. He had never smoked and only drank alcohol occasionally. On examination, he had reduced sensation to light touch and pain over the left side of his chin and lower lip. The sensation over the rest of his face was normal; his corneal reflexes were present bilaterally and his jaw power was normal. Examination of the other cranial nerves and limbs was normal. His general physical examination was unremarkable. His full blood count, erythrocyte sedimentation rate, plasma glucose, urea and electrolytes, serum C reactive protein, calcium and liver function tests were normal apart from a raised …

Journal of Neurology, Neurosurgery & Psychiatry, 2011

Autonomic dysfunction is common in Guillain-Barre syndrome (GBS). Here we report a case, which in... more Autonomic dysfunction is common in Guillain-Barre syndrome (GBS). Here we report a case, which initially presented with an autonomic dysfunction causing fluctuation in blood pressure, confusion and a generalised tonic clonic seizure. MRI brain showed high T2 signal changes in posterior circulation consistent with a diagnosis of posterior reversible encephalopathy (PRES), which was treated with IV labatolol with good recovery. A week after this initial presentation patient developed acute flaccid limb weakness and respiratory muscle weakness requiring ventilatory support. Nerve conduction study performed showed prolonged distal latency and F wave latency consistent with acute GBS. Patient was treated with a course of IVIg for 5 days. This is the third case of PRES as the initial manifestation of GBS in adults. All three cases presented in the similar fashion raises the argument that these are not simply coincident but there must be a cause effect relationship between these two disorders. From practical point of view this case highlights two facts: (1) dysautonomia associated with GBS may precede motor weakness (2) PRES in absence of any other aetiological factor should prompt the search for underlying GBS.

Journal of Medical Ethics, 2009

We were finding volunteers for functional magnetic resonance imaging studies with abnormalities r... more We were finding volunteers for functional magnetic resonance imaging studies with abnormalities requiring referral surprisingly frequently. The bioethics surrounding the incidental findings are not straightforward and every imaging institution will encounter this situation in their normal volunteers. Yet the implications for the individuals involved may be profound. Should all participants have review of their imaging by an expert and who should be informed? The normal volunteers that were imaged with magnetic resonance (MR) which were reviewed by a consultant neuroradiologist. All participants completed a volunteer consent form in addition to a standard departmental MR safety screening form. The volunteer screening form requires the general practitioner details to be completed and asks the participant to consider closely the possibility and implications of finding an unexpected but potentially serious abnormality before signing. 525 different individuals were scanned as normal volunteers, the mean age was 35-years and 330 were males. Of these 525, 46 had definite significant abnormalities (8.8%), mean age 50-years. We have found a high rate of incidental abnormalities amongst individuals participating in imaging studies at our institution. It is our current practice to inform the research study participant of the findings, counsel them and inform their primary care physician. We think that it is advisable for researchers utilising MR imaging of the brain to have access to trained neuroradiologists, a protocol in place to deal with this problem and take consent in a way that allows the participant to realise the possibility of an abnormal finding.

British Journal of Oral and Maxillofacial Surgery, 2010

Acta Radiologica, 2006

Purpose: To evaluate if two gadolinium perfusion studies can be performed during the same table o... more Purpose: To evaluate if two gadolinium perfusion studies can be performed during the same table occupancy without degradation of the derived data in the second study. Material and Methods: Magnetic resonance (MR) perfusion studies of the whole brain were performed on 12 patients during the administration of two gadolinium boluses separated by 8 min. In six patients, gadolinium was given as two 20-ml administrations of standard 0.5 M chelate (Magnevist), whilst the other six patients received two 10-ml administrations of 1.0 M chelate (Gadovist). Results: There were no significant differences in subjective quality between the time–intensity curves of the first and second perfusion studies using either the 0.5 M or 1.0 M gadolinium chelate. The objective measurements in quality of the time–intensity curves (maximum signal change and full width at half maximum) changed by less than 5% of the original values on the second perfusion study. The first-moment mean transit times did not chan...

Postgraduate Medical Journal, 2012

The British Journal of Radiology, 2010

Gut, 2016

Introduction Patients with the postural tachycardia syndrome (PoTS) have anecdotally reported sym... more Introduction Patients with the postural tachycardia syndrome (PoTS) have anecdotally reported symptom improvement on a gluten-free diet (GFD) but there has been no association study between PoTS and coeliac disease. Therefore, we aimed to evaluate the prevalence of coeliac disease and self-reported gluten sensitivity in a cohort of patients with PoTS and compare this with local population data. Methods 100 PoTS patients were recruited from the syncope clinic to complete a validated questionnaire which screened for gluten sensitivity and related symptoms. Case notes were reviewed for relevant GI diagnoses. For comparison, the local coeliac prevalence was determined from a total of 1200 controls (Control Group 1) and a further 400 controls (Control Group 2; frequency matched for age and sex) filled out the same questionnaire. Results Four out of a hundred (4%) patients with PoTS had serology and biopsy-proven coeliac disease. This was significantly higher than the prevalence of coeliac disease in Control Group 1 (12/1200, 1%; OR 4.1, 95% CI 1.3 to 13.0; p = 0.02). In comparison with Control Group 2, patients with PoTS had a higher prevalence of self-reported gluten sensitivity (42% versus 19%; p < 0.001), coeliac disease (4% versus 1%; p = 0.04) and IBS (36% versus 9%; p < 0.0001). Conclusion There is a high prevalence of coeliac disease and self-reported gluten sensitivity in patients with PoTS. We advocate screening for the gluten-related disorders in patients with PoTS. Further studies are required to ascertain the nature of this relationship. Disclosure of Interest None Declared

BMJ Open

IntroductionThere are no disease-modifying treatments for Parkinson’s disease (PD). We undertook ... more IntroductionThere are no disease-modifying treatments for Parkinson’s disease (PD). We undertook the first drug screen in PD patient tissue and idntified ursodeoxycholic acid (UDCA) as a promising mitochondrial rescue agent. The aims of this trial are to determine safety and tolerability of UDCA in PD at 30 mg/kg, confirm the target engagement of UDCA, apply a novel motion sensor-based approach to quantify disease progression objectively, and estimate the mean effect size and its variance on the change in motor severity.Methods and analysisThis is a phase II, two-centre, double-blind, randomised, placebo-controlled trial of UDCA at a dose of 30 mg/kg in 30 participants with early PD. Treatment duration is 48 weeks, followed by an 8-week washout phase. Randomisation is 2:1, drug to placebo. Assessments are performed at baseline, week 12, 24, 36, 48 and 56. The primary outcome is safety and tolerability. Secondary outcomes will compare the change between baseline and week 48 using the...

Journal of the Neurological Sciences, Oct 1, 2017