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Papers by humaira abid

Pakistan Journal of Medical and Health Sciences

Objectives: To determine the correlation of fasting salivary glucose with fasting plasma glucose ... more Objectives: To determine the correlation of fasting salivary glucose with fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) for the diagnosis and monitoring of type 2 diabetes mellitus (T2DM). Methods: A case - control study was carried out from 11th March to 30th August 2021, involving 88 participants out of which 44 were healthy controls and 44 participants were known T2DM who had FPG ≥ 126 mg/dl or 7.0 mmol/L. FPG was measured by Glucose oxidase method and HbA1c by National Glycohemoglobin Standardization Program (NGSP) certified chromatography. Results: T2DM group had significantly higher FPG, HbA1c and salivary glucose values. Both diabetics and healthy controls showed a positive correlation of fasting salivary glucose with FPG. The correlation coefficient (r) was 0.689 and 0.477 for cases and control groups respectively. Similarly, a positive correlation of fasting salivary glucose with HbA1c was observed with the value of r 0.433 and 0.498 for diabetic and heal...

Psychiatric Annals, 2017

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent and chronic neurodevelopmen... more Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent and chronic neurodevelopmental disorder often with residual symptoms throughout the patient's lifespan. Patients with ADHD have a significant disease burden that adversely affects interpersonal, psychosocial, and occupational domains of their life. Stimulants are usually the first-line treatment for all patient age groups. Familiarity with varying aspects of this disorder is important for clinicians, given the significant challenges in treating this chronic condition. Although risks of medication abuse and diversion pose significant challenges, not treating ADHD can gravely affect patients' lives, potentially leading to school dropout, unemployment, legal problems, and more. This article reviews reasons to treat adult ADHD, versus reasons that support refraining from treating, and provides general treatment guidelines for practicing clinicians. [ Psychiatr Ann . 2017;47(6):315–321.]

The Journal of Neuroscience, 2011

The human brain thalami play essential roles in integrating cognitive, sensory, and motor functio... more The human brain thalami play essential roles in integrating cognitive, sensory, and motor functions. In multiple sclerosis (MS), quantitative magnetic resonance imaging (qMRI) measurements of the thalami provide important biomarkers of disease progression, but late development and aging confound the interpretation of data collected from patients over a wide age range. Thalamic tissue volume loss due to natural aging and its interplay with lesion-driven pathology has not been investigated previously. In this work, we used standardized thalamic volumetry combined with diffusion tensor imaging, T2 relaxometry, and lesion mapping on large cohorts of controls (N= 255, age range = 6.2–69.1 years) and MS patients (N= 109, age range = 20.8–68.5 years) to demonstrate early age- and lesion-independent thalamic neurodegeneration.

Journal of the Neurological Sciences, 2012

Multiple sclerosis (MS) is the most common immune-mediated disabling neurological disease of the ... more Multiple sclerosis (MS) is the most common immune-mediated disabling neurological disease of the central nervous system. The pathogenesis of MS is not fully understood. Histopathology implicates both demyelination and axonal degeneration as the major contributors to the accumulation of disability. The application of several in vivo quantitative magnetic resonance imaging (MRI) methods to both lesioned and normal-appearing brain tissue has not yet provided a solid conclusive support of the hypothesis that MS might be a diffuse disease. In this work, we adopted FreeSurfer to provide standardized macrostructure or volumetry of lesion free normal-appearing brain tissue in combination with multiple quantitative MRI metrics (T 2 relaxation time, diffusion tensor anisotropy and diffusivities) that characterize tissue microstructural integrity. By incorporating a large number of healthy controls, we have attempted to separate the natural age-related change from the disease-induced effects. Our work shows elevation in diffusivity and relaxation times and reduction in volume in a number of normalappearing white matter and gray matter structures in relapsing-remitting multiple sclerosis patients. These changes were related in part with the spatial distribution of lesions. The whole brain lesion load and age-adjusted expanded disability status score showed strongest correlations in regions such as corpus callosum with qMRI metrics that are believed to be specific markers of

Journal of Magnetic Resonance Imaging, 2012

Purpose-To investigate the utility of multimodal quantitative magnetic resonance imaging (qMRI) a... more Purpose-To investigate the utility of multimodal quantitative magnetic resonance imaging (qMRI) and atlas-based methods to identify characteristics of lesion-driven injury and neurodegeneration in relapsing remitting multiple sclerosis (RRMS) Materials and Methods-This work is health insurance portability and accountability act compliant. High resolution T1-weighted, dual echo and fluid-attenuated inversion recovery and diffusion tensor MRI images were prospectively acquired on 68 RRMS patients (range 25-58 years) and 68 age-matched controls. The data were analyzed using standardized human brain atlasbased tissue segmentation procedures to obtain regional volumes and their corresponding T2 relaxation times and DTI maps. Results-Group-averaged brain atlas-based qMRI maps of T2, fractional anisotropy and diffusivities are visually presented and compared between controls and RRMS. The analysis shows a widespread injury in RRMS. Atrophy of the CC was substantial in RRMS. The qMRI attributes of the neocortex in combination with the CC such as T2 and diffusivities were elevated and correlated with disability. Conclusion-Using a standardized multimodal qMRI acquistion and analyses that accounted for lesion distribution we demonstrate that cerebral pathology is widespread in RRMS. Our analysis of CC and neocortex qMRI metrics in relation to disability points to a neurodegenerative injury component that is independent from lesions.

Computers in Biology and Medicine, 2011

In this work we provide an up-to-date short review of computational magnetic resonance imaging (M... more In this work we provide an up-to-date short review of computational magnetic resonance imaging (MRI) and software tools that are widely used to process and analyze diffusion-weighted MRI data. A review of different methods used to acquire, model and analyze diffusion-weighted imaging data (DWI) is first provided with focus on diffusion tensor imaging (DTI). The major preprocessing, processing and post-processing procedures applied to DTI data are discussed. A list of freely available software packages to analyze diffusion MRI data is also provided.

Computers in Biology and Medicine, 2011

In this work, we present a framework to fuse and quantify tissue microstructural attributes (e.g.... more In this work, we present a framework to fuse and quantify tissue microstructural attributes (e.g. diffusion, functional, relaxation and perfusion MRI) using high spatial resolution T1-weighted volumetric measurements. The proposed computational procedures can be implemented by utilizing advanced, image segmentation, registration and diffusion tensor image processing software. Feasibility of the framework is also demonstrated using in-house developed software and freely available software such as FreeSurfer for regional tissue segmentation, Advanced Normalization Tools (ANTs) for registration and DTIStudio for fiber tracking and diffusion tensor data processing. We also demonstrate the application of these methods in the provision of quality control measures to assess the fidelity of tissue segmentation and multi-modal MRI registration.

Brain Structure and Function, 2010

Using diffusion tensor tractography, we quantified the microstructural changes in the association... more Using diffusion tensor tractography, we quantified the microstructural changes in the association, projection, and commissural compact white matter pathways of the human brain over the lifespan in a cohort of healthy right-handed children and adults aged 6-68 years. In both males and females, the diffusion tensor radial diffusivity of the bilateral arcuate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, corticospinal, somatosensory tracts, and the corpus callosum followed a U-curve with advancing age; fractional anisotropy in the same pathways followed an inverted U-curve. Our study provides useful baseline data for the interpretation of data collected from patients.

ABSTRACT Introduction: The human brain corpus striatum (CS) is composed of the caudate nucleus (C... more ABSTRACT Introduction: The human brain corpus striatum (CS) is composed of the caudate nucleus (CN), putamen (PUT) and globus pallidus (GP) which are three interconnected structures of the basal ganglia. These three structures are involved in several aspects of human cognition and behavior (1). The degeneration CS has been associated with natural aging (2), and several pathologies. In addition, the abnormal morphometry of these structures has been used as a marker of several acquired, psychiatric, therapy, and neurodevelopmental conditions. The neuronal mass, dendritic architecture and connectivity of these structures have also been shown to decrease using histological assessment due to natural aging (3). Since these structures are also known to contain different iron levels (4), they have been used in MRI literature as benchmarks to model the interplay between MRI intrinsic parameters such as T2 relaxation and diffusion tensor metrics (5, 6). In this work, we report for the first time using brain atlas-based volumetric methods a comprehensive account of the macro and microstructure of CS on a large healthy cohort across the lifespan. Methods: The participants included 281 healthy children, adolescents, young and older adults aged 6-63 years. The cohort consisted of 147 males (age mean ± S.D = 31.2 ± 11.5 years), and 134 females (age mean ± S.D = 34.8 ± 11.7 years). All volunteers were identified as neurologically normal by review of medical history and were medically stable at the time of the assessments. Written informed consent was obtained from the adults, guardians and adolescents and assent from the children participating in these studies. Conventional and DT-MRI Acquisition: All MRI studies were performed on a 3T Philips Intera scanner with a dual quasar gradient system and an eight channel SENSE-compatible head coil. The MRI protocol included fast dual-echo (TE 1 /TE 2 /TR= 9/90/6800) for transverse or T2 relaxation mapping and a high resolution (voxel size 0.9375 mm) 3D axially acquired T1-weighted spoiled gradient sequence. The DTI data were acquired using a single-shot spin-echo diffusion sensitized EPI sequence, b=1000 sec mm -2 , T R /T E = 6100/84 msec (5). The slice thickness was 3.0 mm with 44 contiguous axial slices covering the entire brain; FOV=240x240 mm 2 and matching the dual echo sequence. The number of b=0 images was 8; in addition each diffusion encoding was repeated twice and magnitude averaged to enhance signal-to-noise ratio. Tissue Volume was estimated (Fig. 1) using a novel brain atlas and DTI-based tissue segmentation approach (7). The DTI-based method for volume estimation was also compared with FreeSurfer applied on the 3D T1-weighted volumes (8). Data Processing and Statistical Analyses: The intracranial-volume (ICV) normalized volumes, and corresponding T2 relaxation and DTI metrics (e.g., fractional anisotropy = FA; radial diffusivity = λ ⊥ ; axial diffusivity = λ ||) were computed (5) and modeled for both males and females as y f =β 0 +β 1 *age+β 2 *age 2 , then the general least-squares were used to compute the coefficients, standard errors and their significance using analysis-of-variance methods as detailed elsewhere (9). Results: To demonstrate the validity of the segmentation approach used in this work to obtain estimates of volume, T2 and DTI metrics, we plotted the normalized volume age trajectories obtained using both the DTI method and FreeSurfer on a subset of 180 controls. Both DTI and FreeSurfer predicted a side and gender-independent loss of caudate, putamen and globus pallidus volume (see Fig 2 for the putamen). The lifespan mean T2, Mean diffusivity and FA trajectories for the CN, PUT and GP are shown in Figure 3, 4 and 5, respectively. Note the linear age-dependence and the statistically significant (p<0.001) anisotropy spatial heterogeneity trend FA(GP) > FA(CN) > FA(PUT). Note also that T2 (CN) > T2(PUT) > T2 (GP) at all ages. The mean diffusivity and T2 relaxation follow quadratic curves across the lifespan. The peak at minimum mean diffusivity is attained ~ 33 years, whereas the T2 relaxation minimum is attained at ~ 43 years reflecting that diffusion and relaxation mechanisms may have unique neuronal mechanisms (10).

Pakistan Journal of Medical and Health Sciences

Objectives: To determine the correlation of fasting salivary glucose with fasting plasma glucose ... more Objectives: To determine the correlation of fasting salivary glucose with fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) for the diagnosis and monitoring of type 2 diabetes mellitus (T2DM). Methods: A case - control study was carried out from 11th March to 30th August 2021, involving 88 participants out of which 44 were healthy controls and 44 participants were known T2DM who had FPG ≥ 126 mg/dl or 7.0 mmol/L. FPG was measured by Glucose oxidase method and HbA1c by National Glycohemoglobin Standardization Program (NGSP) certified chromatography. Results: T2DM group had significantly higher FPG, HbA1c and salivary glucose values. Both diabetics and healthy controls showed a positive correlation of fasting salivary glucose with FPG. The correlation coefficient (r) was 0.689 and 0.477 for cases and control groups respectively. Similarly, a positive correlation of fasting salivary glucose with HbA1c was observed with the value of r 0.433 and 0.498 for diabetic and heal...

Psychiatric Annals, 2017

Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent and chronic neurodevelopmen... more Attention-deficit/hyperactivity disorder (ADHD) is a highly prevalent and chronic neurodevelopmental disorder often with residual symptoms throughout the patient's lifespan. Patients with ADHD have a significant disease burden that adversely affects interpersonal, psychosocial, and occupational domains of their life. Stimulants are usually the first-line treatment for all patient age groups. Familiarity with varying aspects of this disorder is important for clinicians, given the significant challenges in treating this chronic condition. Although risks of medication abuse and diversion pose significant challenges, not treating ADHD can gravely affect patients' lives, potentially leading to school dropout, unemployment, legal problems, and more. This article reviews reasons to treat adult ADHD, versus reasons that support refraining from treating, and provides general treatment guidelines for practicing clinicians. [ Psychiatr Ann . 2017;47(6):315–321.]

The Journal of Neuroscience, 2011

The human brain thalami play essential roles in integrating cognitive, sensory, and motor functio... more The human brain thalami play essential roles in integrating cognitive, sensory, and motor functions. In multiple sclerosis (MS), quantitative magnetic resonance imaging (qMRI) measurements of the thalami provide important biomarkers of disease progression, but late development and aging confound the interpretation of data collected from patients over a wide age range. Thalamic tissue volume loss due to natural aging and its interplay with lesion-driven pathology has not been investigated previously. In this work, we used standardized thalamic volumetry combined with diffusion tensor imaging, T2 relaxometry, and lesion mapping on large cohorts of controls (N= 255, age range = 6.2–69.1 years) and MS patients (N= 109, age range = 20.8–68.5 years) to demonstrate early age- and lesion-independent thalamic neurodegeneration.

Journal of the Neurological Sciences, 2012

Multiple sclerosis (MS) is the most common immune-mediated disabling neurological disease of the ... more Multiple sclerosis (MS) is the most common immune-mediated disabling neurological disease of the central nervous system. The pathogenesis of MS is not fully understood. Histopathology implicates both demyelination and axonal degeneration as the major contributors to the accumulation of disability. The application of several in vivo quantitative magnetic resonance imaging (MRI) methods to both lesioned and normal-appearing brain tissue has not yet provided a solid conclusive support of the hypothesis that MS might be a diffuse disease. In this work, we adopted FreeSurfer to provide standardized macrostructure or volumetry of lesion free normal-appearing brain tissue in combination with multiple quantitative MRI metrics (T 2 relaxation time, diffusion tensor anisotropy and diffusivities) that characterize tissue microstructural integrity. By incorporating a large number of healthy controls, we have attempted to separate the natural age-related change from the disease-induced effects. Our work shows elevation in diffusivity and relaxation times and reduction in volume in a number of normalappearing white matter and gray matter structures in relapsing-remitting multiple sclerosis patients. These changes were related in part with the spatial distribution of lesions. The whole brain lesion load and age-adjusted expanded disability status score showed strongest correlations in regions such as corpus callosum with qMRI metrics that are believed to be specific markers of

Journal of Magnetic Resonance Imaging, 2012

Purpose-To investigate the utility of multimodal quantitative magnetic resonance imaging (qMRI) a... more Purpose-To investigate the utility of multimodal quantitative magnetic resonance imaging (qMRI) and atlas-based methods to identify characteristics of lesion-driven injury and neurodegeneration in relapsing remitting multiple sclerosis (RRMS) Materials and Methods-This work is health insurance portability and accountability act compliant. High resolution T1-weighted, dual echo and fluid-attenuated inversion recovery and diffusion tensor MRI images were prospectively acquired on 68 RRMS patients (range 25-58 years) and 68 age-matched controls. The data were analyzed using standardized human brain atlasbased tissue segmentation procedures to obtain regional volumes and their corresponding T2 relaxation times and DTI maps. Results-Group-averaged brain atlas-based qMRI maps of T2, fractional anisotropy and diffusivities are visually presented and compared between controls and RRMS. The analysis shows a widespread injury in RRMS. Atrophy of the CC was substantial in RRMS. The qMRI attributes of the neocortex in combination with the CC such as T2 and diffusivities were elevated and correlated with disability. Conclusion-Using a standardized multimodal qMRI acquistion and analyses that accounted for lesion distribution we demonstrate that cerebral pathology is widespread in RRMS. Our analysis of CC and neocortex qMRI metrics in relation to disability points to a neurodegenerative injury component that is independent from lesions.

Computers in Biology and Medicine, 2011

In this work we provide an up-to-date short review of computational magnetic resonance imaging (M... more In this work we provide an up-to-date short review of computational magnetic resonance imaging (MRI) and software tools that are widely used to process and analyze diffusion-weighted MRI data. A review of different methods used to acquire, model and analyze diffusion-weighted imaging data (DWI) is first provided with focus on diffusion tensor imaging (DTI). The major preprocessing, processing and post-processing procedures applied to DTI data are discussed. A list of freely available software packages to analyze diffusion MRI data is also provided.

Computers in Biology and Medicine, 2011

In this work, we present a framework to fuse and quantify tissue microstructural attributes (e.g.... more In this work, we present a framework to fuse and quantify tissue microstructural attributes (e.g. diffusion, functional, relaxation and perfusion MRI) using high spatial resolution T1-weighted volumetric measurements. The proposed computational procedures can be implemented by utilizing advanced, image segmentation, registration and diffusion tensor image processing software. Feasibility of the framework is also demonstrated using in-house developed software and freely available software such as FreeSurfer for regional tissue segmentation, Advanced Normalization Tools (ANTs) for registration and DTIStudio for fiber tracking and diffusion tensor data processing. We also demonstrate the application of these methods in the provision of quality control measures to assess the fidelity of tissue segmentation and multi-modal MRI registration.

Brain Structure and Function, 2010

Using diffusion tensor tractography, we quantified the microstructural changes in the association... more Using diffusion tensor tractography, we quantified the microstructural changes in the association, projection, and commissural compact white matter pathways of the human brain over the lifespan in a cohort of healthy right-handed children and adults aged 6-68 years. In both males and females, the diffusion tensor radial diffusivity of the bilateral arcuate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, corticospinal, somatosensory tracts, and the corpus callosum followed a U-curve with advancing age; fractional anisotropy in the same pathways followed an inverted U-curve. Our study provides useful baseline data for the interpretation of data collected from patients.

ABSTRACT Introduction: The human brain corpus striatum (CS) is composed of the caudate nucleus (C... more ABSTRACT Introduction: The human brain corpus striatum (CS) is composed of the caudate nucleus (CN), putamen (PUT) and globus pallidus (GP) which are three interconnected structures of the basal ganglia. These three structures are involved in several aspects of human cognition and behavior (1). The degeneration CS has been associated with natural aging (2), and several pathologies. In addition, the abnormal morphometry of these structures has been used as a marker of several acquired, psychiatric, therapy, and neurodevelopmental conditions. The neuronal mass, dendritic architecture and connectivity of these structures have also been shown to decrease using histological assessment due to natural aging (3). Since these structures are also known to contain different iron levels (4), they have been used in MRI literature as benchmarks to model the interplay between MRI intrinsic parameters such as T2 relaxation and diffusion tensor metrics (5, 6). In this work, we report for the first time using brain atlas-based volumetric methods a comprehensive account of the macro and microstructure of CS on a large healthy cohort across the lifespan. Methods: The participants included 281 healthy children, adolescents, young and older adults aged 6-63 years. The cohort consisted of 147 males (age mean ± S.D = 31.2 ± 11.5 years), and 134 females (age mean ± S.D = 34.8 ± 11.7 years). All volunteers were identified as neurologically normal by review of medical history and were medically stable at the time of the assessments. Written informed consent was obtained from the adults, guardians and adolescents and assent from the children participating in these studies. Conventional and DT-MRI Acquisition: All MRI studies were performed on a 3T Philips Intera scanner with a dual quasar gradient system and an eight channel SENSE-compatible head coil. The MRI protocol included fast dual-echo (TE 1 /TE 2 /TR= 9/90/6800) for transverse or T2 relaxation mapping and a high resolution (voxel size 0.9375 mm) 3D axially acquired T1-weighted spoiled gradient sequence. The DTI data were acquired using a single-shot spin-echo diffusion sensitized EPI sequence, b=1000 sec mm -2 , T R /T E = 6100/84 msec (5). The slice thickness was 3.0 mm with 44 contiguous axial slices covering the entire brain; FOV=240x240 mm 2 and matching the dual echo sequence. The number of b=0 images was 8; in addition each diffusion encoding was repeated twice and magnitude averaged to enhance signal-to-noise ratio. Tissue Volume was estimated (Fig. 1) using a novel brain atlas and DTI-based tissue segmentation approach (7). The DTI-based method for volume estimation was also compared with FreeSurfer applied on the 3D T1-weighted volumes (8). Data Processing and Statistical Analyses: The intracranial-volume (ICV) normalized volumes, and corresponding T2 relaxation and DTI metrics (e.g., fractional anisotropy = FA; radial diffusivity = λ ⊥ ; axial diffusivity = λ ||) were computed (5) and modeled for both males and females as y f =β 0 +β 1 *age+β 2 *age 2 , then the general least-squares were used to compute the coefficients, standard errors and their significance using analysis-of-variance methods as detailed elsewhere (9). Results: To demonstrate the validity of the segmentation approach used in this work to obtain estimates of volume, T2 and DTI metrics, we plotted the normalized volume age trajectories obtained using both the DTI method and FreeSurfer on a subset of 180 controls. Both DTI and FreeSurfer predicted a side and gender-independent loss of caudate, putamen and globus pallidus volume (see Fig 2 for the putamen). The lifespan mean T2, Mean diffusivity and FA trajectories for the CN, PUT and GP are shown in Figure 3, 4 and 5, respectively. Note the linear age-dependence and the statistically significant (p<0.001) anisotropy spatial heterogeneity trend FA(GP) > FA(CN) > FA(PUT). Note also that T2 (CN) > T2(PUT) > T2 (GP) at all ages. The mean diffusivity and T2 relaxation follow quadratic curves across the lifespan. The peak at minimum mean diffusivity is attained ~ 33 years, whereas the T2 relaxation minimum is attained at ~ 43 years reflecting that diffusion and relaxation mechanisms may have unique neuronal mechanisms (10).