Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow position... more Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow positioning), oropharyngeal, pharyngeal and esophageal phases. The timing of these phases is controlled by brain stem pattern generators including reflex for oropharyngeal propulsion and transit. Dysphagia in Parkinson‟s disease (PD) commonly observed at late stages with aspiration, pneumonia and hospitalization. Objective: Can subtle oromotor signs (if any) be observed for planning early interventions in PD Methods: The present study investigated oromotor function in fourteen early PD (onset ≤2years; H&Y score ≤2.5) with dynamic MRI using saline (water) bolus and compared with seven agematched healthy controls. Results: All the patients with PD were non-symptomatic for dysphagia by self-reporting, and on clinical assessment (Part-II MDS-UPDRS, Swallowing disturbance questionnaire, SDQ and Clinical assessment of dysphagia in neurodegeneration, CADN). Qualitatively MR images visualized, differenc...
Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow position... more Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow positioning), oropharyngeal, pharyngeal and esophageal phases. The timing of these phases is controlled by brain stem pattern generators including reflex for oropharyngeal propulsion and transit. Dysphagia in Parkinson's disease (PD) commonly observed at late stages with aspiration, pneumonia and hospitalization. Objective: Can subtle oromotor signs (if any) be observed for planning early interventions in PD Methods: The present study investigated oromotor function in fourteen early PD (onset [≤]2years; H&Y [≤]2.5) with dynamic MRI using saline (water) bolus and compared with seven age-matched healthy controls. Results: All the patients with PD were non-symptomatic for dysphagia by self-reporting, and on clinical assessment (Part-II MDS-UPDRS, Swallowing disturbance questionnaire, SDQ and Clinical assessment of dysphagia in neurodegeneration, CADN). Qualitatively MR images visualized, differ...
Computer-aided diagnosis (CAD) of Parkinson's disease (PD) using structural magnetic resonance im... more Computer-aided diagnosis (CAD) of Parkinson's disease (PD) using structural magnetic resonance imaging is an emerging research field for the pattern recognition community. The existing research works have utilized gray matter, white matter and cerebrospinal fluid tissues individually for diagnosis of PD and have ignored the intercorrelation among the three tissues. Thus, there is a need to define a fused feature descriptor (FFD) which can capture information and intercorrelation of all the three tissues simultaneously, and to further enhance the performance of CAD. The present study proposes a simple and efficient FFD, in terms of all the three tissues, for CAD of PD. Each brain volume is represented in terms of the FFD. Then each fused volume is segmented into 118 brain regions. Thereafter, features extraction is carried out from each brain region using 3D local binary pattern. Then, a set of discriminating and uncorrelated features are identified using t-test in conjunction with minimum redundancy maximum relevance feature selection method. Finally, support vector machine is utilized to build a decision model. Volumetric 3D T1-weighted magnetic resonance imaging dataset (age & gender matched 30 PD and 30 healthy subjects) is acquired using 1.5T machine and is utilized to investigate the efficacy of the proposed method. The classification accuracy of 95% is achieved using leave-one-out cross-validation scheme which is superior to the existing methods. Regions namely Hippocampus R, Cingulum Mid L, Frontal Inf Tri L, Precentral R, Precentral L, Frontal Mid L, Frontal Mid Orb L, Cingulum Ant L and Hippocampus L, are observed to be the most discriminative regions for diagnosis of PD. The notable performance of the proposed method suggests that instead of studying the three tissues independently, their intercorrelation should also be considered. Further, the proposed method may be employed as a diagnostic tool for diagnosis of PD.
The present study was conducted with the aim to investigate the peripheral and central auditory m... more The present study was conducted with the aim to investigate the peripheral and central auditory manifestations in individuals with RA. 40 subjects (age range: 25-45 years), diagnosed with RA and 40 age and sex matched otologically normal subjects participated in the study. Participants underwent a comprehensive audiological test battery comprising of conventional and extended high frequency puretone audiometry, impedance audiometry, otoacoustic emissions (OAEs) and auditory brainstem responses (ABR). Significant difference between the puretone thresholds for the two groups was found at high frequencies (beyond 4 kHz). Majority of the subjects in RA group had absent/reduced amplitude for TEOAE. A highly statistically significant difference was observed between the RA and the control group for the absolute latency of wave I, III and V of the left ear. Considering the high incidence of hearing loss in RA group, a regular referral for audiological evaluations is suggested.
Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and... more Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) was sought in strabismic amblyopes. In this hospital-based case-control cross-sectional study, fMRI and DTI were conducted in strabismic amblyopes before initiation of any therapy and after visual recovery following the administration of occlusion therapy. FMRI was performed in 10 strabismic amblyopic subjects (baseline group) and in 5 left strabismic amblyopic children post-occlusion therapy after two-line visual improvement. Ten age-matched healthy children with right ocular dominance formed control group. Structural and functional MRI was carried out on 1.5T MR scanner. The visual task consisted of 8 Hz flickering checkerboard with red dot and occasional green dot. Blood-oxygen-level-dependent (BOLD) fMRI was analyzed using statistical parametric mapping and DTI on NordicIce (NordicNeuroLab) softwares. Reduced occipital activation was elicited when view...
Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulator... more Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulatory movements during speech production. Background: In Parkinson's disease (PD) speech perceptual fea-tures are due to reduced articulatory displacements and improper coordination of muscle groups for consonant production. These skilled motor programs for articulatory and respiratory movements are controlled by cerebral cortex and basal ganglia that deteriorate gradually with progressive degeneration. The training can induce plasticity in motor areas that supports the production and refinement of skilled movement sequences. These changes are studied by using behavioral assessments and functional magnetic resonance imaging (fMRI). Methods: The pilot study included six PD subjects and were clin-ically scored according to UPDRS-III, Hoehn and Yahr stages and Frenchay's dysarthria Scale in 'on-state'. Imaging was done in 1.5T MR scanner (Avanto, Siemens, Germany) using head coi...
International Journal of Imaging Systems and Technology, 2015
Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the basi... more Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the basis of clinical history and examination alone as there are no diagnostic tests available. However, the current diagnosis highly depends on the knowledge and experience of clinicians and hence subjective in nature. Thus, the focus of this study is to develop a computer-aided diagnosis (CAD) method using T1-weighted magnetic resonance imaging (MRI) to differentiate PD from controls. Method: The proposed method utilizes graph-theory-based spectral feature selection method to select a set of discriminating features from whole brain volume. A decision model is built using support vector machine as a classifier with leave-one-out cross-validation scheme. The performance measures, namely, sensitivity, specificity, and classification accuracy, are utilized to evaluate the performance of the decision model. The efficacy of the proposed method is checked on volumetric 3D T1-weighted (1 mm iso-voxel) MRI dataset of 30 PD patients and 30 age and gender matched controls acquired with 1.5T MRI scanner. Results: Experimental results demonstrate that the proposed method is able to differentiate PD from controls with an accuracy of 86.67%, which encourages the use of CAD. The performance of the proposed method outperforms the existing methods except one. In addition, it is observed that the maximum number of selected features belong to caudate region followed by cuneus region. Thus, these regions may be considered as potential biomarkers in diagnosis of PD. Conclusion: The proposed method may be utilized by the clinicians for diagnosis of PD.
Purpose. Subjective tinnitus has different forms and degrees of severity. Many studies in the lit... more Purpose. Subjective tinnitus has different forms and degrees of severity. Many studies in the literature have assessed psychoacoustic characteristics of tinnitus but hardly any of them had focused on the association of audiological profile with onset duration and loudness perception. The aim of this study was to evaluate existence of any association between tinnitus loudness/onset duration and audiological profile to explain differences in prognosis. Method. Study design was prospective. The sample consisted of 26 subjects having tinnitus, which was divided into tinnitus and nontinnitus ears. Audiological profile included pure-tone audiometry, speech audiometry, tympanometry, acoustic reflex test, and auditory evoked potentials (early and middle latency). Unpaired t-test was applied to compare two subgroups. Correlation and association between tinnitus onset duration/loudness perception and audiological profile were also assessed by calculating Spearman’s coefficient and Fischer exa...
Reading creates accessibility to the outer world information and is an integral skill for academi... more Reading creates accessibility to the outer world information and is an integral skill for academic achievement. It involves visual perception, reasoning at symbolic level (text reading) and phonological processing. But does perception, visuospatial processing at pre-symbolic level affect reading skill? To understand and untangle the mechanism fifty children with reading problem (developmental dyslexia, DDC) and twentyfive age-matched typical readers (healthy controls, HC) were studied. In DDC, the variable-performance of non-symbolic visual search (pictorial-level) was associated with bilateral brain activity (functional MRI) of ventral stream (inferior occipital and fusiform) and greater involvement of frontal-prefrontal regions, suggesting the modified dorsal route-gating for figure-ground filtering. Performance variability in picture-concept reasoning (71.9% and significant group mean difference) and visuospatial-organization (51.3%) of DDC children indicate attentional or execut...
Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulator... more Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulatory movements during speech production. Background: In Parkinson's disease (PD) speech perceptual fea-tures are due to reduced articulatory displacements and improper coordination of muscle groups for consonant production. These skilled motor programs for articulatory and respiratory movements are controlled by cerebral cortex and basal ganglia that deteriorate gradually with progressive degeneration. The training can induce plasticity in motor areas that supports the production and refinement of skilled movement sequences. These changes are studied by using behavioral assessments and functional magnetic resonance imaging (fMRI). Methods: The pilot study included six PD subjects and were clin-ically scored according to UPDRS-III, Hoehn and Yahr stages and Frenchay's dysarthria Scale in 'on-state'. Imaging was done in 1.5T MR scanner (Avanto, Siemens, Germany) using head coi...
Background: Idiopathic Parkinson's Disease (IPD) is caused by dopamine deficiency owing to th... more Background: Idiopathic Parkinson's Disease (IPD) is caused by dopamine deficiency owing to the degeneration of dopaminergic neu-rons in the substantia nigra pars compacta (SNpc) of the midbrain. The diagnosis of IPD is usually made on the basis of the presence of symptoms and so the diagnosis may not be clear, especially in early stage of IPD. Many imaging tools have been developed on patho-physiologic changes of IPD. In this study, we aimed to measure the apparent diffusion coefficient (ADC) value at the contralateral SNpc of symptomatic hemibody in IPD patients. Methods: Brain MRI findings were studied in 27 patients with IPD and 17 healthy controls. The ADC values in the manually drawn SNpc area were measured by the MIDAS program. Results: A total of 27 patients comprising of 14 right sided, 13 left sided symptomatic IPD and 17 control subjects were studied. The ratio of ADC value (affected side midbrain/unaffected side midbrain) in the IPD was higher compared to the control ...
Introduction: Chronic subjective tinnitus is associated with cognitive disruptions affecting perc... more Introduction: Chronic subjective tinnitus is associated with cognitive disruptions affecting perception, thinking, language, reasoning, problem solving, memory, visual tasks (reading) and attention. Objective: To evaluate existence of any association between tinnitus parameters and neuropsychological performance to explain cognitive processing. Materials and Methods: Study design was prospective, consisting 25 patients with idiopathic chronic subjective tinnitus and gave informed consent before planning their treatment. Neuropsychological profile included (i) performance on verbal information, comprehension, arithmetic and digit span; (ii) non-verbal performance for visual pattern completion analogies; (iii) memory performance for long-term, recent, delayed-recall, immediate-recall, verbal-retention, visualretention, visual recognition; (iv) reception, interpretation and execution for visual motor gestalt. Correlation between tinnitus onset duration/ loudness perception with neuropsychological profile was assessed by calculating Spearman's coefficient. Results: Findings suggest that tinnitus may interfere with cognitive processing especially performance on digit span, verbal comprehension, mental balance, attention & concentration, immediate recall, visual recognition and visual-motor gestalt subtests. Negative correlation between neurocognitive tasks with tinnitus loudness and onset duration indicated their association. Positive correlation between tinnitus and visual-motor gestalt performance indicated the brain dysfunction. Conclusion: Tinnitus association with non-auditory processing of verbal, visual and visuo-spatial information suggested neuroplastic changes that need to be targeted in cognitive rehabilitation.
Fused feature descriptor Computer-aided diagnosis 3D local binary pattern Magnetic resonance imag... more Fused feature descriptor Computer-aided diagnosis 3D local binary pattern Magnetic resonance imaging Minimum redundancy maximum relevance a b s t r a c t Computer-aided diagnosis (CAD) of Parkinson's disease (PD) using structural magnetic resonance imaging is an emerging research field for the pattern recognition community. The existing research works have utilized gray matter, white matter and cerebrospinal fluid tissues individually for diagnosis of PD and have ignored the intercorrelation among the three tissues. Thus, there is a need to define a fused feature descriptor (FFD) which can capture information and intercorrelation of all the three tissues simultaneously , and to further enhance the performance of CAD. The present study proposes a simple and efficient FFD, in terms of all the three tissues, for CAD of PD. Each brain volume is represented in terms of the FFD. Then each fused volume is segmented into 118 brain regions. Thereafter, features extraction is carried out ...
Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the ... more Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the basis of clinical history and examination alone as there are no diagnostic tests available. However , the current diagnosis highly depends on the knowledge and experience of clinicians and hence subjective in nature. Thus, the focus of this study is to develop a computer-aided diagnosis (CAD) method using T1-weighted magnetic resonance imaging (MRI) to differentiate PD from controls. Method: The proposed method utilizes graph-theory-based spectral feature selection method to select a set of discriminating features from whole brain volume. A decision model is built using support vector machine as a classifier with leave-one-out cross-validation scheme. The performance measures, namely, sensitivity, specificity, and classification accuracy, are utilized to evaluate the performance of the decision model. The efficacy of the proposed method is checked on volumetric 3D T1-weighted (1 mm iso-v...
The present study was conducted with the aim to investigate the peripheral and central auditory m... more The present study was conducted with the aim to investigate the peripheral and central auditory manifestations in individuals with RA. 40 subjects (age range: 25-45 years), diagnosed with RA and 40 age and sex matched otologically normal subjects participated in the study. Participants underwent a comprehensive audiological test battery comprising of conventional and extended high frequency puretone audiometry, impedance audiometry, otoacoustic emissions (OAEs) and auditory brainstem responses (ABR). Significant difference between the puretone thresholds for the two groups was found at high frequencies (beyond 4 kHz). Majority of the subjects in RA group had absent/reduced amplitude for TEOAE. A highly statistically significant difference was observed between the RA and the control group for the absolute latency of wave I, III and V of the left ear. Considering the high incidence of hearing loss in RA group, a regular referral for audiological evaluations is suggested. Keywords: Rhe...
Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and... more Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) was sought in strabismic amblyopes. In this hospital-based case-control cross-sectional study, fMRI and DTI were conducted in strabismic amblyopes before initiation of any therapy and after visual recovery following the administration of occlusion therapy. FMRI was performed in 10 strabismic amblyopic subjects (baseline group) and in 5 left strabismic amblyopic children post-occlusion therapy after two-line visual improvement. Ten age-matched healthy children with right ocular dominance formed control group. Structural and functional MRI was carried out on 1.5T MR scanner. The visual task consisted of 8 Hz flickering checkerboard with red dot and occasional green dot. Blood-oxygen-level-dependent (BOLD) fMRI was analyzed using statistical parametric mapping and DTI on NordicIce (NordicNeuroLab) softwares. Reduced occipital activation was elicited when view...
Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow position... more Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow positioning), oropharyngeal, pharyngeal and esophageal phases. The timing of these phases is controlled by brain stem pattern generators including reflex for oropharyngeal propulsion and transit. Dysphagia in Parkinson‟s disease (PD) commonly observed at late stages with aspiration, pneumonia and hospitalization. Objective: Can subtle oromotor signs (if any) be observed for planning early interventions in PD Methods: The present study investigated oromotor function in fourteen early PD (onset ≤2years; H&Y score ≤2.5) with dynamic MRI using saline (water) bolus and compared with seven agematched healthy controls. Results: All the patients with PD were non-symptomatic for dysphagia by self-reporting, and on clinical assessment (Part-II MDS-UPDRS, Swallowing disturbance questionnaire, SDQ and Clinical assessment of dysphagia in neurodegeneration, CADN). Qualitatively MR images visualized, differenc...
Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow position... more Background: Swallowing is complex phenomena comprising oral (preparatory and pre-swallow positioning), oropharyngeal, pharyngeal and esophageal phases. The timing of these phases is controlled by brain stem pattern generators including reflex for oropharyngeal propulsion and transit. Dysphagia in Parkinson's disease (PD) commonly observed at late stages with aspiration, pneumonia and hospitalization. Objective: Can subtle oromotor signs (if any) be observed for planning early interventions in PD Methods: The present study investigated oromotor function in fourteen early PD (onset [≤]2years; H&Y [≤]2.5) with dynamic MRI using saline (water) bolus and compared with seven age-matched healthy controls. Results: All the patients with PD were non-symptomatic for dysphagia by self-reporting, and on clinical assessment (Part-II MDS-UPDRS, Swallowing disturbance questionnaire, SDQ and Clinical assessment of dysphagia in neurodegeneration, CADN). Qualitatively MR images visualized, differ...
Computer-aided diagnosis (CAD) of Parkinson's disease (PD) using structural magnetic resonance im... more Computer-aided diagnosis (CAD) of Parkinson's disease (PD) using structural magnetic resonance imaging is an emerging research field for the pattern recognition community. The existing research works have utilized gray matter, white matter and cerebrospinal fluid tissues individually for diagnosis of PD and have ignored the intercorrelation among the three tissues. Thus, there is a need to define a fused feature descriptor (FFD) which can capture information and intercorrelation of all the three tissues simultaneously, and to further enhance the performance of CAD. The present study proposes a simple and efficient FFD, in terms of all the three tissues, for CAD of PD. Each brain volume is represented in terms of the FFD. Then each fused volume is segmented into 118 brain regions. Thereafter, features extraction is carried out from each brain region using 3D local binary pattern. Then, a set of discriminating and uncorrelated features are identified using t-test in conjunction with minimum redundancy maximum relevance feature selection method. Finally, support vector machine is utilized to build a decision model. Volumetric 3D T1-weighted magnetic resonance imaging dataset (age & gender matched 30 PD and 30 healthy subjects) is acquired using 1.5T machine and is utilized to investigate the efficacy of the proposed method. The classification accuracy of 95% is achieved using leave-one-out cross-validation scheme which is superior to the existing methods. Regions namely Hippocampus R, Cingulum Mid L, Frontal Inf Tri L, Precentral R, Precentral L, Frontal Mid L, Frontal Mid Orb L, Cingulum Ant L and Hippocampus L, are observed to be the most discriminative regions for diagnosis of PD. The notable performance of the proposed method suggests that instead of studying the three tissues independently, their intercorrelation should also be considered. Further, the proposed method may be employed as a diagnostic tool for diagnosis of PD.
The present study was conducted with the aim to investigate the peripheral and central auditory m... more The present study was conducted with the aim to investigate the peripheral and central auditory manifestations in individuals with RA. 40 subjects (age range: 25-45 years), diagnosed with RA and 40 age and sex matched otologically normal subjects participated in the study. Participants underwent a comprehensive audiological test battery comprising of conventional and extended high frequency puretone audiometry, impedance audiometry, otoacoustic emissions (OAEs) and auditory brainstem responses (ABR). Significant difference between the puretone thresholds for the two groups was found at high frequencies (beyond 4 kHz). Majority of the subjects in RA group had absent/reduced amplitude for TEOAE. A highly statistically significant difference was observed between the RA and the control group for the absolute latency of wave I, III and V of the left ear. Considering the high incidence of hearing loss in RA group, a regular referral for audiological evaluations is suggested.
Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and... more Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) was sought in strabismic amblyopes. In this hospital-based case-control cross-sectional study, fMRI and DTI were conducted in strabismic amblyopes before initiation of any therapy and after visual recovery following the administration of occlusion therapy. FMRI was performed in 10 strabismic amblyopic subjects (baseline group) and in 5 left strabismic amblyopic children post-occlusion therapy after two-line visual improvement. Ten age-matched healthy children with right ocular dominance formed control group. Structural and functional MRI was carried out on 1.5T MR scanner. The visual task consisted of 8 Hz flickering checkerboard with red dot and occasional green dot. Blood-oxygen-level-dependent (BOLD) fMRI was analyzed using statistical parametric mapping and DTI on NordicIce (NordicNeuroLab) softwares. Reduced occipital activation was elicited when view...
Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulator... more Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulatory movements during speech production. Background: In Parkinson's disease (PD) speech perceptual fea-tures are due to reduced articulatory displacements and improper coordination of muscle groups for consonant production. These skilled motor programs for articulatory and respiratory movements are controlled by cerebral cortex and basal ganglia that deteriorate gradually with progressive degeneration. The training can induce plasticity in motor areas that supports the production and refinement of skilled movement sequences. These changes are studied by using behavioral assessments and functional magnetic resonance imaging (fMRI). Methods: The pilot study included six PD subjects and were clin-ically scored according to UPDRS-III, Hoehn and Yahr stages and Frenchay's dysarthria Scale in 'on-state'. Imaging was done in 1.5T MR scanner (Avanto, Siemens, Germany) using head coi...
International Journal of Imaging Systems and Technology, 2015
Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the basi... more Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the basis of clinical history and examination alone as there are no diagnostic tests available. However, the current diagnosis highly depends on the knowledge and experience of clinicians and hence subjective in nature. Thus, the focus of this study is to develop a computer-aided diagnosis (CAD) method using T1-weighted magnetic resonance imaging (MRI) to differentiate PD from controls. Method: The proposed method utilizes graph-theory-based spectral feature selection method to select a set of discriminating features from whole brain volume. A decision model is built using support vector machine as a classifier with leave-one-out cross-validation scheme. The performance measures, namely, sensitivity, specificity, and classification accuracy, are utilized to evaluate the performance of the decision model. The efficacy of the proposed method is checked on volumetric 3D T1-weighted (1 mm iso-voxel) MRI dataset of 30 PD patients and 30 age and gender matched controls acquired with 1.5T MRI scanner. Results: Experimental results demonstrate that the proposed method is able to differentiate PD from controls with an accuracy of 86.67%, which encourages the use of CAD. The performance of the proposed method outperforms the existing methods except one. In addition, it is observed that the maximum number of selected features belong to caudate region followed by cuneus region. Thus, these regions may be considered as potential biomarkers in diagnosis of PD. Conclusion: The proposed method may be utilized by the clinicians for diagnosis of PD.
Purpose. Subjective tinnitus has different forms and degrees of severity. Many studies in the lit... more Purpose. Subjective tinnitus has different forms and degrees of severity. Many studies in the literature have assessed psychoacoustic characteristics of tinnitus but hardly any of them had focused on the association of audiological profile with onset duration and loudness perception. The aim of this study was to evaluate existence of any association between tinnitus loudness/onset duration and audiological profile to explain differences in prognosis. Method. Study design was prospective. The sample consisted of 26 subjects having tinnitus, which was divided into tinnitus and nontinnitus ears. Audiological profile included pure-tone audiometry, speech audiometry, tympanometry, acoustic reflex test, and auditory evoked potentials (early and middle latency). Unpaired t-test was applied to compare two subgroups. Correlation and association between tinnitus onset duration/loudness perception and audiological profile were also assessed by calculating Spearman’s coefficient and Fischer exa...
Reading creates accessibility to the outer world information and is an integral skill for academi... more Reading creates accessibility to the outer world information and is an integral skill for academic achievement. It involves visual perception, reasoning at symbolic level (text reading) and phonological processing. But does perception, visuospatial processing at pre-symbolic level affect reading skill? To understand and untangle the mechanism fifty children with reading problem (developmental dyslexia, DDC) and twentyfive age-matched typical readers (healthy controls, HC) were studied. In DDC, the variable-performance of non-symbolic visual search (pictorial-level) was associated with bilateral brain activity (functional MRI) of ventral stream (inferior occipital and fusiform) and greater involvement of frontal-prefrontal regions, suggesting the modified dorsal route-gating for figure-ground filtering. Performance variability in picture-concept reasoning (71.9% and significant group mean difference) and visuospatial-organization (51.3%) of DDC children indicate attentional or execut...
Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulator... more Objective: To observe the impact of rehabilitation on motor proc-essing and real-time articulatory movements during speech production. Background: In Parkinson's disease (PD) speech perceptual fea-tures are due to reduced articulatory displacements and improper coordination of muscle groups for consonant production. These skilled motor programs for articulatory and respiratory movements are controlled by cerebral cortex and basal ganglia that deteriorate gradually with progressive degeneration. The training can induce plasticity in motor areas that supports the production and refinement of skilled movement sequences. These changes are studied by using behavioral assessments and functional magnetic resonance imaging (fMRI). Methods: The pilot study included six PD subjects and were clin-ically scored according to UPDRS-III, Hoehn and Yahr stages and Frenchay's dysarthria Scale in 'on-state'. Imaging was done in 1.5T MR scanner (Avanto, Siemens, Germany) using head coi...
Background: Idiopathic Parkinson's Disease (IPD) is caused by dopamine deficiency owing to th... more Background: Idiopathic Parkinson's Disease (IPD) is caused by dopamine deficiency owing to the degeneration of dopaminergic neu-rons in the substantia nigra pars compacta (SNpc) of the midbrain. The diagnosis of IPD is usually made on the basis of the presence of symptoms and so the diagnosis may not be clear, especially in early stage of IPD. Many imaging tools have been developed on patho-physiologic changes of IPD. In this study, we aimed to measure the apparent diffusion coefficient (ADC) value at the contralateral SNpc of symptomatic hemibody in IPD patients. Methods: Brain MRI findings were studied in 27 patients with IPD and 17 healthy controls. The ADC values in the manually drawn SNpc area were measured by the MIDAS program. Results: A total of 27 patients comprising of 14 right sided, 13 left sided symptomatic IPD and 17 control subjects were studied. The ratio of ADC value (affected side midbrain/unaffected side midbrain) in the IPD was higher compared to the control ...
Introduction: Chronic subjective tinnitus is associated with cognitive disruptions affecting perc... more Introduction: Chronic subjective tinnitus is associated with cognitive disruptions affecting perception, thinking, language, reasoning, problem solving, memory, visual tasks (reading) and attention. Objective: To evaluate existence of any association between tinnitus parameters and neuropsychological performance to explain cognitive processing. Materials and Methods: Study design was prospective, consisting 25 patients with idiopathic chronic subjective tinnitus and gave informed consent before planning their treatment. Neuropsychological profile included (i) performance on verbal information, comprehension, arithmetic and digit span; (ii) non-verbal performance for visual pattern completion analogies; (iii) memory performance for long-term, recent, delayed-recall, immediate-recall, verbal-retention, visualretention, visual recognition; (iv) reception, interpretation and execution for visual motor gestalt. Correlation between tinnitus onset duration/ loudness perception with neuropsychological profile was assessed by calculating Spearman's coefficient. Results: Findings suggest that tinnitus may interfere with cognitive processing especially performance on digit span, verbal comprehension, mental balance, attention & concentration, immediate recall, visual recognition and visual-motor gestalt subtests. Negative correlation between neurocognitive tasks with tinnitus loudness and onset duration indicated their association. Positive correlation between tinnitus and visual-motor gestalt performance indicated the brain dysfunction. Conclusion: Tinnitus association with non-auditory processing of verbal, visual and visuo-spatial information suggested neuroplastic changes that need to be targeted in cognitive rehabilitation.
Fused feature descriptor Computer-aided diagnosis 3D local binary pattern Magnetic resonance imag... more Fused feature descriptor Computer-aided diagnosis 3D local binary pattern Magnetic resonance imaging Minimum redundancy maximum relevance a b s t r a c t Computer-aided diagnosis (CAD) of Parkinson's disease (PD) using structural magnetic resonance imaging is an emerging research field for the pattern recognition community. The existing research works have utilized gray matter, white matter and cerebrospinal fluid tissues individually for diagnosis of PD and have ignored the intercorrelation among the three tissues. Thus, there is a need to define a fused feature descriptor (FFD) which can capture information and intercorrelation of all the three tissues simultaneously , and to further enhance the performance of CAD. The present study proposes a simple and efficient FFD, in terms of all the three tissues, for CAD of PD. Each brain volume is represented in terms of the FFD. Then each fused volume is segmented into 118 brain regions. Thereafter, features extraction is carried out ...
Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the ... more Introduction: Parkinson's disease (PD) is a neurological disorder, which is diagnosed on the basis of clinical history and examination alone as there are no diagnostic tests available. However , the current diagnosis highly depends on the knowledge and experience of clinicians and hence subjective in nature. Thus, the focus of this study is to develop a computer-aided diagnosis (CAD) method using T1-weighted magnetic resonance imaging (MRI) to differentiate PD from controls. Method: The proposed method utilizes graph-theory-based spectral feature selection method to select a set of discriminating features from whole brain volume. A decision model is built using support vector machine as a classifier with leave-one-out cross-validation scheme. The performance measures, namely, sensitivity, specificity, and classification accuracy, are utilized to evaluate the performance of the decision model. The efficacy of the proposed method is checked on volumetric 3D T1-weighted (1 mm iso-v...
The present study was conducted with the aim to investigate the peripheral and central auditory m... more The present study was conducted with the aim to investigate the peripheral and central auditory manifestations in individuals with RA. 40 subjects (age range: 25-45 years), diagnosed with RA and 40 age and sex matched otologically normal subjects participated in the study. Participants underwent a comprehensive audiological test battery comprising of conventional and extended high frequency puretone audiometry, impedance audiometry, otoacoustic emissions (OAEs) and auditory brainstem responses (ABR). Significant difference between the puretone thresholds for the two groups was found at high frequencies (beyond 4 kHz). Majority of the subjects in RA group had absent/reduced amplitude for TEOAE. A highly statistically significant difference was observed between the RA and the control group for the absolute latency of wave I, III and V of the left ear. Considering the high incidence of hearing loss in RA group, a regular referral for audiological evaluations is suggested. Keywords: Rhe...
Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and... more Evaluation of brain cluster activation using the functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) was sought in strabismic amblyopes. In this hospital-based case-control cross-sectional study, fMRI and DTI were conducted in strabismic amblyopes before initiation of any therapy and after visual recovery following the administration of occlusion therapy. FMRI was performed in 10 strabismic amblyopic subjects (baseline group) and in 5 left strabismic amblyopic children post-occlusion therapy after two-line visual improvement. Ten age-matched healthy children with right ocular dominance formed control group. Structural and functional MRI was carried out on 1.5T MR scanner. The visual task consisted of 8 Hz flickering checkerboard with red dot and occasional green dot. Blood-oxygen-level-dependent (BOLD) fMRI was analyzed using statistical parametric mapping and DTI on NordicIce (NordicNeuroLab) softwares. Reduced occipital activation was elicited when view...
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Papers by sunita gudwani