Browsing by Author "Mathuranath, PS"

Now showing 1 - 20 of 28
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    A case of sporadic Creutzfeldt Jakob disease with anterior visual pathway involvement
    (NEUROLOGY INDIA, 2005) Mooney, T; Sreekumar, J; Hemanth, S; Mathuranath, PS; Sarada, C
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    A Genetic Algorithm Optimized Artificial Neural Network for the Segmentation of MR Images in Frontotemporal Dementia
    (SWARM, EVOLUTIONARY, AND MEMETIC COMPUTING, PT II (SEMCCO 2013), 2013) Kumari, RS; Varghese, T; Kesavadas, C; Singh, NA; Mathuranath, PS
    Frontotemporal Dementia (FTD) is an early onset dementia with atrophy in frontal and temporal regions. The differential diagnosis of FTD remains challenging because of the overlapping behavioral symptoms in patients, which have considerable overlap with Alzheimer's disease (AD). Neuroimaging analysis especially Magnetic Resonance Image Imaging (MRI) has opened up a new window to identify, and track disease process and progression. In this paper, we introduce a genetic algorithm (GA) tuned Artificial Neural Network (ANN) to measure the structural changes over a period of 1year. GA is a heuristic optimization method based on the Darwin's principle of natural evolution. The longitudinal atrophy patterns obtained from the proposed approach could serve as a predictor of impending behavioral changes in FTD subjects. The performance of our computerized scheme is evaluated and compared with the ground truth information. Using the proposed approach, we have achieved an average classification accuracy of 95.5 %, 96.5% and 98% for GM, WM and CSF respectively.
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    A pilot study on utility of Malayalam version of Addenbrooke's Cognitive Examination in detection of amnestic mild cognitive impairment: A critical insight into utility of learning and recall measures
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2014) Menon, R; Lekha, VS; Justus, S; Sarma, PS; Mathuranath, PS
    Aims: This pilot study sought to determine whether the Malayalam adaptation of Addenbrooke's Cognitive Examination (M-ACE) can effectively identify patients with amnestic mild cognitive impairment (a-MCI) and the impact of measures of learning and free recall. Materials and Methods: A cohort of 23 patients with a-MCI aged between 55-80 years diagnosed as per current criteria and 23 group matched cognitively normal healthy controls (CNHC) were studied. The measures of acquisition and delayed recall were the Rey Auditory Verbal Learning Test (RAVLT) and Wechsler Memory Scale (WMS)-III (verbal and visual subsets) and Delayed Matching-to-sample Test (DMS)-48. Test scores of M-ACE registration and recall scores were included. To examine the differences in test performances between the groups, we compared the number of subjects with test scores less than 1.5 standard deviation (SD) of the control scores. Comparisons between a-MCI and controls were drawn using Fisher's exact test and Mann-Whitney U tests. Results: M-ACE registration component ascertained on a 24-point scale failed to demonstrate any differences between a-MCI and controls (P = 0.665) as opposed to recall judged on a cumulative 10-point scale (P = 0.001). Significant differences were noted in RAVLT list learning (P < 0.001) and list recall (P = 0.003), WMS-III paragraph learning (P < 0.001) and recall (P = 0.007), visual learning (P = 0.004) and recall (P = 0.001). Conclusions: M-ACE recall scores are an effective screening tool to identify patients with suspected a-MCI. Both word list and paragraph learning and recall components have been found to be sensitive to concretely identify a-MCI and impairment on at least 2 tests should be considered in the diagnostic criteria of MCI rather than rely on a single screening battery.
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    A review of neuroimaging biomarkers of Alzheimer's disease
    (NEUROLOGY ASIA, 2013) Varghese, T; Sheelakumari, R; James, JS; Mathuranath, PS
    Neuroimaging biomarkers have potential role in the early diagnosis as well as periodic follow-up of neurodegenerative diseases such as Alzheimer's disease (AD). Structural imaging biomarkers can be used to predict those who are at risk or in preclinical stages of AD. It could possibly be useful even in predicting the conversion of Mild Cognitive Impairment (MCI) an early stage of AD to AD. In addition there has been a lot of progress in molecular imaging in AD. This article presents a review of recent progress in selected imaging biomarkers for early diagnosis, classification, and progression, of AD. A comprehensive integrative strategy initiated early in the cognitive decline is perhaps the most effective method of controlling progression to Alzheimer's disease.
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    Acute dysautonomia following mumps
    (NEUROLOGY INDIA, 1999)
    Pure acute or subacute dysautonomia is a rare entity. Its etiology is as yet unknown. However, majority of these cases have a preceding viral infection such as herpes simplex, infectious mononucleosis, rubella or coxsackie B. A unique patient in whom acute dysautonomia followed mumps is reported.
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    Adaptation of the ACE for a Malayalam speaking population in southern India
    (INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, 2004)
    Objective To adapt the Addenbrooke's Cognitive Examination (ACE) as a dementia-screening tool in a community in south India. To establish that items in the adapted version are equivalent to that in the original.Methods The ACE was adapted into the local language, Malayalam (m-ACE), following cultural/linguistic modifications. To establish equivalence, qualitative comparisons were made (on the distribution of scores, percentage scoring at ceiling, and relative difficulty across items) between a UK sample receiving the ACE (n = 50; mean age = 67.9 +/- 7.4; education greater than or equal to9, mean = 10.9 +/- 2.5) and a community-based educationally-stratified Indian sample receiving the m-ACE: 'India greater than or equal to9' (n = 50; mean age = 67.8 +/- 5.2; education greater than or equal to9, mean = 13.9 +/- 2.7) and 'India less than or equal to8' (n = 50; mean age = 67.1 +/- 5.3; education less than or equal to8, mean = 3.1 +/- 2.0).Results Most ACE items were retained. The score distribution (mean +/- ISD), percentage at ceiling, and relative difficulties across items is comparable between the UK and the educationally equivalent India greater than or equal to9 groups. Language, Naming, Attention and Orientation are relatively easy (greater than or equal to80% at ceiling) and Recall and Verbal fluency are relatively difficult (less than or equal to22% at ceiling). Although the percentage at ceiling were lower for the India less than or equal to8 group, the order of relative difficulty was similar and the percentage scoring at floor was less than or equal to10% on all except visuospatial item.Conclusions The m-ACE provides a culture-fair Malayalam adaptation of the ACE with component items of equivalent difficulty. Copyright (C) 2004 John Wiley Sons, Ltd.
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    An instrumental activities of daily living scale for dementia screening in the elderly in developing countries
    (NEUROBIOLOGY OF AGING, 2002) Mathuranath, PS; George, A; Cherian, JP; Alexander, A; Verma, N; Gopinath, N
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    An overview of biomarkers in Alzheimers disease
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2010) Wattamwar, PR; Mathuranath, PS
    Alzheimers disease (AD) is the commonest progressive, dementing neurodegenerative disease in elderly, which affects innumerable people each year, and these numbers are likely to further increase as the population ages. In addition to the financial burden of AD on health care system, the disease has powerful emotional impact on caregivers and families of those afflicted. In this advancing era of AD research, with the availability of new treatment strategies having disease-modifying effects, there is growing need for the early diagnosis in AD, often hampered by paucity of biomarkers of AD. Various candidate biomarkers for AD have been developed that can detect patients with AD at an early stage. In the recent years, the search for an ideal biomarker has undergone a rapid evolution. Novel technologies in proteomics, genomics, and imaging techniques further expand the role of a biomarker not only in early diagnosis, but also in monitoring the response to various treatments. However, the availability of sensitive and specific biomarkers requires the method to be standardized so as to be able to compare the results across studies. Inspite of tremendous advances in this field the quest for an "ideal biomarker" still continues. In this review, we will discuss the various candidate markers in five spheres namely biochemical, neuroanatomical, metabolic, genetic and neuropsychological, and their current status and limitations in AD diagnosis.
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    Beevor's sign in amyotrophic lateral sclerosis
    (NEUROLOGY INDIA, 1997) Pandian, JD; Mathuranath, PS
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    Cognitive bedside assessment in atypical parkinsonian syndromes
    (JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY, 2005) Bak, TH; Rogers, TT; Crawford, LM; Hearn, VC; Mathuranath, PS; Hodges, JR
    Background: Despite the growing recognition of the importance of cognitive symptoms for the diagnosis and management of atypical parkinsonian syndromes, the cognitive assessment of the patients in clinical practice often remains very limited. Objectives: To examine the ability of a brief and simple cognitive screening test to detect cognitive deficits in atypical parkinsonian syndromes. Methods: Addenbrooke's cognitive examination (ACE), the mini-mental state examination (MMSE), and the dementia rating scale (DRS) were applied to 26 patients with multiple system atrophy (MSA), 39 with progressive supranuclear palsy (PSP), and 25 with corticobasal degeneration (CBD). The results were then compared with those obtained in 30 healthy age matched volunteers and 30 patients with Alzheimer's disease. Results: In all four diseases the rate of detection of cognitive impairment on ACE was higher than on MMSE and comparable with DRS. The severity of cognitive impairment was most pronounced in the CBD group, which showed a similar degree of impairment to the Alzheimer group. In contrast, MSA patients were the least cognitively impaired. The PSP group took an intermediate position. Conclusions: Cognitive impairment in atypical parkinsonian syndromes can be detected using a brief and clinically applicable bedside test such as ACE.
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    Effects of age, education and gender on verbal fluency
    (JOURNAL OF CLINICAL AND EXPERIMENTAL NEUROPSYCHOLOGY, 2003)
    The objective was to study the effects of age, education and gender on verbal fluency in cognitively unimpaired, older individuals. The methods used were as follows: cognitively unimpaired elderly (55-84 years) subjects (n = 153), were administered category (animal) (CF) and letter (/pa/) (LF) fluency tasks, in their native language of Malayalam. Results and conclusions were (1) Level of education, but not age or gender, significantly influence LF. (2) Level of education (directly) and in the elderly subjects, age (inversely) affect CF. (3) Age, but not education, has a differential effect on the tasks of verbal fluency, influencing CF more than LF.
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    Face Inversion Reduces the Persistence of Global Form and Its Neural Correlates
    (PLOS ONE, 2011) Strother, L; Mathuranath, PS; Aldcroft, A; Lavell, C; Goodale, MA; Vilis, T
    Face inversion produces a detrimental effect on face recognition. The extent to which the inversion of faces and other kinds of objects influences the perceptual binding of visual information into global forms is not known. We used a behavioral method and functional MRI (fMRI) to measure the effect of face inversion on visual persistence, a type of perceptual memory that reflects sustained awareness of global form. We found that upright faces persisted longer than inverted versions of the same images; we observed a similar effect of inversion on the persistence of animal stimuli. This effect of inversion on persistence was evident in sustained fMRI activity throughout the ventral visual hierarchy, including the lateral occipital area (LO), two face-selective visual areas-the fusiform face area (FFA) and the occipital face area (OFA)-and several early visual areas. V1 showed the same initial fMRI activation to upright and inverted forms but this activation lasted longer for upright stimuli. The inversion effect on persistence-related fMRI activity in V1 and other retinotopic visual areas demonstrates that higher-tier visual areas influence early visual processing via feedback. This feedback effect on figure-ground processing is sensitive to the orientation of the figure.
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    Genetics of frontotemporal lobar degeneration
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2010) Aswathy, PM; Jairani, PS; Mathuranath, PS
    Frontotemporal lobar degeneration (FTLD) is a highly heterogenous group of progressive neurodegenerative disorders characterized by atrophy of prefrontal and anterior temporal cortices. Recently, the research in the field of FTLD has gained increased attention due to the clinical, neuropathological, and genetic heterogeneity and has increased our understanding of the disease pathogenesis. FTLD is a genetically complex disorder. It has a strong genetic basis and 50% of patients show a positive family history for FTLD. Linkage studies have revealed seven chromosomal loci and a number of genes including MAPT, PGRN, VCP, and CHMB-2B are associated with the disease. Neuropathologically, FTLD is classified into tauopathies and ubiquitinopathies. The vast majority of FTLD cases are characterized by pathological accumulation of tau or TDP-43 positive inclusions, each as an outcome of mutations in MAPT or PGRN, respectively. Identification of novel proteins involved in the pathophysiology of the disease, such as progranulin and TDP-43, may prove to be excellent biomarkers of disease progression and thereby lead to the development of better therapeutic options through pharmacogenomics. However, much more dissections into the causative pathways are needed to get a full picture of the etiology. Over the past decade, advances in research on the genetics of FTLD have revealed many pathogenic mutations leading to different clinical manifestations of the disease. This review discusses the current concepts and recent advances in our understanding of the genetics of FTLD.
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    Hereditary ataxias: From phenotype to genotype
    (NEUROLOGY INDIA, 1998) Mathuranath, PS; Thomas, SV
    Inherited ataxias constitute a large group of neurological diseases, Refinement in the classification and understanding of these diseases has been taking place in the recent years with advancement in molecular genetics. This review highlights the evolution and correlation of various classifications, phenotype and genotype correlation, mechanisms of phenotypic heterogeneity, and recent advances in the understanding of some of the commoner entities, in inherited ataxias.
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    Incidence of Alzheimer's disease in India: A 10 years follow-up study
    (Neurol India, 2012-12) Mathuranath, PS; George, A; Ranjith, N; Justus, S; Kumar, MS; Menon, R; Sarma, PS; Verghese, J
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    Instrumental activities of daily living scale for dementia screening in elderly people
    (INTERNATIONAL PSYCHOGERIATRICS, 2005)
    Objective: To develop and validate an Instrumental Activities of Daily Living Scale for elderly people (IADL-E) to use in conjunction with cognitive screening tests for dementia in an educationally and socioculturally heterogeneous population.Method: Eleven IADL items were selected and weighted for major factors causing heterogeneity in the population-gender, education, social (rural/urban) setting and age. Each item was rated for its applicability (yes/no), degree of disability (scored from 0 to 2) and causative impairment (cognitive and/or physical). From this a composite index of cognitive (CDI) or physical (PDI) disability was derived. Validation was performed retrospectively on 240 subjects: 135 without and 105 with dementia by DSM-IV.Results: The IADL-E had a high internal consistency (alpha = 0.95). The area under the receiver operating characteristic (ROC) curve was 0.97 (CI = 0.94-0.99). A cutoff score of 16 on CDI provided a sensitivity of 0.91, specificity 0.99 and positive predictive value 0.76 (at 5% base rate). IADL-E correlated highly with clinical (DSM-IV, K = 0.89), functional (CDR, 0.82) and cognitive (Mini-mental Status Examination, MMSE, 0.74) diagnoses. It showed good responsiveness, with the change on CDI over a median of 23 months correlating significantly with that on MMSE (coefficient =-0.382, CI=-0.667 to -0.098; p=0.009). Individual items had good interrater and test-retest reliability.Conclusions: The IADL-E is a reliable, sensitive and responsive scale of functional abilities useful in dementia screening in a socioculturally heterogeneous population.
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    Interaction with the MAPT H1H1 Genotype Increases Dementia Risk in APOE epsilon 4 Carriers in a Population of Southern India
    (DEMENTIA AND GERIATRIC COGNITIVE DISORDERS, 2016) Jairani, PS; Aswathy, PM; Gopala, S; Verghese, J; Mathuranath, PS
    Background: This study delineates the role of the interaction of apolipoprotein E (APOE) and MAPT alleles in contributing to disease risks of dementia in a southern Indian population. Methods: A sample of 419 patients comprising Alzheimer's disease (AD; n = 156), mild cognitive impairment (MCI; n = 87), frontotemporal dementia (FTD; n = 127), vascular dementia (VD; n = 37), and dementia with Lewy bodies (DLB; n = 12) was analysed in comparison with a control group (n = 138). APOE genotyping and MAPT haplotyping were performed on all study subjects. Results: Multivariate logistic regression analysis showed that variability on the APOE locus influenced the relative risk of dementia in the study population. The APOE e4 allele increased the disease risk most significantly for AD (OR = 3.468, p < 0.0001) and MCI (OR = 2.901, p < 0.0001). The APOE epsilon 2 allele remained protective for AD (OR = 0.205, p < 0.05). For FTD, VD, and DLB, the APOE epsilon 4 allele was ineffectual in modulating disease risk. The MAPT H1 haplotype was not an overrepresented marker of neurodegenerative diseases. The H1H1 genotype had an additive effect in contributing to either disease risk in combination with the APOE epsilon 4 allele or protection in combination with the APOE epsilon 2 or epsilon 3 allele. Conclusions: This study is a reappraisal of the strong association of APOE variability with AD in southern India when compared to other dementia groups, while the transcriptional differences between MAPT haplotypes have a limited role in Indian dementia patients. (C) 2016 S. Karger AG, Basel
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    Longitudinal Evaluation of Structural Changes in Frontotemporal Dementia Using Artificial Neural Networks
    (PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON FRONTIERS OF INTELLIGENT COMPUTING: THEORY AND APPLICATIONS (FICTA) 2013, 2014) Kumari, RS; Varghese, T; Kesavadas, C; Singh, NA; Mathuranath, PS
    Automatic Segmentation of Magnetic Resonance (MR) Images plays an important role in medical image processing. Segmentation is the process of extracting the brain tissue components such as grey matter (GM), white matter (WM) and cerebrospinal fluids (CSF). The volumetric analysis of the segmented tissues helps in determining the amount of GM loss in specific disease pathology. Among the various segmentation techniques, fuzzy c means (FCM) is the most widely used one. The performance of traditional FCM is considerably reduces in noisy MR images. However, in the clinical analysis accurate segmentation of MR image is very important and crucial for the early diagnosis and prognosis. This paper put forward an Artificial Neural Network based segmentation to map the longitudinal structural changes overtime in Frontotemporal dementia (FTD) subjects that could be a better cue to impending behavioural changes. Our proposed approach has achieved an average classification accuracy of 96.7%, 96.4% and 97.96% for GM, WM and CSF respectively
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    MAPT genetic variations are uncommon cause of frontotemporal dementia in south India
    (Neurobiology of Aging, 2013-10) Aswathy, PM; Jairani, PS; Verghese, Joe; Srinivas, G; Mathuranath, PS
    Microtubule-associated protein tau (MAPT) positive neuropathology is the characteristic feature of majority of frontotemporal dementia (FTD) cases, which is due to the mutations or haplotypic variations in the gene encoding MAPT (MAPT). The present study was aimed at determining the frequency of genetic variations in MAPT in a south Indian FTD cohort. The frequency of mutations were determined in 116 FTD, 8 progressive supranuclear palsy (PSP) and 3 corticobasal syndrome (CBS) patients and haplotype diversity were analyzed in a study cohort comprising 116 FTD, 8 PSP, 3 CBS, 194 other dementia groups, 78 mild cognitive impairment (MCI) and 130 cognitively normal individuals and report no pathogenic mutations in FTD/PSP/CBS or haplotypic association with disease risk in FTD or other dementia patients. These findings suggest that there may be other genetic or epigenetic factors contributing to the pathogenesis of FTD in the south Indian population.