A Phase-based EEG Epoch Selection Method for Decoding Bi-directional Hand Movement Imagination in Stroke Patients.

Electroencephalogram (EEG) based non-invasive Brain Computer Interface (BCI) system is gaining significant attention as a promising solution for stroke rehabilitation. Accurate selection of informative EEG time segment, that accommodates the specific neural activity patterns associated with the underlying mental task can help to improve the efficacy of the BCI system. In this work, we propose a phase-based EEG epoch selection algorithm to extract the discriminative EEG time segment corresponding to bi-directional hand motor imagery. The imagined center-out hand movement in two directions is decoded using the selected epoch of the EEG, recorded from 16 stroke patients with hemiparesis and specifically hand weakness. Phase Lock Value (PLV) EEG features extracted from the selected EEG epoch is used as discriminative feature for binary classification of imagined hand movement direction using Linear Discriminant Analysis. The use of selected EEG epoch yielded an improvement of 11.5% and 11.7% in the average direction classification accuracy of calibration and feedback session data respectively, compared to the baseline method employing the whole EEG signal. In addition to improvement in decoding accuracy, the epoch selection also yielded an average Information Transfer Rate (ITR) of 39.8±24.6 bits per minute, which is 86% improvement compared to the baseline method.Clinical Relevance- The proposed Motor Imagery (MI)-BCI system may be of clinical relevance as an active rehabilitation tool for stroke-affected patients, to enhance neural plasticity and recovery of centre-out activities of affected hand and forms a strong platform for MI-BCI coupled with exoskeletons or prosthesis rehabilitation.

Familial Neuromyelitis Optica and Sjogren's Overlap Syndrome-A Rare Case Report.

Familial cases of NMO are rare; and there are very few reports in association with Sjogren's syndrome. To report a familial case of NMO-Sjogren's Overlap syndrome. Mother and daughter presented with phenotypically different neurological episodes; mother had recurrent optic neuritis and myelitis with brainstem episode while the daughter had diencephalic presentation. Both were found to have AQP4 positivity with Ro-52 antibodies and positive Schirmer's test. They responded to steroids and plasma exchange. NMO associated with Sjogren's syndrome association suggests that apart from ethnicity both may have similar genetic predisposition and HLA-linkage.

Motor Imagery Hand Movement Direction Decoding Using Brain Computer Interface to Aid Stroke Recovery and Rehabilitation.

Motor Imagery (MI)-based Brain Computer Interface (BCI) system is a potential technology for active neurorehabilitation of stroke patients by complementing the conventional passive rehabilitation methods. Research to date mainly focused on classifying left vs. right hand/foot MI of stroke patients. Though a very few studies have reported decoding imagined hand movement directions using electroencephalogram (EEG)-based BCI, the experiments were conducted on healthy subjects. Our work analyzes MI-based brain cortical activity from EEG signals and decodes the imagined hand movement directions in stroke patients. The decoded direction (left vs. right) of hand movement imagination is used to provide control commands to a motorized arm support on which patient's affected (paralyzed) arm is placed. This enables the patient to move his/her stroke-affected hand towards the intended (imagined) direction that aids neuroplasticity in the brain. The synchronization measure called Phase Locking Value (PLV), extracted from EEG, is the neuronal signature used to decode the directional movement of the MI task. Event-related desynchronization/synchronization (ERD/ERS) analysis on Mu and Beta frequency bands of EEG is done to select the time bin corresponding to the MI task. The dissimilarities between the two directions of MI tasks are identified by selecting the most significant channel pairs that provided maximum difference in PLV features. The training protocol has an initial calibration session followed by a feedback session with 50 trials of MI task in each session. The feedback session extracts PLV features corresponding to most significant channel pairs which are identified in the calibration session and is used to predict the direction of MI task in left/right direction. An average MI direction classification accuracy of 74.44% is obtained in performing the training protocol and 68.63% from the prediction protocol during feedback session on 16 stroke patients.

Cognitive Dysfunction and its Determinants in Patients with Neurocysticercosis.

INTRODUCTION: Neurocysticercosis (NCC) is the most common parasitic infection of man. In addition to a headache, seizures, and focal deficits, this is associated with significant cognitive dysfunction. Many studies revealed that the number and location of lesions are not always responsible for cognitive dysfunction. Cholinesterase and pseudocholinesterase are found in the walls of the cysticercus which could contribute to cholinergic depletion and thus cognitive dysfunction. PATIENTS AND METHODS: A total of 43 patients who presented with NCC were evaluated for cognitive deficits, as well as cholinesterase levels in cerebrospinal fluid (CSF) with control CSF from patients undergoing spinal anesthesia. Blood levels of interleukin-10 and tumor necrosis factor alpha were also estimated and correlated with cognitive deficits. RESULTS: There is a mild increase in the acetylcholinesterase in CSF of patients compared to controls, but it did not correlate with cognitive deficits. There is an increase in interleukins to a significant level which correlates with vesicular stage of the organism and cognitive impairment. The number of lesions also correlated with cognitive impairment even though the location did not. The domains of cognitive deficits seen are sustained attention, category fluency, verbal working memory, planning, set shifting, verbal learning, visual memory, and construction. DISCUSSION AND CONCLUSION: NCC is associated with multi-domain cognitive impairment correlates with vescicular stage, proinflammatory cytokines and number of lesions but not location, vesicular stage, and proinflammatory cytokines.

Intractable vomiting and hiccups as the presenting symptom of neuromyelitis optica.

Vomiting and hiccups can be due to peripheral or central causes. Neurological diseases causing vomiting and hiccups are due to lesions of medulla involving area postrema and nucleus tractus solitarius. Neuromyelitis optica (NMO) is one such disease which involves these structures. However refractory vomiting and hiccups as the presenting symptom of NMO is unusual. Here we report a patient with NMO in whom refractory vomiting and hiccups were the sole manifestation of the first attack. Diagnosis can be missed at this stage leading to delay in treatment and further complications. This case demonstrates the importance of considering NMO in any patient presenting with refractory vomiting and hiccups and with local and metabolic causes ruled out and linear medullary lesion on magnetic resonance imaging may indicate the diagnosis even when the classical clinical criteria are not met. Anti NMO antibody testing should be done and if positive appropriate treatment should be initiated to prevent further neurological damage.

An unusual case of rapidly progressive contractures: Case report and brief review.

An 8-year-old boy, diagnosed as cervical dystonia, was referred to our tertiary center. After a trivial trauma he had developed painful lumps in the axial region, which was followed by restricted movements of neck, shoulder, and abdominal muscles over 4 months. He had kyphoscoliosis, torticollis, rigid abdomen, and multiple muscle contractures. He also had short great toes. A detailed skeletal survey showed calcification in the soft tissues surrounding the shoulder anterior chest wall, thorax, and paraspinal muscles; there was also beaking of vertebrae, which was confirmed by CT thorax. This report showcases the diagnostic challenge posed by myositis ossificans progressiva, which can rarely cause rapidly progressing muscle contractures. A brief review of literature is also presented.