Correction: Corneal nerve and endothelial cell damage in patients with transient ischemic attack and minor ischemic stroke.

[This corrects the article DOI: 10.1371/journal.pone.0213319.].

Corneal nerve and endothelial cell damage in patients with transient ischemic attack and minor ischemic stroke.

OBJECTIVE: To determine if corneal confocal microscopy can identify corneal nerve and endothelial cell abnormalities and may be useful in the prognostication of patients with transient ischemic attack [1] or minor ischemic stroke (IS). METHODS: Thirty-six patients admitted with TIA (n = 14) or minor IS (n = 22) underwent transcranial Doppler evaluation and corneal confocal microscopy and were compared with 18 healthy controls. RESULTS: Corneal nerve fiber density (P = 0.002), branch density (P = 0.004) and fiber length (P = 0.004) were significantly lower in patients with TIA or minor IS compared to controls, with no difference between patients with TIA and minor IS. Endothelial cell density (P = 0.003) was lower and endothelial cell area (P = 0.003) and perimeter (P = 0.006) were significantly higher in patients with TIA or minor IS compared to controls, with no difference between patients with TIA and minor IS. There were no differences in corneal nerve or endothelial cell morphology between patients with and without abnormal cerebrovascular reactivity. HbA1c was independently associated with CNFL, and endothelial cell polymegathism and pleomorphism were associated with both HbA1c and total cholesterol. CONCLUSION: Corneal confocal microscopy identifies corneal nerve fiber loss and endothelial cell abnormalities in patients with TIA and minor IS and independent associations with HbA1c and cholesterol.

Clinical presentation, epidemiology, neurophysiological findings, treatment and outcome of nonconvulsive status epilepticus: a 3-year prospective, hospital-based study.

Objective: This study reports the prevalence of Nonconvulsive Status Epilepticus (NCSE) in patients with altered mental status (AMS), and describes the clinical presentation, etiology, neurophysiological findings, neuroimaging, treatment, and outcome of NCSE in Qatar. Recording duration of continuous EEG monitoring was also discussed. Methods: This was a 3-year, prospective, hospital-based study involving patients with AMS and continuous EEG monitoring admitted to the Emergency and ICUs of Hamad Hospital, Qatar. Patients with confirmed diagnosis of NCSE were compared to the patients who did not show EEG and clinical features compatible with NCSE. Descriptive statistics in terms of mean with standard deviation, as well as frequency and percentages for categorical variables, were calculated; Student's t test as well as Chi-square tests or Fisher's exact tests were applied. Logistic regressions NSCE was performed using significance level 0.05 for independent variables at univariate analysis. Results: Number of patients with AMS and continuous EEG monitoring was 250. Number of patients with EEG compatible with NCSE: 65 (age range, 12-79 ys; m, 37; f, 28). Number of controls (defined as patients with EEG not compatible with NCSE): 185 (age range, 12-80 ys; m, 101; f, 84). Rate of occurrence of NCSE in patients with AMS: 26%. NCSE group was younger than controls (p < .001). Twenty patients with NCSE (31%) and 35 patients in the control group (19%) died. Death was more frequent in comatose NCSE compared to controls (p < .0007). NCSE proper and comatose NCSE had longer hospital stays than controls (p < .02 and p < .03, respectively). Complete recovery occurred in 26 NCSE patients (40%) and in 98 controls (53%) (p < .08). Twenty-one patients (31%) presented with refractory NCSE: 12 patients survived, 9 died. Conclusion: This was the first prospective study reporting a high number of NCSE in Qatar, a small country in the MENA region. This prevalence (26%) was in the middle range. NCSE patients did not perform better than controls, outcome being worse with comatose NCSE. NCSE is an emergent condition warranting expedited diagnosis and management. Three days of continuous EEG monitoring were able to diagnose most cases of NCSE.

Epilepsy in Qatar: Causes, treatment, and outcome.

OBJECTIVE: Qatar is a small country on the Eastern coast of the Arabian Peninsula. Its population is a unique mixture of native citizens and immigrants. We aimed to describe the features of epilepsy in Qatar as such information is virtually lacking from the current literature. METHODS: We summarized information retrospectively collected from 468 patients with epilepsy seen through the national health system adult neurology clinic. RESULTS: Epilepsy was classified as focal in 65.5% of the cases and generalized in 23%. Common causes of epilepsy were as follows: stroke (9%), hippocampal sclerosis (7%), infections (6%), and trauma (6%). Sixty-six percent of patients were receiving a single antiepileptic drug, with levetiracetam being the most frequently prescribed drug (41% of subjects). When the patients were divided by geographical background, remote infections caused the epilepsy in 15% of Asian patients (with neurocysticercosis accounting for 10%) but only in 1% of Qatari and 3% of Middle East/North African subjects (with no reported neurocysticercosis) (p<0.001). Cerebrovascular and neurodegenerative etiologies were the most prominent in Qataris, accounting for 14% (p=0.005) and 4% (p=0.03) of cases, respectively. The choice of antiepileptic drugs varied also according to the regional background, but the seizure freedom rate did not, averaging at 54% on the last clinic visit. SIGNIFICANCE: To our knowledge, this is the first detailed information about epilepsy in Qatar. The geographical origin of patients adds to the heterogeneity of this disorder. Neurocysticercosis should be in the etiological differential diagnosis of epilepsy in patients coming from Southeast Asian countries, despite the fact that it is not endemic to Qatar. The choice of antiepileptic drugs is influenced by the availability of individual agents in the patients' native countries but had no bearing on the final seizure outcome.

Improved spindle detection through intuitive pre-processing of electroencephalogram.

BACKGROUND: Numerous signal processing techniques have been proposed for automated spindle detection on EEG recordings with varying degrees of success. While the latest techniques usually introduce computational complexity and/or vagueness, the conventional techniques attempted in literature have led to poor results. This study presents a spindle detection approach which relies on intuitive pre-processing of the EEG prior to spindle detection, thus resulting in higher accuracy even with standard techniques. NEW METHOD: The pre-processing techniques proposed include applying the derivative operator on the EEG, suppressing the background activity using Empirical Mode Decomposition and shortlisting candidate EEG segments based on eye-movements on the EOG. RESULTS/COMPARISON: Results show that standard signal processing tools such as wavelets and Fourier transforms perform much better when coupled with apt pre-processing techniques. The developed algorithm also relies on data-driven thresholds ensuring its adaptability to inter-subject and inter-scorer variability. When tested on sample EEG segments scored by multiple experts, the algorithm identified spindles with average sensitivities of 96.14 and 92.85% and specificities of 87.59 and 84.85% for Fourier transform and wavelets respectively. These results are found to be on par with results obtained by other recent studies in this area.

Central fever due to hypothalamic lesion in a patient with tuberculous meningitis.

Abnormalities of body temperature are perhaps the most common features in many systemic pathologic processes. Such pathologic alterations are nearly always the result of extrinsic factors (for example, systemic pyrogens) which affect the hypothalamic thermoregulatory center by way of circulatory system. Much less common is alterations in temperature regulation resulting from intrinsic lesions of the thermoregulatory center in the hypothalamus. We report a patient with tuberculous meningitis who continued to have persistent fever despite the satisfactory treatment of her tuberculosis. A central thermoregulatory defect was documented and was attributed to a small structural lesion in the anterior hypothalamus.