S. Nizam Ahmed

Pearls & Oy-sters: Selective postictal aphasia: Cerebral language organization in bilingual patients

Background: Ictal and postictal language dysfunction is common and strongly predictive of language laterality in monolingual patients. For bilingual patients, selective dysfunction has been reported for a single language with focal cerebral lesions, electrical brain stimulation, and intracarotid sodium amytal. Methods: Two right-handed Ukrainian-English bilingual patients with left perisylvian structural lesions, late onset complex-partial seizures, and postictal aphasia for English are presented and discussed with regard to mechanisms of selective aphasia and factors contributory to language lateralization in bilingual patients. Results: Ukrainian was the native language of both patients with English acquired after 7 years of age. Regular/video-EEG showed left temporal epileptogenesis. A 56-year-old man, who had a left hemorrhagic stroke at age 50 and had not spoken Ukrainian for 40 years, was unable to speak English for ∼20 minutes postictally but had global preservation of Ukrainian. A 71-year-old woman, who had a left temporal epidermoid cyst and had not spoken Ukrainian since childhood, had 10- to 15-minute postictal expressive aphasia in English but not Ukrainian and preservation of comprehension in both languages. Conclusions: These cases are instructive and consistent with the literature on cerebral organization of language in bilingual individuals. For both patients, postictal aphasia with preservation of Ukrainian is consistent with findings from clinical and experimental studies indicating that later age of second language acquisition (>6 years) rather than language proficiency is a primary factor in language laterality. Second, global aphasia in the man with a late lesion vs expressive aphasia with preservation of comprehension of English in the woman with a prenatal/early lesion is consistent with the atypical language laterality described for individuals with left-sided lesions sustained prior to age 5. Although neither Wada test nor fMRI was done to assure left hemisphere laterality of spoken Ukrainian and English, this is probable, and the selective postictal aphasia observed for both patients is consistent with the differential intrahemispheric organization reported for the two languages of bilingual individuals. Possible mechanisms of selective postictal aphasia, e.g., active inhibition, and differences in language networks in bilingual patients are discussed.

Acetaminophen toxicity with concomitant use of carbamazepine

Acetaminophen is a widely used analgesic that can cause acute liver failure when consumed above a maximum daily dose. Certain patients may be at increased risk of hepatocellular damage even at conventional therapeutic doses. We report a case of a 34-year-old man on carbamazepine for complex partial seizures who developed acute liver and renal failure on less than 2.5 grams a day of acetaminophen. This raises caution that patients on carbamazepine should avoid chronic use of acetaminophen, and if required use at lower doses with vigilant monitoring for signs of liver damage.

Cerebral arrhythmia influencing cardiac rhythm: A case of ictal bradycardia

Partial seizures of temporal origin can be associated with clinically significant tachycardia or bradycardia. Ictal bradycardia and asystole has been implicated in the etiology of sudden unexpected death in epileptic patients (SUDEP). Although symptomatic ictal bradycardia has been relatively well described in the literature; information on asymptomatic ictal bradycardia is scarce. We report a case of asymptomatic ictal bradycardia diagnosed during video EEG telemetry that was subsequently implanted with a cardiac pacemaker.

Fully automated segmentation of corpus callosum in midsagittal brain MRIs

In the diagnosis of various brain disorders by analyzing the brain magnetic resonance images (MRI), the segmentation of corpus callosum (CC) is a crucial step. In this paper, we propose a fully automated technique for CC segmentation in the T1-weighted midsagittal brain MRIs. An adaptive mean shift clustering technique is first used to cluster homogenous regions in the image. In order to distinguish the CC from other brain tissues, area analysis, template matching, in conjunction with the shape and location analysis are proposed to identify the CC area. The boundary of detected CC area is then used as the initial contour in the Geometric Active Contour (GAC) model, and evolved to get the final segmentation result. Experimental results demonstrate that the proposed technique overcomes the problem of manual initialization in existing GAC technique, and provides a reliable segmentation performance.

Telemedicine and epilepsy care - a Canada wide survey.

BACKGROUND Canadian provinces boast one of the most sophisticated telemedicine infrastructures in the world. Feasibility of epilepsy care through telemedicine is established, but its use by practicing neurologists is unknown. The Canadian League against Epilepsys telemedicine task force conducted this study to understand the perceptions, barriers and usage of telemedicine in epilepsy care. METHODS Using a 14 item questionnaire we prospectively surveyed all the epileptologists across Canada with regards to current use, perceived benefits and barriers to the use of telemedicine. The survey was mailed out to 76 neurologists who had a primary interest in epilepsy. RESULTS We received 39 responses (54.1%) spanning seven provinces. Majority of the responders were 50 years and over (56.4%). Although 61.5% of the physicians acknowledged a need for tele-epilepsy services, the majority (64.1%) had not used telemedicine. The most common forms of technology were videoconferencing and telephone but some physicians had also used email. Telemedicine was mainly used for clinical and educational purposes. 79.5% of physicians had access to videoconferencing equipment and 61.5% assessed that there was a need/use for clinical telehealth. The main perceived obstacles in the use of telemedicine were: lack of infrastructure support and remuneration problems followed by limitations in clinical examination. CONCLUSIONS Although widely available, telemedicine is under-utilized in epilepsy care. Most of the obstacles can be easily fixed and overcome through education and simple interventions. Partnering of epilepsy centers across Canada in the development of a comprehensive national telemedicine network would create an excellent opportunity to expand epilepsy care.

Hereditary hemorrhagic telangiectasia: transient ischemic attacks

A 39-year-old right-handed man presented to his family physician with sudden-onset weakness in his right arm and leg that had lasted 10 minutes and resolved completely. In the year before presentation, he had an episode of weakness on the right side of his face and difficulty comprehending that had

Uncontrollable movements in patient with diabetes mellitus

The Case: A 63-year-old woman presented to the emergency department after experiencing uncontrollable, irregular jerking movements of her right arm for 1 week. The movements were increasingly painful and were making it difficult for her to sleep; however, they disappeared during sleep. She reported

Establishment of a Comprehensive Epilepsy Center in Pakistan: Initial Experiences, Results, and Reflections

Background. Developing countries, home to 80% of epilepsy patients, do not have comprehensive epilepsy surgery programs. Considering these needs we set up first epilepsy surgery center in Pakistan. Methods. Seventeen teleconferences focused on setting up an epilepsy center at the Aga Khan University (AKU), Karachi, Pakistan were arranged with experts from the University of Alberta Hospital, Alberta, Canada and the University of West Virginia, USA over a two-year period. Subsequently, the experts visited the proposed center to provide hands on training. During this period several interactive teaching sessions, a nationwide workshop, and various public awareness events were organized. Results. Sixteen patients underwent surgery, functional hemispherectomy (HS) was done in six, anterior temporal lobectomy (ATL) in six, and neuronavigation-guided selective amygdalohippocampectomy (SAH) using keyhole technique in four patients. Minimal morbidity was observed in ATL and, SAH groups. All patients in SAH group (100%) had Grade 1 control, while only 5 patients (83%) in ATL group, and 4 patients (66%) in HS group had Grade 1 control according to Engels classification, in average followups of 12 months, 24 months and 48 months for SAH, ATL, and HS, respectively. Conclusion. As we share our experience we hope to set a practical example for economically constrained countries that successful epilepsy surgery centers can be managed with limited resources.

Recurrent strokes in a 46-year-old woman: rapidly progressive nonbacterial thrombotic endocarditis

The Case: A 46-year-old nurse was admitted to the Neurology Department after 6 weeks of recurrent and transient neurologic episodes. She described several episodes of disorientation, language abnormalities and motor weakness, all resolving within an hour. She thought the episodes likely related to

Computer aided detection of cavernous malformation in T2-weighted brain MR images

Cavernous malformation or cavernomas is abnormal development of brain blood vessels and affect an estimated 0.5% of the world population. These could cause seizures, intracerebral hemorrhage and various neurological deficits based on the location of the lesion. Radiologists usually analysis brain magnetic resonance (MR) images to detect cavernomas. However, automatic detection of cavernomas by computer has not been investigated enough. This paper proposes a computer aided cavernomas detection method based on MR images analysis. The proposed method includes three steps: brain extraction based on deformable contour (to remove the non-brain tissues from image), template matching (to find suspected cavernomas regions) and post-processing (to get rid of false positives based on size, shape and brightness information). The performance of the proposed technique is evaluated and a sensitivity of 0.92 is obtained after testing.