No published epidemiologic data on multiple sclerosis (MS) in Qatar exist. Our objectives were to determine the prevalence, demographics and clinical characteristics of MS in the Middle Eastern country of Qatar. We analyzed data for Qatari MS patients fulfilling the McDonald diagnostic criteria. A total of 154 patients fulfilled the inclusion criteria. On 31 April 2010, the crude prevalence of MS in Qatar was 64.57 per 100,000 inhabitants (95% CI: 58.31-70.37). The femaleto-male ratio was 1.33:1. A positive family history was found in 10.4% of included MS patients. We conclude that Qatar is now a medium-to-high risk area for MS, with some important differences in clinical characteristics as compared to other countries in the region.

BACKGROUND AND PURPOSE Delayed cerebral ischemia is a significant cause of morbidity and mortality after aneurysmal SAH, leading to poor outcomes. The purpose of this study was to evaluate the usefulness of CTP in determining delayed cerebral ischemia in patients with aneurysmal SAH. MATERIALS AND METHODS We conducted a systematic review evaluating studies that assessed CTP in patients with aneurysmal SAH for determining delayed cerebral ischemia. Studies using any of the following definitions of delayed cerebral ischemia were included in the systematic review: 1) new onset of clinical deterioration, 2) cerebral infarction identified on follow-up CT or MR imaging, and 3) functional disability. A random-effects meta-analysis was performed assessing the strength of association between a positive CTP result and delayed cerebral ischemia. RESULTS The systematic review identified 218 studies that met our screening criteria, of which 6 cohort studies met the inclusion criteria. These studies encompassed a total of 345 patients, with 155 (45%) of 345 patients classified as having delayed cerebral ischemia and 190 (55%) of 345 patients as not having delayed cerebral ischemia. Admission disease severity was comparable across all groups. Four cohort studies reported CTP test characteristics amenable to the meta-analysis. The weighted averages and ranges of the pooled sensitivity and specificity of CTP in the determination of delayed cerebral ischemia were 0.84 (0.7–0.95) and 0.77 (0.66–0.82), respectively. The pooled odds ratio of 23.14 (95% CI, 5.87–91.19) indicates that patients with aneurysmal SAH with positive CTP test results were approximately 23 times more likely to experience delayed cerebral ischemia compared with patients with negative CTP test results. CONCLUSIONS Perfusion deficits on CTP are a significant finding in determining delayed cerebral ischemia in aneurysmal SAH. This may be helpful in identifying patients with delayed cerebral ischemia before development of infarction and neurologic deficits.

BACKGROUND AND PURPOSE Delayed cerebral ischemia and vasospasm are significant complications following SAH leading to cerebral infarction, functional disability, and death. In recent years, CTA and CTP have been used to increase the detection of delayed cerebral ischemia and vasospasm. Our aim was to perform comparative-effectiveness and cost-effectiveness analyses evaluating CTA and CTP for delayed cerebral ischemia and vasospasm in aneurysmal SAH from a health care payer perspective. MATERIALS AND METHODS We developed a decision model comparing CTA and CTP with transcranial Doppler sonography for detection of vasospasm and delayed cerebral ischemia in SAH. The clinical pathways were based on the “Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage: A Guideline for Healthcare Professionals from the American Heart Association/American Stroke Association” (2012). Outcome health states represented mortality and morbidity according to functional outcomes. Input probabilities of symptoms and serial test results from CTA and CTP, transcranial Doppler ultrasound, and digital subtraction angiography were directly derived from an SAH cohort by using a multinomial logistic regression model. Expected benefits, measured as quality-adjusted life years, and costs, measured in 2012 US dollars, were calculated for each imaging strategy. Univariable, multivariable, and probabilistic sensitivity analyses were performed to determine the independent and combined effect of input parameter uncertainty. RESULTS The transcranial Doppler ultrasound strategy yielded 13.62 quality-adjusted life years at a cost of $154,719. The CTA and CTP strategy generated 13.89 quality-adjusted life years at a cost of $147,097, resulting in a gain of 0.27 quality-adjusted life years and cost savings of $7622 over the transcranial Doppler ultrasound strategy. Univariable and multivariable sensitivity analyses indicated that results were robust to plausible input parameter uncertainty. Probabilistic sensitivity analysis results yielded 96.8% of iterations in the right lower quadrant, representing higher benefits and lower costs. CONCLUSIONS Our model results suggest that CTA and CTP are the preferred imaging strategy in SAH, compared with transcranial Doppler ultrasound, leading to improved clinical outcomes and lower health care costs.

BACKGROUND AND PURPOSE Patients with SAH are at increased risk of delayed infarction. Early detection and treatment of delayed infarction remain challenging. We assessed blood-brain barrier permeability, measured as permeability surface area product, by using CTP in patients with SAH with delayed infarction. MATERIALS AND METHODS We performed a retrospective study of patients with SAH with delayed infarction on follow-up NCCT. CTP was performed before the development of delayed infarction. CTP data were postprocessed into permeability surface area product, CBF, and MTT maps. Coregistration was performed to align the infarcted region on the follow-up NCCT with the corresponding location on the CTP maps obtained before infarction. Permeability surface area product, CBF, and MTT values were then obtained in the location of the subsequent infarction. The contralateral noninfarcted region was compared with the affected side in each patient. Wilcoxon signed rank tests were performed to determine statistical significance. Clinical data were collected at the time of CTP and at the time of follow-up NCCT. RESULTS Twenty-one patients with SAH were included in the study. There was a statistically significant increase in permeability surface area product in the regions of subsequent infarction compared with the contralateral control regions (P < .0001). However, CBF and MTT values were not significantly different in these 2 regions. Subsequent follow-up NCCT demonstrated new delayed infarction in all 21 patients, at which time 38% of patients had new focal neurologic deficits. CONCLUSIONS Our study reveals a statistically significant increase in permeability surface area product preceding delayed infarction in patients with SAH. Further investigation of early permeability changes in SAH may provide new insights into the prediction of delayed infarction.

Biotin is a readily available supplement that is part of the B-complex vitamins. It is an essential co-factor for five carboxylases involved in fatty acid synthesis and energy production. The recommended daily intake (RDI) of biotin ranges from 30 to 70 mcg per day. At high doses (10,000 times RDI), biotin improves clinical outcomes and quality of life in patients with progressive multiple sclerosis (MS). It has been reported to cause interference in immunoassays resulting in abnormal thyroid function tests. Hereby we are describing the case of a patient having MS who was on high-dose biotin, seen in the clinic for a follow-up visit with thyroid function tests suggestive of Graves’ disease with no signs and symptoms of hyperthyroidism and completely normal physical examination. In the case we have described, the laboratory measurements suggestive of thyrotoxicosis were attributed to interference of the patient’s high-dose biotin treatment with the biotin-streptavidin chemistry of the immunoassays. We observed normalization of the thyroid stimulating hormone (TSH) and free T4 measurements when the patient withheld biotin for a week. As our case illustrates, early consideration of biotin interference minimizes unnecessary repeat laboratory studies. As trials in MS are progressing, we expect to see more patients on high-dose biotin treatment with spurious laboratory measurements. Therefore, we advise careful history taking and close communication with the laboratory when the clinical picture does not match with the laboratory results.