Posterior reversible encephalopathy syndrome presenting in the anterior circulation with malignant intracranial hypertension requiring surgical decompression: a case report and literature review.

Posterior reversible encephalopathy syndrome (PRES) is thought to result from endothelial dysfunction and breakdown of the blood-brain barrier with subsequent vasogenic edema. Abrupt hypertension has been identified as one of its risk factors. We present a rare case of PRES in the anterior circulation with sudden onset of left hemiparesis and rapid neurological deterioration on the basis of hypertensive crisis. Due to refractory intracranial hypertension, the patient required emergent right decompressive craniectomy. Further investigations, including a biopsy, revealed an atypical form of PRES. This case illustrates the importance of aggressive medical and early surgical management to prevent permanent neurological deficits.

Analysis of CD4+ CD8+ double-positive T cells in blood, cerebrospinal fluid and multiple sclerosis lesions.

T cells with a CD4(+) CD8(+) double-positive (DP) phenotype are present in small numbers in the peripheral blood of healthy humans and may have anti-viral capacities. Here we investigate numbers and function of DP T cells in patients with relapsing-remitting multiple sclerosis (MS), either treatment-naive or under therapy with natalizumab. Flow cytometry analysis revealed that frequencies of circulating DP T cells in treatment-naive and natalizumab-treated MS patients are comparable to healthy controls. These cells have a memory phenotype with cytotoxic potential, express high levels of CD49d and are similarly functional in treatment-naive as well as natalizumab-treated MS patients. DP T cells were enriched in the cerebrospinal fluid, but do not invade acutely inflamed MS lesions. In conclusion, DP T cells are functional in MS and may play a role in the immune surveillance of the central nervous system, but do not display functional impairment under natalizumab therapy.