Reversible cerebral vasoconstriction syndrome (RCVS) is a rare but increasingly recognized disorder with over 500 cases published in the literature. The condition is characterized by recurrent severe thunderclap headaches with or without other neurological symptoms and diffuse segmental narrowing of the cerebral arteries which is reversible within 3 months. RCVS may occur spontaneously but in over 50% of cases, it is associated with various other conditions, including vasoactive medications or illicit drugs and the post-partum state. One third to a half of cases develop hemorrhagic or ischemic brain lesions or a combination of both. Posterior reversible encephalopathy syndrome (PRES) often occurs in association with RCVS and the conditions are likely to share a common pathophysiology. The pathogenesis of RCVS remains uncertain but autonomic dysregulation, oxidative stress, and genetic predisposition are postulated. Significant differential diagnoses include subarachnoid hemorrhage (SAH) due to aneurysmal rupture, cervical artery dissection, and primary angiitis of the central nervous system (PACNS). Although there is no proven treatment, calcium channel antagonists including nimodipine and verapamil have been administered with reported reduction of headache intensity but without effect on the time course of cerebral vasoconstriction. Glucocorticoids have been reported as an independent predictor of worse outcome and should be avoided. The cornerstone of RCVS management remains largely supportive with bed rest and analgesics and removal of precipitating factors. Invasive neurointerventional techniques should be reserved for severe deteriorating cases. The condition is usually benign and self-limited and the majority of patients have a favorable outcome but around 5-10% are left with permanent neurological deficits and rare cases may die. This review details the importance of the early recognition of this increasingly described condition and current treatment recommendations.

BackgroundTrials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to determine if daily fluoxetine for 6 months after stroke improves functional outcome in Australasian and Vietnamese patients. MethodsAFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial conducted in 43 hospital stroke units in Australia (n=29), New Zealand (4), and Vietnam (10). Eligible patients were adults with a clinical diagnosis of stroke in the previous 2-15 days and a persisting neurological deficit. Patients were randomised via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20mg or matching placebo for 6 months. Patients, investigators and outcome assessors were masked to the treatment allocation. The primary outcome was functional outcome, measured by the modified Rankin scale (mRS), at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Analyses were according to the patient's treatment allocation. The trial is registered with the ACTRN registry, number 12611000774921. FindingsPowered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation 1280 patients were recruited in Australia (n=532), New Zealand (n=42) and Vietnam (n=706) between 11 January 2013 and 30 June 2019; 642 were allocated fluoxetine and 638 placebo. Adherence to trial medication (mean 167 [SD 48] days) was similar between groups. At 6 months, mRS data were available in 624 (97.2%) patients allocated fluoxetine and 632 (99.1%) placebo. The distribution of mRS categories at 6 months was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0.936, 95% CI 0.762-1.150; p=0.53), and consistent among all pre-defined subgroups. Compared to placebo, patients allocated fluoxetine had more falls (20 [3.12%] vs 7 [1.10%]; p=0.02), bone fractures (19 [2•96%] vs 6 [0.94%]; p=0.01) and epileptic seizures (10 [1.56%] vs 2 [0.31%]; p=0.04) at 6 months. InterpretationFluoxetine 20mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and seizures. These results do not support the use of fluoxetine to improve outcome after stroke.

Voluntary activity produces activity-dependent hyperpolarization of the active motor axons. The present study investigated whether this hyperpolarization produces conduction block in chronic inflammatory demyelinating polyneuropathy (CIDP). Studies were performed in 10 healthy control subjects, 7 patients with CIDP, and 3 patients with multifocal motor neuropathy. The compound muscle action potential (CMAP) of the abductor pollicis brevis was recorded in response to supramaximal stimuli to the median nerve at the wrist, alternating with measurements of axonal excitability. After a maximal voluntary contraction for 60 seconds, the amplitude of the maximal CMAP was significantly reduced in symptomatic CIDP patients by 40%, but there were only slight changes in the CMAPs of healthy controls, asymptomatic CIDP patients, and multifocal motor neuropathy patients. In symptomatic CIDP patients, the activity-dependent conduction block paralleled the activity-dependent hyperpolarization and was presumably precipitated by it. In these patients, the safety margin for impulse conduction was estimated to be about 12%. Activity-dependent conduction block may be clinically important in chronic demyelinating diseases and can be demonstrated electrophysiologically if testing occurs across pathological sites.