Extensive Cerebral Venous Thrombosis Secondary to Recreational Nitrous Oxide Abuse.

Nitrous oxide, colloquially known as "whippets," is a commonly abused inhalant by adolescents and young adults. There are limited data describing the adverse effects of this abuse. We present a 16-year-old girl with no medical history who presented to the emergency department for confusion, hallucinations, weakness, and headaches. Imaging revealed extensive cerebral thrombosis. She had no prior history of venous or arterial thrombosis. Hypercoagulability workup demonstrated an elevated homocysteine level. She was treated with effective anticoagulation and vitamin B12 folate supplementation. To our knowledge, there are a very few cases in the medical literature of cerebral venous thrombosis following the use of nitrous oxide. The pathophysiology of the disorder appears to be linked to the metabolism of vitamin B12 inducing hyperhomocysteinemia and a procoagulant state.

Ischemic stroke in giant-cell arteritis: French retrospective study.

Acute cerebrovascular ischemic events are a rare and severe complication of giant cell arteritis (GCA). We aimed to determine the prevalence of GCA-related stroke, the overall survival and the relapse-free survival in patients with GCA. A multicentric retrospective analysis was performed on 129 patients with GCA diagnosed between September 2010 and October 2018 in two University Hospitals. Among 129 GCA patients, 18 (16%) presented an acute ischemic cerebrovascular event. Patients with stroke were older (83 [67-96] years versus 76 [58-96]; p = 0.014) and more frequently males (61% versus 30%; p = 0.014) than those without stroke. The frequency of anterior ischemic optic neuropathy was higher in patients with stroke (n = 6, 33%) than patients without stroke (n = 12, 11%)(p = 0.02). Overall survival was significantly decreased in GCA patients with stroke (4.4 months), comparatively to patients without stroke (221.7 months; log rank test = 0.006). The 3-years relapse-free survival was decreased in patients with stroke (8.42 versus78.0 months; log rank = 0.0001), as well as the time with sustained remission (78 versus 139 months; log rank test = 0.0004). This study shows the prevalence and risk factors of ischemic stroke in GCA.