High-altitude cerebral oedema mimicking stroke

Abstract

High-altitude cerebral oedema (HACO) is the most fatal high-altitude illness seen by rural physicians practising in high-altitude areas. HACO presents clinically with cerebellar ataxia, features of raised intracranial pressure (ICP) and coma. Early identification is important as delay in diagnosis can be fatal. We present two cases of HACO presenting with focal deficits mimicking stroke. The first patient presented with left-sided hemiplegia associated with the rapid deterioration in the sensorium. Neuroimaging revealed features suggestive of vasogenic oedema. The second patient presented with monoplegia of the lower limb. Neuroimaging revealed perfusion deficit in anterior cerebral artery territory. Both patients were managed with dexamethasone and they improved dramatically. Clinical picture and neuroimaging closely resembled acute ischaemic stroke in both cases. Thrombolysis in these patients would have been disastrous. Recent travel to high altitude, young age, absence of atherosclerotic risk factors and features of raised ICP concomitantly directed the diagnosis to HACO.

The Impact of Temporary Stay at High Altitude on the Circulatory System

“…This is important as stroke is treated with thrombolysis, and HACE with dexamethasone. If appropriate treatment is administered quickly enough, there is a chance of a complete cure of the patient [ 87 ].…”

Environmental Risk Factors for Stroke and Cardiovascular Disease

“…In fact, altitude stress and its neuro-cardiovascular consequences differ markedly depending on the cerebrovascular regulation and on the capability to adapt. Impairment of the cerebral autoregulation is the major risk for travelers who rapidly reach altitudes above 2500 m. They may manifest several syndromes: altitude headache (HAH), acute mountain sickness (AMS), high-altitude cerebral oedema (HACO/ HACE), and high-altitude pulmonary oedema (HAPO/HAPE) (Wilson et al, 2009;Yanamandra et al, 2014). Although rarely reported, acute stroke is possible during short-term visits to high-altitude regions .…”

“…Thus, stroke or stroke-like episodes have been described in association with high altitude for the first time in 1895 (Szawarski et al, 2012). Differential diagnosis must consider cerebral venous thrombosis and HACO, which can mimic stroke and provoke deficits; those resolve with the resolution of cerebral oedema (Yanamandra et al, 2014). In case of stroke, an asymptomatic patent foramen ovale should be excluded (Szawarski et al, 2012;Murdoch, 2015).…”

Sudden onset hemiplegia at high altitude

“…Telephone advice from the UK (AM) was provided and supported a diagnosis of a cerebrovascular accident (CVA), although it was considered reasonable to continue administration of dexamethasone, especially as HACE may present with focal deficits and mimic stroke 1. Overnight the casualty's level of response fluctuated with episodes of profoundly depressed conscious level, on one occasion necessitating a jaw thrust to maintain his airway.…”