Thalamic warning syndrome and the artery of Percheron.

Stroke warning syndromes manifest as brief, recurring episodes of focal neurological deficits that precede definitive brain ischaemia. Although the mechanisms remain unclear, intermittent hypoperfusion in specific vascular territories may explain these phenomena. A man in his 60s with vascular risk factors experienced recurrent episodes of sudden loss of consciousness. Initial imaging and tests were normal, excluding other potential causes. MRI revealed bilateral thalamic infarction and the presence of an artery of the Percheron variant. We propose 'thalamic warning syndrome' as a new term for this clinical presentation, characterised by recurrent transient loss of consciousness and a high risk of subsequent thalamic infarction. Early recognition of this syndrome can aid in the initial management and prognosis of similar cases, potentially preventing more severe neurological impairments.