Acute Isolated Thalamic Infarcts: Clinical and Imaging Profile in Oman

Abstract

Introduction— Thalamus is supplied by multiple arteries drawn from both anterior and posterior circulations often
with vascular variants, therefore thalamic infarcts can present with a broad spectrum of symptoms and signs that can
be challenging both clinically and radiologically.
Objectives and Methods— A retrospective observational hospital-based study. Aiming to identify the clinical
profile, arterial territories involved, vascular variations and outcome of patients admitted with acute isolated thalamic
infractions. The ability of the imaging modalities used to pick up the thalamic infarcts in the acute phase was also
evaluated.
Results— Over a period of 33 months, 1260 acute ischemic stroke cases were admitted. 53 (4.2%) were isolated
thalamic infarctions. Hemiparesis and dysarthria were the most common clinical presentation. 29/53 patients
underwent head computerized tomography within 24 hours of the symptom onset. The thalamic infract was only
detected in 5/29 (17.2%) of the scans. Computerized tomographic angiography was used to assess the vasculature
in 49/53 (92%) of patients. Normal posterior circulation was seen in only 17/49 (35%). Bilaterally absent posterior
communicating artery 13/49 (26%) was the commonest variant seen. The majority of the lesions 41/53 (77%) were
localized to the ventrolateral thalamus (thalamogeniculate) artery. There was no mortality, and 40/53 (75%) achieved
a modified Rankin Scale of ≤2 upon discharge.
Conclusions— Isolated thalamic infarcts represent a broad spectrum of clinical syndromes. In more than 80% of
patients, a computerized tomography head can be normal in the first 24 hours. Only less than one-third had a normal
posterior circulation vasculature. The ventrolateral (thalamogeniculate) thalamus artery was the most commonly
involved vascular distribution.