Pure thalamic infarctions: Clinical findings

Our purpose in this study was to evaluate and review the risk factors clinical profiles and neuropsychologic abnormalities in patients with pure thalamic infarctions and to describe the clinical syndromes according to the thalamic arterial territory involved. We studied all patients with acute thalamic stroke admitted to our stroke unit over a 5-year period. We performed magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) on all patients. We classified patients into 4 thalamic artery territory subgroups based on MRI findings: thalamogeniculate paramedian polar and posterior choroidal. Patients with pure thalamic infarction represented 2.4% of patients with ischemic stroke in our registry. There were 59 patients (39 men and 20 women; mean age 62±13 years) with thalamic infarctions that were confirmed by MRI. The main cause of thalamic infarction was small artery disease (75%). Hypertension (68%) hypercholesterolemia (29%) and diabetes mellitus (27%) were the most frequent risk factors. Hemisensory loss with or without motor and neuropsychologic deficit is highly associated with thalamogeniculate infarction the most frequent type of thalamic stroke (51%). Paramedian infarction was the second most common type of thalamic infarction (34%) and is characterized by several neuropsychologic oculomotor and consciousness disturbances. Frontal-like syndrome with sensory motor findings is common in polar artery territory infarction (10%). Visual field defect is associated mainly with infarctions in the territory of the posterior choroidal artery (5%) probably caused by involvement of the lateral geniculate body. Approximately two thirds of the patients returned to their previous normal life. Cognitive deficits in patients with bilateral paramedian infarction persisted during the follow-up period contrary to the other thalamic stroke subtypes. No patient died during follow-up. Acute thalamic stroke is a specific clinical picture that accurately predicts a small artery disease in the posterior circulation. The 4 arterial thalamic territories correspond well clinically to 4 different syndromes. Acute thalamic infarction appears to predict an overall good clinical recovery.