Bilateral thalamic infarction - Clinical, etiological and MRI correlates

To determine clinical, behavioral, topographic and etiological patterns in patients with simultaneous bilateral thalamic infarction in varied thalamic artery territories, we studied 16 patients who were admitted to our stroke unit over a 7-year period. Patients with bithalamic infarction represented 0.6% of our registry which included 2750 ischaemic stroke patients. On com puted tomography and magnetic resonance imaging with gadolinium enhancement , there were 4 topographic patterns of infarction: 1) bilateral infarcts in the territory of paramedian artery (8 patients [50%]); 2) bilateral infarc ts in the territory of thalamogeniculate arteries (3 patients [19%]); 3) bi lateral infarcts involving territory of paramedian and thalamogeniculate ar teries (3 patients [19%]); 4) bilateral infarcts involving territory of pol ar and thalamogeniculate arteries (2 patients [13%]). A specific clinical p icture was found in up to 50% of the patients with bithalamic infarction. T his included patients with bilateral paramedian infarction having disorder of consciousness, memory dysfunctions, various types of vertical gaze palsy and psychic changes. Bilateral sensory loss predicted accurately bilateral infarction in the territory of thalamogeniculate arteries. The main cause of bilateral thalamic infarction was small artery-disease, followed by card ioembolism. Cognitive functions in patients with bilateral paramedian infar ction did not change significantly during the follow-up, in contrast to tho se with infarcts in varied arterial territories. Acute bilateral infarction involving both thalamus is uncommon, although they are often associated wi th specific neurologic-neuropsychological patterns, allowing diagnosis befo re radiological examination.