Anatomically, each thalamus lies rostral to the brainstem, lateral to the third ventricle, and medial to the internal capsule. As most blood to the thalamus arrives from the tip of the basilar artery and the proximal portions of the posterior cerebral arteries (PCAs), thalamic lesions may be associated with simultaneous lesions in the midbrain or in the distal territory of the PCA. Microangiopathy is the cause of most lateral thalamic infarcts although embolic sources are occasionally found. Large thalamic hemorrhages involve more nuclei and tracts, with or without ventricular extension, resulting in overlapping clinical syndromes. Common features seen in patients with thalamic hemorrhages include rapid onset of symptoms, inconstant impairment of consciousness even in large size hematomas, and a relatively good prognosis as compared with that for hemorrhages in the pons and basal ganglia. Venous thrombosis of the deep cerebral venous system usually leads to bilateral thalamic edema.