This is one of the common sites of hypertensive intracerebral hemorrhage. Early neurological symptoms include contralateral sensory loss. With mass effect, patients develop headache, nausea and vomiting. As the lesion expands, patients may become lethargic due to direct compression on the upper brainstem structures (as seen above) or obstructive hydrocephalus. Eye movement abnormalities, especially impaired vertical gaze, are common in thalamic mass lesions.