Hyperpathia and sensory level due to parietal lobe arteriovenous malformation.

A 30-year-old man experienced the sudden onset of prickly dysesthesia in the perineum followed by a "heavy" sensation in the left lower extremity. There was no headache. He had a hyperpathic response to pinprick and temperature testing below the T-6 dermatome on the left and a decrease of light touch below T-10, also on the left. A small ruptured arteriovenous malformation was found in the right parietal lobe, medially, well above the thalamus, and in the region of the postcentral gyrus. The case provides rare and precise clinicoanatomic correlation of the discrete somatotopic organization of the sensory cortex. Furthermore, it indicates that sensory disturbances, characterized by a segmental level of abnormal sensation suggestive of a spinal cord or medullary lesion and by hyperpathia suggestive of a spinal, medullary, or thalamic localization, can be caused by a suprathalamic parietal deficit.