Posterior insular stroke causing selective loss of contralateral nonpainful thermal sensation

Abstract

Isolated lesions of the insular cortex can produce contralateral sensory disturbances; indeed, insular ischemia has been included in the differential diagnosis of pure sensory stroke.1 The affected sensory modalities comprise touch, nonpainful thermal sensation, and both heat and pinprick pain.1–3 The exact topography of the representations of nonpainful vs painful thermal sensations in the insula and secondary somatosensory cortex (SII) is unclear.4,5 Here we describe a patient who developed pure thermal anesthesia on the side of the body contralateral to a small insular stroke. A 59-year-old man had failure to perceive hot temperature with his left hand, until the sensation became painful, for approximately 4 months. He had not noted sensory deficit in other modalities nor any positive sensory symptom. He was hypertensive. Neurologic examination disclosed isolated thermal anesthesia for both cold and warm sensations on the left side of the body, sparing the face (water-filled test-tubes). The facial limits of the sensory loss were …