Neuropsychological Deficits Due to Insular Damage

Abstract

Although our comprehension on the functions of the human insula has greatly benefited from functional neuroimaging and cortical stimulation studies over the past two decades, lesion studies provide unique insights on the role(s) it exerts in neuropsychological functioning. However, cerebral damage confined to the insular cortex is extremely uncommon. The characterization of the neuropsychological deficits due to insular injury is further complicated by the possible specialization of insular functions in each cerebral hemisphere, by the variety of clinical presentations associated with lesions damaging different parts of the insula, and by the fact that almost all insular lesions are unilateral. This chapter reviews the literature on the neuropsychological consequences of insular lesions in humans. A selective review of the literature is performed, with more consideration given to isolated ischemic insular strokes. The effects of insular damage are very heterogeneous, with neuropsychological deficits being reported in the sensory (somatosensory, interoceptive, and vestibular processing, neglect, audition, olfaction, and taste), cognitive (speech, memory, attention, and executive functions), and affective (emotional experience, social cognitive, and risky decision-making) domains. In many cases, the neuropsychological consequences are transient or alleviated with time. The various clinical presentations of insular injury are congruent with the widespread connectivity of the insula with other brain regions.