Cognitive and Behavioral Disorders in Patients with Superior Parietal Lobule Infarcts

The superior parietal lobule (SPL) plays a strategic role in somatosensory and visuomotor integration. This study aims to evaluate the clinical, neurocognitive, and behavioral characteristics of isolated SPL stroke.

We assessed neuropsychological and behavioral findings in 14 patients with isolated SPL stroke among 4200 patients with ischemic stroke. All patients underwent neuroimaging, clinical and neuropsychological assessment after stroke.

Of the 14 patients enrolled, the first complaints were tactile and visuospatial disorders at stroke onset. Except for 6 patients with only 1 cognitive impairment, the majority of patients (57%) experienced more than 1 cognitive impairment category. Functional hemispheric asymmetries have been found in different cognitive processes, such as between visuospatial and body image functions and language process. Among visuospatial abilities disorders, spatial disorientation, visuospatial neglect, and visual extinction were found in two-thirds (63%) of patients with right SPL lesion. Body schema and image disorders were observed in all patients with right-sided lesions, such as alien hand, autotopagnosia for body parts (36%), autotopagnosia for sensory sensations (36%), and fading limb (21%). Two-thirds (57%) of patients with left SPL had impairment in language abilities.

Our findings after stroke suggest that SPL plays a pivotal role in the regulation of visuospatial abilities, body schema and body image processing, and language skills through bilateral frontoparietal networks and interhemispheric parietal networks.