Diabetic striatopathy: cognitive and behavioral insights from case series and literature synthesis

Neurological disorders affecting the striatum are often associated with cognitive impairments and movement abnormalities. Diabetic striatopathy (DS), a rare complication of diabetes mellitus, has been traditionally associated with hyperkinetic movement disorders. However, comprehensive studies exploring the cognitive-behavioral aspects of this condition remain limited. We aimed to examine the cognitive and behavioral profiles of DS patients and explore mechanisms underlying the differential impact on motor versus cognitive-behavioral functions.

Five consecutive Bengali patients with DS presenting with hemichorea, all without reported cognitive complaints prior to disease onset, underwent comprehensive neuropsychological assessments. These evaluations, conducted three months after the onset of movement disorders, included the Montreal Cognitive Assessment, Addenbrooke's Cognitive Examination-III, and Frontal Assessment Battery. Behavioral changes were assessed using the Neuropsychiatric Inventory.

The series included three women and two men (69.7 ± 5.6 years) with poorly controlled diabetes. The cognitive evaluation revealed variable impairments: attention deficits in two patients, executive dysfunction in one, recent memory impairment in two, and language deficits in two patients. Visuospatial and visuoperceptual functions were preserved, while behavioral manifestations included depression, apathy, and obsessive behavior, notably without psychotic features. A literature review identified five previously reported cases of DS with cognitive-behavioral manifestations.

DS may produce less severe cognitive-behavioral impairments than other striatal disorders, likely due to selective circuit involvement and preserved compensatory mechanisms. This unique profile may reflect the acute nature of DS pathology, the potential reversibility of striatal changes, and preserved cortical-subcortical connectivity. These findings expand our understanding of DS beyond its classical motor manifestations.