Neurocognitive profile of a man with Dandy-Walker malformation: Evidence of subtle cerebellar cognitive affective syndrome.

The Dandy-Walker Malformation (DWM) is a congenital birth malformation that is characterized by a triad of features: cerebellar dysgenesis, cystic dilation of the fourth ventricle, and an enlarged posterior fossa that displaces the dural sinuses and the tentorium. Despite this defining triad, clinical presentation can be highly heterogeneous in part due to severity of structural changes. To date, there been limited consideration of cognitive-behavioral symptoms of DWM in relation to nonmotor functions of the cerebellum, specifically cerebellar cognitive affective syndrome (CCAS). In this case study, we describe the neuropsychological and behavioral profile of a 48-year-old man with DWM who was seen due to concerns, expressed solely by the patient's father, about his son's atypical housing, employment and social skills. Neuropsychological test findings revealed high average intellect on standard intellectual measures (WAIS-IV), with stronger verbal (superior) than perceptual reasoning (average) skills. Across all cognitive domains, performance was generally within expectations, although bilateral fine motor skills were impaired. In contrast, he exhibited weaknesses on nontraditional neuropsychological measures assessing orbitofrontal-limbic circuitry, including reward sensitivity decision making and indices of threat-related emotional physiology. Through the use of traditional and nontraditional neuropsychological measures, subtle cognitive weaknesses in fronto-executive and affective regulation were illuminated and likely explain the patient's functional difficulties. Etiologically, these findings are consistent with the nonmotor functions of the cerebellum as described by CCAS.