Executive functioning pattern as a prognostic indicator for shunt implantation surgery in patients with normal...

The problem of executive functions in patients with normal pressure hydrocephalus (NPH) was investigated in the study. Executive function parameters were assumed to be among factors that may differentiate the clinical pattern in NPH. Two major indicators of executive functioning, i.e. flexibility and productivity of thinking, were assessed in neuropsychological examination using the Trail Making Test (TMT), Verbal Fluency Test (COWAT), and the Wisconsin Card Sorting Test (WCST). Participants in the study were 18 patients with NPH divided using a set of diagnostic criteria into two subgroups: with idiopathic active hydrocephalus (ACT) or with arrested hydrocephalus (ARR). Executive functioning patterns were found to differentiate between the two NPH subgroups. Namely, patients diagnosed with active hydrocephalus (who qualify for shunt implantation surgery) tended to present lower levels of verbal fluency in all semantic categories, which suggests a decreased productivity of thinking. Besides, ACT patients' performance on the WCST was significantly inferior on two measures: (1) they committed more non-perseverative errors (which indicates their chaotic way of working on the test and the occurrence of random responses) and (2) displayed lower ability of "learning to learn" (which suggests their impaired flexibility of thinking). These aspects of executive function, with productivity and flexibility of thinking first and foremost, seem promising as additional prognostic indicators to consider in patient selection for shunt implantation.