When to Assess: Cognitive Impact of Ventriculoperitoneal Shunt Operation in Elderly Adults with Normal Pressure Hydrocephalus

Normal pressure hydrocephalus (NPH) has clinical manifestations with different cognitive difficulties. Despite the intense interest, the change in cognitive functions after ventriculoperitoneal shunt (VPS) treatment varies widely. The aims of this study were to monitor the effect of NPH on cognition in elderly and the progress of cognitive abilities after VPS surgery. Patients diagnosed with idiopathic NPH (iNPH) who had ventriculomegaly with narrow callosal angle and/or periventricular signal changes not attributable to ischemic changes were included in study. All patients (n = 30) underwent comprehensive neuropsychological assessment and received programmable VPS. After VPS placement, 2 consecutive examinations were performed at approximately 6-month intervals. At the baseline evaluation, patients with iNPH displayed poorer performance in executive functions (EFs) compared with the matched control group (n = 30). Among those patients, significant improvement was observed in semantic fluency (M = 13.94; standard deviation, 4.95) and clock drawing (M = 3.67; standard deviation, 1.57) at the second follow-up evaluation (P = 0.015 and P = 0.024, respectively). The other prominent finding was in memory process: patients with iNPH showed improvement in delayed recall (P = 0.011), recognition (P = 0.033), and learning scores (P = 0.041) at the second follow-up compared with evaluation before VPS placement. iNPH seems to have a detrimental effect predominantly on EFs. As EFs become corrupted, decline occurs in learning and recall processes of memory. VPS provides an improvement of cognitive deterioration; however, efficacy of this treatment on cognitive abilities is shows in a longer period compared with other iNPH symptoms.