Deficient visuomotor hand coordination in normal pressure hydrocephalus

OBJECTIVE: To investigate if visuomotor coordination of hand movements is impaired in patients with normal pressure hydrocephalus (NPH) identified by dedicated testing procedures. METHODS: Forty-seven patients admitted for diagnostic workup for suspected NPH were studied prospectively with MRI, testing of cognitive and motor functions, lumbar puncture, and visuomotor coordination of hand movements using the PABLO(R)-device before and after a spinal tap of 40–50 ml CSF. Statistical analyses were carried out with repeated measures ANOVA and non-parametric correlation analyses. RESULTS: Fourteen patients were found to suffer from ideopathic NPH. They were severely impaired in visuomotor control of intermittent arm movements in comparison to patients who were found not to be affected by NPH (n = 18). In the patients with NPH the deficient arm control was improved after the spinal tap in proportion to the improvement of gait. There was no improvement of cognitive and motor functions in the patients not affected by NPH, while the patients with possible NPH (n = 15) showed intermediate deficit and improvement patterns. Interpretation: Our data underline the importance of a multiparametric assessment of NPH and provide evidence for a motor control deficit in idiopathic NPH involving leg and arm movements. It is suggested that this motor control deficit resulted from an affection of the output tracts from the supplementary motor area in the periventricular vicinity.