gms | German Medical Science

Objective: There is dispute if ventriculo-peritoneal shunting (VPS) with adjustable valves (AV) should be recommended in patients with normal pressure hydrocephalus (NPH), as positive response to valve pressure adjustment is often lacking over time.

Methods: We retrospectively analyzed the clinical effect of valve pressure adjustments during the postsurgical course in NPH.

Results: 71 patients with presurgical positive spinal tab test were operated between January 2007 and December 2016 for NPH, in whom an AV was implanted. 42 were male, mean age at shunt surgery was 73 years. 8 patients were excluded for statistical analyses as follow-up time was less than 3 months. For 63 patients the mean follow-up time was 52.1 months. A total of 364 follow-up visits was analyzed, 77% of these were regular scheduled controls. During these controls, 127 adjustments of AV opening pressures were performed in 43 patients (median of 3 adjustments per patient). Only 20 (31.5%) of these adjustments lead to improvement of symptoms. Three groups of patients were identified:

1.

16% never benefited, (2) 27% only transiently improved and (3) 57% permanently profited from VPS. In 64.8% of group (2) and 66.7% of (3), improvement of symptoms was achieved by valve pressure adjustments, only. Median time to permanent deterioration of symptoms in group

2.

was 10.9 months. There were no differences in the outcome associated with co-morbidities, the kind of AV, the initial valve pressure chosen or presence of a gravitational unit.

Conclusion: As already known from previous publications, only half of patients with NPH have a long-lasting benefit from shunt placement with a certain decline of symptoms after about 11 months. However, the amount of patients with a beneficial long-term outcome can be doubled by repetitive AV adjustments.