Dutch normal pressure hydrocephalus study: baseline characteristics with emphasis on clinical findings

We present the baseline characteristics of 101 patients with normal pressure hydrocephalus (NPH), entering a study that evaluates the diagnostic reliability of CSF outflow resistance. Patients were assessed by a gait scale consisting of 10 features of walking and the number of steps and seconds necessary for 10 m, a dementia scale comprising the 10 word test, trail making, digit span and finger tapping, the modified Mini Mental State Examination (3MSE) and the modified Rankin scale (MRS). Inclusion criteria were a gait and dementia scale ≥ 12 (range 2-40), a MRS ≥ 2 and a communicating hydrocephalus on CT. Gait disorder and dementia varied from mild to severe leading to MRS 2 in 17%, MRS 3 in 34%, MRS 4 in 21%, MRS 5 in 16% and MRS 6, including akinetic mutism, in 12%. Only one patient showed both normal tandem walking and turning. Small steps, reduced foot floor clearance and wide base were also frequently seen in the 67 patients walking independently; 34 needed assistance or could not walk at all. Applying the 3MSE, 64% were demented; the remaining 36% exhibited a milder cognitive deficit. The 10 word test and trail making decreased with increasing dementia. Digit span and finger tapping declined in the most demented patients. This group of elderly patients with NPH, mostly of the idiopathic type, proved to be vulnerable because of considerable disability and comorbidity.