WHITE-MATTER LESIONS IN PATIENTS WITH IDIOPATHIC NORMAL-PRESSURE HYDROCEPHALUS AND IN AN AGE-MATCHED CONTROL-GROUP - A COMPARATIVE-STUDY

OBJECTIVE: To compare the occurrence of periventricular lesions (PVLs) and deep white matter lesions (DWMLs) in elderly patients with idiopa thic normal pressure hydrocephalus (NPH) and in an age-matched control group. METHODS: PVLs and DWMLs were evaluated using T2-weighted magne tic resonance scans of 37 patients with idiopathic NPH and 35 particip ants from an age-matched control group. All patients with idiopathic N PH included in this study improved after shunting. The control group c onsisted of 16 healthy elderly persons and 19 patients with depression . To allow quantitative assessment and comparison, scores for PVLs and DWMLs were calculated. Furthermore, possible correlations between whi te matter lesion scores, ventricular width, and age were investigated. RESULTS: There was a significantly higher incidence of PVLs and DWMLs in patients with idiopathic NPH. The mean total PVL was 12.1 (range, 2-24) in the NPH group and 3.9 (range, 0-10) in the control group (P < 0.001). The mean total DWML score was 12.9 (range, 3-24) in the NPH g roup and 4.5 (range, 0-16) in the control group (P < 0.001). There wer e significant correlations between the severity of PVL and DWML scores in both groups. Only a weak positive correlation between the severity of DWMLs and age was found in the NPH group, whereas this correlation was significant in the control group. There was a significant negativ e correlation between the width of the anterior horns and the severity of both PVLs and DWMLs in patients with NPH; however, positive correl ations were found in the control group. CONCLUSION: Elderly patients w ith idiopathic NPH have more frequent and more severe PVLs and DWMLs t han people in age-matched control groups. Our data suggest a frequent co-occurrence of idiopathic NPH and vascular subcortical encephalopath y; however, they do not support a direct causal relationship.