1. ^*Academic Neurosurgery Unit, Addenbrooke's Hospital, Cambridge, UK
2. ^†Wolfson Brain Imaging Center, University of Cambridge, Cambridge, UK
3. ^‡Brain Repair Center, University of Cambridge, Cambridge, UK
4. ^§Department of Surgery, University of Sydney, Sydney, Australia.

Correspondence: Brian K Owler, Institute of Clinical Neuroscience, Department of Neurosurgery, Royal Prince Alfred Hospital, Missenden Rd, Camperdown NSW 2050, Australia; e-mail: brianowl@bigpond.com.

Received 9 June 2003; Revised 12 August 2003; Accepted 14 August 2003.

Abstract

Regional cerebral blood flow (CBF) was studied with O¹⁵-water positron emission tomography and anatomic region-of-interest analysis on coregistered magnetic resonance in patients with idiopathic (n = 12) and secondary (n = 5) normal pressure hydrocephalus (NPH). Mean CBF was compared with values obtained from healthy volunteers (n = 12) and with clinical parameters. Mean CBF was significantly decreased in the cerebrum and cerebellum of patients with NPH. The regional analysis demonstrated that CBF was reduced in the basal ganglia and the thalamus but not in white matter regions. The results suggest that the role of the basal ganglia and thalamus in NPH may be more prominent than currently appreciated. The implications for theories regarding the pathogenesis of NPH are discussed.