The stable xenon contrast computerized tomography method for measuring local cerebral blood flow and local lambda values

Evaluation of treatment of normal-pressure hydrocephalus

Ten patients with dementia due to normal-pressure hydrocephalus were evaluated prospectively according to a planned, longitudinal protocol for 4 to 12 months. Information recorded at each visit included clinical history, medical and neurological examination, psychometric scoring by Mini-Mental Status Questionnaire, measurement of ventricular size and local cerebral blood flow, and partition coefficients (local lambda changes) (1 lambda) by xenon contrast computerized tomography scanning. Cerebrospinal fluid shunting was carried out in eight cases. Serial evaluations were repeated at intervals up to 8 months after shunting, and demonstrated that the ventricles decreased in size and periventricular hypodensities decreased. White matter 1 lambda values and blood flows and cortical gray matter flows progressively increased for 3 months after shunting, and remained increased except for one case complicated by chronic alcoholism. Clinical recovery correlated with improved cerebral perfusion. There were returns of urinary continence and improvements in gait and usually in activities of daily living. Mentation was the last factor to improve. Factors negatively influencing cerebral perfusion and clinical recovery were shunt failures and various contributing causes of dementia.