Evaluation of treatment of normal-pressure hydrocephalus

Abstract

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.

Pathophysiology of Cerebral Circulatory Disorders in Idiopathic Normal Pressure Hydrocephalus

“…9). Earlier studies on ischemic sites in iNPH before surgery 16,17,19,20,22,24,[26][27][28][29][30][31][32]34) have reported various patterns of these two pathophysiological conditions according to the disease stage of iNPH. While one group reports only reductions in hypoperfusion, 34) most authors agree that the CBF improves after surgery in shunt-effective cases, in light of the compensatory increase of the blood flow at normoperfusion sites in non-improved hypoperfusion cases after surgery.…”

“…9,[12][13][14][17][18][19][20][21][22]24,[26][27][28][29]31,32,34) The results from reports on preoperative ischemic sites and postoperative sites of increased blood flow have varied, 13,17,19,20,22,24,26,27,31,32) however, and no firm consensus has been reached. In this study we use N-isopropyl-( 123 I)-P-iodoamphetamine single photon emission computed tomography ( 123 I-IMP SPECT) to compare the CBF and perfusion patterns of the cerebral cortex assessed by the three-dimensional stereotactic surface projection (3D-SSP) Z-score images at each site before and after surgery in iNPH cases effectively resolved by shunt intervention (shunt-effective cases).…”

Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus Guidelines From the Guidelines Committee of Idiopathic Normal Pressure Hydrocephalus, the Japanese Society of Normal Pressure Hydrocephalus

“…These findings are supported by other studies. 57,70,74,76,117,128) A PET study reported the mean CBF decreased in the cerebrum and cerebellum with regional decrease in the basal ganglia and thalamus but not in the white matter. 82) There are few studies supporting the correlation between reduced flow and degree of symptoms.…”

“…54B) The involvement of autoregulatory impairment is still controversial. 70,74,82,118) Thus, CBF measurements can show diffuse or regional decrease of CBF in NPH, but they are insufficient for the definite diagnosis of iNPH and also insufficient for the indication of shunt surgery (Recommendation grade C). However, CBF studies are useful in differentiating iNPH from other disorders of dementia, including Alzheimer's disease.…”

“…Measurements of CBF in NPH, including patients with iNPH, have been conducted by the inhalation method or single photon emission computed tomography (SPECT) utilizing radio-labeled materials including xenon-133, 70,[74][75][76]117) technetium-99m hexamethylpropyleneamine oxime ( 99m Tc-HMPAO), 54B) nonradioactive xenon-CT, 118) and positron emission tomography (PET) with [ 15-O]H 2 O. 82,90) In a study measuring CBF in 31 patients of suspected Chapter 1: Diagnosis iNPH with 99m Tc-HMPAO SPECT, 54B) reduced blood flow over a wide area, especially in the cortex and subcortical white matter of the frontal and temporal lobes (expansion of central low-flow area), is seen.…”