Association between shunt-responsive idiopathic normal pressure hydrocephalus and alcohol

Abstract

OBJECTIVE Idiopathic normal pressure hydrocephalus (iNPH) is characterized by ventriculomegaly, gait difficulty, incontinence, and dementia. The symptoms can be ameliorated by CSF drainage. The object of this study was to identify factors associated with shunt-responsive iNPH. METHODS The authors reviewed the medical records of 529 patients who underwent shunt placement for iNPH at their institution between July 2001 and March 2015. Variables associated with shunt-responsive iNPH were identified using bivariate and multivariate analyses. Detailed alcohol consumption information was obtained for 328 patients and was used to examine the relationship between alcohol and shunt-responsive iNPH. A computerized patient registry from 2 academic medical centers was queried to determine the prevalence of alcohol abuse among 1665 iNPH patients. RESULTS Bivariate analysis identified associations between shunt-responsive iNPH and gait difficulty (OR 4.59, 95% CI 2.32-9.09; p < 0.0001), dementia (OR 1.79, 95% CI 1.14-2.80; p = 0.01), incontinence (OR 1.77, 95% CI 1.13-2.76; p = 0.01), and alcohol use (OR 1.98, 95% CI 1.23-3.16; p = 0.03). Borderline significance was observed for hyperlipidemia (OR 1.56, 95% CI 0.99-2.45; p = 0.054), a family history of hyperlipidemia (OR 3.09, 95% CI 0.93-10.26, p = 0.054), and diabetes (OR 1.83, 95% CI 0.96-3.51; p = 0.064). Multivariate analysis identified associations with gait difficulty (OR 3.98, 95% CI 1.81-8.77; p = 0.0006) and alcohol (OR 1.94, 95% CI 1.10-3.39; p = 0.04). Increased alcohol intake correlated with greater improvement after CSF drainage. Alcohol abuse was 2.5 times more prevalent among iNPH patients than matched controls. CONCLUSIONS Alcohol consumption is associated with the development of shunt-responsive iNPH.

Keywords: TUG = Timed Up and Go; aging; alcohol; cognitive impairment; gait disorders; iNPH = idiopathic normal pressure hydrocephalus; incontinence; normal pressure hydrocephalus.

FIG. 1.

Study design. Flow diagram depicting the design for the iNPH study.

FIG. 2.

Univariate analysis of variables associated with shunt-responsive iNPH. Data shown are odds ratios and 95% confidence intervals; p values were calculated using the chi-square test. Hx = history. Figure is available in color online only.

FIG. 3.

Multivariate analysis of variables associated with shunt-responsive iNPH. Data shown are odds ratios and 95% confidence intervals. Pr > χ² indicates that chi-square values were obtained using logistic regression analysis. Figure is available in color online only.

FIG. 4.

A: Percentage of patients who improved (red bars) or did not improve (blue bars) after shunt placement for iNPH, grouped according to amount of alcohol consumed. The number of patients involved in each category is shown at the top of each column. Criteria for classifying the frequency of alcohol consumption were as follows: never (abstinence), rare (3 alcoholic beverages or less weekly), moderate (4–14 alcoholic beverages weekly), and heavy (more than 14 alcoholic beverages weekly). B: Percentage of men and women who improved (red bars) or did not improve (blue bars) after shunt placement for iNPH, grouped according to frequency of alcohol consumption. Criteria for classifying the frequency of alcohol consumption for men were the same as in panel A. Criteria for classifying the frequency of alcohol consumption for women were never (abstinence), moderate (up to 7 alcoholic beverages weekly), and heavy (more than 7 alcoholic beverages weekly). C: Prevalence of drinkers among patients showing no improvement (none), mild improvement, or marked improvement after CSF drainage for iNPH. The number of patients in each category is shown at the top of each column. D: Graph illustrating relationship between the degree of improvement after CSF drainage for iNPH and the frequency of alcohol consumption. E: Graph showing the relationship between the number of drinks consumed weekly and the degree of improvement for men and women.