Article
Outcome after shunt operation in normal pressure hydrocephalus of the elderly: The impact of age, gender and duration of symptoms
Outcome nach Shunt-Operation bei Patienten mit Normaldruckhydrocephalus: Einfluss von Alter, Geschlecht und Anamnesedauer
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Published: | April 23, 2004 |
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Outline
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Objective
In patients with NPH it is known that gait impairment as the leading or only symptom is a predictor of good outcome, and advanced dementia or marked vascular subcortical encephalopathy is associated with less favourable outcome after shunt operation. It is not known, however, if age at the time of operation, gender or the length of history also have an impact on outcome after shunt operation.
Methods
In this prospective study 69 consecutive patients with suspected NPH underwent standardized assessments to select patients for CSF shunting. The evaluations were performed before and after large volume CSF removal. Forty-three patients underwent shunt operation. Outcome was evaluated with the score developed by Krauss. Mean age at surgery was 69.6 years. Improvement indices were calculated between 0 (no improvement) and 1 (excellent improvement). The cut off for useful outcome was set at an improvement index of 0.3 or more. Patients were dichotomised into two groups, with age younger than 70 years or older, respectively. With regard to the duration of symptoms, history of less than one year or more was chosen to dichotomise patients into two groups.
Results
At the last follow-up (mean of 7.3 months after surgery) 29 patients were available. The mean improvement index for all patients was 0.6. There was no significant difference seen in the mean improvement indices between the two cohorts dichotomised for age. The mean improvement index was 0.59 in the group of patients 70 years or older, and 0.67 in the younger age group. There were 12 / 18 patients in the older group who had useful outcome, and 8 / 11 patients in the younger age group. There was no difference in outcome regarding gender. Mean improvement index was 0.6 for women and 0.63 for men. The mean duration of symptoms in group one with up to twelve month history was 7.6 month and 44.7 month in the group two with a history of more than twelve month. Mean improvement index was 0.63 in group one and 0.6 in group two.
Conclusions
Older patients with NPH (70 years or older) experience outcome after shunting which is comparable to that of younger patients. Gender of the patient has no impact on postoperative benefit. As well, the length of preoperative symptoms seems to have no impact on outcome after shunting.