[Diagnostic lumbar puncture performed in the outpatient setting of a memory clinic. Frequency and risk factors of post-lumbar puncture headache].

Lumbar puncture (LP) is growing in relevance for the diagnosis of cognitive impairment in the elderly. Due to the expected risk of post-lumbar puncture syndrome or other complications LPs have rarely been performed in the outpatient setting. Using a questionnaire, the post-lumbar puncture symptoms of 100 patients (54-84 years old; mean: 68.87 years; SD: 7.9) have been prospectively gathered after consecutively performed LPs in the Memory Clinic of the Department of Psychiatry, University of Bonn. Some of these patients were included in the early diagnosis program of the German Dementia Competence Network. Of the patients 9% developed a post-lumbar puncture syndrome of mild or middle intensity. The influence of gender, age, cognitive status, as well as a supplementary diagnosis of depression and needle size (G20 or G22 atraumatic Sprotte needle) on the incidence of the post-LP syndrome was evaluated by means of logistic regression. Only the patients' age was identified as a significant risk factor as with increasing age a diminishing risk of developing a post-lumbar puncture syndrome was found (OR=0.83; CI=0.71-0.97 per year). None of the other factors evaluated proved to be of significant influence. The post-LP symptoms did not necessitate supplementary consultations in any of the cases.