To the Editor: Lumbar puncture is a common and normally safe diagnostic procedure. When used for emergency diagnostic reasons, anticoagulation with low-dose aspirin is not considered a contraindication. In elective lumbar puncture, for example for diagnosing dementia, clinical recommendation regarding discontinuation of aspirin becomes more difficult. Hemorrhagic complications are a rare but serious side effect of lumbar puncture. Complications include epidural, subdural, and subarachnoid hemorrhage. Therefore, one may recommend that aspirin should be discontinued for several days before elective lumbar puncture. Alternatively, there is an increased risk of cardiovascular and cerebrovascular incidents if low-dose aspirin is discontinued for diagnostic interventions.1 This is particularly important in the clinical diagnosis of dementia, because many patients with cognitive deficits who undergo lumbar puncture for early diagnosis of Alzheimer's disease may suffer from vascular dementia and should therefore be treated with aspirin continuously.2 To our knowledge, no reliable data are available assessing the risk of hemorrhage of lumbar puncture in patients treated with low-dose aspirin. One study found a significantly higher incidence of hemorrhage, but patients were anticoagulated after, not before, traumatic lumbar puncture.3 Another study investigated the risk of spinal hematoma associated with spinal or epidural anesthesia, concerning perioperative use of antiplatelet substances, mainly aspirin. They found no correlation between anticoagulation and bloody needle or catheter placement, providing strong evidence that perioperative antiplatelet therapy is not a significant risk factor for the development of spinal hematoma.4 This coincides with the recommendations of the American Society of Regional Anesthesia.5 Furthermore, no controlled studies exist assessing the increased risk of cardiovascular and cerebrovascular incidents during discontinuation of prophylactic aspirin treatment for lumbar puncture. A recent meta-analysis of discontinuation of aspirin for diagnostic or therapeutic interventions recommends that aspirin should only be discontinued if its continuation would be associated with a higher mortality than the greater risk of vascular incidence due to discontinuation.1 The authors found that, in retrospective studies, aspirin withdrawal precedes up to 10.2% of acute cardiovascular syndromes. To our knowledge, there is no evidence for higher mortality from hemorrhage in lumbar puncture under low-dose aspirin treatment than from the increased risk of cardiovascular or cerebrovascular incidence due to discontinuation. The clinical decision about whether to discontinue aspirin for elective lumbar puncture is of high clinical importance because of the high number of patients treated with low-dose aspirin who undergo elective lumbar puncture for early dementia diagnosis. A discontinuation of aspirin for dementia diagnostics should be regarded skeptically especially in patients showing signs of vascular lesions on brain imaging. Controlled prospective studies are necessary to answer this important clinical question. Financial Disclosure: This manuscript was supported by the Kompetenznetz Demenzen, a German nonprofit network of universities investigating dementia that is supported by the Ministry of Health (01 GI 0420). None of the authors has a financial or personal conflict of interest. Author Contributions: All authors were involved substantially in the idea and the writing of this manuscript. Sponsor's Role: The sponsor had no role in writing or preparing this manuscript and has not been involved in any other form.