The cerebrospinal fluid production rate is reduced in dementia of the Alzheimer's type

Objective: To evaluate the production rate of CSF in patients with differin g disease states. Methods: The authors measured the production rate of CSF in three groups of patients: five patients with PD below age 60 (aged 51 +/ - 4 years, mean +/- SD), nine with PD over age 60 (aged 69 +/- 6 years, mea n +/- SD), and seven with dementia of the Alzheimer's type (AD) (aged 72 +/ - 9 years, mean +/- SD). This method, based on the Masserman technique, emp loys ventricular rather than a lumbar access to the CSF space. Furthermore, the volume of CSF removed during the procedure is only 3 mL rather than 10 mL. Results: These measurements indicate that the mean rate of CSF product ion in patients with PD under age 60 was 0.47 +/- 0.13 mL/minute, in patien ts with PD aged 60 or older the mean rate was 0.40 +/- 0.12 mL/minute, and in patients with AD the mean rate was 0.20 +/- 0.06 mL/minute. Conclusion: These results indicate that the rate of CSF production in patients with PD is normal, and that the rate of CSF production in patients with AD is marke dly reduced.