SPECT monitoring of improved cerebral blood flow during long-term treatment of elderly patients with nootropic drugs

Purpose: In normal aging persons, oxygen and glucose consumption progressiv ely decreases with reduced cerebral blood flow (CBF), which could be respon sible for age-related changes in cognitive functions. A data processing mod el with the use of Tc-99m SPECT of the human brain has been developed and f ound to be sensitive for monitoring the effects of drugs that increase CBF. In this study, the effect of two vasodilator drugs (the combination of pen tifylline and nicotinic acid versus piracetam) was compared with the effect of placebo on CBF. Materials and Methods: Thirty elderly volunteers had three different proced ures using the Peelproc method to spatially standardize and compare CBF pat terns by SPECT before and after drug intervention. The 30 patients were div ided into five groups of six persons each who were randomly assigned in a 1 :1 ratio to the treatment sequences consisting of three phases: the combina tion of pentifylline and nicotinic acid (C), piracetam (N), and placebo (P) , or C-N-P; P-N-C; P-C-N; N-C-P; C-P-N; or N-P-C. Phases 1 to 3 each consis ted of a baseline recording of parameters (day 0), treatment for 60 days (d ays 1 to 60), and recording of parameters after treatment (day 61). Results: In elderly human volunteers (ages, 52 to 70 years), after 2 months of oral treatment with a combination of pentifylline and nicotinic acid (8 00 mg pentifylline, 200 mg nicotinic acid daily), SPECT results for the Pee lproc program indicated a statistically significant improvement in CBF of t he total brain, with a more pronounced improvement in the cerebellum and fr ontal regions, where a definite shift from abnormal to normal blood flow wa s detected. Spontaneous communication from most of the volunteers suggested that they experienced an improvement in memory and general wellbeing from the combination treatment. After 2 months of oral treatment with piracetam (2.4 g daily) in elderly human volunteers, SPECT results indicated a region al improvement in CBF, particularly in the cerebellum. However, no benefici al effects with this drug were spontaneously reported. Conclusion: The in vivo method to quantitatively monitor the progress of lo ng-term drug therapy on CBF described here could be useful to assess and ev en direct changes in therapy.