Faculty Bibliography

The management of craniopharyngioma involves balancing adequate reduction in tumor volume and prevention of recurrence while minimizing damage to delicate surrounding structures. Because of the lesion's proximity to the optic chiasm and its relationship to the hypothalamic-pituitary axis, morbidity rates following treatment can be high. Gamma Knife surgery (GKS) is now being considered as a viable method of providing tumor control while ensuring minimal side effects. The authors conducted a literature review of 10 studies in which GKS was used to treat craniopharyngioma; some lesions had been previously treated and some had not. The mean marginal dose ranged from 5 to 16.4 Gy (mean 12.3 Gy). Tumor control was achieved in 75% of cases overall and varied with tumor subtype (cystic, solid, mixed). Control was seen in 90% of solid, 80% of cystic, and 59% of mixed tumors. The overall morbidity rate resulting from radiosurgery was 4% and the overall mortality rate was 0.5%. These results suggest that GKS may provide a favorable benefit-to-risk profile for many patients with craniopharyngiomas.

We have previously found the 5-HT3 receptor antagonist ondansetron to be useful in reducing cocaine self-administration and cocaine induced sensitization in rats when given during cocaine withdrawal. More recently we have found the combination of the dopamine agonist pergolide plus ondansetron, 3.5 h later, to reverse cocaine sensitization and associated changes in NMDA and AMPA receptors. Here we tested this drug combination in 1) a methamphetamine sensitization model and 2) a reinstatement model after intravenous methamphetamine self-administration using a nose-poke task. We found pergolide plus ondansetron given from days 3-7 of methamphetamine withdrawal to reverse methamphetamine induced sensitization and attenuate reinstatement. We hypothesize that pergolide may evoke a methamphetamine associated memory and that ondansetron can disrupt its reconsolidation. These data suggest that pergolide plus ondansetron treatment may be useful as a therapy to reduce relapse in methamphetamine abusers.