Benefits of pre-labyrinthectomy intratympanic gentamicin: contralateral vestibular responses.

OBJECTIVE: To determine the impact of pre-operative intratympanic gentamicin injection on the recovery of patients undergoing translabyrinthine resection of vestibular schwannomas. METHODS: This prospective, case-control pilot study included eight patients undergoing surgical labyrinthectomy, divided into two groups: four patients who received pre-operative intratympanic gentamicin and four patients who did not. The post-operative six-canal video head impulse test responses and length of in-patient stay were assessed. RESULTS: The average length of stay was shorter for patients who received intratympanic gentamicin (6.75 days; range, 6-7 days) than for those who did not (9.5 days; range, 8-11 days) (p = 0.0073). Additionally, the gentamicin group had normal post-operative video head impulse test responses in the contralateral ear, while the non-gentamicin group did not. CONCLUSION: Pre-operative intratympanic gentamicin improves the recovery following vestibular schwannoma resection, eliminating, as per the video head impulse test, the impact of labyrinthectomy on the contralateral labyrinth.

Hypothalamic-pituitary-testicular function in men with PRL-secreting tumors.

We studied the hypothalamic-pituitary-gonadal system in 33 men with PRL-secreting tumors to determine at which level(s) high PRL levels interfere with testicular function. In basal conditions serum PRL levels ranged between 24-4500 ng/ml, serum LH and FSH concentrations were lower than normal in 61% and 39% of patients; low testosterone (T) levels and sexual impotence appeared more common (85% and 88%) than that we expected on the basis of gonadotropin deficiency. Mean T increase after hCG in 14 patients with prolactinomas was significantly less than in normals (3.3 +/- 0.7) ng/Ml vs 7.3 +/- 0.5 ng/ml; p less than 0.025); a significantly higher T response to hCG was obtained in 5 cases retested after PRL levels had been reduced by therapy. GnRH test induced a normal LH rise in 45% of patients, Mean serum LH increase after clomiphene administration did not differ from that in normals, though 4 out of 10 patients showed an impared response. Metoclopramide injection did not cause a rise of LH in 11 patients so tested. These data, while not excluding a central influence of PRL on LHRH, suggest that in men the antigonadotropic effects of PRL are mainly exerted at the gonadal levels.

Effects of serotonin antagonists in sexually impotent men.

Thirty-one men affected with sexual impotence were studied. Since sexual function in the male seems to be controlled by both dopaminergic stimulatory and serotoninergic inhibitory mechanisms, the patients were treated with serotonin antagonists. In basal conditions mean serum LH, FSH, PRL and testosterone did not significantly differ from those found in normal subjects; no significant variations, except for PRL reduction, were observed after treatment. Both methysergide, in association with bromocriptine or mesterolone, and metergoline, either alone or in association with mesterolone, were ineffective in significantly improving sexual activity.