CHIASMAL HERNIATION AS A COMPLICATION OF BROMOCRIPTINE THERAPY

Citation
P. Taxel et al., CHIASMAL HERNIATION AS A COMPLICATION OF BROMOCRIPTINE THERAPY, Journal of neuro-ophthalmology, 16(4), 1996, pp. 252-257
Citations number
15
Categorie Soggetti
Clinical Neurology",Ophthalmology
ISSN journal
10708022
Volume
16
Issue
4
Year of publication
1996
Pages
252 - 257
Database
ISI
SICI code
1070-8022(1996)16:4<252:CHAACO>2.0.ZU;2-A
Abstract
Introduction: Medical treatment of macroprolactinomas with dopamine ag onists decreases tumor mass and improves visual defects. We report an unusual complication of a macroprolactinoma responding to bromocriptin e: a visual field defect caused by downward herniation of the optic ch iasm. Materials and Methods: A 64-year-old woman was found to have a 4 .5 cm macroprolactinoma with superior displacement of the optic chiasm , bitemporal hemianopia, and serum prolactin concentration (P) of 17,0 60 mu g/L. Bromocriptine was initiated at 2.5 mg/day and increased to 7.5 mg/day over 2 months. Results: After 2 months, visual fields impro ved significantly and tumor height decreased to 3 cm with resolution o f the optic chiasm displacement. P decreased to 1,180 mu g/L. After 5 months of therapy, visual fields were normal, and P was 8 mu g/L. Afte r 8 months of therapy, new bilateral visual defects were observed. Mag netic resonance imaging (MRI) revealed further decrease of the tumor h eight to 1.5 cm, and inferior and leftward traction of the optic chias m as the probable mechanism for the new visual field deficit. P was <1 mu g/L. Bromocriptine was decreased to 5 mg/day to allow reduced trac tion on the optic chiasm and its blood supply. Over the next 4 months, visual field abnormalities resolved. Conclusions: We report the devel opment of a visual field abnormally that is explained by chiasmal hern iation caused by a shrinking macroprolactinoma. This complication reso lved with a decrease in the bromocriptine dose. We suggest that patien ts undergoing bromocriptine therapy for macroprolactinomas be followed for this potential complication.