Whyte J, Vaccaro M, Grieb-Neff P, Hart T, Polansky M, Coslett HB: The effects of bromocriptine on attention deficits after traumatic brain injury: a placebo-controlled pilot study. Am J Phys Med Rehabil 2008;87:85–99.
Objective: To evaluate the effects of bromocriptine on a variety of aspects of attention, ranging from laboratory-based impairment measures to caregiver ratings and work productivity, in individuals after traumatic brain injury.
Design: Twelve adults with moderate to severe traumatic brain injury and attention complaints in the postacute phase of recovery were enrolled in a 6-wk double-blind, placebo-controlled, crossover study of bromocriptine, titrated to a dose of 5 mg twice a day. A wide range of attentional measures was administered weekly, including computerized and paper-and-pencil tests of attention, videotaped records of individual work in a distracting environment, real-time observational scoring of attentiveness in a classroom environment, and caregiver and clinician ratings of attentiveness. Data from these 12 participants were used to identify attentional dimensions suggestive of a treatment effect for independent replication.
Results: The effects of bromocriptine on 13 previously identified attentional factors and 13 individual performance scores were assessed via the Wilcoxon signed ranks test, using a relaxed probability cutoff of 0.20 to select those to be studied in a larger replication sample. Only two factor scores and one individual score met the cutoff, and all of these showed trends toward worse performance on bromocriptine than on placebo. A more detailed investigation of bromocriptine's effect on divided attention was also conducted, but the previously reported finding of a beneficial effect on this domain was not replicated. Blood pressure was marginally lower on bromocriptine than on placebo. In view of the lack of cognitive benefit and the fact that several participants experienced possible or probable drug side effects, we did not pursue a larger replication at this drug dose.
Conclusions: Bromocriptine in a dose of 5 mg, given twice a day to individuals with attentional complaints after TBI, does not seem to enhance attentional skills, and it may be associated with an excess of adverse events. It is not clear whether intermittent dosing or lower doses might confer benefit.
From Moss Rehabilitation Research Institute, Albert Einstein Healthcare Network, Philadelphia, Pennsylvania (JW, MV, PG-N, TH, HBC); Thomas Jefferson University, Philadelphia, Pennsylvania (JW, TH); Drexel University, Philadelphia, Pennsylvania (MP); and University of Pennsylvania, Philadelphia, Pennsylvania (HBC).
All correspondence and requests for reprints should be addressed to John Whyte, MD, PhD, Moss Rehabilitation Research Institute, 1200 W. Tabor Rd., Philadelphia PA 19141.
This research was supported, in part, by grant #R01NS39163 from the National Institute on Neurological Diseases and Stroke, and grant # R24HD39621 from the National Center for Medical Rehabilitation Research, at the National Institute on Child Health and Human Development, both at the National Institutes of Health.