Anti-Malaria Drug Mefloquine Induces Motor Learning Deficits in Humans

Mefloquine (a marketed anti-malaria drug) prophylaxis has a high risk of causing adverse events. Interestingly, animal studies have shown that mefloquine imposes a major deficit in motor learning skills by affecting the connexin 36 gap junctions of the inferior olive. We were therefore interested in assessing whether mefloquine might induce similar effects in humans. The main aim of this study was to investigate the effect of mefloquine on olivary-related motor performance and motor learning tasks in humans. We subjected nine participants to voluntary motor timing (dart throwing task), perceptual timing (rhythm perceptual task) and reflex timing tasks (eye-blink task) before and 24 h after the intake of mefloquine. The influence of mefloquine on motor learning was assessed by subjecting participants with and without mefloquine intake (controls: n = 11 vs mefloquine: n = 8) to an eye-blink conditioning task. Voluntary motor performance, perceptual timing, and reflex blinking were not affected by mefloquine use. However, the influence of mefloquine on motor learning was substantial; both learning speed as well as learning capacity was impaired by mefloquine use. Our data suggest that mefloquine disturbs motor learning skills. This adverse effect can have clinical as well as social clinical implications for mefloquine users. Therefore, this side-effect of mefloquine should be further investigated and recognized by clinicians

Long-Term Effect of Prednisolone on Functional Blink Recovery after Transient Peripheral Facial Motor Paralysis

Objective. To determine the functional recovery in patients with severe transient peripheral facial motor paralysis (Bell palsy). Study Design. Prospective controlled trial. Setting. Academic medical center. Subjects and Methods. Blink recovery was studied in 2 groups of severely affected Bell palsy patients during a follow-up period of 84 weeks. The patients in one group received prednisolone within the first week after the onset of symptoms. No medication was given to the other group. A control group of healthy subjects was also included. Simultaneous orbicularis oculi muscle activity and eyelid kinematics were recorded by surface electromyographic (EMG) recording and eyelid search coils, respecti Results. At the beginning of the paralysis, very little integrated orbicularis oculi muscle activity and eyelid movement was measured at the palsied side of the face. Thirteen weeks later, the integrated orbicularis oculi EMG and functional blink recovery gradually improved until 39 weeks. Beyond, only the integrated orbicularis oculi EMG slightly increased. At 84 weeks, the integrated orbicularis oculi EMG was significantly larger in the prednisolone group compared with the control group. The i Conclusion. The authors demonstrate that prednisolone significantly increased the orbicularis oculi muscle activity and significantly improved functional blink recovery in severely affected Bell palsy patients. However, the increase of muscle activity was insufficient to restore functional blinking to normal values