Treatment of Pendular Nystagmus With Gabapentin and Memantine in Patients With Oculopalatal Tremor: a Controled Open-label Study
Pendular nystagmus corresponds to an enduring to and fro eye oscillation without resetting quick phases. The most common causes of acquired pendular nystagmus (APN) are multiple sclerosis (MS) and focal brainstem lesions (oculopalatal tremor, OPT). Based on pathophysiological hypothesis, pharmacological treatments of acquired nystagmus have been thoroughly proposed over different publications of cases, series, reviews or expert opinions. Acquired pendular nystagmus underwent the most rigorous treatment trials, leading to the proposal of gabapentin or memantine as valuable drugs. Whether gabapentin and memantine are effective in APN associated with OPT remains unclear, since none of the previous studies has evaluated the effect of these medications in a group of OPT patients. However, this is an important issue in prospect to a clinical use of these medications. In the current study, the investigators aim is to evaluate the effect of gabapentin and memantine on the mean velocity, amplitude and frequency of pendular nystagmus, as well as on visual acuity and vision-specific health-related quality of life score, in a group of OPT patients
• Patients with a diagnosis of oculopalatal tremor (OPT), following a focal brainstem lesion.
• All patients may present a chronic acquired pendular nystagmus due to OPT, observed over a period of 6 months.
• All patients will be informed about the design and purpose of the study, and all will give their informed, written consent to the protocol, which may have been approved by the local ethics committee.
• Age: above 18
• Able to understand the instructions
• Having a health coverage
• Able to sit down for 1 hour
• Stable dosage of previous medications (beginning 3 weeks previously and terminating at the end of the trial duration), except gabapentin or memantine.
• For women: efficient contraception during the experimental time and in the two month following treatment withdrawal.