Dalfampridine in Parkinson's disease related gait dysfunction: A randomized double blind trial.

BACKGROUND: Disease-related gait dysfunction causes extensive disability for persons with Parkinson's disease (PD), with no effective therapies currently available. The potassium channel blocker dalfampridine has been used in multiple neurological conditions and improves walking in persons with multiple sclerosis. OBJECTIVES: We aimed to evaluate the effect of dalfampridine extended release (D-ER) 10mg tablets twice daily on different domains of walking in participants with PD. METHODS: Twenty-two participants with PD and gait dysfunction were randomized to receive D-ER 10mg twice daily or placebo for 4weeks in a crossover design with a 2-week washout period. The primary outcomes were change in the gait velocity and stride length. RESULTS: At 4weeks, gait velocity was not significantly different between D-ER (0.89m/s±0.33) and placebo (0.93m/s±0.27) conditions. The stride length was also similar between conditions: 0.96m±0.38 for D-ER versus 1.06m±0.33 for placebo. D-ER was generally well tolerated with the most frequent side effects being dizziness, nausea and balance problems. CONCLUSIONS: D-ER is well tolerated in PD patients, however it did not show significant benefit for gait impairment.

Macular Retinal Sublayer Thicknesses in G11778A Leber Hereditary Optic Neuropathy.

BACKGROUND AND OBJECTIVE: To determine macular retinal sublayer thickness changes in G11778A Leber hereditary optic neuropathy (LHON). PATIENTS AND METHODS: The authors performed a cross-sectional study by segmenting spectral-domain Cirrus OCT (Carl Zeiss Meditec, Dublin, CA) 512 × 128 macular cube scans from a prospective, observational study of G11778A LHON. The thickness of the retinal sublayers of LHON affected subjects and asymptomatic carriers were compared to those of a normal group. RESULTS: The study included 20 LHON-affected subjects (13 males; age: 31 years ± 14 years, range: 10 years to 61 years; time since onset of visual loss: 5.9 years ± 8.7 years; 0.4-29.8), 31 asymptomatic LHON carriers (five males; age: 38 years ± 18 years, range: 9 years to 65 years), and 14 normal subjects (five males; age: 39 years ± 13 years, range: 23 years to 61 years). The retinal sublayer thickness parameters were not significantly correlated with age in any of the groups. There were no differences between carriers and normal subjects for thickness of total retina or any sublayer. Affected LHON retinal nerve fiber layer (RNFL) and ganglion cell layer plus inner plexiform layer (GCL+IPL) were thinner, whereas the photoreceptor outer segment (OS) layer was thicker than carriers and normal subjects (P values ranged from .042 to < .001), except for the OS layer in the inferior inner ring and temporal outer ring. Differences between groups were not significant in the inner nuclear layer plus outer plexiform layer (INL+OPL). The affected LHON outer nuclear layer plus inner segment layer was thicker in some quadrants, and the affected LHON choroid layer was generally thinner than carriers and normal subjects; however, these differences were not significant after accounting for age. CONCLUSION: LHON-affected patients have thickened photoreceptor OS layers in spite of having thinner RNFL and GCL+IPL layers. The findings indicate LHON also has an effect on the morphology of the photoreceptors. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:802-810.].