Friedreich's ataxia
Optic neuropathy is a near-ubiquitous feature of Friedreich's ataxia (FRDA).
Friedreich's ataxia (FA) is the most frequent hereditary ataxia syndrome, while painful muscle spasms and spasticity have been reported in 11-15% of FA patients.
Intrathecal baclofen for Friedreich's ataxia
Case series
Thomas-Black et al. investigated 62 genetically confirmed FRDA patients using an integrated approach as part of an observational cohort study. They included measurement of frataxin protein levels, clinical evaluation of visual and neurological function, optical coherence tomography to determine retinal nerve fiber layer thickness and macular layer volume, and volumetric brain MRI.
They demonstrated that frataxin level correlates with peripapillary retinal nerve fiber layer thickness and that retinal sectors differ in their degree of degeneration. They also showed that the retinal nerve fiber layer is thinner in FRDA patients than in controls and that this thinning is influenced by the AAO and GAA1. Furthermore, they show that the ganglion cell and inner plexiform layers are affected by FRDA. The MRI data indicate that there are borderline correlations between retinal layers and areas of the cortex involved in visual processing.
The study demonstrates the uneven distribution of axonopathy in the retinal nerve fiber layer and highlights the relative sparing of the papillomacular bundle and temporal sectors. They show that thinning of the retinal nerve fiber layer is associated with frataxin levels, supporting the use of the two biomarkers in future clinical trials design 1)