To highlight a rare case of very-late-onset Friedreich ataxia (VLOFA) presenting as late-life progressive ataxia.
Friedreich ataxia (FA) is the most common hereditary ataxia, caused by pathological expansion of GAA trinucleotide repeats in FXN gene located on chromosome 9. While it typically manifests in the first or second decade of life, very late-onset Friedreich ataxia—defined as onset after 40 years of age—is rarely reported and often misdiagnosed.
A 57-year-old male with no significant past medical history presented with 5-year history of progressive gait imbalance and difficulty with coordination. Family history included a possible muscular disease in his father during his 70s.
On examination, patient had diffuse muscular atrophy. Neurological evaluation revealed dysarthria, saccadic eye movements, dysmetria on finger-to-nose and heel-to-shin tests, as well as dysdiadochokinesia. There was evidence of diffuse hyperreflexia, along with positive Hoffmann and Romberg signs. Decreased vibratory sensation was observed in lower extremities, and his gait was wide-based with inability to tandem walk. Brain MRI revealed mild pontocerebellar atrophy, and cervical spine MRI was unremarkable. Comprehensive workup for rheumatological conditions, nutritional deficiencies, and paraneoplastic syndromes was unremarkable. Further evaluation with an ataxia panel identified a pathogenic FXN gene variant (1199 and 133 GAA repeats), confirming Friedreich's ataxia. Cardiac evaluation, including EKG and echocardiogram, was normal. Patient was started on Omaveloxolone, with marked symptom improvement.
This case underscores the unusual presentation of VLOFA, diagnosed in patient well beyond the typical age of onset. Unlike the classic presentation, which usually presents with areflexia, dysarthria, sensory neuropathy, amyotrophy, cardiac involvement and scoliosis, this patient displayed atypical symptoms such as spasticity, brisk reflexes, and dysarthria, with no evidence of cardiac complications. These atypical presentations can often lead to delayed or missed diagnoses. Recognizing VLOFA despite atypical features is crucial, especially with new therapies like omaveloxolone that can significantly improve symptoms.