From incidental cerebellar atrophy to progressive motor syndrome: a case within the spectrum of ATXN2-associated neurodegeneration

BACKGROUND: Increasing evidence suggests that ATXN2-related disorders represent a clinical spectrum with variable presentations. CASE PRESENTATION: We report a 70-year-old Chinese man carrying an ATXN2 allele with 34 CAG repeats (20/34 repeats). Cerebellar atrophy was incidentally noted on magnetic resonance imaging (MRI) more than ten years before symptom onset. He later developed bradykinesia and rigidity. After rapid weight loss, he developed a rapidly progressive motor syndrome with clinical upper and lower motor neuron features, followed by type II respiratory failure requiring noninvasive ventilation. CONCLUSIONS: These findings support the notion that ATXN2-associated neurodegeneration may represent a clinical continuum.