Spinal and bulbar muscular atrophy in a patient with Parkinson's disease - Case report.

Spinal and bulbar muscular atrophy and Parkinson's disease rarely coexist. We describe a male patient presenting with parkinsonism, hyposmia, with DAT-SPECT deficits, responsive to dopaminergic therapy, preceding recognition of SBMA confirmed genetically. Dopamine agonist-associated dropped head syndrome unmasked underlying lower motor neuronopathy, highlighting diagnostic pitfalls and overlap between synucleinopathy and polyglutamine disease.