We report a genetically confirmed case of adult-onset Alexander disease (AOAD) presenting with progressive dysarthria and palatal tremor. Brain magnetic resonance imaging revealed medullary atrophy and olivary hyperintensities. A pathogenic variant of the glial fibrillary acidic protein gene (p.R416W) was identified. The palatal tremor indicated involvement of the Guillain-Mollaret triangle. This case underscores the diagnostic value of bulbar signs and neuroimaging in AOAD and highlights the importance of integrating clinical, radiological, and genetic findings for early definitive diagnosis.