An Uncommon Clinical Sign in a Common Neurological Disorder: A Case of Isolated Truncal Ataxia

Neurological diseases often present with varied clinical manifestations, and subtle clinical signs may provide important diagnostic clues. Cerebellar disorders commonly manifest with gait disturbances, limb incoordination, and nystagmus. However, isolated truncal ataxia as a predominant clinical sign is uncommon and may indicate involvement of the cerebellar vermis. Recognition of such atypical presentations is crucial for early diagnosis and appropriate management. We report a case of a 62-year-old male construction worker who presented with sudden onset loss of consciousness for four hours. The patient regained consciousness after initial emergency management but complained of slurring of speech and inability to sit without support. There was no history of seizures, trauma, headache, chest pain, dyspnea, or focal limb weakness. His past medical history was significant for systemic hypertension for three years and a previous ischemic cerebrovascular accident with right hemiparesis three years prior, for which he was not on regular treatment. On examination, the patient was drowsy but oriented to time, place, and person. Vital parameters were stable. Neurological examination revealed horizontal nystagmus and marked truncal ataxia, while limb coordination and gait were relatively preserved. There were no signs of meningeal irritation or autonomic dysfunction. Routine laboratory investigations, viral markers, cerebrospinal fluid analysis, ECG, and chest radiography were within normal limits. Fundus examination was normal. MRI brain was performed to further evaluate the underlying neurological pathology. The patient was managed with supportive care and close neurological monitoring, and further management was guided by neuroimaging findings. This case highlights the clinical importance of recognizing truncal ataxia as a rare but significant neurological sign, which may serve as an early indicator of cerebellar involvement. Careful neurological examination combined with appropriate neuroimaging plays a vital role in identifying the underlying etiology and guiding timely management.