Millard-Gubler Syndrome Associated with Cerebellar Ataxia in a Patient with Isolated Paramedian Pontine Infarction − A Rarely Observed Combination with a Benign Prognosis: A Case Report

Isolated pontine infarction accounts for 7% of all ischemic strokes. Millard-Gubler syndrome is a clinical syndrome which occurs following lesions involving the ventral portion of the caudal pons, resulting in classic clinical features such as ipsilateral abducens and facial nerve palsy and contralateral hemiparesis. We report the case of a 55-year-old male patient having presented to the Yehuleshet Specialty Clinic 6 years back with sudden-onset dysarthria and appendicular ataxia of 10 days duration. He reported having right hemibody weakness and blurred vision, which have significantly improved since then. He had a history of smoking of 30 pack-years. However, he quit smoking 8 years ago. There was no history of prior stroke, transient ischemic attack, diabetes, hypertension, head trauma, or dyslipidemia. On examination, he had horizontal left gaze palsy with horizontal nystagmus suggesting left-sided 6th cranial nerve palsy. He had mild left-sided facial palsy causing dysarthric speech. Right upper limb dysmetria was observed during examination; otherwise, motor, sensory, fundus, and gait examination results were normal. He had low serum vitamin D. Brain magnetic resonance imaging examination showed a 25 × 10 mm segmental lesion in the left median pons involving the basis pontis and tegmentum section. The lesion had T2 and T1 abnormal prolongation with no diffusion restriction, suggesting a subacute pontine infarct. The patient was managed with aspirin 325 mg, atorvastatin 80 mg, physical therapy, and vitamin D supplementation, and advised on behavioral risk factors. Six years after his isolated pontine infarction, the patient is fully recovered from dysarthria, facial palsy, hemiparesis, right-sided appendicular ataxia, and horizontal nystagmus, and the follow-up brain MRI showed radiological evidence of chronic paramedian pontine perforator infarction. Millard-Gubler syndrome may present with cerebellar ataxia if the paramedian pontine infarction area slightly extends laterally, affecting the middle cerebellar peduncles. Isolated pontine infarction may have a good prognosis if diagnosed and managed early.