Guillain-Barré syndrome (GBS) is associated with dysautonomia due to demyelination of nerves in the autonomic system. We present a case of ataxic GBS, a rare variant often including bladder dysfunction and hemodynamic lability, whose illness was complicated by intracerebral hemorrhage (ICH).  ICH is a rare complication of GBS that has only been reported in the literature a handful of times. It has been hypothesized that autonomic dysregulation, particularly in patients with underlying vascular risk factors or vasculopathy secondary to treatment with intravenous immunoglobulin (IVIG), could play a role in blood vessel wall integrity. 

Case Presentation: A 63-year-old man with no significant medical history presented with weakness and urinary retention after a gastrointestinal illness. Examination revealed absent deep tendon reflexes, reduced vibratory sensation, and sensory ataxia, with blood pressure fluctuating from 90/70 to 150/70. Cerebrospinal fluid showed cytoalbuminologic dissociation. Brain and spine MRI showed no nerve root enhancement or microhemorrhages suggestive of cerebral amyloid angiopathy. He received IVIG and was discharged to rehabilitation. Four days later, he returned with altered mental status and right-sided weakness; CT revealed a large left frontal ICH, leading to craniotomy and hematoma evacuation. Blood pressure continued to fluctuate between 80/60 and 170/80, and he re-bled five days later, requiring a second decompression. Clot pathology ruled out vascular malformation, inflammation, or amyloid. He has since shown partial motor and cognitive improvement.