Report a case of endogenous alcohol fermentation as cause of altered level of consciousness.

Gut fermentation syndrome can trigger symptoms of alcohol intoxication resulting in syncope, ataxia, confusion and vertigo. This can be triggered by or preceded by antibiotic use altering the gut flora. It can be managed with a low-carbohydrate diet. Diabetes, obesity-related liver disease, Crohn’s disease, massive small bowel dilation, short bowel syndrome, gastrectomy, antibiotic therapy, immunosuppression or autoimmune conditions, periodontal bacteria, and a high-carbohydrate diet are considered predisposing factors.

Case report and Literature review.

A 58-year-old man with a 5-year history of recurrent episodes of syncope, falls, gait difficulties, altered level of consciousness and confusion was seen in the neurology outpatient clinic. The episodes were described as lasting about 30 minutes often resolving with rest. Collateral history reveals that he seemed “off” for a brief period around this event, sometimes tripping or experiencing wordfinding difficulties during the events, but no clonic to tonic movements had been observed. His past medical history was remarkable for diarrhea since the age of 40 years, and this had been preceded by several antibiotic treatments for viral illnesses in his thirties.

He had presented several times to the local emergency room with elevated serum alcohol levels. Despite denying alcohol intake, his presentation was presumed to be secondary to alcohol consumption.

His neurological examination was non-focal. Routine EEG and MRI of the cervical spine were normal and MRI brain showed non-specific periventricular and subcortical white matter changes. Laboratory investigations were negative.

Gastroenterology consultation confirmed diagnosis of auto-brewery syndrome triggered by prior antibiotic use. He was started on a low carbohydrate diet and serum alcohol blood levels normalized and his symptoms remitted.

Auto-brewery syndrome is a rare cause of recurrent episodes of altered level of consciousness and is treatable.