Reversible encephalopathy possibly associated with bismuth subgallate ingestion

Area of Science:

• Neurology
• Toxicology
• Gastroenterology

Background:

• Abdominoperineal resection for colon carcinoma is a major surgical procedure.
• Patients may receive various medications, including oral bismuth subgallate, for post-operative management.
• Neurological complications following such treatments require thorough investigation.

Purpose of the Study:

• To investigate a peculiar neurological syndrome observed in patients after colon surgery.
• To determine the potential link between oral bismuth subgallate and the observed neurological symptoms.
• To characterize the clinical presentation and potential underlying mechanisms of this syndrome.

Main Methods:

• Case study of four patients presenting with a specific neurological syndrome.
• Clinical assessment including neurological examination and patient history.
• Extensive laboratory investigations, including amino-acid chromatography of urine.
• Postmortem examination of one patient.

Main Results:

• Four patients developed a recurrent, reversible neurological syndrome characterized by confusion, tremulousness, ataxia, myoclonus, and gait disturbance.
• Symptoms significantly improved upon discontinuation of oral bismuth subgallate.
• Cerebellar Purkinje cell loss was noted in one postmortem case.
• An unidentified urinary constituent was detected in three patients via amino-acid chromatography.

Conclusions:

• Oral bismuth subgallate ingestion is strongly suspected as the cause of the observed encephalopathy.
• The syndrome appears to be dose-dependent and reversible upon cessation of bismuth intake.
• Further research is warranted to elucidate the exact mechanism of bismuth neurotoxicity.