# Prolonged Impaired Consciousness and Periodic Sharp Wave Complexes on Electroencephalogram in an Elderly Female With Severe Lithium Intoxication

## TL;DR

An elderly woman with severe lithium poisoning showed prolonged coma and unusual brain wave patterns, emphasizing the need for early detection and careful care.

## Contribution

This case highlights delayed clinical recovery and EEG findings in severe lithium intoxication despite normalized lab values.

## Key findings

- The patient remained in deep coma for nearly two weeks after lithium levels normalized.
- EEG showed periodic sharp wave complexes during the hospital stay.
- Supportive care was necessary for recovery despite normalizing lithium concentrations.

## Abstract

Lithium is commonly used in bipolar disorder but carries a high risk of neurotoxicity. We present a 79-year-old female on lithium for several years who was admitted with fever and altered consciousness that was initially complicated by a urinary tract infection. Based on persistent symptoms and medical history, the patient was found to have a serum lithium level of 3.96 mEq/L (therapeutic range: 0.60-1.20 mEq/L). Despite urgent hemodialysis, her deep coma persisted for nearly two weeks after serum lithium concentration normalized. During the admission course, an electroencephalogram (EEG) revealed periodic sharp wave complexes. This case highlights the importance of maintaining a high index of suspicion for lithium toxicity in bipolar patients with altered mental status and the necessity of supportive care as clinical recovery may be delayed despite normalization of laboratory values.