We report a case of a 63-year-old lady with bipolar
affective disorder on
lithium who was brought to our emergency center in a
comatose state. Neurologically, the patient was
comatose and had generalized
hypotonia and
hyporeflexia.
Lithium toxicity was considered. Laboratory examinations revealed
leukocytosis, normal
blood sugar, blood level of
lithium was 4.7 mEq/L and she had renal dysfunction. Cerebrospinal fluid examination and cranial computerized tomography were unremarkable. Blood
lithium level was 4.7 mEq/L.
Hemodialysis was initiated. However, in spite of dialysis and decreasing
lithium levels, the patient remained unconscious. A possibility of nonconvulsive
status epilepticus was considered; hence, EEG was advised. The EEG demonstrated bihemispheric slowing (4- to 5-Hz theta range) with bilateral periodic triphasic waves of 1- to 2-Hz frequency, similar to the EEG changes seen in
Creutzfeldt-Jakob disease. She was started on
lorazepam. Her sensorium improved gradually, which correlated with the decline in blood
lithium levels. A normal background alpha rhythm on EEG was ensured prior to discharge. At discharge, clinically, she had recovered completely, with no apparent neurological deficit or
cognitive impairment. This case highlights the importance of therapeutic
drug-level monitoring of
lithium, especially where toxicity is suspected, and the important role electroencephalography plays in diagnosing NCSE and its management.