Prolonged confusional state following electroconvulsive therapy--diagnostic clues from serial electroencephalography

Area of Science:

• Neuroscience
• Clinical Psychiatry
• Neurology

Background:

• Cognitive impairment is a known, usually transient, side effect of electroconvulsive therapy (ECT).
• Prolonged or severe cognitive changes warrant further investigation to rule out other causes.
• Ictal states can manifest as cognitive dysfunction, making electroencephalography (EEG) essential.

Observation:

• A patient with treatment-resistant major depression developed severe confusion and amnesia post-ECT.
• Standard laboratory and neuroimaging results were unremarkable.
• EEG demonstrated significant abnormalities, including intermittent slowing and bitemporal sharp waves.

Findings:

• A small dose of lorazepam rapidly improved EEG abnormalities.
• This response suggested a diagnosis of non-convulsive status epilepticus (NCSE).
• Treatment with lorazepam led to clinical improvement and EEG normalization.

Implications:

• Routine EEG is vital for evaluating sudden cognitive decline in patients, especially after procedures like ECT.
• A diagnostic trial of lorazepam can aid in identifying ictal patterns on EEG.
• Early diagnosis and treatment of NCSE can mitigate prolonged cognitive deficits.