Dementia with Lewy bodies versus nonconvulsive status epilepticus in the diagnosis of a patient with cognitive dysfunction, complex visual hallucinations and periodic abnormal waves in EEG: a case report

The diagnosis of dementia with Lewy bodies (DLB) is often challenging in elderly individuals, not only for its various clinical features, sometimes, but also for its rare changes of periodic synchronous discharges (PSD) in electroencephalogram ( EEG). So, we reported one case of DLB and gave a detailed analysis.

A Chinese patient (Female, 56 years old) presented with progressive cognitive decline and complex visual hallucinations. Several days after admission, she gradually showed focal myoclonic jerks. Mini-Mental State Examination (MMSE) score was 19/30, EEG revealed PSD, Cerebrospinal fluid and 14-3-3 brain protein was negative, Magnetic resonance imaging (MRI) showed diffuse atrophy. To differentiate the PSD derived from DLB or from late-onset Absence Status Epilepticus, we have given the treatment with intravenous valproate (1200 mg/24 h) and diazepam 20 mg under the EEG monitor, a clinical improvement was absent and PSD in EEG did not disappear. Two weeks later, the patient showed akinetic-rigid syndrome and PSD in EEG persisted for a long time. According to her history and therapy, a clinical diagnosis of DLB has been made, but no autopsy for confirmation, and in the following visit, she has a poor prognosis.

PSD in EEG may occasionally be recorded in neurodegenerative disorders such as AD, DLB other than CJD or NCSE. Hence it should not dissuade clinicians from the diagnosis of DLB where the clinical and neuropsychological findings were consistent with suggested diagnostic criteria for DLB.