An 82-year-old right-handed woman developed speech disturbance a week before visiting the Department of Neurology. On neurological examination, the patient was alert and followed one-step verbal commands. However, she could not speak spontaneously. Physical examination revealed no abnormalities. Her medical history, as reported by her husband, revealed that she had experienced a mild decline in memory over the past year; however, she could speak and perform daily activities without any difficulty until a week before this visit. Routine laboratory tests revealed no abnormalities. Electroencephalogram (EEG) revealed an intermittent rhythmic delta activity and quasi-rhythmic fast activity in the frontotemporal area bilaterally, with fluctuating frequency and amplitude (Fig. 1D). The patient was aphasic during the EEG recording period. Brain magnetic resonance imaging (MRI) exhibited diffuse atrophy of the cerebral cortex and hippocampal formation (Fig. 1A, B). The symptoms and EEG abnormalities were absent a day after the administration of valproate (loading dose of 25 mg/kg, and maintenance doses of 6 mg/kg) (Fig. 1E). The patient reported remembering nearly all events during the seizure episodes. Brain single-photon emission computed tomography (SPECT) performed after the control of ASE revealed decreased perfusion in the left frontotemporal area (Fig. 1C). The patient score on the Korean version of the Mini-Mental Status Examination (K-MMSE) was 19 (0/3 in memory registration, 1/5 in attention and calculation, 0/1 in repetition, 4/5 in time orientation, and 3/5 in place orientation), and her Global Deterioration Scale (GDS) score was 4. A detailed neuropsychological test (Seoul Neuropsychological Screening Battery [SNSB]) presented global deterioration, particularly in the domains of memory registration and frontal executive function, which was compatible with AD. The patient follow-up revealed that she has been seizure-free for 5 years after discharge, and her cognitive function gradually has declined to a severe state of dementia, with K-MMSE and GDS scores of 3 and 6, respectively.

An 86-year-old right-handed woman developed sudden unresponsiveness and speech disturbances approximately 12 hours before visiting the Emergency Department. Her son reported that she was not able to understand him. She was diagnosed with AD 5 years before the visit to the clinic and has been irregularly treated with 10 mg of donepezil. The patient did not follow-up in the last 2 years before this visit. The patient scores at diagnosis were 15 on K-MMSE (0/3 in memory registration, 1/5 in attention and calculation, 2/3 in following commands, 0/1 in interlocking pentagon, 0/5 in time orientation, and 4/5 in place orientation) and 4 on GDS. The SNSB exhibited global deterioration, particularly in the domains of memory registration, language, and frontal executive function. On neurological examination, the patient was alert but could not follow verbal commands. However, she could look around and make eye-contact. Focal neurological abnormalities were not found. Laboratory test results revealed no abnormalities. Brain MRI revealed diffuse atrophy of the cerebral cortex and hippocampal formation without acute focal lesions (Fig. 2A, B). The initial EEG exhibited intermittent quasi-rhythmic theta and fast activity were observed bilaterally in the frontotemporal area with fluctuating frequency and amplitude (Fig. 2D). The patient remained aphasic throughout the recording period. The symptoms and EEG abnormalities were absent 8 hours after valproate administration (loading dose of 20 mg/kg, and maintenance doses of 6 mg/kg) (Fig. 2E). Brain SPECT performed after the control of ASE revealed decreased perfusion in the left frontal area (Fig. 2C). The follow-up K-MMSE and GDS scores were 10 and 5, respectively. The patient has been seizure-free for 6 months after discharge.