The importance of additional tests in patients with transient global amnesia - a retrospective study

To analyze the patient population diagnosed with transient global amnesia (TGA) concerning their demographic structure, clinical data and results of additional tests performed.

Transient global amnesia is a neurological disorder characterized by the sudden onset of temporary memory disturbances, resolving within 24 hours and not accompanied by other focal neurologic symptoms. The pathomechanism of TGA remains unknown. The prognosis is very favorable. Laboratory tests, electroencephalograms or radiologic imaging scans are typically normal. They are usually necessary to exclude alternative diagnoses.

The study was a retrospective analysis of 18795 patients hospitalized in the Clinical Provincial Hospital from 1 January 2017 to 30 April 2024. Patients with TGA were identified by searching digital data according to the ICD-10 classification. Each patient met Caplan's criteria (in Walrow and Hodges approach). The analysis considered demographic characteristics: age, gender, comorbidities, preceding factors, the time of illness onset, the results of additional tests [magnetic resonance imaging (MRI) and electroencephalogram (EEG)] and their timing.

The study group included 113 patients. Hypertension and lipid disorders were most frequently noted comorbidities. Most common preceding factors were systolic blood pressure above 160 mmHg, (38%), sudden stress-inducing event (13.3%), severe pain (12.4%), physical activity (8.9%). Transient global amnesia episodes occurred most frequently during daytime, between 11 a.m. and 5 p.m. (61 patients, 54%) and 2 patients (1.77%) developed symptoms during nighttime. Magnetic resonance imaging was performed in 83 patients (73.45%). On MRI diffusion weighted imaging (DWI), hippocampal hyperintense areas were found in 15 patients (18.07%). Physical activity and atrial fibrillation were significantly higher in patients with DWI lesions. Electroencephalogram was performed in 102 patients (90.27%). Forty-seven (42%) of them showed abundant and dominant beta rhythm. Approximately one third (n = 39) had no EEG abnormalities. Epileptiform discharges were detected in two cases (1.77%). Abnormal EEG records were significantly higher in patients with present DWI lesions.

Transient global amnesia episodes often occur during daily activity, and the main preceding event was an increase in systolic blood pressure above 160 mmHg. Magnetic resonance imaging and EEG tests support the diagnosis. The sensitivity of MRI is higher when performed between 24-96 hours after symptom onset.