Differential Diagnosis of Transient Loss of Consciousness During Emergency Hospitalization

INTRODUCTION. Emergency differential diagnosis of transient loss of consciousness (TLOC) is frequently compromised by the retrospective nature of clinical assessment and the confounding phenomenon of clinical isomorphism in co-morbid states. AIM. To analyze the etiological spectrum of TLOC during acute hospitalization and identify high-yield clinical and laboratory biomarkers to differentiate between epileptic and non-epileptic events. MATERIALS AND METHODS. A cohort study was conducted on 87 adult patients admitted after a TLOC episode. Postictal clinical severity (NHS3 scale), early oxygenation dynamics (SaO2 within 10 min), and systemic stress biomarkers (CK, white blood cell count within 6 hours) were analyzed. Statistical analysis was performed using SPSS v.27.0 and R. RESULTS AND DISCUSSION. Epileptic seizures were verified in 73.6 % of cases; non-epileptic mimics constituted 26.4 %. A clear age-related distribution was observed: idiopathic and psychogenic conditions predominated in patients aged 18–35, whereas acute symptomatic seizures driven by neuro-oncology (13.8 %) and acute ischemic stroke (9.2 %) prevailed in older adults. Symptomatic seizures exhibited pronounced clinical isomorphism (p > 0.05). However, underlying comorbidities significantly depleted the metabolic reserve, exacerbating NHS3 scores (oncology: M = 23; electrolyte imbalances: M = 19). Lateral tongue biting, total amnesia, and prolonged disorientation were highly specific for true epilepsy. The immediate postictal phase in epilepsy was characterized by a profound drop in SaO2 to 85 % [72 %; 96 %] (vs. 98 % [90 %; 100 %] in mimics), accompanied by a 10-fold increase in CK and a 3.3-fold leukocyte elevation. Transient Todd's paresis occurred in 11.5 % of patients, correlating with structural brain lesions. CONCLUSION. A reliable diagnostic algorithm for TLOC in emergency departments relies on combining specific semiological markers (lateral tongue biting) with rapid pulse oximetry assessment (SaO2 < 90%) and monitoring systemic metabolic shifts (CK and leukocyte levels).