Case Presentation: A 48-year-old woman presented with recurrent episodes of confusion, disorientation, and unexplained falls over several months. Initially, she was treated in multiple healthcare settings for delirium, presumed urinary tract infection, and syncope. Her past medical history included repeated minor head trauma in early adulthood and a long-standing psychiatric evaluation for intermittent behavioral disturbances. Despite extensive workup, including laboratory panels and routine imaging, her symptoms persisted. During one acute episode in a psychiatric unit, she experienced stereotyped jerking of her right arm with preserved awareness, accompanied by a rising epigastric sensation. This prompted neurology consultation. EEG showed intermittent temporal sharp waves, and high-resolution MRI revealed unilateral hippocampal atrophy with T2 hyperintensity, consistent with mesial temporal sclerosis (MTS). Following diagnosis, antiepileptic therapy was initiated, and seizure frequency markedly decreased from multiple weekly episodes to occasional events. The patient exhibited improved cognitive function and behavioral stability, underscoring the delayed recognition of the underlying neurological etiology
Discussion: This case highlights the diagnostic challenges posed by MTS. The patient’s prolonged history of acute confusion, behavioral disturbances, and transient loss of consciousness exemplifies how MTS can mimic both psychiatric and acute medical conditions. Diagnostic delays were compounded by fragmented care across multiple institutions and lack of integration between psychiatry and neurology, allowing misdiagnosis to persist for decades. Subtle seizure features, including olfactory and visceral auras, focal motor jerks, and postictal confusion, were overlooked initially, reflecting a broader pattern seen in the literature. Early neuroimaging, particularly MRI with epilepsy protocol, is critical in identifying hippocampal atrophy and confirming MTS. Cognitive deficits and behavioral changes, often underappreciated, provide valuable diagnostic clues and should prompt consideration of underlying structural pathology rather than attributing symptoms solely to psychiatric disorders. System-level factors, including specialty fragmentation, limited longitudinal follow-up, and uneven access to advanced diagnostic tools, contribute significantly to delayed diagnosis. Once recognized, appropriate antiepileptic therapy and consideration of surgical intervention can dramatically improve seizure control and cognitive outcomes.This case aligns with reports by Puppala et al. and Gayubo Moreo et al, which describe prolonged misdiagnosis of MTS as psychiatric disorders. However, acute presentations resembling delirium, infection, or syncope, as observed in our patient, are less commonly reported, highlighting the need for heightened clinical suspicion in atypical presentations. The 20-year delay in diagnosis underscores the importance of integrated neuropsychiatric evaluation and systematic neuroimaging for patients with recurrent, treatment-resistant, or unexplained neuropsychiatric symptoms
Conclusions: Prompt diagnosis allows targeted antiepileptic therapy and surgical consideration, improving seizure control, cognitive function, and overall quality of life. Increased awareness among clinicians and system-level integration of psychiatric and neurological care are essential to prevent decades-long misdiagnoses