{
  "abstract": "Background Transient global amnesia (TGA) provides a unique perspective into the relationship between stress and memory formation. This study examines the clinical and diagnostic profiles of TGA and its mimics and reviews the current evidence to enhance understanding of its elusive pathophysiology.Methods We retrospectively reviewed 142 consecutive acute amnesia cases (January 2011 to July 2024) at a tertiary centre in Sydney. Cases were identified via diagnostic codes and confirmed through manual review. Patients were classified as either TGA or non-TGA according to established criteria. Clinical data were extracted from electronic medical records. Acute-phase brain MRI was performed in 83% of TGA cases, with all scans independently reviewed by both authors. Additional investigations, including cardiac studies, EEG and cerebrospinal fluid analysis, were evaluated when available.Results Among 142 cases, 69% were TGA and 31% non-TGA, with non-TGA cases demonstrating a broader age range and male predominance (68%). The study identified triggers beyond the commonly recognised physical and emotional stressors. Wake-up TGA occurred in 12.0%, which is higher than previously reported. Repetitive questioning was a highly specific diagnostic feature (sensitivity 63.3%, specificity 93.2%). Brief episodes under 1 hour occurred in 8% of TGA cases. MRI was most informative at 24–48 hours after symptom onset, with 93.3% showing typical hippocampal punctate diffusion lesions, which were lateralised more frequently to the left (51.3%) than to the right (33.3%). A ‘TGA plus’ subgroup (2.4%) was characterised by extrahippocampal punctate diffusion lesions. Common mimics included transient epileptic amnesia, syncope, head injury and drug-induced amnesia.Conclusion The study expands the clinical spectrum of TGA, identifying various precipitating triggers, including wake-up amnesia. A proposed mechanism of catecholamine-mediated hippocampal dysfunction is discussed. Collectively, these findings highlight the interplay of stress, arousal and hippocampal susceptibility, warranting prospective studies incorporating catecholamine measurement.",
  "authors": [
    {
      "affiliations": [
        "Department of Neurology, Westmead Hospital, Westmead, New South Wales, Australia"
      ],
      "name": "Shuo Xi"
    },
    {
      "affiliations": [
        "Department of Neurology, Blacktown Hospital, Blacktown, New South Wales, Australia"
      ],
      "name": "Andrew J Martin"
    }
  ],
  "title": "Exploring transient global amnesia: a 14-year retrospective study of 142 cases",
  "uid": "78746bae-a527-5ce9-8337-7529e75e6624"
}