Clinical Characteristics, Neuroimaging Findings, and Mortality in Korsakoff Syndrome.

IMPORTANCE: Korsakoff syndrome is a severe neurocognitive disorder resulting from thiamine deficiency, most often associated with alcohol use disorder. Contemporary data describing its clinical presentation, neuroimaging findings, and long-term outcomes remain limited. OBJECTIVE: To characterize the clinical features and outcomes of patients diagnosed with Korsakoff syndrome in routine clinical practice and to identify factors associated with mortality. DESIGN, SETTING, AND PARTICIPANTS: This cohort study included electronic health records of adults with a diagnosis of Korsakoff syndrome between August 1, 2017, and December 31, 2022, from the Clinical Data Warehouse of the Greater Paris University Hospitals (AP-HP), which includes 39 hospitals. Data were analyzed March 2023. EXPOSURE: Korsakoff syndrome diagnosis. MAIN OUTCOMES AND MEASURES: The primary outcome was all-cause mortality. Secondary outcomes included clinical manifestations, comorbidities, and neuroimaging findings in patients diagnosed with Korsakoff syndrome. RESULTS: Among 1320 patients with Korsakoff syndrome (mean [SD] age, 62.9 [11.1] years; 962 men [72.9%]), a well-documented subgroup of 114 patients most frequently presented with anterograde amnesia (61.4%). Among this subgroup, 22 patients (19%) had a reported history of Wernicke encephalopathy. Among patients who underwent brain magnetic resonance imaging, abnormalities involving the Papez circuit and vascular leukoencephalopathy were each observed in 40 patients (44.4%) each. During a median (IQR) follow-up of 3.1 (1.2-5.0) years, 398 patients (30.2%) died. In multivariable analyses, malnutrition (hazard ratio [HR], 1.54; 95% CI, 1.15-2.05), alcoholic liver disease (HR, 1.45; 95% CI, 1.10-1.91), male sex (HR, 1.45; 95% CI, 1.13-1.86), and age 80 to 89 years (HR, 1.89; 95% CI, 1.27-2.81) were associated with mortality. CONCLUSIONS AND RELEVANCE: In this large clinical cohort, patients diagnosed with Korsakoff syndrome had a high burden of vascular comorbidities, frequent under-recognition of Wernicke encephalopathy, and substantial mortality. These findings highlight the need for earlier recognition and more standardized diagnostic evaluation of Korsakoff syndrome.