Korsakoff's syndrome
Korsakoff Syndrome is characterized by a pseudo-dementia that is typically irreversible. It is considered to result from disturbances in the metabolism of vitamin B1 (thiamine), in the context of chronic alcoholism in the vast majority of cases in developed countries. However, this syndrome can also be observed, albeit more rarely, in various pathologies affecting the internal temporal lobes.
It usually occurs as a late complication of Wernicke's encephalopathy (not always clinically evident), and less commonly as a de novo condition. Thus, 80% of alcoholic Wernicke cases (lower rates for other etiologies) will retain characteristic sequelae of Korsakoff syndrome.
Clinical Presentation
- Cardinal symptoms: Chronic memory disturbances consisting of predominant anterograde amnesia + retrograde amnesia.
- Other frequently encountered symptoms: Confabulations and false recognitions, anosognosia, disorientation, coordination disturbances, frontal syndrome, emotional lability.
Old memories and other cognitive abilities are typically largely preserved… However, occasionally, there are global cognitive impairments resulting in a true dementia-like presentation.
Additional Examinations
A brain MRI can show sequelae of Wernicke's encephalopathy (++ mammillary body atrophy) and lesions or atrophy of the medial thalamic nuclei, hippocampi, and corpus callosum.
Neuropsychological testing reveals the characteristic cognitive abnormalities.
Other examinations are only useful for excluding differential diagnoses and should only be prescribed based on clinical presentation.
Therapeutic Management - Treatments
No treatment has demonstrated effectiveness. Following the model of Wernicke's encephalopathy, a trial of vitamin supplementation (thiamine 500 to 1500 mg/day IV for 5 days, followed by < 100 mg/day PO) is recommended. A few cases of partial recovery have been reported.
Management is therefore primarily paramedical: social measures, institutionalization, etc.
Author
Dr Shanan Khairi, MD
Bibliography
Bradley WG et al., Neurology in clinical practice, 5th ed., Butterworth-Heinemann, e-dition, 2007
EMC, Traité de médecine AKOS, Elsevier, 2018
ME Charness et al., Overview of the chronic neurologic complications of alcohol, UpToDate, 2024