Temporal Cognitive and Brain Changes in Korsakoff Syndrome

Area of Science:

• Neuroscience
• Neurology
• Cognitive Science

Background:

• Korsakoff syndrome (KS) is a chronic neurological disorder often resulting from thiamine deficiency.
• Understanding the long-term cognitive and brain changes in KS is crucial for patient management and prognosis.

Purpose of the Study:

• To investigate the longitudinal cognitive and brain changes in patients with Korsakoff syndrome (KS) over months and up to 10 years post-diagnosis.
• To compare early-stage KS with long-term KS patients to understand disease progression and stability.

Main Methods:

• Two groups of 8 KS patients underwent neuropsychological, motor, and neuroimaging (structural MRI, 18F-fluorodeoxyglucose-PET) assessments.
• One group (KS^C) was assessed early post-diagnosis and 1 year later; another group (KS^R) was assessed 10 years post-diagnosis.
• Comparisons were made longitudinally within KS^C and cross-sectionally between KS^C-T1 and KS^R against healthy controls.

Main Results:

• No significant cognitive, motor, or brain deterioration was observed over time in KS patients; modest frontocerebellar recovery occurred.
• Early KS patients exhibited severe episodic memory deficits, ataxia, executive dysfunction, widespread atrophy, and hypometabolism.
• Long-term, episodic memory remained impaired, but inhibition abilities were preserved in the 10-year group (KS^R).
• Structural and metabolic alterations in the Papez circuit, thalamus, hypothalamus, and fornix persisted throughout the study period.

Conclusions:

• Structural and metabolic alterations in the Papez circuit in KS are persistent, reflecting the chronic nature of amnesia.
• KS differs from alcohol use disorder recovery and neurodegenerative diseases, showing neither significant recovery nor progressive decline.
• The findings underscore the long-term stability of brain damage and cognitive deficits in Korsakoff syndrome.