What is Korsakoff syndrome primarily caused by?

Korsakoff syndrome is primarily caused by a severe deficiency of thiamine, also known as vitamin B1. This neurological disorder is often associated with chronic alcoholism, which leads to inadequate dietary intake of thiamine and impaired absorption. Thiamine is crucial for glucose metabolism and the functioning of neurons, and its deficiency can result in significant cognitive impairments and memory issues, characteristic of Korsakoff syndrome.

The syndrome usually presents with symptoms such as confusion, memory loss, and confabulation, where the individual creates false memories without the intent to deceive. Understanding the pathophysiology surrounding thiamine deficiency is essential for recognizing and addressing conditions like Korsakoff syndrome, especially in populations at risk, such as individuals with alcoholism, those with malnutrition, or those with gastrointestinal disorders that affect nutrient absorption.

Other deficiencies, such as vitamin B-12 or D, do impact cognitive functions and overall health but are not the primary contributors to Korsakoff syndrome. Thus, thiamine's pivotal role in brain function underscores why severe deficiency of this vitamin is the correct answer.