Dementia due to chronic hypovitaminosis
by Kurt Jellinger
Vitamin deficiency states can lead to a number of important neuro-psychiatric disorders. The most common disorders are associated with deficiencies of the B group of vitamins, particularly thiamine.
Although they are seen particularly in populations suffering from general malnutrition, there are specific groups of people who are particularly susceptible to specific deficiencies.
For example, thiamine deficiency is frequently seen in alcoholics. The possibility of multiple vitamin deficiencies should also taken into consideration.
Symptoms and course
People having dementia due to chronic hypovitaminosis have problems with the eyes include disorders of their control of direction, coordination and movement; problems with gait and a loss of balance or equilibrium called ataxia; and a global confusional state where the person is apathetic, has little awareness of their immediate situation and difficulties with space, attention and concentration.
The symptoms of amnesia fall into two broad categories of impaired memory function and retained memory function.
In impaired memory there is a profound difficulty or total inability to learn new material and the lack of a normal short term memory (where a person would be able to repeat a telephone number after looking it up). This is known as anterograde amnesia. Also the person cannot remember events in their past life particularly the period immediately before their amnesia. This is known as retrograde amnesia.
However, some memory functions can be well retained. Particularly early established skills and habits. The use of language, gesture, and well practised skills may remain unaffected.
However people can also show a tendency towards decreased initiative and spontaneity and a blunting of effect, so events, which would normally be of emotional significance are reacted to in a dull or apathetic manner.
Other psychiatric symptoms include depression, irritable spells and paranoia.
Stable if drinking is stopped, Wernicke-Korsakoff Syndrome shows a mortality of about 10-20% unless it is treated. Of the patients who survive, 70-80% develop Wernicke-Korsakoff Syndrome.
Causes and risk factors
The main cause is chronic thiamine (vitamin B 1) and niacin deficiency.
Studies of vitamin deficiencies show that there are significant variations in the prevalence of these disorders. For example, the highest prevalence of Wernicke-Korsakoff syndrome (WKS), which is caused by thiamine deficiency, has been reported in Australia, whereas in a study of a similar alcoholic population in France, the prevalence of pellagra, a disease caused primarily by niacine (nicotinic acid) deficiency was high (approximately 0.3% vs. WKS around 1.9%). This issue has been addressed in an analysis of the international prevalence of WKS (Harper et al., 1994).
Problem of drinking and of vitamin supplementation.
Care and treatment
Treatment with vitamin substitution; memory rehabilitation programs may be successful.
Treatment services for alcoholics; regular control of vitamin intake by general practitioners and specialists.
Last Updated: vendredi 09 octobre 2009