Neurologic manifestations of gastrointestinal disease

The neurologic manifestations of gastrointestinal disease are generally thought to be uncommon, although an increasing number of previously unidentified associations are being established. These neurologic disorders may result from nutritional or non-nutritional causes. In the absence of clear malnutrition, it is likely that many of these disorders are underdiagnosed. As an example, Wernicke's encephalopathy is found at autopsy in as many as 2 per cent of brains, a very high percentage, given the rare recognition during life. The likely underdiagnosis of nutritional neurologic disorders is unfortunate because many are treatable and, more importantly, are preventable if malabsorption is suspected and appropriate supplementation initiated. For the neurologist, familiarity with the occasional association between neurologic abnormalities and specific gastrointestinal disorders is important, as is familiarity with the neurologic characteristics of disorders, such as Whipple's disease, that may present as isolated neurologic syndromes without gastrointestinal symptoms or signs. Renewed interest in selective deficiency states has resulted in identification of causative factors in several neurologic syndromes of previously presumed degenerative etiology. Recognition of the potential neurologic consequences of prolonged deficiency states also is important for the internist, because many of the syndromes are poorly reversible once symptomatic. The benefits of prevention invariably exceed those of treatment.