Nutritional considerations in the patient with disabling brain disease

Increased nutritional requirements are now recognized as the typical sequellae of head injury. Whether similar nutritional demands routinely accompany nontraumatic, disabling brain diseases is uncertain. Experience with patients suffering from head injury indicates that clinical criteria for differentiating the severity of neurological impairments categorize rather poorly the levels of nutritional need. Based on available data, 'nutritional risk' can only be assigned to broad patient categories. Head-injured patients seem to be at nutritional risk and, by virtue of increased caloric and protein requirements, may benefit, in terms of reduced mortality, from early, intensive nutritional intervention. Because the nutritional risk cannot be established, the indications for aggressive nutritional support in the noninjured patient are even less clear than those for the trauma patient. Parenteral nutrition is often required to meet the goals of nutritional support because inadequacies in gastrointestinal function frequently mitigate successful enteral nutrition. Selective nutritional therapies involving the branched chain amino acids may reduce the attrition of the body cell mass seen in head injury patients. Furthermore, improvements in energy nutrient utilization in other than head-injured patients have been suggested when fat is provided in addition to glucose as a caloric source. When clinically feasible, enteral nutrition offers significant economic and physiological benefits over parenteral nutrition. In this regard, increasing attention has been focused on newer techniques of enteral access. These include percutaneous gastrostomies and nasally inserted small bore feeding tubes. The latter achieve duodenal intubation with a high success rate, and they offer the prospects of improved feeding tolerance and reduced tracheobronchial aspiration by allowing the administration of nutrients distal to the pylorus. Hence, many of the advantages of jejunostomy access are achieved without the need for an abdominal operative procedure.