Dysautonomia after traumatic brain injury: a forgotten syndrome?

OBJECTIVES: To better establish the clinical features, natural history, clinical management, and rehabilitation implications of dysautonomia after traumatic brain injury, and to highlight difficulties with previous nomenclature. METHODS: Retrospective file review on 35 patients with dysautonomia and 35 sex and Glasgow coma scale score matched controls. Groups were compared on injury details, CT findings, physiological indices, and evidence of infections over the first 28 days after injury, clinical progress, and rehabilitation outcome. RESULTS: the dysautonomia group were significantly worse than the control group on all variables studied except duration of stay in intensive care, the rate of clinically significant infections found, and changes in functional independence measure (FIM) scores. CONCLUSIONS: Dysautonomia is a distinct clinical syndrome, associated with severe diffuse axonal injury and preadmission hypoxia. It is associated with a poorer functional outcome; however, both the controls and patients with dysautonomia show a similar magnitude of improvement as measured by changes in FIM scores. It is argued that delayed recognition and treatment of dysautonomia results in a preventable increase in morbidity.

The measurement of distortion: concluding remarks.

The means by which fine measurements can be made and distortions computed have been discussed in this series. However, the fact remains that research of this nature is time consuming and demanding. At every step, and in all machined components, care must be taken to eliminate local inaccuracies. Precalibration, postcalibration, and an ongoing program of maintenance are essential if quality results are to be anticipated. An attempt has been made to introduce automatic reading devices with the ability to compute distortions by having the raw data sent directly to a computer. This latter step can be highly dangerous unless at least one "test case" can be programmed into the system as a check on the data access and computational procedures. These test cases should simulate as closely as possible the actual computational requirements of the system, in order that all program "bugs" be corrected before the research is run. In this area, the GIGO rule, "Garbage in-Garbage out," holds true. Unfortunately, if the computational errors are small and of the order of magnitude of the measured distortions the researcher can accept the results without realizing there is a computational problem.