Evaluation of functional gastrointestinal disorders in autonomic neuropathy

Evaluation of functional gastrointestinal disorders in autonomic neuropathy: The clinical diagnosis of gastrointestinal autonomic neuropathy requires the exclusion of organic diseases since visceral neuropathy is only associated with unspecific symptoms. Until now, no diagnostic clinical tools are available to evaluate visceral neuropathy directly. Because of poor correlation between intestinal and extra-intestinal neuropathies, visceral neuropathy can only be considered by functional disorders of the gut, e.g. motility dysfunctions. Suitable methods to determine gastrointestinal dysfunction are manometry, pH-metry, radiology, scintigraphy and exhalation tests. In future, new technical approaches may extend the possibilities to detect gastrointestinal autonomic neuropathy. These are the electrogastrogram (EGG) by which dysrhytmia of electrical signals from pacemaker cells of the stomach might be detectable and additional methods that allow systematic recording of neural projections between the gastrointestinal tract and the central nervous system (CNS) in humans. By means of these new techniques afferent projections (cortical evoked potentials, magnetic resonance encephalography, positron emission tomography, functional magnetic resonance tomography) and efferent projections from the CNS to the gastrointestinal tract (transcranial magnetic stimulation) can be investigated.