Visceral afferent neuropathy in diabetic gastroparesis

To determine whether a lack of symptoms in diabetic patients with gastrointestinal motility disorders is associated with visceral afferent neuropathy.

We investigated cerebral evoked potentials (EPs) after esophageal stimulation in 10 patients with motor dysfunction of the gastrointestinal tract and in 10 healthy control subjects. All patients had insulin-dependent diabetes mellitus (5 men, 5 women, age range 31-60 yr, diabetes duration 8-36 yr, 10 of 10 with polyneuropathy, 6 of 10 with cardiac autonomic neuropathy). Their esophageal and gastric motor disorders had been diagnosed by scintigraphy, and gastrointestinal stenosis had been excluded by gastroscopy. Only 2 patients had severe symptoms, whereas 6 patients complained of minor discomfort (distension, bloating), and 2 patients were symptom free.

EPs were recorded after electrical stimulation of the esophagus (32 cm from the incisors) at intensity just above the perception threshold. All control subjects exhibited regular EPs at 0.1 ms/30 mA stimulation intensity. In 6 diabetic patients, no EPs were detected at 0.1 and 0.3 ms/30 mA, and the perception thresholds were significantly elevated. In 4 patients with normal perception threshold, EPs of regular shape but decreased amplitude were recorded. These patients had mild or severe gastroparetic complaints.

These data show for the first time an association between a lack of symptoms in diabetic gastrointestinal motility disorders and visceral afferent neuropathy.