Martin Wienbeck

Cerebral responses evoked by electrical stimulation of the esophagus in normal subjects.

Cerebral responses to electrical stimulation of the esophagus were investigated in 11 healthy male volunteers, 20-40 yr old. The stimulus was applied via a probe equipped with bipolar ring electrodes. It was positioned in the middle and distal esophagus at 20 and 37 cm from the incisors, respectively, and sucked to the mucosa. Electrical stimuli (0.1-ms duration, different stimulus voltages) were applied at frequencies of 0.1-1.0 Hz or in randomized order. Cerebral responses to electrical stimulation were recorded after 20-40 stimulations and averaged on a time base of 1000 ms. Evoked potentials consisted of successive peaks and troughs in the averaged electroencephalogram with good reproducibility within and between subjects. Amplitudes of evoked potentials showed a significant reduction with electrical stimulation at 37 cm compared with 20 cm, and with stimulation frequencies of 0.5 and 1.0 Hz compared with 0.2 and 0.1 Hz. Evoked potentials from 37 cm showed longer latencies compared with those from 20 cm. Irregular stimulation and stimulation during mental distraction did not alter these responses. It is concluded that reproducible evoked potentials can be recorded from the scalp after electrical stimulation of the esophagus and that these are transferred centrally via vagal afferents. The technique may become a useful tool in the study of visceral nervous connections to the brain in health and disease.

Cerebral Responses Evoked by Electrical Stimulation of Rectosigmoid in Normal Subjects

We used electroencephalographic methods to evoke and record cerebral responses to electrical stimulation of the rectosigmoid colon in eight healthy male volunteers, 20–40 years old. The stimulus was applied via a probe equipped with bipolar ring electrodes which were attached by suction to the mucosa. The probe was positioned 20 cm above the anus. Cerebral responses were recorded by EEG electrodes. Evoked potentials (EPs) in response to electrical stimulation consisted of a series of successive peaks and troughs in the EEG with good reproducibility within and between subjects. The shape and latencies of the intestinal EPs were comparable to other types of EPs reported before. It is concluded that reproducible EPs can be recorded from the scalp after electrical stimulation of the rectosigmoid. The similarity in appearance of these EPs to those previously reported suggests that visceral afferents were stimulated. The technique may become a useful tool to study visceral nervous connections to the brain in health and disease.

Local inhibition of myoelectrical activity of human colon by loperamide.

In order to study whether the antidiarrheal effects of loperamide are largely brought about by a local inhibition of the drug, we applied doses of 0.2 mg directly on the mucosa of the descending and sigmoid colon of 33 healthy volunteers. Loperamide decreased BER frequencies and reduced spike activity to 6.6±0.3% of time vs 11.3±0.7% in the control recorded from 3 cm aside and to 5.8±0.4% vs 12.7±0.9% in the descending and sigmoid colon, respectively. The same effects became apparent when spike activity was stimulated by neostigmine. Loperamide also reduced the occurrence of groups of spikes to 3.8±0.4/hr vs 10.3±0.6 and to 3.6±0.4/hr vs 14.6±0.7 in the descending and sigmoid colon, respectively. Groups of spikes are thought to be the equivalent of propulsive movements. Thus, loperamide is active locally and exhibits inhibitory effects on the motor activity of the colon. Clinical studies seem warranted to examine the effectiveness of loperamide enemas in motility disturbances of the anorectum.

Repeated noninvasive measurement of gastrointestinal transit in rats

A technique for repeated and noninvasive measurement of oro-cecal transit time in rats and other small animals is described. It is based on the incomplete digestion of carbohydrates such as lactose fed orally to the animals. Since the activity of the enzyme lactase is low in almost all species, lactose is fermented by colonic bacteria after it arrived in the cecum, thus producing hydrogen. Hydrogen is delivered to the lungs via the circulation and exhaled by the animal. An increase in breath hydrogen measured by means of an electrochemical cell or a gas-chromatograph indicates the arrival of the nutrient bolus in the cecum. The method can be used repeatedly in individual animals under various experimental conditions such as investigations of stress effects on gastrointestinal transit.

The effect of trospium chloride on oesophageal motility

Trospium chloride is a muscarinergic antagonist acting on oesophageal smooth muscle and on ganglionic and/or myenteric neurons. The effect of this drug on oesophageal motility was tested in 16 healthy male subjects in a double‐blind randomized cross‐over examination of trospium chloride or placebo following phentolamine or placebo application. Each subject underwent two separate investigations at least one week apart. Trospium chloride was effective in the oesophagus to reduce contractile activity (amplitude and duration of peristalsis) in all parts of the oesophageal body, and this effect was not blocked by phentolamine. Its potent action and its minor side‐effects appear to be promising for clinical use in patients with motility disorders such as the hypercontractile oesophagus.

2 Drug-induced oesophageal lesions

Abstract Persisting retrosternal pain of sudden onset is suggestive of a drug-induced oesophageal lesion, particularly if it starts at night. After exclusion of a myocardial infarction, a carefully taken history and oesophagoscopy will rapidly clarify the cause and severity of the injury. Since almost any pill may produce oesophageal lesions, care has to be taken that tablets, capsules and other pills are always taken in an upright position together with a fluid chaser of at least 120 ml. If possible, less harmful liquid preparations of the drugs should be preferred. Lesions in the oesophageal wall and perioesophageal tissue are almost unavoidable side-effects of sclerotherapy of oesophageal varices. The patient and the doctor should be particularly aware of bleeding from oesophageal ulcers during the first week after sclerotherapy. Numerous drugs may weaken or strengthen contractions of the oesophagus and lower oesophageal sphincter. These potentially unwanted motor effects of the drugs have to be kept in mind, especially in patients with pre-existing gastro-oesophageal reflux disease and hypermotility states.

Exsudative Enteropathie beim Klippel-Trenaunay-Syndrom

SummaryThe triad of the Klippel-Trénaunay Syndrome consists of varicose veins, “port-wine” haemangioma of the skin and bone and soft-tissue hypertrophy with a different extension. Often an obstruction of lymphatic vessels and lymphoedema accompany the syndrome. We observed for the first time a patient with an impressive Klippel-Trénaunay-Syndrome in combination with a symptomatic exsudative enteropathy.In spite of a regular intravenous protein substitution for many years, this patient had develloped a monstrous elephantiasis of the lower extremities. A lymphography demonstrated a blockade of the lymph flow at the height of the middle paraaortic lymph nodes. The cysterna chyli and the Ductus thoracicus were not visualised. The measurement of51Cr-labelled albumin excretion in the stool for two days after the intravenous injection of 3.07 MBq51Cr showed an excretion of 17.9% of the total dose, which means an elevated gastrointestinal protein-loss. However, intestinal lymphangiectasia was not seen on histologic examination of bioptic material of duodenal and jejunal mucosa.These results show that the Klippel-Trénaunay Syndrome may be accompanied by a protein-loosing enteropathy due to obstruction of the gastrointestinal lymph flow. As the intestinal lymphangiectasia may occur locally, it is not always demonstrable directly on pathologic examination of biopsies.