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S Hollerbach

Publications and source records attributed to S Hollerbach.

50 records · Page 3Linked to original sources
PubMed1997

Cerebral evoked responses to gastrointestinal stimulation in humans.

Recent advances have permitted recording of evoked potentials (EPs) in response to electrical and mechanical stimulation of the gastrointestinal (GI) organs via methods used primarily in clinical neurophysiology. Current research involving stimulation of the esophagus, rectum, and colon, and recording the corresponding responses on the scalp, is being practiced in only a few laboratories. This review examines the engineering aspects of recording EPs, such as characteristics of the stimuli, placement of stimulus electrodes in the GI tract, and enhancement of evoked potential signals. We also discuss the physiological concepts involved in the generation of EPs, and how these compare with somatosensory evoked responses. Current experimental techniques employed by various investigators and results reported from their laboratories are compared. We believe that cerebral EPs to GI stimulation could be useful in studying a number of pathophysiological conditions such as gastroesophageal reflux disease, diffuse esophageal spasm, chronic inflammatory bowel disorders, chronic abdominal pain, and irritable bowel syndrome, among others. We hope that the present review will generate interest in the use of EPs arising out of GI stimulation, aiding in understanding their physiological implications in healthy subjects and in GI disorders.

Cerebral Cortex↗
PubMed1996

[Endosonographic demonstration of extrapancreatic and extraintestinal gastrinoma].

HISTORY AND CLINICAL FINDINGS: No cause had been found for chronic diarrhoea in a 57-year-old man. Up to 15 watery stools daily had been without relation to food intake and without blood admixture. But muscular cramps had developed, especially in the legs. The patient had a history of recurrent peptic ulcers for which a selective proximal vagotomy had been performed 13 years ago. Physical examination was unremarkable. INVESTIGATIONS: Alkaline phosphatase activity (182 U/l) and C-reactive protein (9.3 mg/l) were slightly raised; serum iron was 42 micrograms/dl, while all other routine laboratory tests, including protein electrophoresis, blood picture and differential count were within normal limits. Gastroscopy revealed ulcerative duodenitis, gastritis with erosions and numerous ulcers and reflux oesophagitis, grade III-IV. Endosonography showed enlarged gastric mucosal relief as sign of foveolar hyperplasia and a ca. 4 x 3 cm tumour next to the duodenal bulb. Gastrin level was 7537 pg/ml (normal < 150 pg/ml). Computed tomography and somatostatin receptor scintigraphy confirmed the site and size of the gastrinoma. TREATMENT AND COURSE: Treatment with omeprazole (40 mg three times daily) slightly improved the symptoms. The tumour was excised a week after diagnosis. The patient has been symptom-free since then. CONCLUSION: Chronic diarrhoea of unknown aetiology can be caused by an endocrine tumour; endosonography can often provide information on the diagnosis and location of such a tumour.

Chronic Disease↗
PubMed1996

[Asymptomatic choledochal cyst].

HISTORY AND FINDINGS: A 45-year-old woman sustained an ankle fracture in an accident. At examination she was found to have marked pallor of skin and mucosae. There was no hint for melaena or haematemesis. INVESTIGATIONS: Biochemical tests showed marked iron deficiency anaemia (haemoglobin 7.5 g/dl) and raised serum bilirubin and C-reactive protein levels (1.94 mg/dl and 85.2 mg/l, respectively). Abdominal sonography revealed a cystic space-occupying mass (8 x 4.5 cm) projecting onto the gallbladder, interpreted as a choledochal cyst of unknown origins without bleeding. After treatment of the ankle fracture an endoscopic retrograde cholangiopancreatography was performed. This showed a large cyst of the choledochal duct into which the cystic and choledochal ducts entered, without evidence of tumour or haematoma. There was also a 1 cm prepapillary common choledochal and Wirsung duct. TREATMENT AND COURSE: With these findings, the diagnosis of a congenital choledochal cyst (type Ia of Todani) could be made. After healing of the ankle fracture the cyst was removed and a Roux Y-anastomosis created. The cystic tissue was benign. At follow-up 6 months later the patient was symptom-free and no longer anaemic. CONCLUSIONS: Congenital choledochal cysts are very rare in Europeans. The symptom-free course with anaemia and no manifestation until adulthood is also very unusual.

Anastomosis, Roux-en-Y↗
PubMed1995

Subclinical hepatic encephalopathy: the diagnostic value of evoked potentials.

Brainstem auditory (BAEPs) and somatosensory evoked potentials (SEPs) have been shown to be useful in detecting brainstem or cortical dysfunction in neurological diseases and in combination with other methods to diagnose brain death (37,38). These neurophysiological methods are simple and easy to perform. BAEPs and SEPs can even be easily recorded in intensive care units and guarantee a standardized examination. Moreover, these methods require no extensive patient cooperation and are not heavily influenced by learning effects. The role of BAEPs in the evaluation and diagnosis of hepatic encephalopathy is not clear. BAEPs are obviously strongly influenced by the etiology of liver disease and are normal in viral hepatitis, but prolonged in alcoholic liver disease, Wilson's disease or in hepatic coma (8,12). Unfortunately, BAEPs were not compared to psychometric tests. There was no clear-cut differentiation between various hepatic encephalopathy-gradings. At present, the use of BAEPs in the detection of subclinical hepatic encephalopathy cannot be recommended, whereas in comatose patients BAEPs can be useful as a prognostic marker and for follow-up examinations (12). Recently, Pozessere et al. (12) examined 13 comatose patients with advanced coma stages (Glasgow coma scale 5-10) and recorded unspecific changes in their EEG tracings. In all cases of hepatic coma and in one intoxicated patient they found prolongation of interpeak latencies. In addition, in this small study the interpeak latencies correlated well with the clinical outcome of the patients. Only two studies were performed using SEPs to detect neurophysiological alterations in hepatic encephalopathy (32,33). The design as well as the results of these studies are quite different. Despite the small number of patients (n = 10), the prolongation of late components in 50% of patients with hepatic encephalopathy stage 0 could be a promising result (32). The value of SEPs in detecting subclinical hepatic encephalopathy is rather undefined. The fact that the generation of SEPs is due to an activation of complex structures of the central nervous system justifies the need for further investigations with this modality. The recording of visual evoked potentials requires much more methodological and technical effort than the recording of BAEPs or SEPs. The discrimination between pattern reversal (PVEP) and flashlight (FVEP) stimulation is highly important for the proper interpretation of the published data. Most of the studies were done using FVEPs, which are in particular clinically relevant for comatose patients (31). The conclusions of the authors using FVEPs (22-25) are not supported by the American Electroencephalographic Society (31).(ABSTRACT TRUNCATED AT 400 WORDS)

Electrodiagnosis↗
PubMed1995

[Masked course of Whipple disease with uveitis, infection, endocardial involvement and abdominal lymphomas--case report and review of the literature].

Whipple's disease is a systemic disease which may virtually affect any organ system, but in many cases it involves the small intestine causing gastrointestinal symptoms. The differential diagnosis is difficult since symptoms may be nonspecific. We report the case of a 44-year old white male patient with a history of migrating arthralgia and chronic fatigue. The patient newly developed an uveitis and underwent a vitrectomy; the further clinical work-up including gastroscopy with intestinal biopsy revealed no sufficient diagnosis. Subsequently, the patient's condition deteriorated with marked weight loss, fever and progressive weakness. An anaerobic sepsis with a corynebacterium was confirmed and with i.v.-antibiotics the patients's condition improved markedly. The further examinations disclosed enlarged mesenteric lymph nodes and the involvement of other organs (endocard, liver). CT-guided biopsy only showed fatty degeneration, but operative adenectomy confirmed Whipple's disease. The patient remained without relapse on long-term antibiotic treatment with doxycycline until today. Obviously, in our case the intestinal biopsies failed to detect Whipple's disease after the successful initiation of antibiotic treatment. In the absence of gastrointestinal findings and with concomitant secondary diseases the definitive diagnosis can be difficult. In addition, the previous uveitis and the endocardial involvement are most interesting.

Abdominal Neoplasms↗
PubMed1995

[Multiple gastric wall abscesses--a rare differential endosonographic diagnosis of submucous stomach tumors].

We report a rare case of a 52 year old patient with multiple gastric wall abscesses. In 1987 a selective proximal vagotomy was performed. Because of non-specific gastric symptoms in 1993 an endoscopy and an endoscopic ultrasound was performed at another hospital which resulted in the likely diagnosis of multiple leiomyomas. Three months later a control endosonography showed three well demarcated submucosal tumors, partly echo-genic, but with an inhomogeneous echo-pattern. A laparotomy and histological examination of the submucosal gastric tumors revealed multiple gastric abscesses with granulomas after selective proximal vagotomy. Difficulties in the differential diagnosis of submucosal gastric tumors arising from this case are demonstrated and discussed.

Abscess↗
PubMed1995

[Diagnosis of round liver lesions].

Ultrasound and computed tomography are dominant in the diagnosis of liver lesions. Angiography, magnetic resonance imaging, and scintigraphic procedures complete the spectrum. Ultrasound and computed tomography are able to detect focal liver lesions and to distinguish between hypoechoic, anechoic and hyperechoic lesions. We differentiate in addition between liver lesions found accidentally or in patients suffering from a known tumor. For a definite diagnosis of a haemangioma a computerized tomography with rapid contrast bolus or MRI should be performed. If there is suspicion of an adenoma or a focal nodal hyperplasia a hepatobiliary sequence scintigraphy should be performed. In the following the essential procedures for the differential diagnosis of liver lesions based on there sonomorphological appearance is presented.

Adenoma, Liver Cell↗
PubMed1994

[Current status of abdominal pancreatic ultrasound. A retrospective analysis of 585 pancreatic ultrasound examinations].

BACKGROUND: In the recent years several investigations focused on the diagnostic value of abdominal ultrasonography in pancreatic disorders. However, the diagnostic accuracy in these studies ranged between 40 and 90% probably related to variations in study design and other methodologic criteria. PATIENTS: We examined retrospectively 585 patients subdivided into six subgroups. 385 patients had a clinical question aimed at the pancreas and the remaining 200 functioned as screening patients. RESULTS: Using laboratory tests, CT, ERCP, surgery and autopsy as reference methods the positive predictive value for all pancreatic disorders was 85% with the best results for chronic pancreatitis (86% versus 77.5% for acute pancreatitis and 79.5% for malignant tumors). The prevalence of pancreatic disease in symptomatic patients was 28.6% versus only 2.5% in the screening groups. Therefore no significant differences could be detected in groups where the pancreas was not clearly visualized and groups with negative sonographic findings (4% false negative findings versus 1%, respectively). In groups with suspected pancreatic disease the negative predictive value was 86% which was independent of the visualization of the pancreas. CONCLUSION: In summary positive sonographic findings have a high predictive value for pancreatic disorders and negative results are not more reliable than missing visualization of the pancreas. The positive predictive value is independent from the kind of pancreatic disease and in screening examinations negative findings and findings without clearly visualization of the pancreas have both high negative predictive values.

Acute Disease↗
PubMed1994

Clinical significance of sonographic findings in outpatient clinics.

In the literature substantial controversy exists about the clinical significance of abdominal screening procedures. Therefore, the aim of our prospective study was to determine the clinical relevance and the differences of sonographic findings in both symptomatic and asymptomatic screening outpatients. We therefore systematically analyzed the sonographic findings in 200 consecutive patients of a medical outpatient unit. The patients were divided into 2 subgroups: group I consisted of 128 patients without specific clinical symptoms in the abdomen (screening group); group II included 72 patients with abdominal symptoms and therefore well-defined sonographic requests. The consequences drawn from the sonographic results were analyzed separately for both patient groups. All findings were subdivided into relevant, prospectively relevant or not relevant, depending on their individual influence on the patients' course. In all cases the entire abdomen and basal parts of the thorax were examined. In the 1st group (n = 128/93 findings) 6 findings (6.5%) were relevant, 24 (26%) prospectively relevant and 63 not relevant (67.5%). In contrast, the 2nd group (n = 72/68 findings) contained 13 relevant (19%), 27 prospectively relevant (40%) and 28 not relevant sonographic findings (41%). The differences between group I and II were statistically significant for the relevant findings (2p < 0.05) and the not relevant findings (2p < 0.01). In conclusion, abdominal ultrasonography provides--even for the screening of the outpatient population--in up to 30% additional clinically acute or prospectively relevant information. Therefore, it completes the physical examination adding a substantial amount of clinical information to the medical record of outpatients.

Abdomen↗
PubMedDate not supplied

Auditory event-related cerebral potentials (P300) in hepatic encephalopathy--topographic distribution and correlation with clinical and psychometric assessment.

BACKGROUND/AIMS: Early cognitive disturbances in patients with cirrhosis (Ci) are difficult to assess. Therefore, we evaluated the role of topographic auditory evoked cerebral potentials (P300-EP). METHODOLOGY: Prospective longitudinal study. SETTING: Tertiary clinical care institution. PARTICIPANTS: 45 patients with cirrhosis were compared to 22 healthy subjects. MAIN OUTCOME MEASURES: Hepatic Encephalopathy (HE) was assessed using the clinical grading, standardized psychometric tests, and auditory evoked P300-EP by multichannel EEG recordings. RESULTS: In the patients, the mean P300 peak latency was significantly increased (386.7 +/- 26.7 versus 318.6 +/- 22.2 ms in controls, p < 0.00001). Even in patients with cirrhosis but no HE (n = 18) the P300 peak latency was abnormally prolonged (> 384 ms) in 8 cases (44%). In addition, P180 peak latency was significantly longer in patients with liver cirrhosis as compared to controls (p = 0.021). The maximal P300 amplitude was significantly lowered in patients with liver cirrhosis in the frontocentral and central cortical regions (FZ: p < 0.008; Cz: p < 0.04). Liver function and etiology of liver disease were not related to the increased peak latencies of the P300 and P180 peaks. CONCLUSIONS: P300-EP is a sensitive measure to detect functional cognitive impairment in cirrhotic patients with subclinical HE and clinically apparent HE. Typical changes include latency prolongation and decreased central peak amplitude. Some 40% of patients with no clinical evidence of HE and normal psychometric tests show abnormal results during P300 testing, which is likely to reflect early impairment of cognitive function. Auditory evoked P300 potentials are more sensitive than psychometric testing alone.

Adult↗