Syrine Gallas

Sacral nerve stimulation in fecal incontinence: are there factors associated with success?

PurposeSacral nerve stimulation has been used successfully in treating fecal incontinence. This study was designed to evaluate the proportion of patients with unsuccessful implantation despite positive test stimulation and to examine and compare factors associated with the success of the transitory and permanent sacral nerve stimulation.MethodsA total of 61 patients (55 females; median age, 56 (range, 33–77) years) with refractory fecal incontinence underwent temporary stimulation. A 50 percent or greater improvement in the number of episodes of fecal incontinence or urgency was required to proceed to permanent implantation and was the criteria of success of permanent sacral nerve stimulation at the last follow-up visit in implanted patients. The factors compared between the success and the failure groups during temporary and permanent stimulation were patients’ age and gender, diagnosis and characteristics of fecal incontinence, previous surgery, quality of life scores, anorectal manometry, endoanal ultrasound, and electrophysiologic tests performed before stimulation.ResultsTemporary stimulation was successful in 35 patients (57.4 percent). A permanent neurostimulation device was implanted in 33 patients. Age was the only factor related to success of the temporary stimulation (P=0.03). After permanent implantation, 31 percent of patients did not attain screening phase results for the number of episodes of fecal incontinence or urgency. A neurologic disorder was more frequently the origin of fecal incontinence in the success group compared with others (P=0.03). The left bulbocavernosus reflex was more frequently delayed in the success group than in the others (P=0.03), and a prolonged or absent bulbocavernosus reflex was more frequent in the success group than in the failure group (P=0.03).ConclusionsPatients with fecal incontinence from neurologic origins could be good candidates for sacral nerve stimulation.

Gastric electrical stimulation increases ghrelin production and inhibits catecholaminergic brainstem neurons in rats

Gastric electrical stimulation (GES) is a new therapeutic option for functional dyspepsia and gastroparesis. In addition to ameliorating nausea and vomiting, GES results in improved appetite which is not always associated with accelerated gastric emptying. To explore the central and peripheral factors underlying GES‐associated improvement of appetite we developed a GES model in anaesthetized Wistar rats. During laparotomy, two electrodes were implanted into the stomach and high‐frequency low‐energy GES (14 Hz, 5 mA) was applied. The effects of 1 h GES were compared with sham stimulation. After GES, c‐Fos expression was increased in the mucosal and submucosal layers of the stimulated area (174%). In the stomach, GES increased ghrelin mRNA (178%) and doubled the number of ghrelin‐positive cells, resulting in elevated plasma levels of ghrelin (2.3 ± 0.2 vs. 1.6 ± 0.2 ng/mL). In the arcuate nucleus of the hypothalamus, GES increased c‐Fos (277%) and agouti‐related protein (AgRP) mRNA expression (135%). GES reduced the number of c‐Fos‐positive cells throughout the nucleus of the solitary tract (between 93 and 75% from rostral to caudal levels) including catecholaminergic neurons (81% at caudal level). Gastric emptying, plasma glucose and heart rate variability were not affected by GES. This study shows that GES may improve appetite via stimulation of main orexigenic pathways, including ghrelin production in the stomach and AgRP in the hypothalamus, as well as by reducing the activity of catecholaminergic brainstem neurons.

Mylohyoid motor‐evoked potentials relate to swallowing function after chronic stroke dysphagia

Abstract   This work aimed to study mylohyoid motor‐evoked potentials (MHMEPs) and examined if it is related to chronic stroke dysphagia. Conduction time (CT) and amplitudes of the right and left MHMEPs in response to focal cortical magnetic stimulations over affected and unaffected hemispheres were recorded in 16 stroke patients with aspiration (n = 9) or residue (n = 7) and compared with eight control patients. In control group, MHMEPs were present on ipsilateral and contralateral sides after stimulation of both hemispheres and permitted to determine a dominant hemisphere. In stroke patients, after stimulation of the affected hemisphere, ipsilateral MEPs had a longer CT and lower amplitudes in patients with aspiration compared with patients with residue or control patients (P < 0.05). Contralateral CT was not different between the three groups, but amplitudes were lower in patients with residue and aspiration than in control patients (P < 0.01). In the unaffected hemisphere, MHMEPs were present, and not different between the three groups for the ipsilateral side and amplitudes were decreased in contralateral side in patients with residue. In conclusion, MHMEP alterations of the affected hemisphere related to chronic stroke dysphagia severity and were closed to normal in the unaffected hemisphere.

Anal incontinence : the role of medical management

BACKGROUND AND AIMS Consensus recommendations suggest that patients with anal incontinence (AI) should be managed by medical treatment when indicated. Our aims were to prospectively evaluate from two different populations of patients: (1) the proportion of incontinent patients referred to a specialized center who were candidates for first line medical treatment (study 1); (2) the results of medical treatment in incontinent patients (study 2). METHODS In study 1, standardized management of AI based on an algorithmic decision tree was applied to 287 incontinent patients (209 women, ranging from 16 to 84 years old). In study 2, 36 other incontinent patients with transit disorders (28 women, ranging from 29 to 86 years old) seen consecutively, were treated by a medical treatment of their transit disorders. The result of the medical treatment was objectively and subjectively evaluated after 2 months. RESULTS Study 1: medical treatment was indicated in 126 of 287 patients (43.9%) (62 for diarrhea and 64 for constipation) while biofeedback was indicated in 52 patients (18.1%) and surgery specific for AI in 99 patients (34.5%). Eighty percent of the patients who were proposed conservative medical treatment were referred by their gastroenterologist or their general practitioner. Study 2: the continence score decreased from a median of 12 to 6.5 (P<0.001). 61% of patients regarded themselves as cured or improved after medical treatment. CONCLUSION Conservative treatment can be proposed as a first line treatment in more than 50% of patients with anal incontinence referred to a specialized center. Medical treatment for anal incontinence associated with transit disorders improves continence.

Gastric Electrical Stimulation in Intractable Nausea and Vomiting: Assessment of Predictive Factors of Favorable Outcomes

BACKGROUND Gastric electrical stimulation (GES) represents a new therapy in patients with intractable vomiting and nausea. We aimed to determine preoperative factors associated with positive response during GES. Thirty-three consecutive patients received implants for medically refractory nausea or vomiting or both. STUDY DESIGN Symptoms, Quality of Life (QOL), and gastric emptying (GE) were monitored before and 6 months after implantation. Compared with baseline, dyspeptic symptoms including nausea and vomiting, and QOL all improved at 6 months, yielding a significant weight gain while the GE rate remained unchanged. Twenty-four patients reported improvement; nine remained unimproved at 6 months. RESULTS In multivariate analysis, baseline QOL and appetite alterations were predictive of improvement; previous history of gastric surgery was associated with failure. Surprisingly, patients with initial delayed GE (21 of 33) displayed similar improvement compared with patients with normal GE. Likewise, basal GE was not found to be predictive of positive outcomes, QOL, or symptoms improvement. CONCLUSIONS Patients with severe symptoms and altered QOL at inclusion particularly benefit from GES; delay in GE is not predictive of positive outcomes. This suggests that indication for GES should be based on clinical settings rather than initial GE, and then possibly extended to patients with normal GE.

Chemotherapy-induced anorexia is accompanied by activation of brain pathways signaling dehydration.

BACKGROUND AND AIMS Cancer chemotherapy is accompanied by anorexia and mucositis. To clarify the mechanisms of chemotherapy-induced anorexia, we studied the expression of c-fos and appetite-regulating neuropeptidergic and inflammatory mediators in the hypothalamus of rats treated with methotrexate (MTX). METHODS Sprague-Dawley rats received MTX (2.5mg/kg, subcutaneously) on three consecutive days and were compared with ad libitum- and pair-fed control rats five days after the first injection. RESULTS MTX administration inhibited food and water intake and induced lean and fat mass losses. MTX also induced mucositis and diarrhea without changes in plasma osmolality. Pair-fed rats lost a similar amount of body weight but had no mucositis or diarrhea. Increased number of c-fos positive hypothalamic vasopressin neurosecretory neurons as well as numerous c-fos positive cells in the subfornical organ and in the organum vasculosum of the lamina terminalis were found in MTX-treated as compared to control or pair-fed rats. In both MTX and pair-fed rats, a decrease of hypothalamic proopiomelanocortin mRNA expression and low plasma levels of interleukin-1β (IL-1β) were found reflecting probably the energy deficit. No significant changes of IL-1β mRNA expression and intensity of microglial staining in the hypothalamus were found in MTX-treated rats. CONCLUSION The pattern of c-fos expression in the hypothalamus during MTX treatment is similar to that seen with systemic dehydration, which is known to cause anorexia. No evidence of inflammatory origin of anorexia was found, suggesting that chemotherapy accompanied by mucositis and diarrhea may cause anorexia associated with systemic dehydration.

Does magnetic stimulation of sacral nerve roots modify colonic motility? Results of a randomized double‐blind sham‐controlled study

Abstract  Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short‐term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min−1 for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high‐amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8–39) after Bisacodyl administration during active stimulation compared to 14 min (range 5–40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl‐induced colonic contractions.

Ghrelin, appetite and gastric electrical stimulation.

Ghrelin is a peptide hormone produced mainly by the stomach and has widespread physiological functions including increase in appetite. The stimulation of the ghrelin system represents a potential therapeutic approach in various disorders characterized by deficient ghrelin signaling or by low appetite. This stimulation may be achieved via pharmacological targeting of the ghrelin receptor with synthetic ghrelin or ghrelin mimetics or via increased endogenous ghrelin production. Recently, it was demonstrated that gastric electrical stimulation (GES) with Enterra parameters results in increased ghrelin production in rats. Furthermore, recent data revealed putative role of ghrelin-reactive immunoglobulins in the modulation of the ghrelin signaling which can be also stimulated by GES. Here, we review the links between GES and ghrelin in existing GES experimental and clinical applications for treatment of gastroparesis, functional dyspepsia or obesity and discuss if GES can be proposed as a non-pharmacological approach to improve ghrelin secretion in several pathological conditions characterized by low appetite, such as anorexia nervosa or anorexia-cachexia syndrome.