Search results for "reflex"
showing 10 items of 622 documents
A painful tic convulsif due to double neurovascular impingement
2011
Here we present the case of a 50-year-old man suffering from "painful tic convulsif", on the left side of the face, i.e., left trigeminal neuralgia associated with ipsilateral hemifacial spasm. An angio-MRI scan showed a neurovascular confliction of left superior cerebellar artery with the ipsilateral V cranial nerve and of the left inferior cerebellar artery with the ipsilateral VII cranial nerve. Neurophysiological evaluation through esteroceptive blink reflex showed the involvement of left facial nerve. An initial carbamazepine treatment (800 mg/daily) was completely ineffective, so the patient was shifted to lamotrigine 50 b.i.d. that was able to reduce attacks from 4 to 6 times per day…
Enhancement of guinea-pig intestinal peristalsis by blockade of muscarinic M1-receptors
1988
1. The effects of pirenzepine and hyoscine on the peristaltic reflex were investigated in the guinea-pig isolated small intestine. Peristalsis was induced by raising the intraluminal pressure and the volume of fluid propelled was taken as a measure of the efficiency of peristaltic activity. 2. Low concentrations of pirenzepine (0.1-1 nM) and of hyoscine (0.01 nM) significantly enhanced peristalsis, whereas larger concentrations of both drugs caused inhibition. Pirenzepine was about 6 times less potent than hyoscine in increasing peristalsis, but was about 100 times less potent in inhibiting it. 3. Neither tolazoline (1 microM) nor naloxone (0.3 microM) affected the stimulatory action of pir…
Diabetic 3rd nerve palsy: evidence for a mesencephalic lesion.
1990
Eleven consecutive adult chronic diabetic patients presented with an isolated 3rd nerve palsy (8 with pupillary sparing) of which 10 had abnormal ipsilateral or bilateral masseter reflexes (MassR). Three patients had an MRI lesion in the ipsilateral oculomotor fasciculus and 3 had subsequent mild brainstem signs. An additional 13 patients with Weber's syndrome had similar ipsilateral or bilateral MassR abnormalities, while 7 patients with 3rd nerve palsies on a known extra-axial basis had none. The findings suggest that an isolated diabetic 3rd nerve palsy, with or without pupillary sparing, is much more likely on the basis of a focal mesencephalic infarct than a peripheral nerve lesion.
MOTOR DYSFUNCTION OF THE "NON AFFECTED" LOWER LIMB: A KINEMATIC COMPARATIVE STUDY BETWEEN HEMIPARETIC STROKE AND TOTAL KNEE PROSTHESIZED PATIENTS
2009
In patients with hemispheric stroke, abnormal motor performances are described also in the ipsilateral limbs. They may be due to a cortical reorganization in the unaffected hemisphere; moreover, also peripheral mechanisms may play a role. To explore this hypothesis, we studied motor performances in 15 patients with hemispheric stroke and in 14 patients with total knee arthroplasty, which have a reduced motility in the prosthesized leg. Using the unaffected leg, they performed five superimposed circular trajectories in a prefixed pathway on a computerized footboard, while looking at a marker on the computer screen. The average trace error was significantly different between the groups of pat…
Inhibition of gastric acid secretion by stress: A protective reflex mediated by cerebral nitric oxide
1996
Moderate somatic stress inhibits gastric acid secretion. We have investigated the role of endogenously released NO in this phenomenon. Elevation of body temperature by 3°C or a reduction of 35 mmHg (1 mmHg = 133 Pa) in blood pressure for 10 min produced a rapid and long-lasting reduction of distension-stimulated acid secretion in the rat perfused stomach in vivo . A similar inhibitory effect on acid secretion was produced by the intracisternal (i.c.) administration of oxytocin, a peptide known to be released during stress. Intracisternal administration of the NO-synthase inhibitor, N G -nitro- l -arginine methyl ester ( l -NAME) reversed the antisecretory effect induced by all these stimul…
Increased muscle sympathetic nerve activity and impaired baroreflex control in isolated REM-sleep behavior disorder.
2021
Changes in baroreflex sensitivity have been reported in patients with idiopathic Parkinson's disease (PD). We sought to investigate the hypothesis that patients with isolated rapid eye movement (REM)-sleep behavior disorder (iRBD), known to be a prodromal stage for PD, will show abnormalities in baroreflex control.Ten iRBD patients were compared to 10 sex- and age-matched healthy controls. Their cardiovascular parameters and muscle sympathetic nerve activity (MSNA) were evaluated at rest and during baroreflex stimulation.MSNA at rest was higher in iRBD patients (burst frequency [BF]: 44 ± 3 bursts/min; burst incidence [BI]: 60 ± 8 bursts/100 heartbeats) as compared to the controls (BF: 29 ±…
Differences in intermittent postural control between normal-weight and obese children.
2016
Abstract Aim The main objective of this study was to determine differences in postural control between obese and non-obese children. Methods The study design was cross-sectional, prospective, between-subjects. Postural control variables were obtained from a group of obese children and a normal-weight control group under two different postural conditions: bipedal standing position with eyes open and bipedal standing with eyes closed. Variables were obtained for each balance condition using time domain and sway-density plot analysis of the center of pressure signals acquired by means of a force plate. Results Pairwise comparisons revealed significant differences between obese and normal-weigh…
Central Contribution to Electrically Induced Fatigue depends on Stimulation Frequency
2017
International audience; PURPOSE: This study analyzed the impact of several protocols of neuromuscular electrical stimulation (NMES), matched with a similar total torque-time integral, on muscle activation pathways and neuromuscular fatigue.METHODS: Ten young healthy participants (age: 24.6 +/- 4.2) performed 3 randomized NMES sessions on the triceps surae muscles with 20 Hz, 60 Hz or 100 Hz stimulation frequencies (pulse duration: 1 ms), with pulse amplitude (IES) set at 20 % of isometric maximal voluntary contraction (MVC). Muscle activity during NMES was assessed by means of the twitch, the soleus H-reflex and M wave responses evoked by single muscle stimulation at IES. Neuromuscular fati…
Gastric acid secretory responses induced by peptone are mediated by capsaicin-sensitive sensory afferent neurons
1992
The involvement of capsaicin-sensitive afferent neurons in modulating acid-secretory responses to peptone, a product of protein digestion, has been investigated in the continuously perfused stomach of the urethan-anesthetized rat. Systemic neonatal pretreatment with capsaicin, which destroys primary afferent neurons, does not modify basal levels of acid secretion. Acid responses to intragastric perfusion with isotonic (0.5, 1, and 2.4%) or hypertonic (10 and 20%) solutions of peptone were reduced in capsaicin-treated rats. Intragastric perfusion with hypertonic mannitol (18%) did not stimulate secretion of acid. Systemic capsaicin pretreatment did not modify acid responses to intraperitone…
Activation of angiotensin II type 1 receptors and contractile activity in human sigmoid colon in vitro.
2015
We propose and validate a non-invasive method that enables accurate detection of the discharge times of a relatively large number of motor units during excitatory and inhibitory reflex stimulations. HDsEMG and intramuscular EMG (iEMG) were recorded from the tibialis anterior muscle during ankle dorsiflexions performed at 5%, 10%, and 20% of the maximum voluntary contraction (MVC) force, in 9 healthy subjects. The tibial nerve (inhibitory reflex) and the peroneal nerve (excitatory reflex) were stimulated with constant current stimuli. In total, 416 motor units were identified from the automatic decomposition of the HDsEMG. The iEMG was decomposed using a state-of-the-art decomposition tool a…