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Clinical Neurophysiology : Official... Mar 2023This retrospective (case-control) collaborative study evaluates tendon reflex recordings combined with transcranial magnetic stimulation motor evoked potentials...
OBJECTIVE
This retrospective (case-control) collaborative study evaluates tendon reflex recordings combined with transcranial magnetic stimulation motor evoked potentials recordings (T-MEPs) at lower limbs in amyotrophic lateral sclerosis (ALS).
METHODS
T-MEPs were recorded in 97 ALS patients distinguished according to their patellar reflex briskness. Patients' electrophysiological data were compared with values measured in 60 control patients matched for age and height. Correlations studies between parameters or with some patients' clinical characteristics were also performed.
RESULTS
The central motor conduction time yields the highest sensitivity (82%) and specificity (93%), allowing twice more upper motor neuron (UMN) dysfunction detection than clinical examination, and being more altered in late stages of the disease. The T response to MEP response amplitude ratio (T/MEP ar) is nearly as sensitive to detect ALS and better identifies abnormal hyperreflexia. It is not correlated with evolutive stage, contrarily to conduction time-related parameters. In addition, T-MEPs detect asymmetries escaping clinical examination.
CONCLUSIONS
The corticospinal conduction to lower limbs is slowed in ALS. The T/MEP ar helps deciding when patellar reflexes are abnormal in a given patient suspected of ALS.
SIGNIFICANCE
The T-MEP technique provide powerful electrophysiological biomarkers of UMN involvement in ALS. This simple and painless procedure introduces the clinically useful concept of electrophysiological hyperreflexia and might be expanded to future exploration of proximal upper limbs and bulbar territories.
Topics: Humans; Amyotrophic Lateral Sclerosis; Evoked Potentials, Motor; Reflex, Stretch; Retrospective Studies; Reflex, Abnormal; Transcranial Magnetic Stimulation
PubMed: 36753809
DOI: 10.1016/j.clinph.2022.12.013 -
Diseases of the Colon and Rectum Jul 2010Rectal hyposensitivity commonly causes anorectal disorders, but its underlying mechanism is unknown. We hypothesized that subjects with rectal hyposensitivity have... (Comparative Study)
Comparative Study
PURPOSE
Rectal hyposensitivity commonly causes anorectal disorders, but its underlying mechanism is unknown. We hypothesized that subjects with rectal hyposensitivity have altered rectoanal reflexes and/or sensorimotor response.
METHODS
We performed stepwise graded balloon distensions of the rectum in 30 subjects with constipation and rectal hyposensitivity and in 23 healthy controls. Thresholds for first sensation, desire, and urgency to defecate were assessed. The lowest balloon volume that evoked rectoanal inhibitory reflex, rectoanal contractile reflex, and sensorimotor response and manometric characteristics and rectal compliance were examined.
RESULTS
Reflex responses were present in all subjects. The balloon volumes were higher in subjects with rectal hyposensitivity for inducing rectoanal inhibitory reflex (P = .008) and contractile reflex (P = .001) compared with controls. All controls showed a sensorimotor response, but in 13 hyposensitive subjects (43%) the onset of sensorimotor response was associated with absent sensation and in 17 (57%), with a transient rectal sensation. Thresholds for eliciting sensorimotor response were similar between patients and controls, but the amplitude, duration, and magnitude of response were higher (P < .05) in patients. Rectal compliance was similar between controls and hyposensitive subjects with transient sensation but higher (P = .001) in subjects with absent sensation.
CONCLUSIONS
Constipated subjects with rectal hyposensitivity demonstrate higher thresholds for inducing rectoanal reflexes and abnormal characteristics of sensorimotor response. These findings suggest either disruption of afferent gut-brain pathways or rectal wall dysfunction. These altered features may play a role in the pathogenesis of bowel dysfunction in rectal hyposensitivity.
Topics: Afferent Pathways; Anal Canal; Catheterization; Compliance; Constipation; Female; Humans; Male; Manometry; Middle Aged; Rectal Diseases; Rectum; Reflex, Abnormal; Sensation; Somatosensory Disorders
PubMed: 20551758
DOI: 10.1007/DCR.0b013e3181dcb2d6 -
Investigative Ophthalmology & Visual... Aug 2013To assess the relationship between the pupillary light reflex (PLR) and visual field (VF) mean deviation (MD) and retinal nerve fiber layer (RNFL) thickness.
PURPOSE
To assess the relationship between the pupillary light reflex (PLR) and visual field (VF) mean deviation (MD) and retinal nerve fiber layer (RNFL) thickness.
METHODS
A total of 148 patients with glaucoma (mean age 67 ± 11, 49% female) and 71 controls (mean age 60 ± 10, 69% female) were included in this study. Using a pupillometer, we recorded and analyzed pupillary responses at varied stimulus patterns (full field, superonasal and inferonasal quadrant arcs). We compared the responses between the two eyes, compared responses to stimuli in the superonasal and inferonasal fields within each eye, and calculated the absolute PLR value of each individual eye. We assessed the relationship among PLR, MD, and RNFL thickness using the Pearson correlation coefficient. For analyses performed at the level of individual eyes, we used multilevel modeling to account for between-eye correlations within individuals.
RESULTS
For every 0.3 log unit difference in between-eye asymmetry of PLR, there was an average 2.6-dB difference in visual field MD (correlation coefficient R = 0.83, P < 0.001) and a 3.2-μm difference in RNFL thickness between the two eyes (R = 0.67, P < 0.001). Greater VF damage and thinner RNFL for each individual eye were associated with smaller response amplitude, slower velocity, and longer time to peak constriction and dilation after adjusting for age and sex (all P < 0.001). However, within-eye asymmetry of PLR between superonasal and inferonasal stimulation was not associated with corresponding within-eye differences in VF or RNFL.
CONCLUSIONS
As measured by this particular device, the PLR is strongly correlated with VF functional testing and measurements of RNFL thickness.
Topics: Aged; Cell Count; Cell Size; Female; Glaucoma; Humans; Male; Middle Aged; Multivariate Analysis; Photic Stimulation; Pupil; Reflex, Abnormal; Reflex, Pupillary; Regression Analysis; Retina; Retinal Ganglion Cells; Tomography, Optical Coherence; Visual Field Tests; Visual Fields
PubMed: 23860751
DOI: 10.1167/iovs.13-12142 -
Acta Otorrinolaringologica Espanola 2015
Topics: Adult; Arteries; Diagnosis, Differential; Female; Hearing Loss, Conductive; Hearing Loss, Unilateral; Humans; Otosclerosis; Reflex, Abnormal; Stapedius
PubMed: 24626047
DOI: 10.1016/j.otorri.2013.12.006 -
British Medical Journal Aug 1973Three patients with severe tetanus had episodes of profound arterial hypotension lasting from minutes to hours. The blood pressure was recorded continuously for 13, 19,...
Three patients with severe tetanus had episodes of profound arterial hypotension lasting from minutes to hours. The blood pressure was recorded continuously for 13, 19, and six days respectively by an intra-arterial catheter, and other measurements included heart rate, central venous pressure, cardiac output, and blood gases.The hypotension was distinguished from that of "shock", for there was no clinical evidence of peripheral vasoconstriction and no tachycardia. It could not be attributed to disturbances of salt and water balance. During episodes of hypotension the blood pressure fell as low as 32/16 mm Hg, the heart rate fell from a mild tachycardia to normal values or a mild bradycardia, and the central venous pressure did not rise. The onset and the end of such episodes was often abrupt and the hypotension was often produced in response to a stimulus. In one patient extreme hypotension followed the aspiration of secretions from the trachea. These changes may represent another effect of tetanus on autonomic nervous activity, including impairment of baroreceptor reflexes.
Topics: Aged; Blood Pressure; Bradycardia; Cardiac Output; Cardiac Volume; Central Venous Pressure; Drainage; Female; Heart Rate; Humans; Hypotension; Male; Pressoreceptors; Reflex, Abnormal; Sympathetic Nervous System; Tetanus; Trachea; Vascular Resistance
PubMed: 4726136
DOI: 10.1136/bmj.3.5877.423 -
Cleveland Clinic Journal of Medicine Jan 2019
Topics: Acute Disease; Aged; Diagnosis, Differential; Humans; Male; Quadriplegia; Reflex, Abnormal
PubMed: 30624189
DOI: 10.3949/ccjm.86a.18049 -
Heart (British Cardiac Society) Jan 2006Skeletal muscle abnormalities are highly prevalent in chronic heart failure and are associated with an increase in the ergoreflex, a muscle reflex stimulated by work... (Review)
Review
Skeletal muscle abnormalities are highly prevalent in chronic heart failure and are associated with an increase in the ergoreflex, a muscle reflex stimulated by work done. Stimulation of the ergoreflex results in increased ventilation and contributes to the increased sympathetic activation of the heart failure syndrome. The origin of the skeletal myopathy is related to a chronic imbalance between catabolic and anabolic processes, presumably as a consequence of chronic haemodynamic stress. Symptoms arise from the skeletal myopathy, causing the sensation of fatigue and contributing to the sensation of breathlessness as the myopathy affects respiratory muscle. Ergoreflex activation causes a greater ventilatory response to exercise than normal, contributing to the sensation of breathlessness.
Topics: Chronic Disease; Dyspnea; Exercise; Exercise Tolerance; Fatigue; Heart Failure; Hemodynamics; Humans; Lung Diseases; Muscle, Skeletal; Muscular Diseases; Reflex, Abnormal
PubMed: 16159969
DOI: 10.1136/hrt.2005.066886 -
American Journal of Physiology. Heart... Oct 2017Previous studies have shown that diabetic peripheral neuropathy affects both unmyelinated and myelinated afferents, similar to those evoking the exercise pressor reflex....
Previous studies have shown that diabetic peripheral neuropathy affects both unmyelinated and myelinated afferents, similar to those evoking the exercise pressor reflex. However, the effect of type 1 diabetes (T1DM) on this reflex is not known. We examined, in decerebrate male and female T1DM [streptozotocin (STZ)] and healthy control (CTL) rats, pressor and cardioaccelerator responses to isometric contraction of the hindlimb muscles during the early and late stages of the disease. STZ (50 mg/kg) was injected to induce diabetes, and experiments were conducted at 1, 3, and 6 wk after injection. On the day of the experiment, we statically contracted the hindlimb muscles by stimulating the sciatic nerve and measured changes in mean arterial pressure and heart rate. We found that the pressor but not cardioaccelerator response was exaggerated in STZ rats at 1 wk (STZ: 21 ± 3 mmHg, = 10, and CTL: 14 ± 2 mmHg, = 10, < 0.05) and at 3 wk (STZ: 26 ± 5 mmHg, = 10, and CTL: 17 ± 3 mmHg, = 11, < 0.05) after injection. However, at 6 wk, and only in male rats, both the pressor (STZ: 13 ± 3 mmHg, = 12, and CTL: 17 ± 3 mmHg, = 13, < 0.05) and cardioaccelerator responses (STZ: 7 ± 3 beats/min, = 12, and CTL: 10 ± 3 beats/min, = 13, < 0.05) to contraction were significantly attenuated in STZ rats compared with CTL rats. These data indicate that T1DM exaggerates the exercise pressor reflex during the early stages of the disease in both male and female rats. Conversely, T1DM attenuates this reflex in the late stage of the disease in male but not female rats. This is the first study to provide evidence that the pressor and cardioaccelerator responses to skeletal muscle contraction vary depending on the duration of type 1 diabetes.
Topics: Animals; Arterial Pressure; Case-Control Studies; Decerebrate State; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Electric Stimulation; Female; Heart Rate; Hindlimb; Male; Muscle Contraction; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Rats, Sprague-Dawley; Reflex; Reflex, Abnormal; Sciatic Nerve; Sex Factors; Vasoconstriction
PubMed: 28778915
DOI: 10.1152/ajpheart.00399.2017 -
Scientific Reports May 2023Hyperreflexia is common after neurological injury such as stroke, yet clinical interventions have had mixed success. Our previous research has shown that hyperreflexia...
Hyperreflexia is common after neurological injury such as stroke, yet clinical interventions have had mixed success. Our previous research has shown that hyperreflexia of the rectus femoris (RF) during pre-swing is closely associated with reduced swing phase knee flexion in those with post-stroke Stiff-Knee gait (SKG). Thus, reduction of RF hyperreflexia may improve walking function in those with post-stroke SKG. A non-pharmacological procedure for reducing hyperreflexia has emerged based on operant conditioning of H-reflex, an electrical analog of the spinal stretch reflex. It is currently unknown whether operant conditioning can be applied to the RF. This feasibility study trained 7 participants (5 neurologically intact, 2 post-stroke) to down-condition the RF H-reflex using visual feedback. We found an overall decrease in average RF H-reflex amplitude among all 7 participants (44% drop, p < 0.001, paired t-test), of which the post-stroke individuals contributed (49% drop). We observed a generalized training effect across quadriceps muscles. Post-stroke individuals exhibited improvements in peak knee-flexion velocity, reflex excitability during walking, and clinical measures of spasticity. These outcomes provide promising initial results that operant RF H-reflex conditioning is feasible, encouraging expansion to post-stroke individuals. This procedure could provide a targeted alternative in spasticity management.
Topics: Humans; Quadriceps Muscle; Reflex, Abnormal; Walking; Gait; Knee Joint; Muscle Spasticity; Stroke; Gait Disorders, Neurologic; Biomechanical Phenomena
PubMed: 37208394
DOI: 10.1038/s41598-023-34709-4 -
Arquivos de Neuro-psiquiatria Jun 2014
Topics: Aged; Fascia Lata; Humans; Male; Pyramidal Tracts; Reflex, Abnormal
PubMed: 24964117
DOI: 10.1590/0004-282x20140052