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PubMed1981

Inappropriate renin secretion and abnormal cardiovascular reflexes in coarctation of the aorta.

The response of the renin-angiotensin system to high and low sodium diets, to standing, and to saralasin infusion was assessed before and after surgical correction of aortic coarctation in a 27-year-old man. The cardiovascular responses to tests of autonomic function were measured. The heart rate responses to the Valsalva manoeuvre and standing were abnormal before operation, and plasma renin levels were high and renin secretion responded poorly to changes in dietary sodium, to standing, and to saralasin. Renin responsiveness and cardiovascular reflexes returned to normal after operation. The results are consistent with the hypothesis that there is a high level of sympathetic efferent activity in coarctation of the aorta and that factors other than increased activity of the renin-angiotensin system may cause high blood pressure.

Adult↗
PubMedDate not supplied

The negative on/off effect in cochlear and early stapedial otosclerosis.

Acoustic reflex patterns were reviewed for 100 patients suspected of having cochlear otosclerosis (group 1) and 73 patients with confirmed stapedial otosclerosis and conductive hearing losses of less than 5 years duration (group 2). Three abnormal reflex patterns were exhibited by these patients--"negative on/off," "no response when the probe was in the affected ear," and "no response when the stimulus was in affected ear." Results showed that the negative on/off pattern was equally as common for the two subject groups. The "no response" patterns were more common for the early stapedial otosclerosis group. The presence of acoustic reflex patterns classically associated with stapedial otosclerosis in patients with cochlear otosclerosis leads us to predict that some degree of stapedial fixation is common in many cases of cochlear otosclerosis. Based upon these findings, the presence of the negative on/off pattern in patients with mild sensorineural hearing loss, excellent speech discrimination, and a family history of hearing loss, is now considered indicative of cochlear otosclerosis.

Adolescent↗
PubMed1991

The ubiquity of contraction enhanced H reflexes: normative data and use in the diagnosis of radiculopathies.

Surface recorded contraction enhanced H reflexes to single stimuli were obtained from muscles supplied by the C5, 6, 7, 8, L3, 4, 5, S1 and 2 nerve roots. For each of 12 such muscles, these reflexes were recorded from 25 control subjects as well as standard unenhanced H reflexes from the gastrocnemius muscles. Amplitude and latency criteria for normality were determined. Thirty-two patients with typical histories and physical findings of radiculopathy secondary to degenerative disease of the spine (C6 nerve root - 9 patients, C7 - 10, C8 - 4, L4 - 4, L5 - 4, S1 - 1) were studied with these H reflexes and the needle electrode. Thirty patients had H reflex abnormalities appropriate to the signs and symptoms. Eighteen had absent H reflexes and 16 had abnormalities to amplitude criteria. None were abnormal by latency criteria. Twelve patients had abnormal needle examinations and all also had abnormal H reflexes. These results indicate that contraction enhanced H reflexes are ubiquitous, readily obtainable and sensitive to the presence of clinically clear-cut radiculopathies.

Adolescent↗
PubMed1978

The effect of induced hyperthermia on the blink reflex in multiple sclerosis.

In 76 patients with multiple sclerosis, the blink reflex was elicted electrically at normal body temperature and during induced hyperthermia to observe the effect on conduction within the reflex pathway through the brainstem. Special attention was directed to 31 patients with electrophysiologic evidence of reflex slowing, presumably because of demyelination in the reflex pathway. Hyperthermia did not induce any significant changes in mean reflex latency, amplitude, or duration in either the overall group of 76 or in the 31 patients with baseline blink reflex abnormalities. While the mean reflex latency did not change, 13 (33 percent) of 39 abnormal R1 responses from the 31 patients changed by 1.5 msec or more during hyperthermia, whereas change of similar magnitude was noted in only three (3 percent) of 90 normal R1 responses.

Body Temperature↗
PubMed1990

Idiopathic and symptomatic trigeminal pain.

The trigeminal reflexes (corneal reflex, blink reflex, masseter inhibitory periods, jaw-jerk) and far field scalp potentials (nerve, root, brainstem, subcortical) evoked by percutaneous infraorbital stimulation were recorded in 30 patients with "idiopathic" trigeminal neuralgia (ITN) and 20 with "symptomatic" trigeminal pain (STP): seven postherpetic neuralgia, five multiple sclerosis, four tumour, two vascular malformation, one Tolosa-Hunt syndrome, and one traumatic fracture. All the patients with STP and two of those with ITN had trigeminal reflex abnormalities; 80% of patients with STP and 30% of those with ITN had evoked potential abnormalities. The results indicate that 1) trigeminal reflexes and evoked potentials are both useful in the examination of patients with trigeminal pain, and in cases secondary to specific pathologies provide 100% sensitivity; 2) in "symptomatic" and "idiopathic" paroxysmal pain the primary lesion affects the afferent fibres in the proximal portion of the root or the intrinsic portion in the pons; 3) primary sensory neurons of the A-beta fibre group are involved in both paroxysmal and constant pain, but in the latter the damage is far more severe.

Adult↗
PubMed1997

Distinctive abnormalities of facial reflexes in patients with progressive supranuclear palsy.

Spontaneous and voluntary eyelid motility is often abnormal in patients with progressive supranuclear palsy. In contrast, their eyelid reflex responses are relatively preserved, and only those generated by an acoustic startle have been found absent or severely reduced. We hypothesized that, because of their relevant brainstem pathology, patients with progressive supranuclear palsy might have other brainstem reflex abnormalities which, on detection, could help with their neurophysiological characterization. In this study, we examined facial reflex responses in 14 patients with progressive supranuclear palsy, 12 patients with multisystem atrophy, 10 patients with Parkinson's disease, six patients with corticobasal ganglionic degeneration, 11 patients with various non-parkinsonian neurological illnesses and 10 normal subjects. EMG activity was simultaneously recorded from the orbicularis oculi and mentalis muscles following electrical stimulation of the median nerve at the wrist. Mentalis responses were obtained in two normal subjects and in all patients except one with Parkinson's disease, one with progressive supranuclear palsy and one with corticobasal ganglionic degeneration; there were no differences between groups of subjects regarding latency or peak amplitude. Orbicularis oculi responses were always present in control subjects and patients who exhibited mentalis responses, with the significant exception of patients with progressive supranuclear palsy, in whom only the response of mentalis was obtained. Blink-reflex responses to supraorbital nerve electrical stimuli were present at a normal latency and amplitude in all patients. An abnormally enhanced blink-reflex excitability recovery curve to paired stimuli was found in a similar percentage of patients with progressive supranuclear palsy, multisystem atrophy and Parkinson's disease, but in only two patients with corticobasal ganglionic degeneration. Patients with progressive supranuclear palsy have a functional involvement of circuits mediating orbicularis oculi responses to median nerve electrical stimuli, that is a distinctive feature with respect to other parkinsonian syndromes.

Adult↗
PubMed1998

Reflex responses of venous capacitance vessels in patients with hypertrophic cardiomyopathy.

1. The aim of this study was to determine if there is impaired reflex venoconstriction in patients with hypertrophic cardiomyopathy and whether this is related to a history of syncope or exercise hypotension. 2. Thirty percent of patients with hypertrophic cardiomyopathy have exercise-induced hypotension associated with a failure of arteriolar constriction. Impaired venoconstriction could exacerbate this situation. 3. We evaluated 43 patients with hypertrophic cardiomyopathy and 24 controls. Nuclear venous plethysmography was used to measure forearm venous capacitance during lower body negative pressure, splenic venous volume changes during bicycle exercise and blood pressure responses to treadmill exercise. We assessed any association between abnormal reflex venous control and a history of syncope and exercise hypotension. 4. The percentage reduction in unstressed forearm venous volume during lower body negative pressure was similar in patients and controls (8.9 +/- 7.1% versus 9.7 +/- 5.9%, P not significant). Patients with a history of syncope demonstrated a less marked percentage reduction in volume than those without (-2.1 +/- 6.9% versus -10.6 +/- 6.0%, P = 0.001). In three patients with a history of syncope there was a paradoxical increase in forearm venous volume during lower body negative pressure. During exercise there was a substantially smaller decrease in splenic venous volume in patients compared with controls (-20.1 +/- 14.0% and -42.6 +/- 12.6% respectively, P = 0.0001). Furthermore, there was an association between attenuated splenic venoconstriction or venodilation and exercise hypotension in patients (P = 0.005). 5. Abnormal reflex control of venous capacitance beds in patients with hypertrophic cardiomyopathy was associated with both syncope and exercise hypotension.

Adult↗
PubMed2001

Gait festination in Parkinson's disease.

Background: Festinating gait (FSG) was first associated with parkinsonism by Sir James Parkinson, in his original essay on "The Shaking Palsy". Its frequency and relation to other parkinsonian features have never been assessed.Objective: To study the relationships between gait festination and other parkinsonian clinical features among patients with Parkinson's disease (PD).Method: During an open lecture to patients with PD who are followed at the Movement Disorders Unit (MDU) of Tel-Aviv Sourasky Medical Center one of us explained verbally and imitated festinating gait on stage. All attending patients with the help of their care-givers or family members, were asked to answer two written questions regarding their own experience with FSG as well as the degree of disability it causes. Clinical information about each patient was taken from his/her chart at the MDU and missing data was completed during the next office visit or from the family physician. Statistical analysis was performed using t-tests for comparison between groups, Chochran-Armitage test for trends and logistic regression to assess the contribution of age of onset, disease duration and disease severity to the development of FSG.Results: Eighty-one PD patients (58 males, mean age 67.5+/-10.7years) answered the FSG questionnaire. Our study population's mean disease duration was 8.5+/-6.4years, mean Hoehn and Yahr (H&Y) clinical stage of 2.6+/-0.8 and mean levodopa dose of 608+/-375mg/day (15 patients were not on levodopa). Twenty-six patients (32.1%) experienced FSG during the previous month and 56% of them reported that FSG was a significant and disabling symptom. FSG was strongly associated with higher stage of H&Y (p<0.001) with a significant trend as the disease progresses (p=0.001) but not with total score in the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS). Longer disease duration was the only clinical factor, which was found to be associated with FSG in the multivariate model. Thirty seven percent (37%) of the patients with FSG reported frequent falls with association between occasional or frequent falls, as reported on the activity of daily living (ADL) part of the UPDRS, and the presence of FSG (p<0.08). There was no association between significant postural reflex abnormalities as rated on the objective part of the UPDRS and the presence of FSG. There was a significant association between the presence of freezing of gait (FOG) as reported in the ADL part of the UPDRS and the presence of FSG (p<0.001) as well as a significant trend towards more frequent FSG in patients with more severe FOG (p<0.001).Conclusion: FSG was clearly associated with longer duration of PD symptoms but not with disease severity as reflected in the motor part of the UPDRS. The relationships between FSG and postural reflexes abnormalities is unclear but it is frequently associated with falls and freezing of gait.

Journal Article↗
PubMed2000

Sudomotor abnormalities in reflex sympathetic dystrophy.

BACKGROUND: Intractable pain and sweating dysfunction can occur in patients with reflex sympathetic dystrophy (RSD). We, therefore, investigated autonomic function by measuring sympathetic skin response (SSR) in these patients. This method provides useful information regarding the pathophysiologic changes in and clinical evaluation of RSD. METHODS: Twenty-six RSD patients and 22 age-matched normal subjects were involved in our investigation. Three significant stages of RSD were classified through three-phase bone scanning of the wrist, carpal and metacarpal bones. There were 11 patients in stage I RSD, nine in stage II and six in stage III. SSRs were recorded from the bilateral palms of each subject simultaneously using electrical stimulation of the median nerve in the wrist. Latency and amplitude side ratios were calculated and compared with the control group. RESULTS: The affected/normal (A/N) hand amplitude ratios were significantly lower in stage I RSD, and stage II RSD patients exhibited significantly higher A/N amplitude ratios compared with the control group. A/N amplitude and A/N latency ratios in stage III RSD did not change significantly. The A/N latency ratios in stage I RSD were significantly higher than those of the control group and those of stage II RSD. In one stage I patient and three stage III patients, SSRs were bilaterally unobtainable. CONCLUSIONS: It appears that abnormal SSRs may be associated with autonomic disturbance in RSD patients.

Adult↗
PubMed1995

Abnormal vestibuloocular reflex cancellation in multiple system atrophy and progressive supranuclear palsy but not in Parkinson's disease.

We have measured the gain of the vestibuloocular reflex (VOR) in darkness and its cancellation by fixation in 37 patients with Parkinson's disease (PD), 26 patients with multiple system atrophy (MSA), 11 patients with progressive supranuclear palsy (PSP), and 19 normal volunteers. The capacity to cancel the VOR by fixation (VOR cancellation) was significantly reduced in the MSA and PSP patients compared with the PD and normal subjects (p < 10(-4)). A VOR cancellation < 90% (i.e., the mean VOR cancellation of the normals--2 SD) was present in four PD patients, 23 MSA patients, and 11 PSP patients. This criteria distinguished PD and MSA with a 89% sensitivity and a 89% specificity. Our results demonstrate that the VOR cancellation is impaired in most patients with MSA and PSP but not with PD. In MSA patients, the abnormal VOR cancellation is probably not related to the nigrostriatal dopaminergic deficit and more likely reflects a cerebellar dysfunction. Impaired VOR cancellation is a clinical criteria to differentiate MSA and PSP from PD.

Age Factors↗
PubMed1981

Experimentally induced thiamine deficiency in beagle dogs: clinical observations.

Twenty-three 2- to 5-month-old Beagle dogs were fed a purified thiamine-deficient ration (2 to 3 micrograms of thiamine/100 g of ration) at a rate of 40 to 70 g/kg of body weight/day depending on age. Eleven dogs were used as principles, 6 as pair-fed controls, and 6 as ad libitum-fed controls. Controls were treated once a week with an IM dose of 300 micrograms of thiamine hydrochloride/kg of body weight. Three stages of clinical disease occurred in the principals: (i) an initial short (18.0 +/- 7.9 days) stage of induction, during which the dogs usually grew suboptimally, but were otherwise healthy, (ii) an intermediate stage of preliminary clinical signs of deficiency, characterized by a variable period (58.5 +/- 37.0 days) of progressive inappetance, failure to grow, loss of body weight, and coprophagia, and (iii) a terminal stage, which, in most dogs, was abrupt in onset and short (7.6 +/- 6.0 days) and consisted of either a neurologic syndrome or sudden unexpected death syndrome. Eight of the principals developed the neurologic syndrome characterized by anorexia, emesis, CNS depression, paraparesis, sensory ataxia, torticollis, circling, exophthalmos, tonic-clonic convulsions, profound muscular weakness, recumbency, and then died. Common reflex abnormalities included exaggerated patella reflex, proprioceptive and supporting reflex deficits, induced torticollis and ventroflexion of head, and absent eye menace (blink) reflex. Three other principals developed the sudden unexpected death syndrome. Common signs of deficiency were inappetance and paresis. Two were found dead and 1, with severe ECG abnormalities (including elevation of ST segment and tall or deeply inverted T waves), was killed.

Animals↗
PubMed1994

Neuropeptide Y plasma levels and serum dopamine-beta-hydroxylase activity in MS patients with and without abnormal cardiovascular reflexes.

An impairment in the autonomic function has been demonstrated in patients with multiple sclerosis (MS) using electrophysiological, pupillary and biochemical tests. Particularly evident were alterations in the cardiovascular reflexes, cutaneous sympathetic response and lymphomonocyte adrenergic binding. Electrophysiological and biochemical findings in MS patients have only occasionally been compared. Among the peripheral markers of the autonomic system, Neuropeptide Y (NPY) and dopamine-beta-hydroxylase (DBH) have been singled out as reliable indices of sympathetic function. The former is a peptide with a strong vasoconstrictive action, which is released from adrenergic endings together with noradrenaline following sympathetic activation. The latter is the enzyme which catalyses the conversion of dopamine to norepinephrine. It is located both in sympathetic endings and the chromaffin granules of adrenal medulla. To verify a failure in autonomic function in the course of MS, a battery of cardiovascular tests (assessing sympathetic and parasympathetic functions) was performed on 25 MS patients. The results were compared with a group of 20 age- and sex-matched control individuals. The plasma levels of NPY and the serum DBH activity were also determined in both groups. 52% of patients showed an impairment in sympathetic function in one or more tests (sustained handgrip, postural hypotension, cold face test). 48% of the patients had abnormal values in deep breathing test, indicating a failure of the parasympathetic function. 44% of patients showed also a paroxysmal tachycardia after cold face test, indicating an abnormal function of the vagal-cardiac and sympathetic-vascular smooth muscle pathways of the trigeminal nerve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Abnormal cough reflex in canine acrylamide neuropathy.

Coughing in response to irritation of the airways is a fundamental protective reflex that is dependent on rapidly adapting bronchopulmonary receptors and their vagal afferent fibers; reflex airway constriction, which is effected by vagomotor efferent fibers, usually accompanies coughing. Although dysfunction of vagally mediated cardiovascular and gastrointestinal reflexes is a well-documented complication of autonomic neuropathy, to date there have been no studies of the effect of peripheral autonomic failure on the cough reflex. In the study reported here, we examined the effect of acrylamide-induced neuropathy, a distal axonopathy, on the ventilatory and tracheomotor components of the cough reflex in conscious dogs. There was a reduction in the cough reflex in response to mechanical irritation of the large airways in the preclinical phase of the neuropathy, and the cough reflex was virtually abolished when the dogs had moderate neuropathy. Following withdrawal of the neurotoxin, there was a substantial recovery of the cough reflex in surviving animals. It is possible that the cough reflex may be reduced in patients with vagal neuropathy and that this might compromise protection of the airway.

Acrylamide↗
PubMed2001

Enhanced ventilatory response to exercise in patients with chronic heart failure and preserved exercise tolerance: marker of abnormal cardiorespiratory reflex control and predictor of poor prognosis.

BACKGROUND: In patients with chronic heart failure (CHF) and preserved exercise tolerance, the value of cardiopulmonary exercise testing for risk stratification is not known. Elevated slope of ventilatory response to exercise (VE/VCO(2)) predicts poor prognosis in advanced CHF. Derangement of cardiopulmonary reflexes may trigger exercise hyperpnea. We assessed the relationship between cardiopulmonary reflexes and VE/VCO(2)and investigated the prognostic value of (VE/VCO(2)) in CHF patients with preserved exercise tolerance. METHODS AND RESULTS: Among 344 consecutive CHF patients, we identified 123 with preserved exercise capacity, defined as a peak oxygen consumption (PEAK VO(2)) >/=18 mL. kg(-1). min(-1) (age 56 years; left ventricular ejection fraction 28%; peak VO(2) 23.5 mL. kg(-1). min(-1)). Hypoxic and hypercapnic chemosensitivity (n=38), heart rate variability (n=34), baroreflex sensitivity (n=20), and ergoreflex activity (n=20) were also assessed. We identified 40 patients (33%) with high VE/VCO(2) (ie, >34.0). During follow-up (49+/-22 months, >3 years in all survivors), 34 patients died (3-year survival 81%). High VE/VCO(2) (hazard ratio 4.3, P<0.0001) but not peak f1.gif" BORDER="0">O(2) (P=0.7) predicted mortality. In patients with high VE/VCO(2), 3-year survival was 57%, compared with 93% in patients with normal VE/VCO(2) P<0.0001). Patients with high VE/VCO(2) demonstrated impaired reflex control, as evidenced by augmented peripheral (P=0.01) and central (P=0.0006) chemosensitivity, depressed low-frequency component of heart rate variability (P<0.0001) and baroreflex sensitivity (P=0.03), and overactive ergoreceptors (P=0.003) compared with patients with normal VE/VCO(2). CONCLUSIONS: In CHF patients with preserved exercise capacity, enhanced ventilatory response to exercise is a simple marker of a widespread derangement of cardiovascular reflex control; it predicts poor prognosis, which VO(2) does not.

Chronic Disease↗