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Results for “REFLEX, ABNORMAL”

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At least 19 recordsLinked to original sources
PubMed1993

Cardiovascular reflex abnormalities in children and adolescents with diabetes mellitus.

OBJECTIVE: To assess the usefulness of specific cardiovascular reflex tests in childhood and to estimate the prevalence of cardiovascular reflex abnormalities among children with IDDM. In adults, abnormal cardiovascular reflexes are a frequent complication of diabetes, associated with increased morbidity and mortality. RESEARCH DESIGN AND METHODS: We measured heart-rate responses to deep breathing and standing in ambulatory children with and without IDDM between 6-19 yr of age. A subgroup of the IDDM patients was retested after 1 yr. RESULTS: We found the best techniques for detecting cardiovascular reflex abnormality in children were as follows: to record heart-rate responses to deep breathing either as the change in heart rate corrected for inspiratory heart rate or as the ratio of R-R intervals during expiration and inspiration; and to use the Maximum-minimum ratio for heart-rate responses to standing. HR-DBc was lower in diabetic than nondiabetic children (28.6 +/- 9.2% [n = 248] vs. 33.6 +/- 6.8% [n = 60]; P < 0.0005). Similarly, E:I was lower in children with IDDM than control subjects (1.42 +/- 0.19 [n = 248] vs. 1.52 +/- 0.15 [n = 60]; P < 0.0005). In the IDDM group, 21% of the children had abnormal HR-DBc or E:I responses. HR-STND M/m was lower in children with IDDM than control subjects (1.28 +/- 0.20 [n = 167] vs. 1.38 +/- 0.22 [n = 45]; P < 0.014). Among children with IDDM, 11.4% had abnormal HR-STND M/m responses. Overall, 29% of IDDM children tested abnormal in either HR-DBc or HR-STND M/m; 3% were abnormal in both tests. We found no correlation of HbA1c levels (n = 74) or duration of diabetes with either HR-DB, expiration to inspiration (n = 248), or HR-STND M/m (n = 167). In patients who were reevaluated after 1 yr we found a high correlation of the first and repeat HR-DBc tests (r = 0.47, n = 75, P < 0.0001), E:I (r = 0.53, n = 75, P < 0.0001), and HR-STND M/m (r = .49, n = 37, P < 0.002), but no evidence of an increased number of children with cardiovascular reflex abnormality. CONCLUSIONS: With easily performed HR-DB and HR-STND tests, we detected cardiovascular reflex abnormality in 29% of children with IDDM. We found no correlation of changes in HR-DB and HR-STND with HbA1c or duration of diabetes. These tests provide an objective clinical measurement to monitor autonomic neuropathy in children with diabetes.

Adolescent↗
PubMed1997

Brief report: HIV-exposed newborns show inferior orienting and abnormal reflexes on the Brazelton Scale.

Assessed 48 infants of HIV-positive and HIV-negative mothers on the Brazelton Neonatal Behavioral Assessment Scale. Infants exposed to HIV-positive mothers were disadvantaged from birth due to their mothers having obstetric complications and to the infants having orienting problems and abnormal reflexes on the Brazelton Newborn Scale. These problems may be early precursors of the later visual-spatial delays and hypertonicity noted in these infants.

Case-Control Studies↗
PubMed2001

Masseter reflex and blink reflex abnormalities in Chiari II malformation.

Masseter reflex and blink reflex were evaluated in 64 patients with a myelomeningocele and Chiari II malformation. In 46 patients, no brainstem signs or symptoms were present. Brainstem dysfunction related to Chiari II malformation occurred in 18 patients. The masseter reflex was more frequently abnormal in the symptomatic than asymptomatic patients (P = 0.02). Although the blink reflex was similarly affected in the two groups of patients (P > 0.1), it was very sensitive, being abnormal in 83% of symptomatic and 65% of asymptomatic patients. Concomitant abnormality of masseter reflex and the late contralateral blink reflex component (R2c) was almost exclusively found in symptomatic patients and reached the highest significance in separating the two groups (P = 0.002).

Adolescent↗
PubMed1985

Acoustic reflex abnormalities in behaviorally disturbed and language delayed children.

Contralateral and ipsilateral acoustic reflex thresholds were measured in 62 subjects referred for suspected delays in development of language, learning disabilities, or disorders of auditory processing, with normal peripheral hearing thresholds and normal tympanometry. Thirty-two percent of the subjects in this study showed abnormal contralateral and ipsilateral acoustic reflex thresholds. Both contralateral and ipsilateral acoustic reflex thresholds were involved when subjects showed abnormal reflex thresholds. Although a high percentage of abnormal acoustic reflexes occurred in this population, no strong correlation could be found with specific areas of language delay. A slight positive correlation was found between abnormal acoustic reflexes and delayed psychomotor development. Increased or absent acoustic reflex thresholds are usually associated with peripheral or low brain stem pathologies. While not conclusive, these results suggest brain stem involvement in this population.

Adolescent↗
PubMed2004

Blink reflex abnormalities in Tourette syndrome.

OBJECTIVE: Tourette syndrome (TS) is a not uncommon disorder which represents the most complex manifestation of the spectrum of tic disorders, with onset during childhood or early adolescence. There are no definitive tests for diagnosis of TS. The objective of this study has been to demonstrate whether neurophysiological abnormalities of the blink reflex can be observed in patients affected with TS and correlate with the severity of TS. METHODS: We enrolled 17 patients with Tourette syndrome, diagnosed according to DSM IV Diagnostic Criteria, and 10 healthy volunteers. Tic severity was assessed using a self rating scale (Tourette Syndrome Symptom List, TSSL) and examiner ratings (Yale Global Tic Severity Scale (YGTSS), and Tourette-Syndrome Global Scale (TSGS)). The blink reflex was elicited by stimulating the supraorbital nerve in order to measure the early response (R1), homolateral and contralateral R2 (late) responses, amplitude of R1 and duration of R2. RESULTS: We observed a mean duration of R2 significantly longer in the patient group than in the control group (P<0.01, Student t test), without any statistically significant differences of R1 and R2 latencies and of R1 amplitude between the patient group and the control group. Correlations between changes in clinical rating scores and R2 duration were tested by simple linear regression analysis, which has not demonstrated a significant correlation between TSSL scores, clinical rating scores (measured by TSGS and YGTSS) and duration of R2. CONCLUSIONS: A pattern as to excitability of the blink reflex can be a frequent abnormality in TS patients, not correlated with its severity.

Adult↗
PubMed1976

The grasp reflex of the foot and related phenomena in the absence of other reflex abnormalities following cerebral commissurotomy.

The grasp reflex of the foot and related pheonomena were examined in six subjects with no abnormalities of deep tendon or plantar (and related) reflexes 6 to 10 years after cerebral comissurotomy. In all subjects they were more marked on the same side as the more damaged hemisphere. These tonic phenomena seem to be facillitated by sitting and standing postures. Practical and theoretical implications of the tonic foot responses in the absence of similar phenomena of the hand are discussed.

Adult↗
PubMed1984

Abnormal reflex vasoconstriction to cold stimulation in forearm of patients with variant angina.

The responses of the blood vessels of the forearm to cold pressor test and mental stress were examined in patients with variant angina and in control subjects. In response to cold pressor test, blood pressure, heart rate and forearm vascular resistance increased with statistical significance in both groups. Percentage changes in blood pressure and heart rate were not significantly different in patients and control subjects. Percentage change in forearm vascular resistance in patients with variant angina (120 +/- 101%) was significantly greater (p less than 0.05) than that in control subjects (47 +/- 26%). In response to mental stress, percentage change in forearm vascular resistance was -20 +/- 19% in patients with variant angina and -24 +/- 18% in control subjects and there was no significant difference in the two groups. We conclude that, in some patients with variant angina, not only the coronary artery but the forearm vessels show the abnormal reflex vasoconstriction and it may be postulated that it represents the generalized abnormality of vascular smooth muscle or of their neural control which exists in some patients with variant angina.

Adult↗
PubMed2004

Blink reflex abnormalities in chronic alcoholics.

PURPOSE: The aim of the present study was to evaluate the efficacy of blink reflex as a method for obtaining early diagnosis of cranial nerve involvement in alcoholic patients. MATERIALS AND METHODS: The study was conducted on 30 male alcoholics with a mean age of 43 years. They had histories of alcohol abuse for at least 6 years (mean: 25). At the time of recording, they had undergone detoxification treatment for a mean of 27 days. RESULTS: R1 (early response), R2Y (second ipsilateral response), and R2C (second contralateral response) latencies in alcoholics were prolonged relative to controls and the differences were statistically significant (p < 0.02, p < 0.001, p < 0.001, respectively). According to the defined criteria, 40% of the patients had abnormal responses, and the most common abnormality was the unilateral prolongation of R1 (13%). CONCLUSION: Finding abnormal blink reflex responses in alcoholic patients has suggested that blink reflex testing is a useful method for the evaluation of subclinical cranial nerve involvement in alcoholic patients. Blink reflex testing may be useful in detecting early changes and in the follow-up of alcoholic disorder.

Adult↗
PubMed2001

Sympathetic and reflex abnormalities in heart failure secondary to ischaemic or idiopathic dilated cardiomyopathy.

Congestive heart failure (CHF) is characterized by a sympathetic activation and a baroreflex impairment whose degree is directly related to the clinical severity of the disease. However, whether these abnormalities vary according to the ischaemic or idiopathic dilated nature of the CHF state has not been conclusively documented. In patients with a clinically stable, chronic CHF state in New York Heart Association functional class II and III, due either to ischaemic heart disease (IHD; n=22, age 60.3+/-2.4 years, means+/-S.E.M.) or to idiopathic dilated cardiomyopathy (IDC; n=20, age 58.9+/-2.8 years), and in 30 age-matched controls, we measured arterial blood pressure (using a Finapres device), heart rate (by electrocardiogram) and postganglionic muscle sympathetic nerve traffic (by microneurography) at rest and during baroreceptor manipulation induced by the vasoactive drug-infusion technique. Blood pressure values were not significantly different in CHF patients and controls. Compared with controls, heart rate was similarly increased and left ventricular ejection fraction (by echocardiography) similarly reduced in CHF patients with IHD or IDC. Muscle sympathetic nerve traffic was significantly greater in CHF patients than in controls, and did not differ between patients with IHD or IDC (67.3+/-4.2 and 67.8+/-3.8 bursts/100 heart beats respectively). This was also the case for the degree of baroreflex impairment. These data show that CHF states due to IHD or to IDC are characterized by a similar degree of peripheral sympathetic activation and by a similar impairment of the baroreflex function. Thus the neuroadrenergic and reflex abnormalities characterizing CHF are independent of its aetiology.

Adult↗
PubMed1994

Orthotopic cardiac transplantation reverses abnormal reflex regulation of the microvasculature in the lower leg.

OBJECTIVE: The aim was to investigate the effect of cardiac transplantation on reflex control of lower leg subcutaneous blood flow. METHODS: The reflex regulation of subcutaneous blood flow of the lower leg was studied in 11 patients following orthotopic cardiac transplantation, in 11 patients with severe congestive heart failure (New York Heart Association functional class III or IV), and in 11 healthy subjects. Four patients were studied before and after cardiac transplantation. Cause of heart failure was classified as idiopathic dilated cardiomyopathy in all heart failure patients and in all the cardiac transplant patients before transplantation. Blood flow was measured by the local 133xenon washout method in the supine position and during 45 degrees head up tilt. RESULTS: When performing head up tilt without activation of the local nervous venoarteriolar axon reflex in patients with congestive heart failure, the relative subcutaneous blood flow increased abnormally, by 50(SD 25)%, but in patients after cardiac transplantation a normal decrease was seen [-28(13)%, p < 0.001]. The responses in the transplant group were similar to those observed in normal controls with a decrease in blood flow [-32(15)%; NS]. Head up tilt with simultaneous activation of the local venoarteriolar axon reflex increased blood flow [31(22)%] in patients with heart failure as compared to the decrease in blood flow found in the transplants [-44(17)%, p < 0.001]. The decrease of blood flow was not significantly different between the transplant group and control subjects [-53(19)%; NS]. CONCLUSIONS: These results indicate that abnormal reflex regulation in severe congestive heart failure with peripheral vasodilation of the lower leg during orthostasis is reversed and even normalised after cardiac transplantation. The haemodynamic consequence may be a regaining of an oedema-protective mechanism that eliminates the stress (capillary hypertension) on the microcirculation seen in severe heart failure.

Adult↗