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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↗
PubMed2005

Association between in utero organophosphate pesticide exposure and abnormal reflexes in neonates.

The detrimental effects of organophosphate pesticide (OP) exposure on neurodevelopment have been shown in animals. The present study aimed to assess the relationship between in utero and early postnatal OP exposure and neonatal neurobehavior in humans, as measured by seven clusters (habituation, orientation, motor performance, range of state, regulation of state, autonomic stability, and reflex) on the Brazelton Neonatal Behavioral Assessment Scale (BNBAS). We assessed 381 infants < or = 2 months old and born to women participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study, a longitudinal, birth cohort study of low-income, Latina women living in the agricultural community of the Salinas Valley, California. Exposure to OP pesticides was determined by urinary levels of dialkylphosphate (DAP) metabolites, including dimethyl and diethylphosphate metabolites, measured twice during pregnancy (M = 14 and 26 weeks gestation) and once post-delivery (M = 7 days postpartum). The relationship between exposure and BNBAS performance was examined for the entire sample and stratified by the median age at assessment, 3 days. We observed a significant association between exposure and the reflex cluster for the entire sample and for infants >3 days old (n = 184). Among the >3 day old infants, increasing average prenatal urinary metabolite levels were associated with both an increase in number of abnormal reflexes (total DAP: adjusted beta = 0.53, 95% CI = 0.23, 0.82; dimethyls: adjusted beta = 0.41, 95% CI = 0.12, 0.69; diethyls: adjusted beta = 0.37, 95% CI = 0.09, 0.64), and the proportion of infants with more than three abnormal reflexes (total DAP: adjusted OR = 4.9, 95% CI = 1.5, 16.1; dimethyls: adjusted OR = 3.2, 95% CI = 1.1, 9.8; diethyls: adjusted OR = 3.4, 95% CI = 1.2, 9.9). No detrimental associations were found between postnatal urinary metabolite levels and any of the BNBAS clusters for infants < or = 3 or >3 days old at assessment. Whether neonatal reflex functioning is predictive of neuropsychological functioning as the child matures will continue to be evaluated in this birth cohort.

Adult↗
PubMed2005

Prevalence and clinical significance of superficial abdominal reflex abnormalities in idiopathic scoliosis.

To determine prevalence and significance of abnormal superficial abdominal reflexes (SARs) in idiopathic scoliosis. Study of 73 patients with presumed idiopathic scoliosis referred for magnetic resonance imaging (MRI), either as a routine pre-operative assessment (n=42) or because of abnormal symptoms or neurological signs (n=31). All patients were examined prior to magnetic resonance imaging (MRI), and the presence of abnormal SARs was noted. All patients then underwent MRI of the whole spine from the foramen magnum to the sacrum. The presence of Chiari 1 malformation and syrinx was recorded. The study group consisted of 11 males and 62 females with a mean age at time of MRI of 18 years (range 5-51 years) and a mean Cobb angle of 48 degrees (range 10-104 degrees). Abnormality of the SARs was recorded in eight cases (prevalence 11%). An abnormal MRI study was recorded in nine cases (12.3%), all patients having a syrinx and four having in addition, a Chiari 1 malformation. Of the patients with abnormal SARs, only 2 (25%) had an abnormal MRI study; 1 had unilateral absence of the reflexes whereas the other had complete absence of SARs. Of patients referred for MRI as a routine pre-operative assessment, 5 (11.6%) had an abnormal MRI study. In patients with idiopathic scoliosis, abnormality of the SARs was recorded in 11% of cases. Unilateral absence was present in one case only and was associated with the presence of syrinx. Other patterns of abnormality were not a useful indicator of underlying cord abnormality.

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↗
PubMed2006

Reduced peripheral skeletal muscle mass and abnormal reflex physiology in chronic heart failure.

BACKGROUND: The muscle hypothesis implicates abnormalities in peripheral muscle as a source for the stimulus to the symptoms and reflex abnormalities seen in chronic heart failure (CHF). We investigated the relationship between skeletal muscle mass (with dual-energy x-ray absorptiometry) and activation of the ergoreflex (a peripheral reflex originating in skeletal muscle sensitive to products of muscle work) in CHF patients and whether this rapport is affected by the progression of the syndrome. METHODS AND RESULTS: We assessed 107 consecutive CHF patients (mean age, 61.9+/-10.9 years; 95% male; 25 cachectics) and 24 age-matched normal subjects (mean age, 59.0+/-11.1 years; 91% male). Compared with normal subjects, patients had a higher ergoreflex (in ventilation, 6.2+/-.6.1 versus 0.6+/-0.6 L/min; P<0.0001) and a reduction in muscle mass (51.9+/-10.0 versus 60.3+/-8.8 kg; P<0.001). The ergoreflex was particularly overactive in cachectics (P<0.05), accompanied by marked muscle mass depletion (P<0.0005). In CHF, ergoreceptor hyperresponsiveness in both the arm and leg correlated with reduced muscle mass, abnormal indexes of exercise tolerance (peak V(O2), V(E)/V(CO2) slope), ejection fraction, and NYHA functional class (P<0.0001). In the cachectic population, the ventilatory response from ergoreflex to arm exercise was strongly inversely correlated with arm (r=-0.65), leg (r=-0.64), and total (r=-0.61) lean tissues (P<0.001 for all). Multivariate analysis showed that these relationships were independent of NYHA class, peak V(O2), and V(E)/V(CO2) slope. CONCLUSIONS: Depleted peripheral muscle mass is associated with ergoreflex overactivity and exercise limitation in CHF, particularly in cachectic patients. The systemic activation of the muscle reflex system in CHF may reflect progression and deterioration of the clinical syndrome.

Aged↗
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↗
PubMed2006

Blink reflex abnormalities in children with Tourette syndrome.

Tourette syndrome (TS) is a common disorder which typically occurs during childhood or early adolescence. There is no definitive diagnostic test for TS. The objective of this study was to demonstrate whether neurophysiological abnormalities of the blink reflex can be observed in children with TS. We enrolled 15 children with TS, diagnosed according to DSM IV Diagnostic Criteria, and 15 controls. 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. The mean duration of R2 was significantly longer in TS patients than in the controls (P < 0.001, Student's t-test). An abnormal pattern of the blink reflex can be, even in childhood, an early neurophysiologic marker of TS, which is not related to the duration of TS or to the age of onset.

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↗