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PubMedDate not supplied

Contralateral influences on patellar tendon reflexes in young and old adults.

In an effort to more fully investigate age-related changes in spinal reflex parameters, we measured force-time characteristics of the patellar tendon reflex in aged subjects and contrasted these with data obtained from college-age individuals. We also conditioned the tendon jerk with a tap to the contralateral tendon. The results showed a marked tendon reflex enhancement in the old group, consisting of greater overall reflex force produced by the quadriceps. In both groups, the contralateral conditioning stimulus produced a short-latency inhibition (at 25 msec) followed by a longer-latency facilitation (beginning at 75 msec). Both the early inhibition and the later reflex enhancement were greater in the aged subjects. We suggest that some age-related change may occur at the spinal level to compensate for decrements in more complex motor functioning.

Achilles Tendon↗
PubMed1999

Early onset cerebellar ataxia with retained tendon reflexes: foot deformity in a first grade family member.

Early onset cerebellar ataxia with retained tendon reflexes (EOCA) is a clinical syndrome characterised by progressive cerebellar ataxia with an onset before the age of 25 years and a wide spectrum of associated features. It is distinguished from Friedreich's ataxia (FA) mainly by the preservation of tendon reflexes, a better prognosis, and the absence of GAA expansion in the frataxin gene. Although EOCA is thought to be a hereditary disorder with an autosomal recessive mode of inheritance, genetic heterogeneity might underlie the spectrum of clinical features. In this case report we describe a patient with EOCA accompanied by pes cavus, hammer toes and peripheral neuropathy. The patient's father did not have any ataxia, but had the same foot deformities as his daughter and a slight peripheral neuropathy. The possible relationship between these clinical features is discussed.

Adult↗
PubMed1985

Effects of an inverted position on blood pressure, pulse rate, and deep tendon reflexes of healthy young adults.

This study reports the effects of an inverted position on pulse rate, blood pressure, and deep tendon reflexes of the biceps muscle, triceps muscle, and Achilles tendon. Twenty healthy adults were used as subjects. We collected data both before and after the subjects were in the inverted position for eight minutes on a specially designed tonic labyrinthine inverted table. A significant decrease in systolic blood pressure and all tendon reflexes was observed along with a significant increase in diastolic blood pressure (p less than .05). Pulse rate showed no change. The findings indicate that the inverted position is likely to be effective for decreasing muscle tone and systolic blood pressure. Although this study used healthy subjects, the inverted position may be used as a therapeutic technique, provided the clinician monitors closely the physiological effects on patients.

Achilles Tendon↗
PubMed2002

Deep tendon reflexes: a study of quantitative methods.

OBJECTIVE: The deep tendon reflex (DTR) is routinely used by clinicians to evaluate the nervous system. Depressed and hyperactive DTRs suggest peripheral and central nervous system compromise, respectively. Limitations of DTRs are: qualitative nature of the assessments based upon subjective grading, and limited inter-rater reliability. This preliminary study was undertaken to quantify the tendon tap used by clinicians to elicit DTRs and the reflex response elicited. METHODS: Tendon taps were applied to a force transducer in hypo-, normo-, and hyperreflexic ranges by 2 clinicians, using 3 different tendon hammers (Babinski, Queen Square, and Taylor). Patellar DTRs, measured as joint angle excursion with an electrogoniometer, were compared in hyper- and normoreflexic individuals. RESULTS: Median peak tap force was 1 2.8, 38.0, and 85.2 Newtons (Nt), respectively, for eliciting hyper-, normo-, and hyporeflexic DTRs. Peak tap force was similar in the hyper- and normoreflexic ranges for all 3 hammers; in the hyporeflexic range, peak tap forces with the Taylor hammer were lower. A good distinguishing feature between hyper- and normoreflexic patellar DTRs was briskness, measured as the quotient of knee excursion divided by peak tendon tap force. Knee excursion is a non-linear patellar DTR response, when measured sitting. CONCLUSIONS: Peak tap forces used by clinicians fall into 3 ranges: 0-20 Nt for hyperreflexia, 21-50 Nt for normoreflexia, and >50 Nt for hyporeflexia. The Taylor hammer, with small mass and short handle, has a ceiling effect in the hyporeflexic range. We propose a systematic method for DTR testing.

Central Nervous System Diseases↗
PubMed1987

Tendon reflex variability and method of stimulation.

Human tendon reflexes show large fluctuations, even when accurate mechanical instruments are used for stimulation. To examine the contribution of stimulus factors to reflex variability two methods of stimulation were compared in healthy subjects. One method consisted of a normal hand-held reflex hammer, with a transducer to measure stimulus intensity. The results with this hammer, both after maximal stimuli and after stimuli over a wide range of intensities, showed a similar variability of reflexes as with a more accurate instrumental stimulator. In previous studies in human subjects an equal or larger variability of reflexes was found. It is concluded that for many applications a simple hand-held reflex hammer gives equally reliable results as more complicated instrumental stimulators.

Adult↗
PubMedDate not supplied

Deep tendon reflexes in premature infants.

Ten classic deep tendon reflexes (DTRs) were evaluated in 62 premature infants of greater than 27 weeks post-conceptional age. The pectoralis major was the most readily elicitable reflex in all infants (100%), regardless of maturity. Achilles, patellar, biceps, thigh adductors, and brachioradialis reflexes also were obtained in at least 98% of babies of greater than 33 weeks gestation. Among these reflexes, less mature infants (less than 33 weeks gestation) had decreased elicitation rates for patellar and biceps reflexes and overall had diminished reflex intensity when compared to older infants (33-36 weeks gestation). By order of decreasing rate, finger flexors, jaw, crossed adductors, and triceps reflexes were less frequently elicited in both groups. Equal DTRs were obtained often in healthy and previously ill infants of less than 33 weeks gestation. Head position had no apparent affect on the ability to elicit reflexes. Theophylline therapy tended to intensify the Achilles reflex and the quiet, wakeful state appeared to be the most optimal state for the elicitation of DTRs.

Gestational Age↗
PubMed2006

Brisk deep-tendon reflexes as a distinctive phenotype in an Argentinean spinocerebellar ataxia type 2 pedigree.

Slow saccades, postural/intention tremor, peripheral neuropathy, and decreased deep-tendon reflexes are valuable neurological signs for clinical suspicion of spinocerebellar ataxia type 2 (SCA2). We report the presence of abnormally brisk deep-tendon reflexes in nonsymptomatic carriers and mildly and severely affected subjects of a large Argentinean SCA2 pedigree. The identification of this distinctive SCA2 phenotype in an entire pedigree reinforces the current concept that clinical algorithms are of limited value as indicators for genetic testing in SCA. Combined with published pedigrees of SCA2 manifesting as levodopa-responsive parkinsonism, this finding suggests that modifier genes could influence the clinical phenotype of SCA2.

Adult↗
PubMed1975

[About the effect of alcohol and tiredness on the activity of tendon reflexes (author's transl)].

In order to estimate the combined effect of ethanol and fatigue on the activity of tendon reflexes, the mechanical threshhold and the latency of the patellar tendon, the radial and the biceps reflexes as well as the time of contraction of the musculus quadriceps femoris was investigated in men, with an ethanol level in blood at 80 mg % during elimination-period, and with tired subjects meaning that they hade done their usual daywork and had been awake for about 20 to 22 hours. The group, consisting of 21 male students, was then investigated under both these conditions. The patellar reflex was elicited by a specially constructed reflexhammer, by which the mechanical power could by measured exactly, from the angle of the position the hammer was released from and its known weight. The latency and the muscular contraction time were registered with electrodes on the skin by an oscillograph. The mechanical threshhold of the patellar, biceps and radial reflexes and the latency of there reflexes were significantly and equally impaired by ethanol as well as by fatigue. The combination of both these factors resulted in an almost exactly additional effect. The contractiontime of the m. quadriceps was prolonged more by fatigue than by ethanol. Comparing these results with fromer findings, a depressing effect of the formatio reticularis of the brainstem on the activity of the spinal motorcells is to be discussed. This impairment of neuro-muscular coordination and activity obviously is dangerous for drivers. It should especially be noted, that the effect of a wake period of 20 to 22 hours can be compared with that of a bloodlevel of 80 mg % ethanol as to the impairment of the tendon reflexes.

Adult↗
PubMed1996

Erb's explanation for the tendon reflexes. Links between science and the clinic.

OBJECTIVE: To determine whether 19th-century experimental neurophysiological concepts directly influenced Erb's initial explanation for the deep tendon reflexes (DTRs). BACKGROUND: There is extensive literature on the discovery of the clinical utility of the DTRs on the one hand and on the development of 19th-century experimental neurophysiological concepts and early scientific concepts of reflexology on the other. While it seems logical to assume that Erb's 1875 discovery of the clinical utility of the DTRs and his initial interpretation of the physiological meaning of heightened DTRs were grounded in some of these scientific concepts, the important link between the clinical and scientific realm has not, to our knowledge, been the subject of previous analysis. METHODS: Review of the 19th-century neurophysiological literature and translation of seminal manuscripts written by Erb in the years 1875 and 1876. RESULTS: The concepts of spinal inhibition and reflex action arose from 19th-century neurophysiological experimentation. Erb first described the term Patel-larsehnenreflex (patellar tendon reflex) in 1875, and his publications reveal clear insight into several fundamental scientific concepts, including spinal inhibition, the reflex arc, distinct motor and sensory neurons, and an excitomotor system in the spinal gray matter. CONCLUSION: While Erb's initial description and interpretation of the DTRs may be regarded as a fortuitous discovery by a keen clinical observer, on another level his observations were not made in isolation, but were based on his knowledge of the physiological work of the preceding decades.

History, 19th Century↗
PubMedDate not supplied

Surface EMG and Achilles tendon reflexes during a foot movement in a reaction time task.

A forewarned simple visual reaction time (RT) experiment was conducted to study the relation between surface EMG of the soleus muscle and Achilles tendon reflex amplitudes during the initiation of a voluntary plantar flexion of the right foot. In two conditions the tension of the response-involved soleus muscle was manipulated: (1) gradual isometric contraction towards the end of the foreperiod (FP) and (2) complete relaxation during the FP. Gradual contraction of the involved soleus muscle produced faster RTs. It was found in both conditions that reflex amplitudes and EMG of the involved soleus muscle were equally informative about the growing motor excitation during the execution of the response. In the tension condition reflex amplitudes in the involved leg were smaller than the reflex amplitudes in the non-involved leg prior to the initiation of the movement, 0-50 msec after the expiration of the FP. The EMG, however, showed a reversed involved/non-involved difference in this condition. In the relaxation condition, neither the EMG nor the reflex amplitudes showed a significant involved/non-involved difference. It was concluded from these results that changes in Achilles tendon reflex amplitudes should only cautiously be interpreted as an indication of motor preparation.

Achilles Tendon↗
PubMed1998

Mayo and NINDS scales for assessment of tendon reflexes: between observer agreement and implications for communication.

The purpose of this study was to assess the between observer reliability of two standard notation scales for grading tendon reflexes, The Mayo Clinic scale and the NINDS scale. In a university department of neurology two or three physicians judged the biceps, triceps, knee, and ankle tendon reflexes in two groups of 50 patients using either scale. The interobserver agreement was assessed by means of kappa statistics. The agreement among doctors was never better than "fair" for both scales (highest kappa value 0.35). A verbal description rather than a codified scale may improve communication among doctors.

Adult↗
PubMed1983

Characteristics of the triceps brachii tendon reflex in man.

The quantitative characteristics of the triceps brachii tendon reflex have been investigated in nine healthy adults. Particular consideration was given to the normal latency and amplitude values in response to a standardized tendon percussion. The effects of Jendrassik maneuver, head position (tonic neck reflex influences) and elbow joint angle were also evaluated. The latency of the triceps brachii reflex (mean = 11.2 msec) under normal conditions was found to be substantially shorter than previously reported values for the monosynaptic response. These differences are apparently attributable to the different methods that have been used to elicit the reflex. The present results are shown to be quite compatible with the known conduction velocity properties of the radial nerve. The mean amplitude of the reflex (means = 1.6 mV) was shown to be significantly (p less than 0.05) influenced by head position and Jendrassik maneuver. The magnitude of these effects are interpreted with respect to the proportion of the motoneuron pool activated by Ia inputs. Their neurophysiological basis and clinical usefulness are also discussed briefly.

Adult↗
PubMed2004

The reference values of the T-wave of the patellar tendon reflex in normal dogs.

The T-wave of the patellar tendon reflex (PTR) was recorded in 24 neurologically normal dogs. The surface electromyogram (EMG) was recorded as the T-wave from the vastus lateralis muscle (VL) in response to percussion of the patellar tendon. The distance of the reflex arc (DRA) was measured along the straight line between the spinous process of L5 and the greater trochanter (GT), and between GT and the patellar ligament (PL). There was a significant correlation (P<0.001) of the latency with the DRA on each side, but no difference in the slopes of the relationships between right and left VL was shown. The regression line between the DRA and the latency of all data was Y = 0.0216X + 1.693, where Y = latency in ms, X = DRA in mm. The mixed sensory-motor conduction velocity was estimated as 84.6 +/- 5.5 m/s. In contrast, there was no significant correlation between the DRA and the amplitude of the T-waves. The mean (mean-CV) and standard deviation (SD-CV) of all CV (coefficient of variation) in each dog were 9.14 +/- 3.65% in latency and 3.54 +/- 1.14% in amplitude, indicating that the use of a simple hand-held reflex hammer is sufficient to record the reproducible T-wave of the PTR even in unanesthetized dogs. This method was applied to a case with minimal paraparesis, and the latency of the T-wave of the PTR in the right hind limb with slight proprioceptive deficit was outside of the upper limit of the 95% confidence interval between latency and the DRA. In conclusion, this method may be used in neurological diagnosis to quantify more precisely the PTR in dogs.

Animals↗
PubMed2005

Quadriceps force generation in patients with osteoarthritis of the knee and asymptomatic participants during patellar tendon reflex reactions: an exploratory cross-sectional study.

BACKGROUND: It has been postulated that muscle contraction is slower in patients with osteoarthritis of the knee than asymptomatic individuals, a factor that could theoretically impair joint protection mechanisms. This study investigated whether patients with osteoarthritis of the knee took longer than asymptomatic participants to generate force during reflex quadriceps muscle contraction. This was an exploratory study to inform sample size for future studies. METHODS: An exploratory observational cross sectional study was carried out. Two subject groups were tested, asymptomatic participants (n = 17), mean (SD) 56.7 (8.6) years, and patients with osteoarthritis of the knee, diagnosed by an orthopaedic surgeon, (n = 16), age 65.9 (7.8) years. Patellar tendon reflex responses were elicited from participants and measured with a load cell. Force latency, contraction time, and force of the reflex response were determined from digitally stored data. The Mann-Whitney U test was used for the between group comparisons in these variables. Bland and Altman within-subject standard deviation values were calculated to evaluate the measurement error or precision of force latency and contraction time. RESULTS: No significant differences were found between the groups for force latency (p = 0.47), contraction time (p = 0.91), or force (p = 0.72). The two standard deviation measurement error values for force latency were 27.9 ms for asymptomatic participants and 16.4 ms for OA knee patients. For contraction time, these values were 29.3 ms for asymptomatic participants and 28.1 ms for OA knee patients. Post hoc calculations revealed that the study was adequately powered (80%) to detect a difference between the groups of 30 ms in force latency. However it was inadequately powered (59%) to detect this same difference in contraction time, and 28 participants would be required in each group to reach 80% power. CONCLUSION: Patients with osteoarthritis of the knee do not appear to have compromised temporal parameters or magnitude of force generation during patellar tendon reflex reactions when compared to a group of asymptomatic participants. However, these results suggest that larger studies are carried out to investigate this area further.

Aged↗
PubMed1986

Measurement of knee tendon reflex latencies in lumbar radicular syndromes.

The latency of the knee tendon reflex (KTR) in the vastus medialis muscle was measured by eliciting the reflex manually with a metal hammer. Normal values were obtained in a reference group of 35 subjects. The difference in right and left KTR was used as the parameter in the investigation of 20 patients with a proven L3 or L4 monoradicular syndrome; it was abnormal in 65% of the cases. In 10 patients an asymmetrical KTR was the only relevant abnormality in the combined electromyography and reflex study. Measurement of the KTR seems to be useful in the assessment of patients suspected of a lumbar radicular syndrome.

Adult↗
PubMed2001

[Proximal muscle weakness, depressed tendon reflexes and autonomic dysfunction: the Lambert-Eaton myasthenic syndrome].

Three patients with Lambert-Eaton myasthenic syndrome (LEMS), two men aged 61 and 64 and a woman aged 55 years, all developed proximal weakness, depressed tendon reflexes and autonomic dysfunction. Although this clinical triad is highly suggestive for LEMS, the disorder had not been recognized initially. The woman had a small-cell bronchial carcinoma, treated successfully by chemotherapy, whereafter the LEMS symptoms gradually disappeared. The first man was treated with 3,4-diaminopyridine and azathioprine, whereupon his symptoms diminished. The other man had only slight complaints and refused drug treatment. The three cases illustrate that presentation and course of LEMS can vary between patients. Furthermore, clinical and electrophysiological features can suggest myasthenia gravis, myopathy or axonal polyneuropathy. Therapeutic options and the risk of underlying malignancy make early diagnosis important. In conclusion, in every patient presenting with unexplained proximal weakness, LEMS should be considered, especially if depressed tendon reflexes and autonomic dysfunction are found as well.

Autonomic Nervous System↗