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[A 85-year-old right-handed woman with aphasia and left hemiparesis].

We report a 85-year-old woman who developed speech disturbance and left hemiparesis. She had a gradual onset of gait disturbance 3 years prior to the present admission. Five days before admission, she started to pace up and down in her house; she did not want to take food on the following day, and she developed fever of 39 degrees C; it was also noted that she became mute. On the next day, she developed left hemiparesis; she was still mute but was able to communicate by hand writing to some extent. She was admitted to our service on February 24, 1992. On admission, she was alert but mute; her body temperature was 37.1 degrees C, and her BP 110/70 mmHg. The lungs were clear and general physical examination was unremarkable. Neurologic examination revealed that she did not utter even a word. She was unable to understand examiner's simple questions; communication by hand writing was also difficult, but she could draw her name and a circle; repetition was also impaired. Examination of other higher cerebral functions such as praxis and gnosis was impossible. Her optic fundi were unremarkable; no anisocoria was noted; extraocular muscles appeared intact, and the vestibulo-ocular reflex was normally elicited. The nasolabial fold was shallower on the left; the tongue showed a slight deviation to the left. She had near complete spastic left hemiplegia; deep tendon reflexes were increased bilaterally.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Traumatic focal posterior tibialis muscle denervation.

The purpose of this case presentation is to demonstrate posterior tibialis muscle (PTM) denervation as a cause of traumatic plantarflexion inversion weakness. In a 42-year-old woman, severe pain, swelling, and ecchymosis over the medial aspect of her left ankle developed after she twisted it while playing tennis. Plantarflexion inversion weakness developed (grade 3/5). The strength of all other muscle groups of the lower extremity was normal. Her pin and light touch sensation were normal in the left lower extremity. Deep tendon reflexes were equal and active at both knees and ankles. A magnetic resonance image of the left leg, ankle, and foot performed 1 month after injury demonstrated an intact posterior tibialis tendon behind the medial malleolus and edema-like increased signal intensity in the PTM on the T1-weighted image consistent with denervation. On electromyographic testing, there were continuous fibrillation and positive sharp wave potentials in every site tested in the PTM without any voluntary motor unit activity. The left extensor hallucis, left gastrocnemius, and lumbar paraspinal muscles were normal. In conclusion, combined magnetic resonance imaging and electromyographic studies supported denervation of the PTM as the cause of plantarflexion inversion weakness, rather than posterior tibialis tendon rupture in this patient.

Adult↗

Appearance of reciprocal facilitation of ankle extensors from ankle flexors in patients with stroke or spinal cord injury.

The purpose of the present study was to investigate the pathophysiological role of reciprocal facilitation between antagonistic motoneuron pools in spasticity. The soleus H-reflex was conditioned by prior stimulation of the peroneal nerve in 15 healthy subjects, six hemiplegic patients and 11 spinal cord injured (SCI) patients. The hemiplegic patients were tested from soon after the onset of hemiplegia and up to 2 years later. Whereas stimulation of the peroneal nerve produced short-latency inhibition of the soleus H-reflex in healthy subjects, it produced facilitation in spastic SCI and hemiplegic patients. This facilitation was demonstrated to have a low threshold compatible with activation of group I afferents and was most likely mediated by an oligosynaptic (reciprocal) excitatory pathway. The facilitation appeared in parallel with the development of hyperactive Achilles tendon reflexes, which was the only clinical finding that could be correlated positively with the facilitation. It is suggested that the appearance of reciprocal excitation plays a role in the pathophysiology of spasticity.

Achilles Tendon↗

Exaggeration of knee-jerk following spinal hemisection in monkeys.

In 18 monkeys ipsilateral flaccid hemiplegia of the hind-limb was produced by spinal cord hemisection at T8. As a result of systematic observations of various phenomena subsequent to the hemisection for several months, it was found that an ipsilateral marked exaggeration of the knee-jerk gradually developed in 2--3 weeks after the infliction, along with slight atrophy of the hind-limb muscles on the same side. The exaggeration reached a maximum in about 6 weeks and persisted thereafter for several months until the final experiments. The exaggeration of knee-jerk was confirmed by measuring quantitatively photographed trajectories of a small lamp attached to the malleolus, a specially devised hammer being used. The trajectories showed larger amplitudes, shorter rise times and lower thresholds on the hemisected side. Achilles tendon reflex was also observed to be hyperactive. However, there was no evidence of other pathological phenomena such as clonus or Babinski's sign in the present experiment. It was noted that total spinal cord transection one segment below the hemisected site did not abolish the exaggeration of knee-jerk. Another noticeable finding was that quadriceps afferent volleys picked up from the L6 dorsal root following tendon taps were smaller on the hemisected side, in spite of the fact that distinct augmented reflex potentials were observed in the ipsilateral L6 ventral root. These results strongly suggest that the exaggeration of knee-jerk was not induced by a release from tonic supraspinal inhibition nor by augmented quadriceps afferent volleys, but by some neural mechanisms which developed gradually within the lumbo-sacral segments below the hemisected site.

Animals↗

Neurological and electroneuromyographic assessment of the adverse effects of acrylamide on occupationally exposed workers.

Seventy-one acrylamide workers and fifty-one unexposed referents were studied. Weak legs and numb hands and feet, preceded by skin peeling from the hands, were the early symptoms of the acrylamide workers; their early signs were impairment of vibration sensation in their toes and loss of ankle reflexes. Three cases had cerebellar involvement followed by polyneuropathy due to heavy exposure. Electroneuromyographic changes, including a decrease in the sensory action potential amplitude, neurogenic abnormalities in electromyography, and prolongation of the ankle tendon reflex latency, are of greater importance in the early detection of acrylamide neurotoxicity since they can precede the neuropathic symptoms and signs. The diagnostic criteria for occupational acrylamide intoxication of this study revealed three severe poisonings, six moderate poisonings, and 43 mild poisonings. The total prevalence of acrylamide poisoning was 73.2%. The prevention of dermal exposure to acrylamide should be emphasized.

Acrylamide↗

[Bilateral spontaneous rupture of the patellar tendon in systemic lupus erythematosus. A case report and review of the literature].

A rupture of the patella ligament occurs after acute trauma or if there are factors that could have predisposed to the rupture like former injuries or operations of the knee or systemic diseases. If symptoms like loss of active extension, no patella tendon reflex, and a proximally displaced patella in radiograph appear in cases of those diseases, it should be thought of the rare rupture of the patella ligament. It will be treated operatively by suture of the tendon supporting by a wire, applying a cast for six to eight weeks and following physical therapy.

Female↗

Lateral ankle instability as a cause of superior peroneal retinacular laxity: an anatomic and biomechanical study of cadaveric feet.

The role of the competent superior peroneal retinaculum (SPR) as a primary restraint to peroneal tendon subluxation and mechanical attritional wear is clear. Injury to the SPR has classically been described as a dorsiflexion eversion movement of the ankle coupled with a forceful peroneal tendon reflex contraction. This mechanism, however, does not cause injury to the lateral collateral ligaments of the ankle and does not explain the coexistent findings of lateral ankle instability, laxity of the SPR, and concurrent peroneal tendon pathology. Anatomic studies reveal a parallel alignment of the calcaneal band of the SPR and the calcaneofibular ligament. A cadaveric model of ankle instability created by serial sectioning of the lateral collateral ligaments revealed increasing visual strain on the SPR with increasing degrees of ankle instability. These findings suggest the SPR serves as a secondary restraint to ankle inversion stress and that the force or forces that result in chronic ankle instability can also injure and attenuate the superior peroneal retinaculum.

Ankle Joint↗

H-reflex latency in uremic neuropathy: correlation with NCV and clinical findings.

Sixty-two uremic patients on dialysis of varying durations were tested bilaterally for posterior tibial nerve H-reflex latency, at 3-month intervals. Bilateral nerve conduction velocities (NCVs) of the peroneal, tibial, and sural nerves were concomitantly determined in all subjects. Proprioception sense, vibration perception threshold at the great toes, and deep tendon reflexes at the knee and ankle were determined in all subjects on the day of electrodiagnostic testing. The sensitivity of the H-reflex latency in detection of the onset and severity of uremic neuropathy was assessed. H-reflex latency changes were compared to NCV and clinical test results. The following was found: (1) of the parameters studied, the H-reflex latency appeared to be the most sensitive indicator of early uremic polyneuropathies, (2) electrodiagnostic tests were more sensitive to the onset of neuropathies than the clinical testing parameters studied, and (3) the sural sensory nerve appeared to be involved earlier than peroneal and tibial motor nerves in neuropathies studied.

Adolescent↗

Central effects of baroreceptor activation in humans: attenuation of skeletal reflexes and pain perception.

Activating the arterial baroreceptors blunts pain sensation and produces other forms of central nervous system inhibition in animals. These effects may be important to blood pressure regulation but have not been rigorously verified in humans. We describe (i) a noninvasive behaviorally unbiased method for baroreceptor stimulation and (ii) the application of this method to measurement of baroreceptor-mediated attenuation of pain perception and of the Achilles tendon reflex. The findings are relevant to basic mechanisms of blood pressure stabilization and cardiovascular reactivity and may also have implications for noncompliance with antihypertensive medications and for the pathophysiology of essential hypertension.

Achilles Tendon↗

Effects of postural changes of the upper limb on reflex transmission in the lower limb. Cervicolumbar reflex interactions in man.

The influence of passive changes in upper limb position on the excitability of three myotatic arc reflexes (soleus, quadriceps, and biceps femoris) of the lower limb has been explored on 42 volunteers. The results indicate that the excitability of the three myotatic arcs can be influenced at a distance by postural modifications of the upper limb. When the ipsilateral upper limb is forwards or the contralateral backwards, a facilitation of both soleus and quadriceps tendon reflexes is observed while the biceps femoris reflexes are reduced. This pattern of facilitation and inhibition is reversed when the ipsilateral upper limb is backwards or the contralateral forwards. The facilitations as well as inhibitions of proximal myotatic arc reflexes are quantitatively more marked than that of the soleus reflex. Facilitation and inhibition are not linearly related to the angle of the arm with the trunk. Effects begin at a considerable angle, become maximal at 45 degrees, and progressively disappear for greater values. It is suggested that the distinct pattern of facilitation and inhibition which is exerted in reciprocal fashion on extensor and flexor motor nuclei might depend on the long propriospinal neurones connecting cervical and lumbar enlargements.

Achilles Tendon↗

Loss of reflex inhibition following muscle tendon stimulation in essential tremor.

Electrical stimulation of human upper limb muscle tendons produces a reflex inhibition (I(1)) in the same muscles. This inhibition is reduced in Parkinson's disease (PD), prompting a similar study of essential tremor (ET). In essential tremor, two of eight subjects had no discernible inhibition, even following supramaximal stimulation (< 80 mA) of the tendons from extensor digitorum communis and extensor pollicis brevis. In the remaining six subjects, the mean thresholds for I(1) in these muscles were increased by 270 and 320%, respectively, relative to controls. The maximal amplitude of the inhibition was significantly reduced in the ET group, as was the following excitation (E(1)). The latency and duration of I(1) were not different in ET subjects and controls. The maximal duration of I(1) was correlated with tremor frequency in individuals, and tendon stimulation was effective in initiating ongoing tremor cycles. These results disclose a peripheral reflex abnormality in ET that is mediated by tendon afferents and can be linked to the coexistent tremor. The response in ET was distinguished from that in PD by its different time-course and by failure of the response to appear in the antagonist muscle. The abnormality may prove a useful marker for ET, which currently lacks a definitive pathological or neurophysiological marker to support objective clinical diagnosis.

Electric Stimulation↗

The Hoffmann reflex of the soleus muscle. A study in leprosy.

The H reflex of the soleus muscle was used to investigate the monosynaptic reflex arc of two groups of leprosy patients compared with a similar group of normal subjects. The H reflex recordings show two abnormalities: (1) An increase in the latency of the reflex without difference between lepromatous and borderline patients. (2) A decrease of the Hmax:Mmax amplitude ratio more pronounced in the lepromatous group. The discrepancy between these results and the commonly described preservation of the deep tendon reflexes in leprosy is discussed and the hypothesis that leprosy neuropathy would affect all nerve trunks related to blood vessel changes in suggested.

Adolescent↗

The role of the brachioradialis H reflex in the management and prognosis of obstetrical brachial plexus palsy.

The H reflex was investigated to determine if it can be useful in the prognosis of obstetrical brachial plexus palsies. The H reflex is an electrically stimulated monosynaptic or oligosynaptic response which can be recorded in peripheral nerves in all muscles of infants up to approximately two years of age. It is essentially the electrophysiologic counterpart of the deep tendon reflex, and its presence indicates intact afferent and efferent axons at the particular spinal segment. Our objectives were to document the Brachioradialis H (Br H) reflex latency and amplitude in normal upper extremities of infants, to evaluate the presence or absence of the Br H reflex in obstetrical palsy neonates and infants between one and seven months of age and to determine if this test was a valid predictor of final clinical outcome. A prospective study of 109 patients was performed to measure the Br H reflex in the affected and the contralateral normal limb. The results from the abnormal limb were compared to the final clinical decision made by nine months for or against surgical intervention. In the normal limbs, a Br H latency of 10.7 +/- 0.8 msec was determined with an amplitude of 1.2 +/- 1.2 mV. The chi 2 analysis in infants from one month to seven months old revealed a strong relationship between an absent Br H reflex and little or no clinical improvement (p < 0.0001), with a sensitivity for predicting poor outcome of 85.7%. The odds ratio (with a 95% confidence interval) of a child with an absent Br H reflex not significantly improving by nine months was 8.4 times higher than if the Br H reflex was present. The false positive rate was 42% however, indicating that a significant number of patients improved clinically, despite having a nonrecordable Br H reflex at age seven months or less. The low false negative rate of 14.3% suggested that in the presence of a Br H reflex, the majority of patients recover. Therefore, the presence of the Br H reflex is a helpful test in the prognostication of good recovery in obstetrical upper plexus palsy patients.

Birth Injuries↗

On the cause of tendon areflexia in the Holmes-Adie syndrome.

A case of Holmes-Adie syndrome was studied clinically and electrophysiologically. A total loss of tendon reflexes was observed in upper and lower limbs. The main electrophysiological finding was a marked increase of the central conduction time after stimulation of peroneal and tibial nerves. Motor evoked potentials in soleus muscle after transcranial magnetic stimulation showed normal threshold and latencies. We suggest that tendon areflexia could be a consequence of a dysfunction of somatosensory large diameter afferent fibres at the spinal level.

Adie Syndrome↗

Hoffmann-reflex is delayed during 6 degree head-down tilt with balanced traction.

BACKGROUND: Increased spinal height due to the lack of of axial compression on spinal structures in microgravity may stretch the spinal cord, cauda equina, nerve roots, and paraspinal tissues. HYPOTHESIS: Exposure to simulated microgravity causes dysfunction of nerve roots so that the synaptic portion of the Achilles tendon reflex is delayed. METHODS: Six healthy male subjects were randomly divided into two groups with three in each group. The subjects in the first group underwent horizontal bed rest (HBR) for three days. After a two week interval they underwent bed rest in a position of head-down tilt with balanced traction (HDT). So that each subject could serve as his own control, the second group was treated identically but in opposite order. Bilateral F waves and H-reflexes were measured daily (18:30-20:30) on all subjects placed in a prone position. RESULTS: By means of ANOVA, differences between HDT and HBR were observed only in M-latency and F-ratio, not in F-latency, central latency, and H-latency. Differences during the course of the bed rest were observed in M-latency and H-latency only. Tibial H latency was significantly lengthened in HDT group on day 2 and 3, although no significant difference between HDT and HBR was observed. CONCLUSION: The monosynaptic reflex assessed by H-reflex was delayed during 6 degree HDT with traction. The exact mechanism of this delay and whether the change was due to lengthening of the lower part of the vertebrae remain to be clarified.

Action Potentials↗

Clinical and molecular studies in five Brazilian cases of Friedreich ataxia.

Friedreich ataxia (FRDA), the most common autosomal recessive ataxia, is caused in 94% of cases by homozygous expansions of an unstable GAA repeat localised in intron 1 of the X25 gene. We have investigated this mutation in five Brazilian patients: four with typical FRDA findings and one patient with atypical manifestations, who was considered to have some other form of cerebellar ataxia with retained reflexes. The GAA expansion was detected in all these patients. The confirmation of FRDA diagnosis in the atypical case may be pointing out, as in other reports, that clinical spectrum of Friedreich's ataxia is broader than previously recognised and includes cases with intact tendon reflexes.

Adult↗

[A case of transient parkinsonism due to mesencephalic hemorrhage].

A 68-year-old man was admitted because of sudden onset gait disturbance and bradykinesia. He experienced left putaminal bleeding following mild right hemiparesis and emotional incontinence without any difficulties in his daily life since three years before admission. On neurological examination the patient was alert and oriented. He showed forced crying. Myerson's sign was positive. There were no abnormal findings in ocular movements, pupillary reflexes and other cranial nerves. Muscle tone was increased with cog-wheel phenomenon in bilateral upper extremities. Coordination was preserved. He showed severe akinesia and small steppage gait with stooped posture. Freezing phenomenon was observed in initiation of gait and turning. The deep tendon reflexes were increased in the right side with bilateral pathological reflexes. There was no definite weakness and sensory disturbance in all extremities. Brain CT revealed a small high density lesion in the medial side of right cerebral peduncle and a lens-shaped low density lesion in the left putamen. On T1 and T2 weighted images of MRI, right peduncular lesion showed low signal. It extended to the substantia nigra which was partially destructed. His parkinsonism was rapidly improved and completely disappeared within following two weeks. High density lesion of right peduncle on CT also disappeared. We discussed the mechanisms of parkinsonism following unilateral mesencephalic hemorrhage in this patient.

Aged↗

Topical anesthetics: effects on the Achilles tendon and H-reflexes. II. Stroke patients.

This study determined whether the Achilles tendon reflex, H-reflex, and ankle range of motion (ROM) during ambulation undergo significant changes after application of benzocaine spray applied to the triceps surae skin area of eight stroke patients displaying spasticity in ankle plantar flexor muscles. The H-reflex amplitude increased significantly (p less than 0.05) at 30 minutes after both the benzocaine (0.346 +/- 0.101V) and the placebo (air spray, 0.324 +/- 0.078V) when the placebo was given first; however, there was no significant difference between the two interventions. A significant decrease in ankle ROM occurred during midswing at 20 (placebo administered first) and 30 (benzocaine administered first) minutes after the placebo, but this decrease was not significantly greater than the change after the benzocaine. Benzocaine spray did not change motor neuron excitability level or improve the subject's ability to perform a functional task.

Achilles Tendon↗