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PubMed1985

Relative prognostic value of best motor response and brain stem reflexes in patients with severe head injury.

The object of this study was to determine whether the addition of information on brain stem reflexes improves the prognostic precision of the Glasgow coma scale for patients with severe head trauma. The study is based on 109 patients with a Glasgow coma score of 7 or less during the first 24 hours after injury. The average age was 23 years. The patients were classified into three groups according to their actual outcome after 6 months: dead, 44 patients; persistent vegetative state and severe disability, 13 patients; moderate disability and good recovery, 52 patients. We then compared, by means of multiple group logistic regression, the prognostic ability of motor responses alone using the Glasgow criteria and of brain stem reflexes via an original approach. We showed that the predictive capabilities of brain stem reflexes were greater than those of motor responses. Although closely related (r = 0.68), the use of these two parameters in a single scale, the Glasgow-Liege scale, improves the precision of prognosis, especially for those head trauma patients with initial and complete loss of consciousness. Age was also revealed to be an important factor for outcome prediction.

Adolescent↗
PubMed1985

Neuropsychological outcome after severe pediatric near-drowning.

Between April 1979 and August 1983, 49 nearly drowned children in serious condition were admitted to Childrens Hospital of Los Angeles (CHLA) with Glasgow coma scores of 3, 4, or 5 and underwent intracranial pressure monitoring and brain resuscitative therapy. Of the 49 patients, 29 (59%) died in the hospital 1 day to 3 months after admission, 13 (27%) were discharged in vegetative states, and 7 (14%) made good recoveries. No patient made a partial neurological recovery. The sustained mean highest intracranial pressure was significantly higher and the sustained lowest cerebral perfusion pressure was significantly lower for those who died than for survivors (P less than 0.05), but these data did not significantly distinguish between intact and vegetative survivors. Pupillary reactivity noted on arrival at CHLA also significantly discriminated survivors and fatalities (P less than 0.05), but not between intact and vegetative survivors. The presence of any motor activity after arrival at CHLA, even posturing or twitching, indicated a significant chance for intact survival (P less than 0.05), although such activity did not discriminate between death and vegetative survival. Extensive neuropsychological testing indicated that the apparently intact recovered patients generally showed nearly average levels of cognitive functioning, with mild residual gross motor and coordination deficits.

Adolescent↗
PubMed1994

Diagnostic problems in patients with benign paroxysmal positional vertigo.

The steps of the examination procedure applied for a correct diagnosis of benign paroxysmal positional vertigo (BPPV) are reviewed. A precise diagnosis is important in view of treatment of this type of vertigo by rehabilitation therapy. Clinical experience supports the concept that the diagnosis has to be based not only on a typical history, but also on the presence of a reproducible vertigo and paroxysmal positioning nystagmus. In the procedure applied in the department, this nystagmus can be reproduced by the Dix-Hallpike maneuver under Frenzel's glasses, during electronystagmography (ENG) recording in the position tests, or it can be present in the vestibular habituation training test battery (a battery of 19 maneuvers applied for defining the adequate exercises in the rehabilitation treatment for BPPV). Analysis of the reviewed data in 95 patients showed that one third of the patients described the vertigo in a rather atypical way, while the further testing revealed a typical BPPV. This experience denies any absolute reliability to only history. In fact, only the finding of such a paroxysmal positioning nystagmus is conclusive for confirming BPPV. However, also the presence of such a nystagmus appeared not to be a constant datum, so that in some patients more than one examination was necessary to come to a reliable diagnosis. It is obvious that, for detecting a paroxysmal positioning nystagmus, ENG is less reliable than the Dix-Hallpike maneuver under Frenzel's glasses.

Adult↗
PubMed1979

Segmental neurophysiological mechanisms in scoliosis.

Segmental spinal reflexes (stretch reflexes) were studied in patients with scoliosis. The proprioceptive responses to the phasic stretch of the paraspinal muscles were asymmetric in all patients, and were increased on the convex side. The asymmetry was more pronounced when the patients were standing. The observed asymmetry of the reflex responses was taken to indicate asymmetry in the tone and postural activity of the superficial layer of the paraspinal muscles. A reciprocal relationship was found in the segmental reflex organisation between the superficial and deep layers of the paraspinal muscles. The increase in reflex response of the superficial muscles on the convex side can be due to diminished reciprocal inhibition from weak, deep muscles. Thus a segmental neurogenic disorder involving predominantly the deep paraspinal muscles of the convexity of the curve may be the primary lesion responsible for the development of scoliosis.

Adolescent↗
PubMed2002

Ultrastructural abnormalities of muscle spindles in the rat masseter muscle with malocclusion-induced damage.

Human temporomandibular disorders due to disturbed occlusal mechanics are characterized by sensory, motor and autonomic symptoms, possibly related to muscle overwork and fatigue. Our previous study in rats with experimentally-induced malocclusion due to unilateral molar cusp amputation showed that the ipsilateral masseter muscles undergo morphological and biochemical changes consistent with muscle hypercontraction and ischemia. In the present study, the masseter muscle spindles of the same malocclusion-bearing rats were examined by electron microscopy. Sham-operated rats were used as controls. In the treated rats, clear-cut alterations of the muscle spindles were observed 26 days after surgery, when the extrafusal muscle showed the more severe damage. The fusal alterations affected predominantly capsular cells, intrafusal muscle fibers and sensory nerve endings. These results suggest that in the malocclusion-bearing rats, an abnormal reflex regulation of the motor activity of the masticatory muscles may take place. They also allow us to hypothesize that muscle spindle alterations might be involved in the pathogenesis of human temporomandibular disorders.

Animals↗
PubMedDate not supplied

The influence of age on patellar reflex response in the dog.

The patellar tendon reflex is a clinical parameter commonly used to assess neurological status. Factors such as quadriceps muscle fiber composition, femur length, and patient age have been reported to influence total and fractionated reflex times in human beings. The purpose of this blinded, cross-sectional study was to examine the effect of age on the patellar reflex in the dog. Eighty-six dogs without evidence of neurological impairment or orthopedic disease of the stifle (eg, patellar luxation or cranial cruciate ligament rupture) were assigned to 1 of 2 groups on the basis of age: group 1, <10 years old (n = 72); or group 2, > or =10 years old (n = 14). Patellar reflexes were elicited in both pelvic limbs by a reflex hammer while the dog was in lateral recumbency. The reflex was scored as present or absent by a blinded individual. Two dogs in group I had reflexes absent in both limbs, 3 dogs in group 2 had reflexes absent in both limbs, and 1 dog in group 2 lacked a response in 1 limb. The proportion of dogs with absent patellar reflexes in group 2 (4 of 14, 95% CI, 8-58%) was significantly higher than the proportion of dogs with absent patellar reflexes in group 1 (2 of 72, 95% CI, 0-10%) (P < .006). Furthermore, dogs lacking at least 1 patellar reflex were older than those having both reflexes present (P = .04). Weight was not related to the presence of both reflexes (P = .49). These findings suggest that neurologically normal dogs may have an age-dependent decline in patellar reflex magnitude or a prolongation of total reflex time (TRT).

Aging↗
PubMed2001

Neural influences on sprint running: training adaptations and acute responses.

Performance in sprint exercise is determined by the ability to accelerate, the magnitude of maximal velocity and the ability to maintain velocity against the onset of fatigue. These factors are strongly influenced by metabolic and anthropometric components. Improved temporal sequencing of muscle activation and/or improved fast twitch fibre recruitment may contribute to superior sprint performance. Speed of impulse transmission along the motor axon may also have implications on sprint performance. Nerve conduction velocity (NCV) has been shown to increase in response to a period of sprint training. However, it is difficult to determine if increased NCV is likely to contribute to improved sprint performance. An increase in motoneuron excitability, as measured by the Hoffman reflex (H-reflex), has been reported to produce a more powerful muscular contraction, hence maximising motoneuron excitability would be expected to benefit sprint performance. Motoneuron excitability can be raised acutely by an appropriate stimulus with obvious implications for sprint performance. However, at rest H-reflex has been reported to be lower in athletes trained for explosive events compared with endurance-trained athletes. This may be caused by the relatively high, fast twitch fibre percentage and the consequent high activation thresholds of such motor units in power-trained populations. In contrast, stretch reflexes appear to be enhanced in sprint athletes possibly because of increased muscle spindle sensitivity as a result of sprint training. With muscle in a contracted state, however, there is evidence to suggest greater reflex potentiation among both sprint and resistance-trained populations compared with controls. Again this may be indicative of the predominant types of motor units in these populations, but may also mean an enhanced reflex contribution to force production during running in sprint-trained athletes. Fatigue of neural origin both during and following sprint exercise has implications with respect to optimising training frequency and volume. Research suggests athletes are unable to maintain maximal firing frequencies for the full duration of, for example, a 100m sprint. Fatigue after a single training session may also have a neural manifestation with some athletes unable to voluntarily fully activate muscle or experiencing stretch reflex inhibition after heavy training. This may occur in conjunction with muscle damage. Research investigating the neural influences on sprint performance is limited. Further longitudinal research is necessary to improve our understanding of neural factors that contribute to training-induced improvements in sprint performance.

Adaptation, Physiological↗
PubMed1979

Startle reflex habituation in children with cerebral palsy.

Two groups of children (9 with cerebral palsy and 10 normals, matched for sex and age) participated in a study of the startle reflex. Each child was instructed to press a button as soon as possible after the onset of a visual stimulus on a box on the table at which they were seated. During some of the trials, a sudden and intense auditory stimulus (85 dB) was presented concomitantly with the onset of the visual stimulus, and effects on reaction time recorded. Mean reaction time of normal children was significantly faster than that of the group with cerebral palsy. The magnitude of disruption associated with the first startle stimulus presentation was signicantly greater for cerebral palsied children. The course between groups of habituation to the startle stimuli was not significantly different. Data support the hypothesis that startle reflexes of children with cerebral palsy are more marked than are those of normal children.

Acoustic Stimulation↗
PubMed2004

Neurologic sequela of hydrogen sulfide poisoning.

A 25-year-old man, a field operator in a petroleum refinery was found unconscious. He was exposed to hydrogen sulfide and presented with Glasgow Coma Score of 5, severe hypoxemia on arterial blood gas analysis, normal chest radiography, and normal blood pressure. On hospital day 7, his mental state became clear, and neurologic examination showed quadriparesis, profound spasticity, increased tendon reflexes, abnormal Babinski response, and bradykinesia. He was also found to have decreased memory, attention deficits and blunted affect, which suggested general cognitive dysfunction, but which improved soon. MRI scan showed abnormal signals in both basal ganglia and motor cortex, compatible with clinical findings of motor dysfunction.

Adult↗
PubMed1995

The auditory, vestibular, and oculomotor system in facioscapulohumeral dystrophy.

Auditory, vestibular and oculomotor function tests were performed in 14 FSHD patients (7 men, 7 women, aged 19-74 years) with autosomal dominant facioscapulohumeral dystrophy (FSHD) due to chromosome 4q35 associated DNA rearrangements. (Cochlear) sensorineural hearing loss (SNHL) in excess of that expected for their age was found in 6 patients: in 3 at the higher frequencies and in 3 also at the lower (speech) frequencies. Brain-stem auditory evoked potentials were generally normal. Oculomotor functions were normal. Four patients showed vestibular hyperreflexia, perhaps secondary to diminished head movements. Despite the apparent genetic homogeneity of the present patients, the above-mentioned findings showed significant associations with certain families, the cases of new mutations, or a certain generation. Therefore, FSHD in our patients demonstrated clinical heterogeneity.

Adult↗
PubMed2000

Physiological basis for human autonomic rhythms.

Oscillations of arterial pressures, heart periods, and muscle sympathetic nerve activity have been studied intensively in recent years to explore otherwise obscure human neurophysiological mechanisms. The best-studied rhythms are those occurring at breathing frequencies. Published evidence indicates that respiratory fluctuations of muscle sympathetic nerve activity and electrocardiographic R-R intervals result primarily from the action of a central 'gate' that opens during expiration and closes during inspiration. Parallel respiratory fluctuations of arterial pressures and R-R intervals are thought to be secondary to arterial baroreflex physiology: changes in systolic pressure provoke changes in the R-R interval. However, growing evidence suggests that these parallel oscillations result from the influence of respiration on sympathetic and vagal-cardiac motoneurones rather than from baroreflex physiology. There is a rapidly growing literature on the use of mathematical models of low- and high-frequency (respiratory) R-R interval fluctuations in characterizing instantaneous 'sympathovagal balance'. The case for this approach is based primarily on measurements made with patients in upright tilt. However, the strong linear relation between such measures as the ratio of low- to high-frequency R-R interval oscillations and the angle of the tilt reflects exclusively the reductions of the vagal (high-frequency) component. As the sympathetic component does not change in tilt, the low- to high-frequency R-R interval ratio provides no proof that sympathetic activity increases. Moreover, the validity of extrapolating from measurements performed during upright tilt to measurements during supine rest has not been established. Nonetheless, it is clear that measures of heart rate variability provide important prognostic information in patients with cardiovascular diseases. It is not known whether reduced heart rate variability is merely a marker for the severity of disease or a measurement that identifies functional reflex abnormalities contributing to terminal dysrhythmias.

Adult↗
PubMed2003

One-level one-sided lumbar disc surgery with and without microscopic assistance: 1-year outcome in 114 consecutive patients.

OBJECT: The aim of this study was to compare the outcomes following macrodiscectomy and microsurgery for one-level one-sided lumbar disc excision. METHODS: The authors prospectively studied 114 consecutive patients who underwent microdiscectomy (Group A, 63 patients [36 men, 27 women]) and macrodiscectomy (Group B, 51 patients [29 men, 22 women]) for one-level unilateral first-time lumbar disc herniation. Microdiscectomy was considered to involve a small incision with removal or opening of the ligamentum flavum, no or minimal bone excision, and use of the operating microscope to remove the disc material. Laminectomy combined with macrodiscectomy was defined as any operation requiring a large opening in or complete removal of the unilateral lamina. Diagnosis was confirmed by magnetic resonance imaging. A 1-year follow-up investigation was also conducted. Relief of radicular pain, improvement in muscle power, and changes in sensory and/or reflex abnormality were documented. Assessment of outcome was performed using the modified Stauffer-Coventry criteria. Good or excellent results were demonstrated in 90% of Group A and 89% of Group B patients (p > 0.05). One patient in each group underwent reoperation. There was infection over the fascia in two Group A patients. Mean operative time (+/- standard deviation) was 54 +/- 5.65 minutes in Group A and 25 +/- 7.07 minutes in Group B (p < 0.01). Median length of the incision was 4 and 6 cm in Group A and Group B, respectively (p < 0.05). The length of postoperative inpatient stay was 1 day in both groups (p > 0.05). Patients in the microsurgery-treated group returned to work in less time: 85% of Group A and 58% of Group B patients returned to their work within 4 weeks (p < 0.001). Some patients in each group (15% in Group A and 45% in Group B) needed narcotic analgesic medication at least twice between the 1st month and 1st year after the surgery (p < 0.001). CONCLUSIONS: Microdiscectomy allows the surgeon good visualization and is less traumatic to the involved tissues. Interestingly, the results of this study indicated that microsurgery does not reduce hospitalization time, nor does it improve the overall surgery-related outcome. The main differences between the two procedures were length of the incision and operative time. The author found that lumbar microdiscectomy allows patients earlier return to work and/or normal life with less reliance on postoperative narcotic analgesic agents.

Activities of Daily Living↗