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Herniated L4-L5 disc after placement of Harrington instrumentation for a fracture of the thoracolumbar spine.

The authors report a case in which L5 radiculopathy developed acutely after surgery for placement of Harrington rod instrumentation for an L1 body fracture. Computed tomographic myelography demonstrated a large L4-L5 herniated disc that had not been present in preoperative studies. An emergency laminectomy was performed, and a large, free, subligamentous disc fragment was removed. The patient subsequently regained L5 sensorimotor function. The postoperative development of lumbar radiculopathy is an uncommon complication of Harrington rod instrumentation that may result from several biomechanical features of the instrumentation. These injuries may not be detected by intraoperative monitoring of somatosensory evoked potentials, and therefore, the postoperative neurological examination assumes a crucial role in the early diagnosis of these lesions. As our case demonstrates, these radicular deficits may be reversible if their cause is promptly recognized and treated.

Aged

Pathogenesis of spinal cord injury and newer treatments. A review.

Many victims of traumatic spinal cord injury (SCI) suffer immediate paralysis as well as a subsequent progressive worsening of the cord pathology. Certain sensorimotor functions that might otherwise have returned are irreversibly lost because of this delayed response. An understanding of the pathophysiology behind this progressive, self-destructive sequence is yet to be acquired; however, numerous proposals have been set forth involving processes such as edema formation, vascular changes, an inflammatory reaction, and destruction of the neuronal plasma membranes. In this review, the authors outline many of the chemical, anatomic, and functional changes associated with SCI as well as a number of treatment regimens that have been found to improve recovery from SCI (including parenteral glucocorticoid therapy, localized cord cooling, calcium channel blockers, and opiate antagonism). From this, a number of mechanisms accounting for the mediation and/or prevention of the secondary destructive response are synthesized.

Animals

Physiological factors associated with injurious falls in older people living in the community.

Performance in six tests of sensorimotor function was measured in 50 subjects who were admitted to an acute hospital because of a fall (ICD codes E880-888), but who did not suffer a fracture of the lower limbs as a result. Performances in these tests were compared with 50 subjects of the same age and sex who had not fallen in the previous 12 months. It was found that those admitted to hospital because of a fall had decreased tactile sensation, reduced quadriceps strength and increased body sway on firm and compliant surfaces. The fallers also performed poorly in clinical tests of static and dynamic balance. Psychoactive-drug use was associated with falling and a number of test measures, including body sway, static balance, dynamic balance and quadriceps strength. Twenty-seven percent of fallers had poor outcomes, in that 1 year after testing, they had either suffered three or more additional falls, been readmitted to hospital, been transferred to nursing homes or died.

Accidental Falls

Photochemical stroke model: flunarizine prevents sensorimotor deficits after neocortical infarcts in rats.

We produced unilateral photochemical infarcts in the hindlimb sensorimotor neocortex of 186 rats by intravenous injection of the fluorescein derivative rose bengal and focal illumination of the intact skull surface. Infarcted rats showed specific, long-lasting deficits in tactile and proprioceptive placing reactions of the contralateral limbs, mostly the hindlimb. Placing deficits were most prominent during transition to immobility and/or when independent limb movements were required. Administration of flunarizine, a Class IV calcium antagonist, 30 minutes after infarction resulted in marked sparing of sensorimotor function in 30 rats. In contrast to 20 vehicle-treated rats, which remained deficient for at least 21 days, 15 (75%) of the rats treated with 1.25 mg/kg i.v. flunarizine showed normal placing on Day 1 after infarction, whereas the remaining five (25%) recovered within 5 days. Oral treatment of 10 rats with 40 mg/kg flunarizine was also effective. Neocortical infarct volume and thalamic gliosis, assessed 21 days after infarction, did not differ between 30 flunarizine- and 30 vehicle-treated rats. However, when 4-hour-old infarcts were measured in 16 rats, posttreatment with intravenous flunarizine reduced infarct size by 31%. In combination with appropriate behavioral analyses, photochemical thrombosis may constitute a relevant stroke model, in which flunarizine preserved behavioral function during a critical period, corresponding to the spread of ischemic damage.

Animals

Neglect induced by thalamotomy in humans: a quantitative appraisal of the sensory and motor deficits.

Stereotactic lesions for the treatment of tremor and rigidity in patients with Parkinson's disease are occasionally followed by neglect of the use of contralateral extremities for spontaneous movement when there are no specific sensory or motor deficits. A group of patients with neglected extremities was compared with a group of patients in which thalamotomy did not produce neglect. Neglect was shown by changes in motor performance, somatosensory evoked potentials (SEP) and electroencephalographic frequency induced by the lesion, as well as radiological evidence of brain atrophy and place and extension of lesions. Reaction time to both auditory and somatosensory stimuli was significantly increased only in the extremities contralateral to the lesion of patients with neglect; tremor decreased equally in both groups, and other motor abilities remained unchanged. P-200 component of SEP decreased in amplitude and increased in latency only in cases with neglect, particularly ipsilateral to the lesion; early components and mean electroencephalographic frequency remained unchanged. Brain atrophy was significant in patients with neglect, particularly for the posterior portion of the 3rd ventricle. No differences in size and location of the lesions were found between the groups. Results indicate that this type of neglect is not secondary to lesions in specific sensory of motor pathways, but to lesions of structures coupling sensorimotor functions and the process of attention and that midline thalamic nuclei atrophy precipitates the neglect, perhaps by critically decreasing the amount of reticulothalamocortical projections engaged in selective attention.

Adult

Drug-induced ego states. I. Cocaine: phenomenology and implications.

The ego state experienced by chronic users of cocaine is described in terms of sensorimotor functioning, cognitive functioning, emotionality, spatiality , temporality , causality, and materiality . At low use levels the state is pleasurable, but at high levels fear, anxiety, and paranoia increase, and ultimately reality contact breaks down. Q-sort, Semantic Differential, and other data suggest that low-level users take cocaine to overcome personal insecurities and relieve boredom. Heavy users take it to support overvaulting ambitions and intense strivings for self-sufficiency. Psychotherapy with such persons must deal with their counterdependency , anger, and despair, and with their underlying sense of betrayal . These persons have unacknowledged needs for spiritual experience that must be dealt with openly. A description of persons most vulnerable to heavy use of cocaine is provided, and recommendations for research and social policy are presented.

Adult

Visually monitored postrotary nystagmus in seven autistic children.

Therapists who evaluate the sensorimotor functions of autistic children have become increasingly interested in monitoring their responses to vestibular stimulation. In this study, the duration of the nystagmus reflex is visually monitored and then measured by means of a stop-watch. Each of 7 autistic subjects received 18 sessions (36 trials) of horizontal semicircular canal stimulation during a period of 25 days. In each trial a graduated acceleration in a hand operated rotating chair preceded an abrupt stop, with a rapid deceleration from 180 degrees/second to 0 degree/second. Although subject option (intentional response) imposes limitations on the data interpretation, inspection of the nystagmus functions over time suggests the following: substantial trial-to-trial variability; substantial subject-to-subject variability; greater scores following trials to the subjects' left (the direction of the second trial in each session) than to the right (the direction of the first); and no evidence of consistent change for most subjects in nystagmus duration across the 36 trials. Implications for clinical evaluation of nystagmus are discussed.

Autistic Disorder

Decrement in manual arm performance during whole body cooling.

Six subjects performed three manual arm tasks: 1) prior to immersion in 8 degrees C water; 2) soon after immersion to the neck, but prior to any decrease in core temperature; and 3) every 15 min until core temperatures decreased 2-4.5 degrees C. The tasks were speed of flexion and extension of the fingers, handgrip strength and manual dexterity. There was no immediate effect of cold immersion; however, all scores decreased significantly after core temperature decreased 0.5 degrees C. Further decrease in core temperature was associated with a progressive impairment of performance, although at a slower rate than during the first 0.5 degrees C decrease. Flexion and extension of the fingers was affected relatively more than handgrip strength or manual dexterity. Decrement in performance is a result of peripheral cooling on sensorimotor function with a probable additional effect of central cooling on cerebral function.

Adult

[Effect of the depth of anesthesia on the postoperative course].

An assessment of the influence of several variables during the perioperative period revealed a cause-determining correlation between the explanatory variables age, body size, weight, duration of operation, loss of blood, and pain level and the physiologic variables adrenaline, total protein, blood glucose level, transferrin, cholinesterase and immunoglobulin G that could be statistically be proven. An evaluation of the influence of the depth of anesthesia on this cause-determining correlation demonstrated significant advantages for a deep level of anesthesia. The depth of anesthesia should be seen as an influential factor during the perioperative period. Anesthesia should therefore not be regarded simply as analgesia and loss of consciousness; rather, one should stress the psychophysiological attenuation and its negative influence on the sensorimotor functions that are accompanied by changes in physiology. The central organ of regulation controls the physiological levels of the organism, and changes in brain function result in changes in physiology. During the perioperative period, rapid and programmed functional mechanisms that are controlled by more primitive parts of the brain and thus are not influenced by individual inappropriate decisions of the "higher" brain centers are needed for the patient's convalescence. This would explain the advantage of a deep level of anesthesia. The usual grading of stages of anesthesia according to Güdel provides little help in this respect; therefore, an assessment of the depth of anesthesia using EEGs and evoked potentials should be combined with an evaluation of physiological variables at several other levels of the organism such that further information can be obtained on the conditions existing at the onset of the postoperative course.

Adolescent

NMDA receptors mediate poly- and monosynaptic potentials in motoneurons of rat embryos.

We determined the contribution of glutamate receptor subtypes to developing excitatory synaptic transmission in isolated spinal cord of rat embryos. Using electrophysiological and morphological techniques, we studied the pattern of development of synapses between dorsal root afferents and motoneurons in lumbar spinal cords of 15- to 21-d-old rat embryos. Motoneuron dendritic fields and afferent projections onto motoneurons were identified by labeling with HRP. Afferents first entered the gray matter at Day 15 of gestation, and by Day 16 they terminated close to motoneuron dendritic trees. Afferent axons projected onto motoneuron dendritic fields at Day 17, when boutons were detected on motoneuron dendrites that were crossed by afferent axons. To determine the time course of formation of functional sensorimotor synapses and their pharmacological properties, a dorsal root was stimulated while recording intracellularly from segmental motoneurons. At Day 16, excitatory postsynaptic potentials (EPSPs) with long latencies, slow rates of rise, and long durations were recorded. The amplitudes of these EPSPs increased with membrane depolarization and in the absence of extracellular Mg2+. These EPSPs were blocked by D-2-amino-5-phosphonovalerate (APV) and ketamine, which are selective antagonists of N-methyl-D-aspartate (NMDA) receptors. These findings suggest that initial synaptic transmission in embryonic motoneurons is mediated solely by NMDA receptors. Short-latency EPSPs with fast rates of rise were first recorded in most motoneurons by Day 17. These EPSPs were composed of fast- and slow-rising potentials. The slow component was blocked by APV, while the fast component was eliminated by 6-cyano-7-nitroquinoxaline-2,3-dione and kynurenate. This indicates that the short-latency EPSPs are mediated by both NMDA and non-NMDA receptors. Dose-response curves of motoneurons to L-glutamate, NMDA, and kainate demonstrated that motoneurons are sensitive to these agonists prior to the formation of synapses between afferents and motoneurons. Motoneuron responses to NMDA and kainate increased immediately after the onset of short-latency EPSPs. This increased sensitivity could be due to extracellular factors influenced by growing sensory axons or intrinsic properties of differentiating motoneurons.

Animals

Relations between sensorimotor attainments and development of language comprehension in retarded children.

Although cognitive precursors of language production have received considerable attention, the relationship between cognitive development and language comprehension is still largely unknown. We report here on an investigation into the relationship between sensorimotor attainments and receptive language skills in normal and retarded infants aged 12-26 months. A major goal of this study was to translate some current notions about onset of representational language and its cognitive prerequisites into some clinically useful procedures both for early diagnosis and treatment of disabled infants. The Uzgiris-Hunt ordinal scales and receptive language tests were administered to 32 infants with motor delay and to 15 normal infants matched for chronological age. Comparison of the resulting scores indicated significant differences in favor of the normal infants on the six Uzgiris-Hunt scales and on the receptive language measures. The cognitive profile of the retarded infants was not homogeneous, some sensorimotor areas (object permanence, vocal and gestural imitation, schemes in relation to objects) showing later onset and slower development than others. Evidence for the parallel emergence of representational ability in language and thought was not as strong as stated by Piagetian theorists. No single stage of sensorimotor functioning prerequisite to language comprehension could be discerned, especially in the retarded infants, who showed considerable gaps between the two domains.

Age Factors

Synaptic plasticity and learning: selective impairment of learning rats and blockade of long-term potentiation in vivo by the N-methyl-D-aspartate receptor antagonist AP5.

This paper reports a series of 5 experiments concerned with a possible role for N-methyl-D-aspartate (NMDA) receptors in certain types of learning. The results show that chronic intraventricular infusion of the NMDA receptor antagonist D,L-2-amino-5-phosphonopentanoic acid (D,L-AP5) caused an impairment of spatial but not of visual discrimination learning in rats. Such selectivity of the learning impairment occurred despite widespread distribution of the drug throughout the CNS. AP5 sometimes caused a disturbance of sensorimotor function during learning, but one experiment addressing whether this disturbance could be responsible for the spatial learning impairment established that it was statistically independent. Another experiment showed that AP5 did not affect the retention of previously acquired spatial information. These behavioral effects were all obtained with a concentration of AP5 that, in a final study, was found to be sufficient to block hippocampal long-term potentiation (LTP) in vivo without affecting normal synaptic transmission. Taken together, these observations (1) implicate NMDA receptors in certain types of learning, and (2) extend recent work showing that saturation of LTP causes an anterograde spatial amnesia (McNaughton et al., 1986). A preliminary report of parts of this work has been published (Morris et al., 1986a).

Animals

Pharmacological basis for the use of nimodipine in central nervous system disorders.

Nimodipine, a Ca2+ antagonist with cerebrovasodilatory and anti-ischemic effects, binds to rat, guinea pig, and human brain membranes with high affinity (less than 1 nM). Only at higher concentrations has nimodipine been reported to block the release of some neurotransmitters and hormones from neuronal tissue. Nimodipine has no consistent effect on brain oxygen consumption or cortical ATP or phosphocreatine levels, although the ischemia-induced fall of brain ATP levels in gerbils or the lowering of intracellular brain pH in rabbits with focal cerebral ischemia were antagonized by the drug. In rats and baboons with middle cerebral artery occlusion, nimodipine was found to reduce neurological deficits without an increase in intracranial pressure or brain edema. Electrophysiological studies with nimodipine suggested a direct neuronal action. In rabbit dorsal root ganglion cells, concentrations as low as 20 nM were reported to block inward Ca2+ currents. Recent studies have suggested that nimodipine may also improve memory in brain-damaged or old rats, restore sensorimotor function and abnormal walking patterns of old rats, and accelerate acquisition of associative learning in aging rabbits. Blockade of age-related changes in Ca2+ fluxes in rat hippocampal neurones by nimodipine in vitro pointed to neuronal plasma membrane as the site of nimodipine action. The therapeutic usefulness of nimodipine appears not to be limited to cerebral ischemia, but may include dementia, age-related degenerative diseases, epilepsy, and ethanol intoxication.

Aging

Placement from community-based mental retardation programs: how well do clients do after 8 to 10 years?

The placement success and quality of life of 85 mentally retarded persons placed into independent housing and competitive employment 8 to 10 years ago was evaluated. Three groups emerged on the basis of the clients' current programmatic status, living-work placement, and financial status. A number of variables were found to discriminate between successful and unsuccessful living and work outcomes, including family involvement, social-emotional behavior, number of disabilities, sensorimotor functioning, symbolic operations, and auditory-visual processing. For assessed quality of life, significant correlates included family involvement, income, number of disabilities, and age. Those who were successful had a higher assessed Quality of Life Index than those who were unsuccessful.

Activities of Daily Living

[Comparative value of anorectal manometry and electrocardiography in the diagnosis of diabetic autonomic neuropathy].

Searching for silent anorectal autonomic neuropathy, we investigated the anorectal sensorimotor function in 79 continent diabetics. Thirty four per cent of the patients had a basal anal sphincter pressure lower than 40 mm Hg N = 54.5 +/- 15.5 mm Hg and 11 p. 100 had a threshold of conscious rectal sensation higher than 20 ml (N less than or equal to 20 ml). An electrocardiogram was performed and the change in heart rate resulting from successive deep breaths was recorded for each patient. Cardiac autonomic neuropathy was diagnosed when cardiac frequency did not change with ventilation. This was reflected by a ratio E/I (largest RR space during expiration on the electrocardiogram to the shortest during inspiration) close to one. Compared to cardiac criteria for autonomic neuropathy, the sensitivity of anorectal manometry in the detection of diabetic autonomic neuropathy was 77.2 p. 100 and specificity was 82 p. 100. Low basal anal sphincter pressure in asymptomatic diabetics seems to be a sensitive and specific criteria for the assessment of diabetic autonomic neuropathy and correlates closely with cardiac criteria.

Adult

[Event-related slow potentials (ERSPs) of the brain in cases of temporal psychomotor and petit mal status].

Two cases have been studied by means of the usual method for eliciting CNV (S-1.5 OR 1 SEC-S-operant response) during and after the end of an episode of prolonged epileptic twilight state with almost continuous strictly unilateral temporal lobe discharge. From the clinical viewpoint in both cases the twilight state, lasting respectively about 12 and 48 hours, was characterized by a slightly clouded consciousness and moderate impairment of awareness and of psychic performances, at times associated with simple and complex psychomotor automatism and hallucinations. The EEG recorded an almost continous left temporal discharge of pseudorhythmic mixed slow waves and sharps. The third case had typical prolonged petit mal states with continuous spike-and-slow-wave activity, impaired intellectual and motor performances (very long reaction time etc.). In this patient for eliciting ERSPs, besides the standard method, we have used a paradigm in which S consisted of a colored slide, with various semantic contents, remaining visible for 5 seconds on a screen. At the trials of the standard paradigm during the epiliptic twilight state, all patients showed they had understood the signal to interrupt (S loud repetitive tone) in the shortest time possible and could clearly distinguish them from the S. The operant response was almost always made with sufficient precision and sometimes with fairly short reaction time, especially by the patients with temporal psychomotor status. During the episodes of prolonged clouded consciosness in all series of trials administered to the patients, no negative slow potential shifts were observed in the averaged EEG recordings obtained from F-T, F-T or F, FCZ and referred to to linked mastoids. On repetition of the examinations some time after the end of the epileptic twilight state, fairly normal ERSPs were obtained in all cases. Taking also into account the results of previous researches, these studies show that the temporal lobe and "centrencephalic" epileptic discharges, under certain conditions, may influence negatively the neurophysiological mechanisms which contribute to the information of complex contingent connections and which also underly the particular attentional, cognitive and sensorimotor functions involved in the inhibiting the appearance of ERSPs probably related to more specific perceptual and integrative functions. Some AA. maintain that negative slow potential shifts express the functional activity of the brain structures, particularly of determined cerebral cortex regions, involved not only in attentional, perceptual, cognitive and psychomotor functioning, but also in information processing (memory recording mechanism). Hence, the negative influence of prolonged temporal lobe or meso-diencephalic epileptic discharges on these structures may explain the almost complete amnesia that patients generally show at the termination of this kind of twilight state.

Adult

Neurobehavioral changes in adult Fischer 344 rats exposed to dietary levels of chlordecone (Kepone): a 90-day chronic dosing study.

Chlordecone (Kepone) given in the diet at 10 and 30 ppm for 90 days to adult male Fischer 344 rats produced significant behavioral changes. Rats were tested in a battery of behavioral screening tests for sensorimotor functions at 30, 60, and 90 days of dosing, and 30 days postdosing. Body weight loss was significant by 90 days of dosing with 30 ppm chlordecone; no weight change was seen at the lower dose. Variable effects on grip strength were seen during and after dosing. The magnitude of startle responsiveness to an air puff stimulus was significantly increased by 30 days of dosing in the 30 ppm dose group. Both 10 and 30 ppm doses produced increased responsiveness to an acoustic stimulus by 60 days of dosing. Negative geotaxis and tail flick response to thermal stimulation did not change. By 30 days postdosing, significant behavioral alterations still persisted in startle responsiveness.

Animals

Incremental exposure facilitates adaptation to sensory rearrangement.

The rate of adaptation to unusual patterns of vestibular stimulation is enhanced if the final stimulus level is achieved gradually rather than in a single step (6,7). Measurements of adaptation to visual rearrangement elicited by stepwise and single-step exposure indicate that incremental exposure also facilitates adaptation to visual rearrangement; adaptation is diminished when the optical displacement is varied nonsystematically during exposure. Enhancement of adaptation to unusual patterns of sensory stimulation by incremental exposure may reflect a general principle of sensorimotor function.

Adaptation, Ocular