Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The postural adjustments that accompany the limb flexion following stimulation of the motor cortex in the cat are in part at least mediated by the lateral vestibular nucleus (LVN). In fact, inactivation of vestibulospinal (VS) neurons by unilateral injection of GABA agonists into the LVN decreased the early component of the responses in all of the postural limbs without modifying the threshold, latency, or amplitude of the cortically induced flexion movement. Just the opposite result was obtained after injection into the same structure of GABA antagonists. Experiments were performed to find out whether these VS influences were somatotopically organized. Microinjection of 0.25 microL of the GABA-A agonist muscimol or the GABA-B agonist baclofen (at 1.5 to 4 micrograms/microL saline) into the rostroventral part of the LVN (rvLVN) of one side produced hypotonia in the ipsilateral and hypertonia in the contralateral forelimb. The same injection also reduced the early component of the postural responses to cortical stimulation in both forelimbs, but not in the hindlimbs. On the other hand, unilateral injection of the same agents into the dorsocaudal part of the LVN (dcLVN) produced similar effects, but they were limited to the hindlimbs. The results obtained, which lasted for about 2 to 3 h, were not only site-specific but were also dose-dependent. Injection into the rvLVN or dcLVN of 0.25 microL of the GABA-A antagonist bicuculline or the GABA-B antagonist phaclofen (at 8 or 5 micrograms/microL saline) produced localized changes in posture as well as in the post-urokinetic responses to cortical stimulation. These were opposite in sign to those elicited by the corresponding agonists. In conclusion, it appears that: 1) the motor cortex utilizes descending volleys passing through the LVN in order to elicit the early postural adjustments during a cortically induced limb movement; 2) the resulting VS influences are somatotopically organized; 3) the amplitude of these postural responses can be affected by inhibitory influences probably exerted by Purkinje cells of the cerebellar vermis on the related VS neurons through both GABA-A and GABA-B receptors.
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PMID:Somatotopical effects of local microinjection of GABAergic agents in Deiters nucleus on the posturokinetic responses to cortical stimulation. 827 73

Two-hundred fifty infants with high and no risk history transitory neurological findings (TNF) were examined during the first year of life. The neurological situation and the developmental progress were reconsidered in these children at 2.5-4.5 and 5-7 years of age. TNF were diagnosed mainly during the first two trimesters. Hyperirritability and asymmetries resolved to about 70% during the first half of the first year of life. In contrast, isolated central hypotonia resolved over a much longer period. No correlations of distinct types of TNF could be found with VLBW and LBW-infants, with fullterm infants, with birthweights, nor with risk factors. Children who developed spastic CP presented permanent hypertonia beside other specific neurological symptoms during the second half of the first year of life. Children with lasting non-spastic handicaps showed permanent hypotonia combined with other neurological abnormalities and symptoms of psychomotor retardation, which evolved also during the second half of the first year. From these results the question arises: which parts of TNF are essentially neurobiological findings indicating processes of transformation of the sensory motor system from non-intentional fetal to intentional motor behaviour of early infancy. TNF, then, should not longer be looked at as symptoms of pathological value only.
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PMID:Transitory neurological findings in a population of at risk infants. 827 75

We report two sibs with Angelman syndrome or an apparently new syndrome. In addition to severe mental retardation and seizures, clinical examination showed an ataxic and stiff legged gait, truncal hypotonia with hypertonia of the limbs, dysmorphic facial features (brachycephaly, large mouth, pointed chin and a prominent jaws) and scoliosis. Brain CT scan and MRI revealed ventricular enlargement and squared frontal horns. Pregnancy and delivery were uneventful. Karyotypes were normal. No deletion of chromosome 15q11-13 region was shown by molecular genetic techniques. The parents who are normal are second cousins. The condition is therefore probably inherited as an autosomal recessive one.
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PMID:Mental retardation, ataxia, seizures, dysmorphia, and hydrocephaly in two sibs. Angelman syndrome or new syndrome. 835 66

We studied a cohort of 73 children exposed to cocaine in utero to characterize the spectrum of neurologic and ophthalmologic abnormalities; 36 children with no documented in utero drug exposure were selected as a control group. Most referrals of cocaine-exposed children to the child neurologist were made in the 1st year of life (81%). Reasons for referral were hypertonia (29%), seizures (22%), developmental delay (11%), tremulousness (11%), and hypotonia (4%). The most common abnormal finding in the cocaine-exposed children was hypertonia/hyperreflexia (63%), which was rarely seen in the control group. In addition, hypertonia/hyperreflexia was underdiagnosed by referring physicians. Similarly, hypotonia was seen on neurologic examination of cocaine-exposed children more frequently than documented by referral (16% versus 4%). Hypotonia was rarely seen in the control group. Twelve (43%) of 28 cocaine-exposed children seen by a pediatric ophthalmologist had structural ophthalmologic abnormalities. Neurologic and ophthalmologic findings suggesting structural lesions of the nervous system must be considered in cocaine-exposed children.
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PMID:Neurologic and ophthalmologic findings in children exposed to cocaine in utero. 874 81

In a newborn boy with characteristics of Brachmann-de Lange syndrome (BDLS) high temperatures were observed on the second day after birth and recurred 2-6 times daily during the 7 months of the patient's life. After transient hypertonia hypotonia developed. In muscle biopsy specimen taken on the 51st day of life, serious and progressive distortion of mitochondria was observed. In several mitochondria the cristae structure was broken, other mitochondria were shrunken and the damage progressed towards further deterioration in other organelles. At several points between the myofibrils amorphous material was seen possible debris of destroyed mitochondria. Most myofibrils seemed to be intact; however, in some areas myolytic signs were present. Analysis of the mitochondrial DNA (mtDNA) showed multiple deletions in skeletal and heart muscles, liver, lung and kidney. Since the mtDNA encodes several proteins of the respiratory complexes, the deleted mtDNA certainly affected the integrity of the mitochondrial oxidative phosphorylation process by synthesis of abnormal proteins. In the present case the hyperthermia may have been a result of the mtDNA damage.
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PMID:Multiple mitochondrial DNA deletions and persistent hyperthermia in a patient with Brachmann-de Lange phenotype. 891 46

Nine infants with an underlying static encephalopathy (confirmed as cerebral palsy in a later follow-up examination) and newly diagnosed infantile spasms were entered in an open study with adrenocorticotropic hormone (ACTH) and vigabatrin as the initial therapy regimen. The ACTH was discontinued after 4-6 weeks and the infants were maintained on vigabatrin alone. Following an initial response with complete suppression of spasms in all patients, a long term response maintained for a mean of 19.2 months was confirmed in all but one child. Tolerability appeared excellent with 7 of 9 patients reporting no side effects; vigabatrin related hypotonia presented in all patients and turned out to be a 'positive' side-effect on the abnormally increased muscle tone of these infants. Given the very poor prognosis of infantile spasms especially in such conditions as cerebral palsy, the combination of ACTH and vigabatrin appears to be an interesting therapy advance with very few side effects.
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PMID:Adrenocorticotropic hormone and vigabatrin treatment of children with infantile spasms underlying cerebral palsy. 898 Aug 41

Injections of bicuculline into the medial segment of the globus pallidus (GPi) of the monkey induced dose-dependent hypokinesia with dystonic attitudes in contralateral limbs whereas muscimol injections elicited choreiform movements. Injections of the same drugs in substantia nigra pars reticulata (SNr) provoked severe axial postural anomalies with rotational behavior. Conversely, contralateral hypertonia after bicuculline and contralateral hypotonia after muscimol injections were observed. These data suggest that GABA inputs into GPi and SNr play different roles in terms of motor and postural control and add new insights into the pathophysiology of dystonias.
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PMID:Movement disorders induced by gamma-aminobutyric agonist and antagonist injections into the internal globus pallidus and substantia nigra pars reticulata of the monkey. 947 11

One hundred and fifty-three infants were assessed by a method specific to preterm infants and appropriate to the intensive-care nursery environment. The presence or absence of six atypical features (coarse jitters, dominant asymmetrical tonic neck reflex, paucity of movement, 'contradictory' development, hypotonia, or hypertonia) resulted in neonatal classification. There were 116 'usual' (an absence of atypical features with progressive development), 26 'unusual' (a transient occurrence of any atypical feature), and 11 'suspect' (dominance of one or more atypical features). At 6 years of age the motor subsystems of balance, coordination, fine and gross motor, and associated movements were assessed. Nine of 11 children with cerebral palsy had neonatal categories of 'suspect' (7) and 'unusual' (2), of the remaining four other 'suspect' children, two failed two motor subsystems and two failed motor items. A 'usual' neonatal assessment predicted normal motor outcome for 72 of 116 (62%) whereas a 'suspect' assessment predicted major motor dysfunction for seven of 11 of the children.
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PMID:Assessment of preterm infants in the intensive-care unit to predict cerebral palsy and motor outcome at 6 years. 963 Feb 58

We prospectively studied motor symptoms in 32 patients with CT- or MRI-proven acute pure parietal stroke. A transient, mild, 'pseudoparesis' of the hand (90%), was noted, improved by visual attention and prompting, associated with non-awareness of muscle power (53%), transient soft pyramidal signs (50%), unilateral akinesia (100%) and motor hemineglect (37%) in non-dominant lesions. Lower motoneurone-type atrophy was not observed in this acute phase. We called 'poikilotonia' the striking unpredictable variations in muscle tone, ranging from extreme hypertonia to hypotonia, found in all patients. When maintaining postures, patients showed large oscillations (100%), laterodeviation or levitation of the arm (60%), especially in the case of large or posterior lesions, or, occasionally (3%), motor persistence or even hemicatalepsy (3%). Limb kinetic and manipulatory apraxia, with inadequate organization and anticipation of motor sequences and synergies, motor arrests, perplexity, unrecognizable gestures and loss of bimanual coordination, was a constant finding (100%). Other apraxias (62%) and difficulty in copying intransitive gestures of the hand (84%) were associated with posterior lesions involving the supramarginal gyrus. When reaching towards objects, all patients showed abnormal anticipatory hand shaping, but visuomotor ataxia (3%) was only seen with bilateral posterior stroke. Sensory (70%) or pseudocerebellar (4%) ataxia, was seen in both anterior and posterior lesions. Avoidance behaviors (34%) were not uncommon, but had no localizing value. Of the dyskinesias, hand dystonia (84%) was frequent, but athetosis (16%), asterixis (15%), postural tremor (15%), myoclonus (9%) and stereotypia (9%), were uncommon. The abnormal eye movements were unilateral hypo-akinesia of exploratory saccades (43%), abnormal ipsilateral pursuit and contralateral optokinetic nystagmus in the case of posterior lesions, and oculomotor apraxia with bilateral posterior lesions. In conclusion, parietal motor syndrome can be recognized during bedside examination, and probably reflects the loss of multiple sensory feedback to motor programs, especially those directed to the extrapersonal space.
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PMID:Parietal motor syndrome: a clinical description in 32 patients in the acute phase of pure parietal strokes studied prospectively. 987 53

We reviewed 90 consecutive patients with various neuromuscular diseases and a progressive spine deformity treated with a prefabricated Boston-type underarm corrective brace. Of these, 38 patients had spastic tetraplegia; seven, syndrome-related muscular hypertonia; 24, muscular hypotonia; and 21, myelomeningocele. The mean age at the treatment start was 9.2 years (range, 1.4-17.7 years). Twenty-four were ambulating and 66 wheelchair-bound. Hypotonia was the dominant type of muscle involvement in 49, spasticity in 28, and athetosis in 13 patients. The mean pretreatment Cobb angle was 47 degrees, with a range from 23 to 95 degrees. The mean brace-induced Cobb-angle correction was 60%, thus well comparable to that in idiopathic scoliosis. However, this did not predict favorable treatment results. At the follow-up, on average 3.1 years (range, 1-5.5 years) after weaning from the brace, the brace treatment was successful in 23 patients. Successful was defined as <10 degrees curve progression during the observation time and a good brace compliance. Forty-one patients discontinued the brace treatment, and 19 progressed despite adequate brace wear. Five patients are still in treatment, and two have died. Successful treatment was seen in ambulating patients with muscle hypotonia and short thoracolumbar/lumbar curves measuring <40 degrees as well as in nonambulating patients with spastic short lumbar curves. These types of neuromuscular scoliosis may be the only ones to respond to brace treatment. In other cases, the brace treatment cannot be expected to have a lasting corrective effect although it can be used as sitting support.
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PMID:Brace treatment in neuromuscular spine deformity. 1034 23


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