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Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Achondroplasia, the most common type of dwarfism, involves several physical characteristics that can cause pre- and intraoperative respiratory problems. The characteristics include rib-cage deformities, midface hypoplasia, choanal stenosis, muscular hypotonia, foramen magnum compression, and cervical abnormalities. Specific pre- and postoperative strategies for dealing with achondroplastic dwarfs are discussed.
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PMID:Achondroplasia: pre- and postsurgical considerations for midface advancement. 813 Feb 46

Increased intracranial pressure and ventricular and subarachnoidal dilatation are common manifestations in achondroplasia. They rarely lead to major neurologic and/or psychomotor deficits and neurosurgical intervention is seldom needed. The present study was undertaken to detect signs of minor cerebral dysfunction and discuss possibilities of their prevention. Thirty children with achondroplasia were compared to 3 control groups: their next-born sibs, 30 children with other forms of dwarfism, and 30 children with normal height. Early development was assessed by means of questionnaires. Cognitive skills were evaluated with the German version of the Cognitive Abilities Test and the Lorge-Thorndike Intelligence Test. Personality data were tested using standardized neuroticism, extraversion, and anxiety scales. Children with achondroplasia had more frequent histories of delayed motor development, retarded speech development, and lower school grades in language-related specialties. Psychometric testing disclosed total and subtest scores in the population-based normal range. In comparison with their sibs and matched controls children with achondroplasia had significantly lower total scores mainly caused by low scores in the subtest "verbal comprehension." We conclude that verbal comprehension is significantly impaired in children with achondroplasia. This partial deficiency is probably related to frequent middle ear infections and resulting conductive hearing loss. Hypotonia with delayed oropharyngeal muscle coordination and parental response to an altered, more infantile instinctive releasing pattern may be contributing factors.
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PMID:Cognitive skills in achondroplasia. 826 16

Achondroplasia (ACh) is the most frequent bone dysplasia. The mode of inheritance is autosomal dominant. The incident of neurological complications ranges between 20% and 47%; frequently the symptoms are subtle but are due to such serious conditions as cervicomedullary compressive syndromes, syringomyelia or hydrocephalus; thus, the early identification of this disorder is very important. We made a prospective study of 39 patients (20 female, 19 male) with ACh; their ages ranged from 3 months to 17 years (mean 4 years and 6 months). All patients had hypotonia and psychomotor delay; 3 had recurrent apnea, 1 developed radicular syndrome and 1 had leg paresthesias. The CT scan was normal in 5, 20 had cortical atrophy and 18 communicating hydrocephalus; we identified foramen magnum abnormalities in 28 patients, and reduced craniocervical junction with cervicomedullary compression in 6. Myelography and myelotomography demonstrated spinal compression in 12 patients. The MRI showed cervicomedullary infarct in 1, syringomyelia in 2 and diastematomyelia in 1. The somatosensory evoked responses (SSER) were very useful in the early identification of brain stem and spinal abnormalities. We concluded that the neurological manifestations of pediatric patients with ACh are frequent and very important, demanding comprehensive clinical evaluation even in asymptomatic patients, especially those with severe hypotonia or SSER alterations.
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PMID:Early detection of neurological manifestations in achondroplasia. 920 56

Virtually all infants with achondroplasia exhibit variably severe hypotonia in infancy. This hypotonia contributes to delays in motor development and risks for sudden death. Some have proposed that this hypotonia is a direct result of impaired function of long tracts of the spinal cord, secondary to the intrinsic narrowing of the foramen magnum, which also is present in variable severity in all children with achondroplasia. We postulated that if foraminal constriction causes infantile hypotonia, then there should be a strongly positive correlation between foraminal size and severity of hypotonia. Therefore, clinical and computed tomographic data in 71 infants were retrospectively reviewed. We found no correlation. These results suggest that there is no direct relationship and foraminal size does not affect severity of hypotonia. Other potential explanations for this infantile hypotonia are considered.
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PMID:Absence of correlation between infantile hypotonia and foramen magnum size in achondroplasia. 1134 36

Achondroplasia is the most common genetic disorder associated with bone dysplasia. The mode of inheritance is autosomal dominance, while most cases appear to represent a new mutation. Achondroplastic patients suffer from dwarfism, and from typical features of the head and limbs (rhizomelia, macrocephaly, frontal bossing and kyphosis). Half of the patients show various neurological complications. The most serious complication of achondroplasia is respiratory impairment, apnea and sudden infant death, resulting from compression of the medulla oblongata. This study describes the neurosurgical sequels in 10 achondroplastic patients, who underwent 12 surgical procedures. The average age was 14 years (ages ranged from 3 months to 40 years). The patients suffered from back pain, muscle weakness, incontinence, hypotonia, psychomotor delay, apnea and respiratory arrest. Four patients were diagnosed as suffering from obstructive sleep apnea. Craniocervical MRI showed: narrowing of the foramen magnum, fusion of C1, spinal stenosis, and severe cervicomedullary or spinal cord compression. In 5 patients the MRI also showed ventriculomegaly of the lateral and third ventricles. Seven patients underwent foramen magnum decompression and C1 laminectomy. Three patients with severe spinal cord compression underwent laminectomy of the involved spines (T12-L5). Two of the patients required more then one operation due to the recurrence of their neurological symptoms. There was no need for duraplasty or shunt procedures. The average hospital stay was 6 days. Eight patients showed improvement or resolution of symptoms, with an average follow-up period of 13.5 months after the last operation (ranged 6-24 months). We conclude that early neurological and MRI evaluations are required in achondroplasia patients, in order to prevent the high morbidity and mortality during infancy and childhood. In adults, MRI evaluation is needed if the patient has neurological symptoms. Early identification and immediate cervicomedulary decompression procedure can prevent the serious complications occurring in achondroplasia, including respiratory failure, apnea and sudden death.
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PMID:[Neurosurgical aspects in achondroplasia: evaluation and treatment]. 1175 76

Achondroplasia is the most common skeletal dysplasia in children. Achondroplasic patients have a short cranial face and midface hypoplasia. They often have sleep-related respiratory disturbances that lead to hypoxemia caused by midfacial hypoplasia, a small upper airway, hypotonia of airway muscles, or brain stem compression. It has been well described that obstructive sleep apnea can cause pulmonary hypertension (PH) through the mechanism of chronic hypoxemia. However, severe PH due to obstructive-type sleep disorder is rare in patients with achondroplasia. In this report, we describe a 5-year-old girl with achondroplasia whose severe PH was caused by upper-airway obstruction and was resolved gradually after adenotonsillectomy.
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PMID:A case of achondroplasia with severe pulmonary hypertension due to obstructive sleep apnea. 1667 Sep 17

Achondroplasia is the most common of the heritable skeletal dysplasias. Compression at the cervicomedullary junction can result in myelopathy, hypotonia, sleep apnea, and even sudden death. However, most children with achondroplasia do not suffer from severe neurological symptoms and achieve normal motor and intellectual development without surgical intervention. At the authors' institution, magnetic resonance (MR) imaging and cerebrospinal fluid (CSF) flow studies have been incorporated in the assessment of children with achondroplasia for cervicomedullary junction compression. The authors recently identified four children with achondroplasia who had normal findings on MR imaging and flow studies obtained in the neutral position. On flexion studies, however, three had complete blockage of CSF flow, and more dramatic posterior cervicomedullary compression was demonstrated on extension studies. Some of these patients had severe neurological abnormalities and sleep apnea, while others just developed headaches and/or had apnea episodes when sleeping or in a car seat. Three children underwent decompressive surgery with dramatic improvement or resolution of signs and symptoms. The fourth patient had increased CSF pressure on MR images obtained in the flexed position, possibly due to venous outflow obstruction. Her condition improved dramatically after placement of a ventriculoperitoneal shunt. The increased risk of dynamic cord compression and alterations in CSF dynamics in patients with achondroplasia constitute indications for surgical intervention.
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PMID:Dynamic cervicomedullary cord compression and alterations in cerebrospinal fluid dynamics in children with achondroplasia. Report of four cases. 1815 22