Congenital hyperekplexia: five sporadic cases.

UNLABELLED: We report fives sporadic cases of hyperekplexia or startle disease characterized by a highly exaggerated startle reflex and tonic attacks. Affected neonates suffer from prolonged periods of stiffness and are at risk for sudden death from apnea. An early diagnosis is needed. Sudden loud sounds, unexpected tactile stimuli or percussion at the base of the nose can also elicit excessive jerking or tonic attack. The diagnosis of hyperekplexia is a purely clinical one. A defect of the alpha1 subunit of inhibitory glycine receptor (GLRA1) has been observed in the dominant form with a mutation in the chromosome 5. Clonazepam is effective and decreases the severity of the symptoms. The disease tends to improve after infancy and the psychomotor development is normal. The major form of "hyperekplexia" should be considered whenever one is confronted with neonatal hypertonicity associated with paroxysmal tonic manifestations (without electroencephalography anomalies). CONCLUSION: the diagnosis of hyperekplexia should be evaluated in any neonate with tonic attacks without evident cause.

Preterm fetal hypoxia-ischemia causes hypertonia and motor deficits in the neonatal rabbit: a model for human cerebral palsy?

Prenatal hypoxia-ischemia to the developing brain has been strongly implicated in the subsequent development of the hypertonic motor deficits of cerebral palsy (CP) in premature and full-term infants who present with neonatal encephalopathy. Despite the enormous impact of CP, there is no animal model that reproduces the hypertonia and motor disturbances of this disorder. We report a rabbit model of in utero placental insufficiency, in which hypertonia is accompanied by marked abnormalities in motor control. Preterm fetuses (67-70% gestation) were subjected to sustained global hypoxia. The dams survived and gave spontaneous birth. At postnatal day 1, the pups that survived were subjected to a battery of neurobehavioral tests developed specifically for these animals, and the tests were videotaped and scored in a masked manner. Newborn pups of hypoxic groups displayed significant impairment in multiple tests of spontaneous locomotion, reflex motor activity, and the coordination of suck and swallow. Increased tone of the limbs at rest and with active flexion and extension were observed in the survivors of the preterm insult. Histopathological studies identified a distinct pattern of acute injury to subcortical motor pathways that involved the basal ganglia and thalamus. Persistent injury to the caudate putamen and thalamus at P1 was significantly correlated with hypertonic motor deficits in the hypoxic group. Antenatal hypoxia-ischemia at preterm gestation results in hypertonia and abnormalities in motor control. These findings provide a unique behavioral model to define mechanisms and sequelae of perinatal brain injury from antenatal hypoxia-ischemia.

Bladder neck cinch for pediatric neurogenic outlet deficiency.

PURPOSE: The fascial bladder neck sling achieves continence in 50% to 90% of children with neurogenic outlet deficiency. Most slings apply only partial pressure around the bladder neck. We evaluated the effectiveness of a rectus fascia bladder neck cinch which applies circumferential pressure around the bladder neck and elevation as a means of increasing outlet resistance. MATERIALS AND METHODS: Fifteen children with spina bifida underwent a fascial bladder neck cinch procedure at the time of augmentation cystoplasty. A 1 to 1.5 cm width of variable length rectus fascia was harvested and a vertical slit was made in 1 end. The fascia was "cinched" tightly around the bladder neck and secured to the symphysis or rectus fascia. RESULTS: The 14 girls and 1 boy ranged in age range from 4 to 17 years. All children had neurogenic intrinsic sphincter deficiency and a poorly compliant and/or small capacity bladder. Followup ranged from 10 to 36 months (followup in 12 greater than 1 year). Postoperatively, all children perform clean intermittent catheterization. At the last followup 8 girls and the boy (60%) were dry (no leak and no pads at 4 hours from the last catheterization and dry throughout the night). CONCLUSIONS: Rectus fascia used as a bladder neck cinch is effective but no better than other bladder neck slings for decreasing urinary incontinence. The bladder neck cinch appears to be an acceptable addition to the technique of fascial slings. However, we have subsequently changed our technique because these results did not meet our expectations.

Congenital familial hypertonia.

1. This complex of symptoms appears to be congenital, familial, and hereditary. It is apparently transmitted by a dominant gene, probably on chromosome 5. 2. Hypertonicity with rigidity of all voluntary muscles usually presents at birth. 3. Feeding problems are due to dysphagia or laryngospasm associated with aspiration and dyspnea. 4. Respiratory problems are characterized by apneic episodes due to muscle spasm. 5. Prolonged episodes of muscular rigidity secondary to sudden stimuli result in frequent falls, characteristically en bloc, like a statue. 6. Continuous electromyographic activity even at rest (with absence of fasciculations) improves after intravenous diazepam.

Neonatal sporadic hyperekplexia: a rare and often unrecognized entity.

We report the case of a newborn infant with transient generalized stiffness, obvious from the first days of life, increased muscle tone and repeated myoclonic jerks, who was unsuccessfully treated with phenobarbital until the diagnosis of neonatal sporadic hyperekplexia. To our knowledge this is the first case successfully treated with clobazam, a 1.5 dibenzodiazepine.

Hyperekplexia: abnormal startle response due to glycine receptor mutations.

BACKGROUND: Hyperekplexia is a rare but well-delineated clinical syndrome of pathological startle response and neonatal hypertonia. Many cases result from mutations in the alpha 1 subunit of the glycine receptor (GLRA 1). METHOD: The clinical features, management and recent genetic studies of hyperekplexia are reviewed. RESULTS: Diagnosis of the disorder should not be difficult, if one is aware of the syndrome. The treatment of first choice is with the benzodiazepine drug clonazepam, which often causes a dramatic although incomplete diminution of startle. Both recessive and dominant mutations in GLRA 1 have been found in affected individuals. The study of mouse mutants with startle phenotypes suggests that the remainder of cases may well be due to mutations in the beta subunit of the glycine receptor. CONCLUSIONS: Hyperekplexia is the first human disease shown to result from mutations within a neurotransmitter gene. The demonstration of both dominant and recessive inheritance resulting from different mutations in the same gene is of considerable interest, as other neuropsychiatric disorders may result from mutations in ligand-gated ion channels. Mutation analysis of GLRA 1 is also likely to be useful as an aid to genetic counselling and in diagnostic evaluation of neonatal hypertonia.

Startle disease, or hyperekplexia: response to clonazepam and assignment of the gene (STHE) to chromosome 5q by linkage analysis.

Familial startle disease (also known as hyperekplexia and congenital "stiff-man" syndrome) is an autosomal dominant disorder characterized by an exaggerated startle reaction of sudden, unexpected auditory or tactile stimuli; affected neonates also have severe and occasionally fatal hypertonia. We recently encountered a large, five-generation family with startle disease, and treated 16 patients (including 1 neonate) with clonazepam; all experienced dramatic and sustained improvement. We performed systematic linkage analysis in this family, and found tight linkage between the disease locus and a polymorphic genetic marker locus (colony-stimulating factor receptor, or CSF1R) that has been physically mapped to chromosome 5q33-q35. The maximum odds ratio favoring linkage over nonlinkage is greater than 10,000,000:1 (lod score, 7.10) at 3% recombination. Several genes encoding neurotransmitter receptor components have been physically mapped to the subtelomeric region of chromosome 5q, and are thus candidates for the startle disease gene. The availability of additional large pedigrees with startle disease should facilitate identification and characterization of the gene for this disorder.

[Hyperexplexia: the startle disease]. / L'hyperexplexia: la "maladie du sursaut".

A case of hyperexplexia is reported in a newborn. Hyperexplexia or "startle disease" is very uncommon and is of autosomal dominant transmission. Clinical features consist in particular physical features during the neonatal period and subsequently in an abnormal startle reaction; the electromyogram shows particular patterns.

[Craniofacial dysmorphism with flexion of the fingers. Marden-Walker syndrome?]. / Dysmorphie crânio-faciale avec flexion des doigts. Syndrome de Marden-Walker?

The Marden-Walker syndrome was first described in 1966. The main features are microcephaly, peculiar facies due to blepharophimosis, micrognathia, low-set ears, joint contractures, muscular hypotonia, growth failure, and developmental delay. We report the case of a child presenting with almost all of these features, but with muscular hypertonia. Differential diagnosis includes Schwartz-Jampel syndrome. Pathogenesis is unknown.