1/9. Brainstem dysfunction in chiari malformation presenting as profound hypoglycemia: presentation of four cases, review of the literature, and conjecture as to mechanism.OBJECTIVE: We report four patients whose cases resulted in our observation that profound hypoglycemia resulting from intermittent hyperinsulinism plays a significant role in patients with brainstem dysfunction from Chiari I or II malformations who have intermittent autonomic dysfunction ("blue spells"). methods: The records of four children with severe brainstem dysfunction associated with hindbrain herniation (Chiari I or II malformation) were reviewed retrospectively. Each patient had severe lower cranial nerve dysfunction that required tracheotomy and feeding tube placement. After we found that profound hypoglycemia had occurred during a spell of autonomic dysfunction in one patient, the charts of the other three patients were reviewed for evidence of hypoglycemia. Now, whenever one of them has evidence of autonomic dysfunction, prospective studies of glucose and insulin levels are performed. Three of the patients had Chiari II malformation in association with myelomeningocele, and one patient had a Chiari I malformation resulting from Pfeiffer's syndrome. RESULTS: hypoglycemia occurred in these patients episodically, and usually when their shunts were functioning. The hypoglycemia was associated with hyperinsulinemia in each patient. The brainstem structures of these children (presumably the dorsal motor nuclei of the vagus) were extremely sensitive to changes in local or regional intracranial pressure. These changes were triggered by intermittent shunt failure, agitation from pain, abdominal distention from constipation, and retention of CO2. In patients with Chiari malformations, even mild increases in intracranial pressure lead to brainstem dysfunction. One possible explanation is that pressure on the deformed Xth cranial nerve nuclei may lead to insulin release and life-threatening hypoglycemia. Continuous-drip feeds are necessary to prevent this complication. CONCLUSION: patients with severe intermittent brainstem dysfunction after decompression of Chiari I or Chiari II malformations should have laboratory studies of glucose levels performed at the time of the episodes to rule out hypoglycemia.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
2/9. Coexistence of oto-palato-digital syndrome type II and Arnold-Chiari I malformation in an infant.A Taiwanese infant with clinically apparent oto-palato-digital syndrome type II had Arnold-Chiari I malformation. Arnold-Chiari I malformation has not been reported previously to occur in association with oto-palato-digital type II syndrome. The pathogenesis of both conditions has remain unclear although the Arnold-Cliari I malformation is most likely due to a developmental abnormality of improperly times or incomplete closure of the neural tube. We propose the physician who care for children with OPD type II must be aware of one more condition.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
3/9. karyotyping for isolated neural tube defects. A report of two cases.BACKGROUND: neural tube defects occur in approximately 1 in every 1,000 live births. In the united states, chromosomal abnormalities have been noted in 2-10% of fetuses with neural tube defects; however, there is no consensus on whether to offer karyotype analysis to patients with isolated neural tube defects found on ultrasound. CASE: We reviewed the prenatal diagnosis database for the University of washington between 1985 and 1997. We report on two fetuses who, on ultrasound, were found to have "isolated" neural tube defects. karyotype analysis revealed trisomy 18 in both fetuses. The pregnancies were subsequently terminated, and autopsy revealed subtle syndromic findings that were not identified on ultrasound. CONCLUSION: Fetuses with isolated neural tube defects also appear to have a high risk of chromosomal abnormalities, so patients should be offered fetal karyotyping to define recurrence risks for future pregnancies.- - - - - - - - - - ranking = 9keywords = tube (Clic here for more details about this article) |
4/9. Chiari II malformation and occult spinal dysraphism. case reports and a review of the literature.We report two cases of children with occult spinal dysraphism who were also found to have many associated brain anomalies seen in the Chiari II malformation. No previous report has commented on the possible association between the Chiari II malformation and the 'closed' form of neural tube defect. One child had symptoms referable to pathology at the craniocervical junction. Neither child had cutaneous stigmata associated with occult spinal dysraphism over the caudal midline spine. These cases, although seemingly rare, lend support to the theories that the association between the Chiari II malformation and patients with myelomeningoceles is due to dysgenesis of the rostral and caudal neural tube. These cases are also important as refutation of earlier theories that link these two entities by proposing that the Chiari II malformation is due to overdrainage of cerebrospinal fluid at the site of myelomeningocele.- - - - - - - - - - ranking = 2keywords = tube (Clic here for more details about this article) |
5/9. Thoracic meningocele, meningomyelocele or myelocystocele? Diagnostic difficulties, consequent implications and treatment.spina bifida cystica is a closing disorder of the neural tube which infrequently occurs in the thoracic region. A rare lesion called myelocystocele is a variant of spina bifida cystica and is associated with syringomyelia, Chiari type 2 malformation and hydrocephalus. Usually the patient has no neurological deficit, but future deterioration can occur due to posterior tethering of the spinal cord by adhesions. The prenatal diagnosis by ultrasound study can be misleading and in order to attain the correct diagnosis, especially if abortion is considered, a prenatal MRI scan should be done before the parents are counselled, and should be repeated prior to operative treatment. Surgical correction of myelocystocele is not only for cosmetic reasons, but also to untether the spinal cord prophylactically to prevent future neurological deterioration. In this case report, we present a child born with a thoracic myelocystocele, the diagnostic difficulties, consequent implications and surgical treatment.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
6/9. Syringobulbia in a pediatric population.OBJECTIVE: To better understand the presentation, management, and outcome of syringobulbia in the pediatric age group. methods: The University of iowa pediatric neurosurgery database was searched for patients under the age of 18 with a diagnosis of syringobulbia. The patients' records were retrospectively reviewed for demographic data, chief complaint and presenting symptoms, neurological and radiographic findings, treatment, outcome, and complications. Children with open neural tube defects and Chiari II malformations were excluded. RESULTS: Six pediatric patients were identified as meeting inclusion criteria. The average age at time of surgery was 14.8 years. The chief complaints were vision impairment in three children and numbness, gait instability, and headache worsened with Valsalva in one patient each. Other prominent symptoms included sleep apnea and weakness. All patients showed at least one cranial nerve dysfunction. Radiographs revealed hindbrain herniation and associated syringomyelia in all cases. Two patients had scoliosis. Treatment was posterior fossa decompression with cerebellar tonsillar shrinkage, opening of foramen of Magendie, and duraplasty. Two patients also required concomitant ventral decompression. The cavity of syringobulbia communicated with syringomyelia and the fourth ventricle in most children but was distinct from the fourth ventricle. Two patients received fourth ventricle to subarachnoid shunts. Follow-up averaged 3.2 years, and all patients clinically improved after surgery. magnetic resonance imaging documented resolution of syringobulbia in all cases, with syringomyelia improving in all cases. There was no permanent morbidity or mortality in the series. CONCLUSION: Syringobulbia is strongly associated with Chiari malformation and syringomyelia, and patients often present because of cranial nerve palsies. Posterior fossa decompression is a safe and effective treatment.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
7/9. Endoscopic observation of the syrinx in Chiari malformation--case report.The cervical syrinx cavity in a 27-year-old male with Chiari 1 malformation was inspected with a flexible small-caliber endoscope during syringo-subarachnoid shunting. A cleft was observed in the midline on the ventral wall of the cavity, from which blood vessels emerged and ran along the wall. Several strands accompanying the blood vessels passed from one wall to another. The endoscope was also used to evaluate whether any obstacles to the passage of a shunt tube were present in the subarachnoid space. Endoscopic observation of the syrinx cavity is helpful in performing the shunt operation.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |
8/9. prenatal diagnosis of neural tube defect before 12 weeks' gestation: direct and indirect ultrasonographic semeiology.We describe the direct and indirect ultrasonographic features of a case of lumbar open spina bifida. The spinal defect was the prominent feature at 10 weeks 5 days' gestation; however, cranial signs including narrowing of the frontal bones and flattening of the occiput were helpful at 12 weeks. This 'acorn' sign is likely to precede the 'lemon' sign, describing scalloping of the frontal bones at a later gestation. The diagnosis of spina bifida was confirmed by electrophoresis of the amniotic fluid, which showed an abnormal migration of acetylcholinesterase. Postmortem ultrasound examination of the same fetus proved useful in refining the diagnosis and also revealed the presence of the arnold-chiari malformation. Development of ultrasound screening in the first trimester of pregnancy should allow further evaluation of these findings. It seems reasonable to confirm such an early diagnosis by electrophoresis of the amniotic fluid as an alternative to ultrasonographic confirmation at 13-14 weeks.- - - - - - - - - - ranking = 4keywords = tube (Clic here for more details about this article) |
9/9. Cervical arachnoid cysts after craniocervical decompression for Chiari II malformations: report of three cases.OBJECTIVE AND IMPORTANCE: We describe three cases in which ventrally situated cervical arachnoid cysts led to spinal cord or cervicomedullary compression after repeat craniocervical decompression for Chiari II malformations. CLINICAL PRESENTATION: All three patients underwent craniocervical decompression when their Chiari malformations became symptomatic. The first patient developed chronic vertiginous spells and headache and was treated with repeated craniocervical decompression procedures during several years. Seven months after undergoing her third decompression procedure, she developed severe dizzy spells, which were determined to be of brain stem origin. The second patient had a small, asymptomatic arachnoid cyst anterior to the brain stem discovered at age 6 years. After undergoing repeat craniocervical decompression for headaches 8 years after undergoing his first procedure, the patient developed severe neck pain and acute quadraparesis. A third patient underwent repeat craniocervical decompression at age 14 years for cranial nerve dysfunction. Postoperatively, he acutely developed paresis of extraocular movements and incoordination of the upper extremities. All three patients were found to have anteriorly situated arachnoid cysts compressing the brain stem and/or cervical spinal cord. INTERVENTION AND TECHNIQUE: Fenestration of the arachnoid cyst or drainage with cystoperitoneal shunting adequately treated acute brain stem or cervical spinal cord compression. All three patients had achieved satisfactory relief from their acute symptoms of neural compression at their follow-up examinations. CONCLUSION: An association between spinal arachnoid cysts and neural tube defects has previously been reported. However, the development of previously undetected spinal arachnoid cysts after craniocervical decompression was unexpected. We hypothesize that extensive craniocervical decompression may alter the cerebrospinal fluid pressure dynamics in such a way that the anterior subarachnoid space, previously compressed, may dilate. Occasionally, because of perimedullary arachnoiditis, the cerebrospinal fluid may become loculated and act as a mass. Direct fenestration or shunting may successfully treat this problem, and less extensive craniocervical decompression may avoid it.- - - - - - - - - - ranking = 1keywords = tube (Clic here for more details about this article) |