Infantile hypoventilation syndrome, neurenteric cyst, and syringobulbia

Syringohydromyelia in association with syringobulbia and syringocephaly: case report

The authors present the case of a 14-year-old boy with holocord syringohydromyelia extending into the brainstem, cerebral peduncle, internal capsule, and cerebral cortex. At the posterior fossa exploration, an opaque thickened arachnoid with occlusion of the foramen of Magendie was encountered. Careful documentation of postoperative regression of the syringocephaly, syringobulbia, and syringohydromyelia was made. The pathophysiology is discussed.

Hypoventilation syndromes

A wide variety of mechanisms can lead to the hypoventilation associated with various medical disorders, including derangements in central ventilatory control, mechanical impediments to breathing, and abnormalities in gas exchange leading to increased dead space ventilation. The pathogenesis of hypercapnia in obesity hypoventilation syndrome remains somewhat obscure, although in many patients comorbid obstructive sleep apnea appears to play an important role. Hypoventilation in neurologic or neuromuscular disorders is primarily explained by weakness of respiratory muscles, although some central nervous system diseases may affect control of breathing. In other chest wall disorders, obstructive airways disease, and cystic fibrosis, much of the pathogenesis is explained by mechanical impediments to breathing, but an element of increased dead space ventilation also often occurs. Central alveolar hypoventilation syndrome involves a genetically determined defect in central respiratory control. Treatment in all of these disorders involves coordinated management of the primary disorder (when possible) and, increasingly, the use of noninvasive positive pressure ventilation.

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.

Iso-intense neuroenteric cyst in the lower cervical spine treated with ventral resection and anterior fusion utilising sternal notch exposure: case report, technical note and literature review

A 36-year-old female patient with a long-standing asymptomatic lower thoracic scoliosis presented with sensory symptoms involving all limbs. MRI scan demonstrated a rounded ventral intradural mass causing major deformity of the cervical cord at C6 and C7 levels. Unlike most previously reported neurenteric cysts, the MRI signal characteristics of this mass were such that it could not be determined if it is cystic or solid, being iso-intense on T1- and hyperintense T2-weighted images. Resection was performed through a median corporectomy of C6 and C7, the lesion being found to be a neurenteric cyst with an attachment to the anterior median fissure of the cord. Strut graft and cervical locking plate fixation from C5 to C6 was facilitated by extending the cervical incision into the sternal notch, with detachment of left-sided strap muscle insertion. The patient made an excellent recovery with complete resolution of neurological symptoms and solid fusion. The postoperative course was complicated by an anterior cervical CSF collection which resolved spontaneously within 2 months. The literature regarding this rare condition and its management is reviewed. Although the majority of intraspinal neurenteric cysts are situated ventral to the cord, most reports of excision have been from a dorsal approach. Drainage and subtotal excision of neurenteric cysts have been previously advocated; however, the recurrence rate is such that complete excision is advocated. This is facilitated by a ventral approach. A simplified method of utilising the sternal notch exposure is reported. The literature regarding the anatomical peculiarities pertinent to the sternal notch approach, and the reported literature regarding spinal neurenteric cysts is reviewed.

Compressão medular alta por cisto neuroentérico: relato de caso

É relatado o caso raro de uma criança com cisto neuroentérico comprimindo a medula cervical alta de C1 a C3. A paciente foi submetida a laminectomia osteoplástica com retirada total do tumor. São discutidos a sintomatologia, o tratamento e o resultado satisfatório obtido. É feita revisão da literatura pertinente.

Syringobulbia: a surgical appraisal

Syringobulbia is a term which has been clinically applied to brain stem symptoms or signs in patients with syringomyelia. Syringobulbia clefts are found on investigation or at necropsy caused by cutting outwards of the CSF under pressure from the fourth ventricle into the medulla. These should be differentiated from the ascending syringobulbia which may occur from upward impulsive fluid movements in a previously established syringomyelia. Clinical analysis of 54 patients suggests that bulbar features are most often found with neither of the above mechanisms but are due to the effects of pressure differences acting downward upon the hind-brain with consequent distortion of the cerebellum and brainstem, traction on cranial nerves or indentation of the brain-stem by vascular loops. The commonest symptoms in the 54 patients were headache (35), vertigo (27), dysphonia or dysarthria (21), trigeminal paraesthesiae (27), dysphagia (24), diplopia (16), tinnitus (11), palatal palsy (11) and hypoglossal involvement (11). Careful attention to hydrocephalus is advisable before craniovertebral surgery, but the decompression of the hindbrain and the correction of craniospinal pressure dissociation remains the mainstay of surgical treatment. The results of careful surgery are good, 45 of the 54 cases reported improvement. Most of the reported deterioration occurred in a few patients who did conspicuously badly.