Syrinx-fourth ventricle and lateral ventricle-peritoneal shunts for congenital hydrocephalus with syringobulbia and syringomyelia: case report

Holocord Syrinx Associated with Shunt Malfunction in Tetraventricular Hydrocephalus

We present an uncommon case of holocord, "rosary bead-like," multiloculated syringomyelia consistent with a fourth ventricle outlet obstruction in a 2-month-old infant who was previously shunted for posthemorrhagic hydrocephalus of prematurity. The shunt malfunction resulted in a syringomyelia because of the simultaneous obstruction of the 3 outlets of the fourth ventricle, resulting in an enlargement of the central canal of the spinal cord. The syringomyelia resolved with shunt revision, avoiding further complex surgical procedures.

Syringomyelia in Patient with Concurrent Posttraumatic Hydrocephalus and Tethered Spinal Cord: Implications for Surgical Management

BACKGROUND

Posttraumatic syringomyelia is a significant source of disability following spinal cord injury (SCI). Despite this, its etiology and optimal treatment remain controversial. Early identification of and intervention at a presyrinx state may halt progression. Here, we present a unique case illustrating the continuum between presyrinx and syrinx in an adult following severe distraction cervical SCI and traumatic brain injury, resulting in both tethered spinal cord and posttraumatic hydrocephalus and subsequent isolated fourth ventricle. The interplay between these etiologic factors and their therapeutic implications are discussed.

CASE DESCRIPTION

A 48-year-old female developed rapidly progressive cervical spinal cord edema and hydromyelia almost 6 months after severe SCI and traumatic brain injury, with an initial Glasgow Coma Scale score of 3. Imaging demonstrated both ventral tethering of her cord at the site of injury (C5/6), as well as a trapped fourth ventricle following lateral ventricular shunting for posttraumatic hydrocephalus, with diminished flow of cerebrospinal fluid at the craniocervical junction. Additional shunting of the fourth ventricle led to significant clinical improvement and dramatic radiologic regression of her cord abnormality.

CONCLUSIONS

Cognizance of the possible presence of multiple etiologic contributors to posttraumatic syringomyelia and an intricate understanding of their interplay are crucial to the optimal management of this complex pathology.

Shunt malfunction presenting with symptomatic syringomyelia: Demonstrated on contrast ventriculogram

Ventriculoperitoneal (VP) shunt malfunction commonly presents as raised intracranial pressure. Rarely, when the central canal of the spinal cord communicates with the 4^th ventricle, shunt malfunction can present as an expanding syrinx. The diagnosis is often delayed, resulting in severe morbidity. Some of these patients undergo repeated syrinx surgeries without much benefits. We report a case of chronic tuberculous meningitis with shunt malfunction presenting as an expanding spinal canal syrinx and quadriparesis. Fourth ventricular communication with syrinx was demonstrated with the help of a contrast ventriculogram. After shunt revision, syrinx resolved completely and the patient made significant improvement in his neurological deficits. The present case illustrates that a historical and rarely used investigation like contrast ventriculogram aids in the diagnosis and management even in the current neurosurgical practice. All patients with late onset syrinx and a previous VP shunt need to be investigated for shunt malfunction before considering syrinx surgery. A simple shunt revision resolves the syrinx in such conditions and avoids more complex procedures like Foramen magnum decompression. Relevant literature has been reviewed; pathophysiology and management options have been discussed.

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.

Syringocephaly

Syringomyelia is associated with Arnold-Chiari Type I malformations. Syringobulbia describes the phenomenon of syrinx extension into the brain stem. Syringocephaly is the further dissection of the fluid-filled cavity into the cerebral peduncles and cerebrum. In this case report, we describe a patient who presented with bulbar, sensory, motor, and coordination deficits both ipsilateral and contralateral to the lesion. This is most likely attributable to the wandering course the syrinx takes as it dissects through the spinal cord and into the internal capsule. This ill-defined syrinx disrupts various nuclei and fasciculi, both pre- and post-decussation, thus explaining the multiple deficits on each side. We initially treated this patient with a suboccipital craniectomy, C1 laminectomy, and duraplasty, which mildly improved his deficits. During follow-up, the patient was then found to have an exacerbation of his symptoms, at which time we performed a VP shunt revision (the patient had a history of hydrocephalus treated by a functioning VP shunt). Approximately 2 weeks after revision of the VP shunt, the patient had worsening of his symptoms, which we treated with a syringopleural shunt. This proved to be the most effective treatment with the greatest clinical improvement. Several months later, however, the patient died secondary to pulmonary disease exacerbated by VP shunt infection. In this paper, we also review the literature regarding the formation and treatment of syringocephaly, a rare and poorly understood entity.