Makindo Medical Notes

Related Subjects: |Syringomyelia |Syringobulbia |Dandy Walker syndrome

Syringobulbia is a neurological condition characterized by the presence of a fluid-filled cavity, or syrinx, within the brainstem, specifically in the medulla oblongata. This condition is often associated with syringomyelia, where a similar syrinx forms within the spinal cord. Syringobulbia can lead to various neurological symptoms due to its location in the brainstem, affecting vital functions and cranial nerve nuclei.

About

• Syringobulbia refers to a fluid-filled cavity (syrinx) within the brainstem, typically affecting the medulla oblongata. It is often associated with syringomyelia, a similar condition involving the spinal cord.

Aetiology

• Formation of a longitudinal cyst within the brainstem, usually the medulla oblongata.
• Frequently associated with blockage of cerebrospinal fluid (CSF) outflow from the fourth ventricle, often due to an Arnold-Chiari malformation (Chiari Type I).
• May occur as an extension of syringomyelia, where the syrinx begins in the spinal cord and ascends into the brainstem.

Causes

• Chiari Malformation: Congenital malformation where brain tissue extends into the spinal canal, leading to syrinx formation.
• Spinal Cord Injury: Trauma can cause syrinx formation in the spinal cord, which may extend into the brainstem.
• Intramedullary Tumours: Tumours in the spinal cord or brainstem can obstruct CSF flow, leading to syringobulbia.
• Post-Infectious or Post-Inflammatory Changes: Inflammatory or infectious conditions of the CNS can lead to the formation of a syrinx.
• Arachnoiditis: Inflammation of the arachnoid membrane, often following surgery, trauma, or infection, can obstruct CSF flow, resulting in syringobulbia.

Clinical Features

• Onion-skin distribution of sensory loss: Loss of pain and temperature sensation over the face, often sparing the nose, due to involvement of the trigeminal nerve.
• Facial pain: May occur along with sensory loss.
• Horner’s syndrome: Ptosis, miosis, and anhidrosis due to disruption of sympathetic pathways in the brainstem.
• Bulbar palsy: Dysphagia, dysarthria, and other symptoms due to cranial nerve IX, X, XI involvement.
• Cranial nerve palsies:
  • Facial nerve (VII): Weakness or palsy of facial muscles.
  • Glossopharyngeal and vagus nerves (IX, X): Impaired swallowing, hoarseness, or vocal cord palsy.
  • Accessory nerve (XI): Weakness of the sternocleidomastoid and trapezius muscles.
  • Hypoglossal nerve (XII): Wasting and fasciculations of the tongue.
• Cerebellar signs: Ataxia, dysmetria, and other signs of cerebellar involvement if connections are affected.

Investigations

• MRI: The imaging modality of choice to visualise the syrinx in the brainstem and assess its extent. MRI can also identify associated anomalies such as Chiari malformation.
• CT Scan: May be used if MRI is unavailable, though it is less sensitive in detecting syrinx cavities.

Management

• Conservative Management: In asymptomatic or mildly symptomatic cases, periodic monitoring with MRI is sufficient.
• Surgical Intervention:
  • Decompression Surgery: Performed in cases of Chiari malformation to relieve pressure and improve CSF flow, which may help reduce the size of the syrinx.
  • Syrinx Shunting: A surgical procedure where a shunt is placed to drain the syrinx, preventing further expansion.
  • Tumour Resection: In cases where a tumour causes syringobulbia, surgical removal of the tumour may be required.
• Rehabilitation: Physical therapy (PT), occupational therapy (OT), and speech-language therapy (SLT) can help manage neurological deficits and improve quality of life.
• Symptomatic Treatment: Medications to manage pain, muscle spasticity, and other symptoms may be prescribed. Baclofen or gabapentin may be used for neuropathic pain.