🧠 Syringobulbia is a neurological disorder where a fluid-filled cavity (syrinx) develops within the medulla oblongata of the brainstem. It is frequently associated with syringomyelia (syrinx within the spinal cord) and may cause severe cranial nerve and brainstem dysfunction.

📌 About

A fluid-filled syrinx forms in the brainstem, most commonly the medulla oblongata.
Often occurs as an extension of syringomyelia.
Disrupts cranial nerve nuclei, sympathetic pathways, and brainstem tracts.

🧬 Aetiology

Formation of a longitudinal cyst in the medulla oblongata.
Frequently linked to Chiari I malformation (blockage of CSF outflow from the 4th ventricle).
May complicate syringomyelia as the syrinx ascends into the brainstem.

⚠️ Causes

Chiari Malformation: Congenital herniation of brain tissue into the spinal canal.
Spinal Cord Injury: Trauma causing syrinx formation extending into the medulla.
Intramedullary Tumours: Block CSF pathways and precipitate syrinx formation.
Post-Infectious/Inflammatory: CNS inflammation (TB, meningitis) may trigger syrinx development.
Arachnoiditis: Post-surgical, post-trauma, or post-infectious obstruction of CSF flow.

🩺 Clinical Features

🔥 Onion-skin sensory loss: Pain & temperature loss over the face, sparing the nose (trigeminal nucleus involvement).
😣 Facial Pain alongside sensory loss.
👁 Horner’s Syndrome: Ptosis, miosis, anhidrosis from sympathetic pathway damage.
🗣 Bulbar Palsy: Dysphagia, dysarthria from CN IX, X, XI involvement.
🙃 Cranial Nerve Palsies:
- CN VII → facial weakness
- CN IX/X → swallowing difficulty, hoarseness
- CN XI → sternocleidomastoid/trapezius weakness
- CN XII → tongue wasting, fasciculations
⚖️ Cerebellar signs: Ataxia, dysmetria, gait unsteadiness.

📊 Comparison: Syringomyelia vs Syringobulbia

Feature	Syringomyelia	Syringobulbia
Definition	Fluid-filled cavity (syrinx) within the spinal cord	Fluid-filled cavity within the brainstem (medulla)
Common Association	Chiari I malformation, trauma, tumours	Chiari I malformation, extension of syringomyelia, brainstem tumours
Main Structures Affected	Spinothalamic tracts → pain & temperature loss	Cranial nerve nuclei & brainstem tracts → bulbar & cranial nerve palsies
Classic Clinical Signs	🌀 Cape-like loss of pain & temperature over shoulders/arms Weakness & wasting of hand muscles	🎭 Onion-skin facial sensory loss 🗣 Bulbar palsy (dysphagia, dysarthria) 😮 Horner’s syndrome
Cranial Nerves	Usually spared	Involvement of CN VII, IX, X, XI, XII → facial weakness, hoarseness, tongue wasting
Cerebellar Involvement	Occasional (if syrinx is large)	More likely due to brainstem–cerebellar connections → ataxia
Investigations	MRI spine	MRI brain & spine (to check medulla and extension)
Management	Posterior fossa decompression, syrinx shunting, treat cause	Posterior fossa decompression (Chiari), syrinx shunting, tumour resection if present

🔬 Investigations

MRI: Gold standard. Defines syrinx size, location, and Chiari association.
CT Scan: Less sensitive but useful if MRI unavailable.

💊 Management

Conservative: Asymptomatic/mild cases → regular MRI monitoring.
Surgical:
- 🧩 Posterior Fossa Decompression: For Chiari malformation to restore CSF flow.
- 🚰 Syrinx Shunting: Diverts fluid to another body cavity to collapse syrinx.
- 🧀 Tumour Resection: If intramedullary tumour is causal.
Rehabilitation: PT, OT, and SLT to aid motor, balance, and speech function.
Symptomatic: Neuropathic pain control (e.g., gabapentin, baclofen), swallowing support, and pain relief.

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Syringobulbia