syringomyelia

definition

· progressive often chronic disorder

· associated with spinal cord

· cavitation

· gliosis

· which causes

· muscle wasting

· dissociate anaesthesia

· scoliosis

· neuropathic arthropathy

epidemiology

· males > females

· no familial tendancy

aetiology

· idiopathic

· hindbrain herniation

· Arnold-Chiari

· post-traumatic

· arachnoiditis

· intramedullary tumour

· extrinsic compression

· with central cord necrosis

· necrotic myelitis

pathogenesis

Hindbrain herniation

· abnormalities in pressure and circulation of CSF

Posttraumatic

· occurs in 3%

· more common in complete tetraplegics

· delayed presentation

· 3 mths to 30 yrs

· may be due to subarachnoid block secondary to adhesive arachnoiditis

pathophysiology

Cord damage

· anterior dissection of cavity with interruption of decussating spinothalamic fibres

· pain and temperature (not light touch)

· extension into lateral columns

· spastic paraparesis

· involvement of second order neurones

· pain with causalgia

Consequences

· dissociative sensory loss and spastic paraparesis

· neuropathic joints

· scoliosis

pathology

Gross

· level

· most common in lower cervical

· may progressively extend up to medulla and down to lumbar cord

· fluid-filled cavity

· separate from but usually communicating with central canal

Histology

· cystic spce

· lined by thick layer of glial tissue

· gliosis with tendancy to infiltrate white matter

associations

· craniovertebral anomalies

· myelomeningocoele

1. cause of deterioration

· shunt malformation

· Arnold Chiari

· cord tether / diastomatomyelia / neuroenteric cyst

· syrinx

· platybasia

· hydrocephalus

clinical features

Classic triad

· dissociate sensory loss in cape distribution

· muscle wasting with diminished reflexes

· high thoracic kyphoscoliosis

General

· sensory loss

· dissociate

· loss of pain and temperature

· preservation of light touch

· weakness

· loss of deep tendon reflexes

Cervicothoracic

· dissociate sensory loss in arms and trunk

· weakness and wasting of arms

· absent abdominal reflexes

Lumbar

· dissociate lumbosacral sensory loss

· weakness and wasting of legs and pelvic girdle

· diminished reflexes

· negative Babinski reflex

· impaired bowel and bladder function

Cervicomedullary (syringobulbia)

· palatal and vocal paralysis

· dysarthria

· nystagmus

· dizziness

· tongue weakness

Post-traumatic

· in cord-injured paraplegic or quadriplegic

· deterioration may be due to syrinx

· presents with

· pain

· numbness

· increased muscle weakness

· increased spasticity

investigations

Plain x-rays

· spine

· base of skull

MRI

· most sensitive investigation

differential diagnosis

· amyotrophic lateral sclerosis

· multiple sclerosis

· cervical myelopathy

· thoracic outlet syndrome

· Klippel-Feil syndrome

treatment

Indications

· rapid progression of neurology

· short history

· respiratory compromise

· pseudobulbar palsy

· pre-spinal corrective surgery

Technique

· shunt

· syrnigo-cisternal

· syringo-peritoneal

· suboccipital compression and C1-2 laminectomy

· for Arnold-Chiari malformation

orthopaedic implications

Neuropathic joints

· syrinx is most common cause of upper limb Charcot joint

· shoulder

· elbow

· hot swollen joint may be first presentation of syrinx

· must differentiate from

· infection

· peripheral neuropathy (diabetes)

· myelomeningocoele

· tabes dorsalis, leprosy

Scoliosis

· scoliosis is usual first presentation of syrinx

· curve is

· idiopathic-type

· often left-sided

· usually thoracic

· corresponds with level of syrinx

· more common in males

· 20% of males with scoliosis have syrinx (cf. 2% of girls)

· often no neurological deficit

· treatment

· must correct syrinx first

· malignant progression if syrinx untreated

· progression like idiopathic once syrinx treated