Neurosurgery Flashcards
What is a myelopathy
Neurological disorder caused by compression of spinal cord
What is a cervical myelopathy
Myelopathy/injury to spinal cord either due to direct compression or ischaemic injury from compression of anterior spinal artery
Aetiology cervical myelopathy
COMPRESSION OF SC:
Blunt penetrating trauma e.g., #, epidural haematoma
Infection e.g., abscess
Radiation therapy
Neoplasms e.g., meningoma, mets, nerve sheath tumour
Cysts e.g., epidermoid
Ossification of PLL
Spinal stenosis
OA and osteophytes
Discogenic myelopathy (central disc herniation)
Spondylosis = degeneration of IVD
Spondylolisthesis = displacement of vertebra
Congenital narrowing of cervical spinal canal
Ankylosing spondylitis
MS
Autoimmune disorders e.g., RA (rheumatoid synovitis)
What is the pathophysiology of a myelopathy
Intramedullary or extramedullary (i.e., originating from within or outside the spinal cord) mass lesions compress the spinal cord and impair its perfusion → mechanic and ischemic axonal injury → intramedullary edema → further narrowing of the medulla
Clinical features of cervical myelopathy
Features depend on the level of compression and the onset may be sudden (e.g., with trauma), step-wise, or slowly progressive (e.g., degenerative diseases)
Neck, shoulder, upper limb, or lower limb pain (neck stiffness may be present)
Signs and symptoms of lower motor neuron lesions at the level of the lesion (e.g., weakness and atrophy in intrinsic muscles of hand –> impaired fine hand movements)
- weakness in pyramidal pattern
Signs and symptoms of an upper motor neuron lesion below the level of the lesion (e.g., abnormal spastic gait is often an early sign; hyperreflexia or a positive Babinski’s sign may be present)
Damage to sensory tracts esp. dorsal columns
- impaired sensation and proprioception –> falls, sensory ataxia, reduced fine touch sensation, reduced vibratory sensation, reduced fine finger dexterity and hand paraesthesias
Impaired bladder, bowel control, autonomic Sx cautonomic Sx) due to damage to sympathetic chain
What is a pyramidal pattern of weakness
Weakness that preferentially spares the antigravity muscles = integral part of upper motor neuron syndrome
Extensor weakness > flexor weakness in upper limb
Flexor weakness > extensor weakness in lower limb
What are provocative manouvres for cervical myelopathy
Positive Hoffman sign = finger flexor reflex
- Flick nail of middle finger down while loosely holding pts hand to allow it to flick up reflexively: +ve if quick flexion and adduction of thumb and/or index finger on same hand
What does a positive Hoffman sign indicate
UMN and corticospinal pathway dysfunction
- likely due to cervical cord compression
Diagnosis of cervical myelopathy
Thorough neuro exam
MRI demonstrates extent and level of cord compression and underlying pathology/degenerative changes
- If MRI is contraindicated e.g., metal stents –> myelography +/- CT
Management of cervical myelopathy
Conservative in mild cases or peri-operatively for severe cases
- Analgesia (neuropathic pain e.g., TCAs/gabapentin)
- Corticosteroids (reduced oedema)
- Physio but avoid neck manipulation
- Bracing
- Anti-spastic medications
Surgical decompression if severe/progressive with anterior cervical discectomy (or laminectomy in some cases)
What is a radiculopathy
Compression/irritation of spinal nerve roots producing pain/paraesthesia/weakness/hyporeflexia along distribution supplied by nerve root
What disc is affected in a C3/C4 radiculopathy and what are the sensory and motor features
Disc affected: C2-C4
Sensory: neck and shoulder
Motor: scapula winging
What disc is affected in a C5 radiculopathy and what are the sensory and motor features
Disc affected: C4-C5
Sensory: anterior shoulder
Motor: biceps and deltoid –> reduced biceps reflex
What disc is affected in a C6 radiculopathy and what are the sensory and motor features
Disc affected: C5-C6
Sensory: upper lateral elbow, radial forearm –> thumb and index finger
Motor: biceps, wrist extensors –> reduced biceps and bracioradialis reflex
What disc is affected in a C7 radiculopathy and what are the sensory and motor features
Disc affected: C6-C7
Sensory: palmar finger II-IV, dorsal-medial forearm –> fingers II-IV
Motor: triceps, wrist flexors, finger extensors –> weakness and wasting and reduced triceps reflex
Provocative manouvres for cervical radiculopathy
Spurling manouvre/neck compression test
- tilt and rotate neck to affected side while applying downwards pressure/axial loading
- +ve test: pain/paraesthesia in distribution of affected nerve root
Shoulder abduction test
- place palm of affected arm on head while seated
- +ve test: pain relief obtained
When is the neck compression test CI
Rheumatoid arthritis
Metastatic cancer
Myelopathy
Management of cervical radiculopathy
CONSERVATIVE
1. Non-narcotic analgesia e.g., NSAIDs, neuropathic pain meds, short low dose oral corticosteroids if severe
2. Avoidance of provocative activities
3. Short-term neck immobilisation (collar and/or pillow)
4. Physio when pain is tolerable
5. Reassess in 6-8 weeks
CONTINUED PAIN
1. If no improvement with 6 weeks of conservative Tx or progressive motor/neuro deficits/bilateral Sx –> MRI
2. Consider corticosteroid epidural injections
3. If Ix show disc herniation/foraminal stenosis consider surgical disccectomy/laminectomy or foraminal decompression otherwise continue conservative management
4. Tx vascular/inflammatory/neoplastic pathology if revealed by Ix
Diagnosis for cervical radiculopathy
Clinical Dx: imaging not routinely recommended
Consider MRI:
- if no improvement with 6 wks of conservative Mx without improvement
- if serious pathology (neoplasm, abscess, myelopathy)
- if progressive motor/neuro defecit or bilateral Sx
Causes of radiculopathy
Disc herniation/protrusion
Degenerative stenosis
What are more general features for cervical radiculopathy
Neck pain
Arm pain
Assoc. shoulder pain, headache
Loss of fine motor skills/dropping objets etc.
Which way do IVDs herniate and why
Intervertebral disks usually protrude/herniate posterolaterally, as the posterior longitudinal ligament is thinner than the anterior longitudinal ligament.
What disc is affected in a L4 radiculopathy and what are the sensory and motor features
Disc: L3-L4
Sensory: Anterolateral thigh, patella, medial leg, medial malleolus
Motor: Knee extension, hip adduction –> loss of patellar reflex
