Spinal cord pathology - myelopathy + cauda equina + sciatica Flashcards
What is myelopathy?
Spinal cord compression
What spinal cord levels makes the spinal cord?
C1 -> L1/2
What is the cauda equina?
L3 –> conus medullaris and cauda equina (lumbar and sacral nerve roots)
What are the 2 types of paralysis and what do they indicate?
- Hemiplegia: one side of body (brain lesion)
- Paraplegia: both legs (cord lesion)
What are the main tracts?
DCML
Spinothalamic
Corticospinal
Which tracts are sensory?
DCML
Spinothalamic
Which tract is motor?
Corticospinal
What type of tract is DCML?
Ascending
Dorsal root –> medulla then decussates
What is DCML responsible for?
Fine touch
2 point discrimination
Proprioception
What type of tract is spinothalamic
Ascending
Decussates 1-2 spinal levels above dorsal entry
What is spinothalamic tract responsible for?
Pain and temp
What type of tract is corticospinal?
Descending UMN
Decussates at medulla –> ventral root
Do sensory spinal cord lesions show ipsilateral or contralateral signs?
Ipsilateral
Do motor spinal cord lesions show ipsilateral or contralateral signs?
Contralateral
What spinal cord level is the knee jerk?
L3/4
Which spinal cord level is the big toe jerk?
L5
Which spinal cord level is the ankle jerk?
S1
Define myelopathy/spinal cord compression
Compression of C1-L1/2
What are causes of spinal cord compression?
- Vertebral body neoplasms (main cause- metastases from lung, breast, RCC, melanoma)
- Spinal pathology (eg disc prolapse/herniation)
What are symptoms of spinal cord compression?
- Progressive leg weakness w/ UMN signs:
- eg contralateral hyperreflexia, Babuski +ve, spasticity
- Sensory loss BELOW lesion (ascending sends info up)
- Sphincter involvement uncommon (late very bad sign)
What investigations do you do for spinal cord compression?
MRI of spinal cord ASAP (risk of permanent damage if not)
CXR if malignancy suspected
How do you treat spinal cord compression?
Neurosurgery (laminectomy, microdiscectomy)
Define cauda equina syndrome
- Compression below conus medullaris
Describe the pathophysiology of cauda equina syndrome
- surgical emergency where the nerve roots of the cauda equina at the bottom of the spine are compressed
- The cauda equina is a collection of nerve roots that travel through the spinal canal after the spinal cord terminates around L2/L3
What are causes of cauda equina syndrome?
→ Herniated disc - most common (occurs in 2% lumbar herniation)
→ tumours - mets
→ spondylolisthesis - anterior displacement of vertebra out of line with one below
→ Abscess infection
→ trauma
What are the signs and symptoms for cauda equina syndrome?
→ Bilateral or severe motor weakness in the legs w/ LMN signs (ipsilateral hypotonia, fasciculations, hyporeflexia)
→Saddle anaesthesia (loss of sensation in the perineum – around the genitals and anus)
→ Loss of sensation in the bladder and rectum (not knowing when they are full) + sphincter involvement common
→ Urinary retention or incontinence
→ Faecal incontinence
→ Bilateral sciatica
→ Reduced anal tone on PR examination
What investigations do you do for cauda equina syndrome?
MRI cord (diagnostic)
Testing nerve roots/reflexes
How do you treat cauda equina syndrome?
- Neurosurgery ASAP (eg. microdiscectomy, spinal fixation, spinal cord decompression)
- Immobilise spine
What is sciatica?
- L5/S1 lesion due to spinal or non spinal causes
What is a spinal cause of sciatica?
IV disc herniation/prolapse
What are non spinal causes of sciatica?
Piriformis syndrome, tumours, pregnancy
What are symptoms of sciatica?
- Pain from buttock down lateral leg –> pinky toe
- Weak plantarflexion + absent ankle jerk
How do you diagnose sciatica?
Exam: can’t do straight leg raise test without pain
What investigations do you do for sciatica?
MRI
How do you treat sciatica?
Analgesia + physiotherapy
Neurosurgery
