SPINE Flashcards
Where are motor neurons found in the spinal cord?
the ventral (anterior) horn
Where is somatosensory information received in the spinal cord?
the dorsal (posterior) horn
Which vertebral levels have a lateral horn containing the autonomic neurons?
T1-L2
Which spinal tract controls fine touch, pressure and vibration?
Dorsal column-medial leminiscus (DCML)
Which spinal tract controls pain and temperature?
Lateral Spinothalamic
Which spinal tract controls crude touch?
anterior spinothalamic
What do the spinocerebellar pathways do?
provide unconscious proprioceptive information to the cerebellum in order to coordinate posture and the movement of the lower limb and upper limb musculature.
Which spinocerebellar pathways provide info from the upper limbs?
cuneocerebellar
Which spinocerebellar pathways provide information for the lower limbs?
dorsal and ventral
Name the two pyramidal descending tracts
corticospinal and corticobulbar
What type of movement does the corticospinal tract control?
voluntary
What is the function of the corticobulbar tract?
it contains UMN of the CN to innervate face head and neck
Is the forehead unaffected in an UMN or LMN lesion of the facial nerve?
unaffected if UMN –> facial palsy
Name the extrapyramidal tracts
vestibulospinal, reticulospinal, rubrospinal, tectospinal
Where do the extrapyramidal tracts originate from?
the brainstem
What does the vestibulospinal tract control?
balance and posture by innervating the anti-gravity muscles (extensors for legs and flexors for arms).
What are the two parts of the reticulospinal tract?
pontine and medullary
Which part of the reticulospinal tract facilitates movement?
the pontine
Which spinal tract excites flexor muscles and inhibits extensor muscles of the upper body?
Rubrospinal
Which spinal tract co-ordinates movements of head and neck to vision stimuli?
tectospinal
Reflex pneumonic
1,2 buckle my shoe: ankle reflex S1,2
3,4 kick the door: patellar reflex L3,4
5,6 pick up sticks: biceps reflex C5,6
7,8 shut the gate: triceps reflex C7,8
describe C1
THE ATLAS no body or spinous process
What part of the vertebrae is only present in c2?
dens
Name the 2 parts of the intervertebral disc
annulus fibrosis (outer fibrocartilage)
Nucleus pulpsosis (water, dehydrates with age)
Ligaments spine
Anterior longitudinal ligament:
Connects the anterolateral aspects of vertebral bodies and IV discs.
Posterior longitudinal ligament:
It runs within the vertebral canal posterior to the vertebral bodies.
Ligamentum flavum:
It is so called because it is rich in elastin and therefore appears yellow. It runs vertically connecting the lamina of adjacent vertebrae. It helps maintain an upright posture and assist straightening the spine after flexion.
Supraspinous ligament:
Runs along the tips of the spinous processes.
Interspinous ligament:
Runs between the spinous processes.
Layers lumbar puncture goes through starting from the skin
- Skin
- Fascia
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Epidural space
- Dura
Signs that back pain is mechanical
Morning stiffness that resolves with movement, pain worse on sitting and when rising from a seated position
What are the most common locations for lumbar disc herniation?
L4/5 level and L5/S1
When do herniated discs occur in a) young and b) elderly patients?
young - sprain on the spine eg carrying a heavy load
old - degeneration of the vertebrae or spondylosis
Which nerve root is damaged in a a paramedian (posterolateral) herniation?
the transversing nerve ie. the nerve root that exists below the level of prolapsed disc
Which nerve root is damaged when a far lateral (extraforaminal) herniation occurs?
the exiting nerve (the nerve root that exists at that level)
Name two consequences of a central disc herniation
Lumbar stenosis or cauda equina
What is radiculopathy?
dysfunction of a nerve root causing a dermatomal sensory deficit with weakness of the muscle groups supplied by that nerve.
Which nerve roots are compressed in sciatica?
L4-S3
Describe the general clinical features of sciatica
- shooting pain radiating from the buttocks to posterior knee
- pain exaggerated by coughing/ sneezing
- numbness or tingling along nerve distribution
- weakness
- straig leg raise +ve (leg raised to <45 causes pain)
What features would be present if S1 root is compressed
Pain along the posterior thigh with radiation to the heel.
Weakness of plantar flexion (on occasion).
Sensory loss in the lateral foot.
Reduced or absent ankle jerk.
What features would be present if L5 was compressed?
Pain along the posterior or posterolateral thigh with radiation to the dorsum of the foot and great toe.
Weakness of dorsiflexion of the toe or foot.
Paraesthesia and numbness of the dorsum of the foot and great toe.
Reflex changes unlikely.
What features would be present if L4 was compressed?
Pain in the anterior thigh.
Wasting of the quadriceps muscle.
Weakness of the quadriceps function and dorsiflexion of foot.
Diminished sensation over anterior thigh, knee and medial aspect of lower leg.
Reduced knee jerk.
What are the indications for discectomy?
Failure of conservative treatment (physiotherapy and analgesia) - First line management
Pain
Central disc prolapse: Patients with bilateral sciatica or other features indicating a central disc prolapse, such as sphincter disturbance and diminished perineal sensation, should be investigated promptly.
Tumour
Neurological deficits
What are the clinical features of cauda equina?
- urinary retention
- saddle paraesthesia
- incontinence (both internal and external anal sphincters)
- low back pain
- bilateral sciatic leg pain
Why do some patients with cauda equina syndrome have bladder incontinence?
Their bladder problems will be intermittent. Severe exacerbation of lower back pain can cause bladder spasm and incontinence.
Look for absent ankle reflexes to confirm cauda equina syndrome.
How do you investigate cauda equina?
MRI lumbrosacral spine and PR exam (lack of anal sphincter tone and perianal numbness)
Treatment of cauda equina
If it was due to a herniated disc –> discectomy
If it was due to a fracture –> decompression +- fixation
If it was due to a hematoma –> evacuation
What is the risk of permanent incontinence and/or impotence even if there is prompt surgery for cauda equina?
10%
What is spinal stenosis?
narrowing of the spinal canal which compresses the lowest most spinal cord, conus medullaris, nerve roots, the latest will lead to symptoms of neurogenic claudication. Symptomatic lumbar stenosis occurs most commonly at the L4/5 level followed by L3/4. Occurs mainly in older patients >50 years old.
What are the clinical features of lumbar spinal stenosis?
- insidious and progressive unilateral or bilateral hip/buttocks/lower extremity pain or burning - precipitated by standing or back extension - relieved by sitting, lumbar flexion or walking uphill
- neurogenic claudication: leg weakness, tingling, numbness and paraesthesia
Treatment of lumbar spinal stenosis
conservative: physio and analgesia
surgery once symptoms untolerable and pain uncontrolled by analgesia: lumbar surgical decompression by laminectomy
What is cervical spondylosis?
A degenerative arthritic process involving the cervical spine
Affects the intervertebral disc and zygapophyyseal joints
Most patients are over 50
Degeneration causes stress on the articular cartilage causing osteophytic spurs to develop around the margins that can grow posteriorly into the spinal canal and arteriorly into the prevertebral space
How do patients with cervical spondylosis present?
either present as degenerative cervical myelopathy (UMN signs) or radiculopathy (LMN signs).
What are the clinical features of cervical spondylosis?
Radiculopathy: LMN signs in the upper and lower limbs, neck pain
Myelopathy
What are the radiographic findings of cervical spondylosis?
Narrowed disc space (C5/6 and C6/7)
Osteophyte formation
Treatment of cervical spondylosis
- Multi-level pathologies/posterior compression due to osteophyte or ligamentum flavum hypertrophy –> decompressive cervical laminectomy
- Predominant anterior compression due to disc –> anterior cervical discectomy
- Unilateral nerve root compression can be approached through a posterior cervical foraminotomy
What is degenerative cervical myelopathy?
Spinal cord compression causing UMN signs (Especially in the lower limbs)
Older patients
Clinical features of degenerative cervical myelopathy
- imbalance and disturbance in gait –> falls
- clumsy hands
- urinary or faecal incontinence (Rare)
- pain (non-dermatomal)
- legs jump at night (hyperreflexia)
Why does degenerative cervical myelopathy cause falls?
due to hypertonia causing spasticity and decreased proprioception
What is found on examination of degenerative cervical myelopathy?
- weakness, hyperreflexia and spasticity
- positive babinksi and hoffman’s signs
- loss of dexterity using fingers
How do you investigate degenerative Cervical myelopathy?
MRI of the cervical spine is the gold standard: may reveal disc degeneration and ligament hypertrophy +/- spinal cord signal change.
How is degenerative cervical myelopathy treated?
Decompressive spinal surgery to prevent deterioration
What is anterior cord syndrome?
anterior spinal artery infarction
paralysis and loss of pain and temperature below
preserved proprioception and vibration
Describe presentation of a complete cord transection
INITIAL: flaccid, arreflexic
then UMN signs
What is Brown-Sequard syndrome?
cord hemisection
ipsilateral UMN paralysis and loss of proprioception below
contralateral loss of pain and temperature 1 or 2 segments below
What is central cord syndrome?
bilateral uper limb weakness > lower limb
cape like loss of pain and temperature
dorsal column preserved
Name 3 potential causes of central cord syndrome
acute extension injury to a stenotic neck
syringomyelia
tumour
Burning down back of legs that is not as bad uphill
Spinal stenosis
A 66 year old has several falls over a few months. He has symetrical weakness of his legs and mild weakness of his hand. He had an abnormal gait. His reflexes were extremely brisk in his legs with upgoing plantars bilaterally.
Degenerative cervical myelopathy due to cervical spondylosis
Stab wound to the back causing R weakness at T5 and left sided loss of pinprick and temperature at T7.
Brown-sequard syndrome
A 39-year-old woman presented with severe headaches whenever she sneezed. She also had decreased sensation to pinprick over her upper back, shoulders, and upper arms. Her power in her arms was 2/5 but her lower body power was 5/5.
syringomelia
Which cervical nerve root comes out below the verebrae?
C8
