Spine Flashcards
The spinal cord extends from which structure?
Medulla
At what level does the spinal cord terminate?
L1/L2
What information is received by the dorsal horns of grey matter?
Somatosensory
What is contained within the ventral horns of grey matter?
Motor neurones
At what levels is the lateral horn of grey matter found?
T1-L2
What is contained within the lateral horn of grey matter?
Autonomic neurones
What are the main ascending tracts of the spinal cord?
Dorsal column medial lemniscus (DCML)
Spinothalamic
What sensory modalities are carried within the DCML pathway?
Fine touch
Pressure
Vibration
DCML fibres from below T6 travel up the spinal cord in what?
Fasciculus gracilis
DCML fibres from T6 and above travel up the spinal cord in what?
Fasciculus cuneatus
Where do first order DCML fibres synapse?
Medulla
The DCML fibres decussate to which structures?
Contralateral medial lemniscus
After decussating to the contralateral medial lemniscus, what happens?
The fibres synapse in the thalamus before signal is relayed to the somatosensory cortex
What sensory modalities are carried within the spinothalamic tract?
Pain
Temperature
Where do the first order neurones of the spinothalamic tract synapse?
Dorsal horn
The spinothalamic fibres decussate after synapsing in the dorsal horn. True/false?
True
Where do the second order neurones of the spinothalamic tract synapse?
Thalamus
What is the function of the spinocerebellar pathways?
Provide unconscious proprioceptive information to cerebellum
The dorsal spinocerebellar pathway carries proprioceptive information from where?
Muscle spindles of lower limbs
The cuneocerebellar pathway carries proprioceptive information from where?
Upper limbs
The ventral spinocerebellar pathway carries proprioceptive information from where?
Golgi tendons of lower limbs
The spinocerebellar tracts transmit information to the ipsi-/contra-lateral cerebellum
Ipsilateral
What are the main pyramidal tracts?
Corticospinal
Corticobulbar
The corticospinal tract is responsible for what?
Voluntary movements
The majority of the corticospinal tract fibres decussate at the medullary pyramids. True/false?
True
What do decussated corticospinal tract fibres descend within?
Lateral corticospinal tract
What do undecussated corticospinal tract fibres descend within?
Anterior corticospinal tract
What is contained with corticobulbar tracts?
UMN of cranial nerves
Pyramidal tracts originate at the brainstem and extra-pyramidal tracts originate at the motor cortex. True/false?
False - pyramidal tracts originate at motor cortex and extra-pyramidal at brainstem
What does the vestibulospinal tract control?
Balance and posture (innervates anti-gravity muscles)
What do the reticulospinal tracts control?
Reflex responses
Tone
What does the rubrospinal tract do?
Excites flexor muscles and inhibits extensor muscles of upper body
What does the tecto-spinal tract co-ordinate?
Movement of head and neck
What are the innervations of the ankle, triceps, biceps and knee reflexes?
Biceps - C5/6
Triceps - C7/8
Knee - L3/4
Ankle - S1/2
What occurs in disc herniation?
The nucleus pulposis herniates through a tear in the annulus ring
A paramedian herniated disc typically compresses the transversing/exiting nerve
Transversing (the nerve root that exits below the level or prolapse)
A lateral herniation at L4/L5 will damage which nerve?
L4
What is radiculopathy?
Dysfunction of a nerve root causing dermatomal sensory deficit
Give some clinical features of cauda equina syndrome
Painless urinary retention
Saddle paraesthesia
Incontinence
Lower back pain
What is treatment for cauda equina syndrome?
Surgical decompression
What is spinal stenosis?
A narrowing of the spinal cord leading to neurogenic claudication
Give some clinical features of spinal stenosis
Hip/buttock/lower extremity pain
Burning sensation
Relieved by walking uphill
How is spinal stenosis treated?
Conservatively (physio and analgesia)
Lumbar laminectomy
What occurs in cervical spondylosis?
Degenerative arthritic process of the cervical spine
How can patients with cervical spondylosis present?
Degenerative cervical myelopathy (UMN signs)
Radiculopathy (LMN signs)
How is cervical spondylosis treated?
Surgery (laminectomy/disectomy)
What are some clinical features of degenerative cervical myelopathy?
Imbalance of gait
Clumsy hands
Pain
Hyperreflexia
What investigation is the gold standard for cervical myelopathy?
MRI
What occurs in anterior cord syndrome?
There is cord infarction in the area supplied by the anterior spinal artery
What sensations are lost in anterior cord syndrome?
Pain and temperature below level of injury
How do patients with cord transection present initially?
Flaccid arreflexic paralysis
What sensation is lost ipsilaterally in Brown-Sequard syndrome?
Proprioception
What sensations are lost contralaterally in Brown-Sequard syndrome?
Pain and temperature
What is the cause of central cord syndrome?
Acute extension injury to already stenotic neck
Give some clinical features of central cord syndrome
Bilateral upper limb weakness
“Cape-like” spinothalamic sensory loss
