Week 129 - Spinal Cord Compression Flashcards
Where does lordosis and kyphosis occur?
Lordosis - cervical and sacral
Kyphosis - thoracic
Describe the progression of a disc prolapse
1) Disc Bulge
2) Disc Protrusion
3) Disc Extrusion
4) Disc Sequestration
Where are spinal fractures most commonly seen?
Where mobile areas meet immobile areas (e.g. T12-L1)
Name stable and unstable fractures and what they involve
Stable - anterior column involved (e.g. wedge fracture)
More Unstable - anterior & middle columns involved (e.g. Burst Fracture)
Unstable - anterior, middle & posterior columns involved (e.g. seat belt fracture)
What is the function of the Atlanto-occipital joint?
Head nodding
What is the function of the Atlanto-axial joint?
Rotation
Where do the vertebral arteries arise from and where do they enter the spinal cord?
Arise from subclavian artery and enter at C6
Travel in transverse foramen of cervical vertebrae
What type of joints join adjacent vertebrae?
Facet Joints (synovial joints) Subject to osteoarthritis
Where does the spinal cord end?
Ends at L1
from there it is known as Cauda equina
What what level would CSF fluid sample be taken?
L4/L5
What muscles produce rotation of cervical spine?
Obliquus capitis inferior
Rectus capitis posterior major + minor
Splenius capitis
Contralateral sternocleidomastoid & semispinalis capitis
What muscles produce side flexion of cervical spine?
Iliocostalis cervicis Longissimus capitis & cervicis Splenius capitis & cervicis Intertransverarii Scalenes
What muscles produce flexion of trunk?
Rectus abdominis
Psoas major
What muscles produce extension of trunk?
Erector spinae multifidus
Semispinalis thoracis
What does C1 (the atlas lack)?
Vertebral Body (therefore no intervertebral disc between CI and CII
What is abnormal lateral curvature of vertebral column called?
Scoliosis
What is the central portion of intervertebral discs called and their function?
Nucleus Pulposus - centre + gelatinous
Absorbs compression forces
What is the outer ring of fibrocartilage called?
Anulus fibrosus - limits the rotation between vertebrae
What type of joints are the joints between vertebral arches (zygapophysial joints)?
Synovial Joints
Name the function and level of decussation of Descending Tracts.
Motor
Pyramidal decussation
Name the sensory modalities and the level of decussation of the Spinothalamic Tract
Pain, Temperature
Decussation at level of entry
Name the sensory modalities and the level of decussation of the Dorsal Columns
Proprioception, Soft Touch, Vibration
Crosses over in brain stem region
What would Brown-Sequard Syndrome at T5 (L) present like?
Left sided block of spinal cord at T5
R leg - Pain, Temp loss
L leg - weak, proprioception loss, hyporeflexia
What are the consequences of an Anterior Spinal Artery Infarction?
Loss of motor + spinothalamic pathways
Dorsal Columns Spared
What symptoms would a patient with an Anterior Spinal Artery Infarction (T level) present?
Motor = weak
Hyporeflexia
Pain, Temp = sensation loss
Constipation, bowel + urine problems
What symptoms would a radiculopathy at C6 (nerve root compression) result in? - Ventral root only
Hyporeflexia of brachioradialis reflex
What symptoms would an expanded central canal in cervical region - syringomyelia result in?
L + R arm = Pain + Temp sensation loss
Name 3 causes of spinal cord compression
Disc & vertebral lesions Trauma Spinal Cord Tumours (extramedullary tumours or mets) TB Abscess/Haemorrhage
What can vitamin B12 deficiency cause, and abuse of what substance may precipitate functional B12 deficiency?
Degeneration of the cord
NO
What do Muscle Spindles do?
Detect changes in muscle length
Stretching generates an action potential
What do Golgi Tendon Organs do?
Detects muscle stretch
Can inhibit muscle -> prevent damage
What is a myotactic reflex?
Aka stretch reflex
What is the function of the Renshaw cell?
Makes reflex transient
Releases glycine onto α-motor neurone - inhibiting it
Negative feedback
What toxin prevents glycine release?
TTX
What is the function of γ-motor neurones?
Keep the muscle spindles taut
By causing their contraction
Allow them to continue detecting changes
What control does the corticospinal tract provide?
Motor Control
Where does the corticospinal tract originate? (parts of the cortex)
Primary Motor - 30%
Primary Somatosensory - 40%
Premotor
Supplementary Motor Area
What is Apraxia?
Inability to produce a specific motor act even though sensory and motor pathways remain intact
Name the two type of Apraxia
Ideomotor apraxia - cannot execute movement upon request
Ideational apraxia - cannot conceptualize movement required
What is the function of the Reticulospinal tract?
Modulation of spinal extensor reflexes (motor control)
What is the function of the Vestibulospinal tract?
Posture and balance (motor control)
Name three ascending tracts
Spinothalamic (Pain, Temp, Pressure)
Spinocerebellar (Proprioception)
Dorsal Columns (Joint position, fine discriminatory touch)
Where do Lower Motor Neurones arise and what do they release?
Arise in Brainstem and Spinal Cord
Alpha and Gamma
Release ACh
Where do Upper Motor Neurones arise and what do they release?
Arise in brain
Glutamatergic
What are the signs and symptoms of a Lower Motor Neurone Lesion?
Hyporeflexia Fasciculations Muscle Atrophy Denervation These are not present in UMN lesions
What are the signs and symptoms of an Upper Motor Neurone Lesion?
Paralysis/Weakness
Hyperreflexia
Immediately after lesion: flaccid paralysis, hypotonia, loss of reflexes
BUT afterwards: hypertonia, spasticity, babinski reflex
What is Lhermitte’s sign?
“electric shock” kinda feeling
What is Cervical Spondylotic Myelopathy?
Narrowing of spinal canal due to “aging”
Compression leads to pain, weakness, and numbness
Name some causes of weakness
Damage to motor pathway
NMJ disease
Muscle Disease
Arthritis, endocrine disorders, systemic disease, fatigue
What does paresis mean?
Weakness
What is plegia?
Paralysis
What is paraplegia?
Paralysis of both legs
What is monoparesis?
One limb weakness
What does Myelo- mean?
Relating to spinal cord
What does Radiculo- mean?
Pertaining to nerve root
What does Myo- mean?
Pertaining to muscle
Where does the initiation of movement take place?
Frontal lobes & the basal ganglia
What is the general pattern of weakness in arms and legs in UMN lesions?
extensors weaker than FLEXORS in ARMS
flexors weaker than EXTENSORS in LEGS
Giving a person that looks like had a stroke
What is the pattern of weakness in muscle disease?
Tends to affect proximal muscles (pt. will waddle)
Affected muscles may be wasted OR hypertrophied (fat deposition)
What conditions can result in proximal weakness?
Muscle Disease (e.g. Myasthenia Gravis)
What conditions can cause distal weakness?
Polyneuropathy, Peripheral Neuropathy
What conditions can cause paraparesis?
LMN lesion, spinal cord disease
What conditions can cause hemiparesis?
UMN lesion
What is dysarthria?
Poor articulation of speech
What are the signs of pseudo bulbar palsy?
Dysarthric
Slow tongue movements
Brisk Jaw Jerk
due to damage to lower cranial nerves
What is Amyotrophic Lateral Sclerosis (ALS)?
Degenerative disease of motor pathway
Degeneration of both UMN and LMN
5% get frontpotemporal demetia
How is diagnosis of ALS made?
History + Examination
Moderately elevated creatine kinase
Electromyography
What is myositis?
Inflammation of muscles
What are the symptoms of Polymyositis?
Proximal muscle weakness
What are the symptoms of Dermatomyositis?
Proximal muscle weakness
Rash over hands + face
Associated with malignancy
What are the symptoms of Inclusion Body Myositis?
Proximal leg muscles and long finger flexors
Elderly
What are the symptoms of Cauda equina syndrome?
Weakness of ankle and plantar flexion (foot drop)
?Bilateral sciatica
Bilateral loss of ankle reflexes
Loss of anal tone
Patchy sensatory loss over the perineum and genitals
What symptoms would anterior spinal artery infarction present with?
Paraparesis Upgoing plantars Brisk reflexes Temp + Pain sensation lost Proprioception spared
What are the possible causes of quadraplegia?
Trauma - Spinal Shock
Acute onset - Guillain-Barré Syndrome
What are the features of spastic hemiparesis?
Elbow flexed
Arm + fingers flexed across chest
Leg = extended +circumducts to prevent toe scuffing
What artery supplies dorsal columns of spinal cord?
Posterior spinal artery
