Neurological Diseases - Spinal Disorders Flashcards
what makes up the vertebral column?
Cervical spine
Thoracic spine
Lumbar spine
Sacrum and Coccyx
what are the three regions of the cervical spine?
Atlanto-axial joint (C1–C2)
Subaxial spine (C3–C6)
Transitional vertebra C7
how would you describe the features of C1 (atlas)?
Ring-shaped
consists of an anterior (shorter) and posterior (longer) arch that fuses laterally to the lateral masses.
Has no body or spinous process but has large transverse processes that serve as attachments for superior and inferior oblique muscles.
The transverse processes are penetrated by the foramen transversarium accommodating the vertebral artery on either side.
what is C1 known as?
atlas
what is C2 known as?
axis
what is the main feature of the C2 (atlas)?
Has body and a distinct 15mm (range 9–21mm) high odontoid process (dens) that projects anteriorly at an average angle of 13°.
how would you describe C3-C6 vertebrae?
The vertebral bodies are small, concave on the superior surface, and convex on the inferior surface and have AP diameter smaller than the lateral diameter.
The spinal canal has a triangular shape and a sagittal diameter at C3–C6 of ~18mm.
what is C7 known as?
prominens
what does C7 mark?
cervicothoracic junction.
The sagittal diameter of the spinal canal is 15mm, the smallest in the cervical spine.
what are features that apply to all cervical vertebrae?
The uncinate (‘hook-like’) processes: are bony prominences of the superolateral aspects of the C3–C7 vertebral bodies which restrict lateral flexion.
The uncovertebral joint : between the uncinate process and the superior vertebra. The distance between the tip of the uncinate process and the laterally placed vulnerable VA is ~ 1mm (range 0–3mm).
The spinous processes: bifid and project inferiorly. The large spinous process of C7 is not bifid and serves as a surgical landmark
what are The uncinate (‘hook-like’) processes of cervical vertebrae?
bony prominences of the superolateral aspects of the C3–C7 vertebral bodies which restrict lateral flexion.
what is the uncovertebral joint of cervical vetebrae?
between the uncinate process and the superior vertebra. The distance between the tip of the uncinate process and the laterally placed vulnerable VA is ~ 1mm (range 0–3mm).
how would you describe the thoracic spine?
Heart-shaped body
Small circular spinal canal which provides the least spacious accommodation for the spinal cord.
The height and width of the thoracic pedicles increase in a superior to inferior direction.
The ribs articulate with the thoracic vertebrae in the body (costovertebral joint) and in the transverse process (costo-transverse joints).
Rib attachments render the thoracic spine biomechanically stiffer.
how would you describe the body of the lumbar spine?
massive kidney-shaped bodies, transmitting the body’s weight to the sacrum, and also have sturdy laminae and no costal facets.
Similar to the thoracic spine, the widths of the lumbar pedicles increase from L1 to L5.
what three zones is the sacrum divided into?
Lateral zone crossed medially to laterally by the sympathetic trunk, lumbosacral trunk, and obturator nerve
Intermediate zone which includes the sacral foramina
Medial zone which includes the sacral vertebrae
how do the sacral verebrae fuse?
The sacral vertebrae fuse and become progressively smaller forming the triangular sacrum that effectively transmits the body weight to the pelvis.
what are the spinal ligaments?
anterior and posterior atlanto-occipital membrane
transverse ligament
cruciate ligament
apical ligament
alar ligaments
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
supraspinous ligament
what is the anterior and posterior atlanto-occipital membrane?
stretched from the anterior and posterior arches of C1 to the corresponding parts of the foramen magnum.
what is the transverse ligament?
transverse ligament is a strong ligament: grooves and holds the dens in position.
what does rupture of the transverse ligament result in?
Rupture or inflammatory degeneration of the transverse ligament results in atlanto-axial dislocation.
what is the cruciate ligament?
formed by two weaker ligamentous bands that run form the dens, superiorly to the basiocciput, and inferiorly to the body of C2.
what is the apical ligament?
runs from the tip of the dens to the anterior part of the FM
what is the anterior longitudinal ligament?
on the anterior surfaces of the vertebral bodies as the continuation of the anterior atlanto-occipital membrane and ends at the upper sacrum.
what is the posterior longitudinal ligament?
on the posterior surface of the vertebral bodies as a continuation of the tectorial membrane.
what is the ligamentum flavum?
composed of yellow elastic fibres which are perpendicularly oriented, and extends from facet joints to the base of spinous processes (from C2–C3 to L5–S1).
what is the supraspinous ligament?
connects the tips of the spinous processes and extends from C7 to the sacrum.
what is the atlanto-occipital joint?
This joint allows flexion, extension (the nodding ‘yes’ joint) and some lateral flexion.
what are the atlanto-axial joints?
A median pivot joint: anterior part of the dens articulates with the back of anterior arch of C1.
A lateral gliding joint: inferior facet of C1 articulates with the superior facet of C2). These joints allow mainly rotation (the shaking ‘no’ joint) as the skull and C1 rotate on C2 as a unit.
what is a median pivot joint?
anterior part of the dens articulates with the back of anterior arch of C1
what is a lateral gliding joint?
inferior facet of C1 articulates with the superior facet of C2). These joints allow mainly rotation (the shaking ‘no’ joint) as the skull and C1 rotate on C2 as a unit.
where are the intervertebral discs located?
C2–3 to L5–S1
which intervertebral discs are the thinnest?
thoracic discs are the thinnest
lumbar discs are the thickest, and have greater height anteriorly to maintain the lordotic curve.
what is the nucleus pulposus?
centrally and posteriorly placed, avascular and receives its nutrients from the vertebral body and the periphery of the annulus
what is the annulus fibrosus?
peripherally placed, composed of oblique layers of lamellae and is strongly attached to the vertebral end-plates.
what are the end plates?
allows diffusion of nutrients from the bone to the disc.
what does spinal stability depend on?
at least two intact columns
what are the three different columns of three-column theory?
anterior: anterior longitudinal ligament, anterior half of annulus fibrosus, and vertebral body.
Middle: posterior longitudinal ligament, posterior half annulus fibrosus, and vertebral body.
Posterior: Osseous and ligamentous structures posterior to the posterior longitudinal ligament (interspinous ligaments).
describe the anterior column?
anterior longitudinal ligament, anterior half of annulus fibrosus, and vertebral body.
describe the middle column?
posterior longitudinal ligament, posterior half annulus fibrosus, and vertebral body.
describe the posterior column?
Osseous and ligamentous structures posterior to the posterior longitudinal ligament (interspinous ligaments).
how many pairs of spinal nerves are there?
31 pairs of spinal nerves
list the different types of spinal nerves?
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
what is located at C2?
occipital protuberance
what is located at C3?
supraclavicular fossa
what is located at C4?
top of acromioclavicular joint
what is located at C5?
lateral side of antecubital fossa
what is located at C6?
thumb, dorsal surface, proximal phalanx
what is located at C7?
middle finger, dorsal surface, proximal phalanx
what is located at C8?
little finger, dorsal surface, proximal phalanx
what is located at T4?
nipple line
what is located at T10?
umbilicus
which dermatomes are responsible for the biceps reflex?
(C5-C6)
which dermatomes are responsible for the siponator reflex?
(C6-C7)
which dermatomes are responsible for the triceps reflex?
(C7-C8)
which dermatomes are responsible for the abdominal reflex?
(T8-T9/T10-12)
which dermatomes are responsible for the creamasteric reflex?
(L2-L3)
which dermatomes are responsible for the knee jerk reflex?
(L3-L4)
which dermatomes are responsible for the ankle jerk?
(S1-S2)
which dermatomes are responsible for the Anal cutaneous reflex?
(S2,S3,S4)
which dermatomes are responsible for the Bulbocavernosus reflex?
(S2,S3,S4)
what is the loss of the bulbocavenosus reflex seen in?
Spinal shock
Conus medullaris and Cauda equine lesions
describe the gross anatomy of the spinal cord?
About 45cm long and cylindrical in shape.
Starts from the foramen magnum and tapers into the conus medullaris, ending at L1–L2 in the adult at L3 in the newborn, and at S2 in the fetus.
Below the conus medullaris are found motor and sensory roots only (cauda equina), floating in the subarachnoid space before exiting though lumbar and sacral foramina.
Possesses a cervical (C5–T1) and a lumbosacral (L2– S3) enlargement for the brachial, lumbar, and sacral plexuses.
Has three columns of funiculi divided by the anterior median fissure ventrally, the posterior median sulcus dorsally, and the anterior and posterior nerve roots laterally.
On section, the butterfly or H-shaped centrally placed grey matter is surrounded by ascending and descending tracts
what type of sensation is the dorsal column responsible for?
Fine touch
Joint position
Vibration
Proprioception
what type of sensation is the lateral spino-thalmic tract responsible for?
Pain and temperature
what type of sensation is the anterior spino-thalmic tract responsible for?
Light crude touch
describe the different aspects of the dorsal column?
Meissner’s & pacinian corpuscles, free nerve endings.
heavily myelinated neurons
dorsal root ganglion
nucleus proprius (Rexed III & IV)
Ipsilateral posterior columns
nucleus gracilis (below T6)/cuneatus (above T6)
internal arcuate fibers, decussate in lower medulla
medial lemniscus
VPL thalamus
internal capsule
describe the different aspects of the lateral spino-thalmic tract?
free nerve endings
finely myelinated neurons
dorsal root ganglion
Substantia gelatinosa of rolandi (Rexed II)
Cross the midline in the anterior white commissure
Lateral spino-thalamic tract
VPL thalamus
Internal capsule
postcentral gyrus
describe the progression from notochord to the neural tube?
notochord - neural plate (formation by ectoderm) - neural groove - neural fold - close (neurulation) - neural tube - takes 28 days after conception
what does the neural tube give rise to?
brain and spinal cord
what does the notochord form?
inducing factors - mesoderm forms the bony elements of the spine
when does the anterior neuropore close?
24 days
what does failure of closure of the anterior neuropore result in?
anacephaly - most common brain defect
when does the posterior neuropore close?
26-28 days
what does failure of closure of the posterior neuropore result in?
spina bifida?
what can identify open neural tube defects in high risk mothers?
alpha - fetoprotein and acetylcholinesterase obtained from amniocentesis?
what is the definition of spina bifida?
birth defect in which there is incomplete closing of the spine and the memebranes around the spinal cord during early development in pregnancy
what is the epidemiology for spina bifida?
1:1000-2000 live births
what are the risk factors for spina bifida?
low levels of folic acid before and during early pregnancy
family history of a birth defect
diabetes
obesity
anti-seizure drugs
what is spina bifida classified into?
spina bifida aperta (open spina bifida) {meningocele and myelomeningocele}
spina bifida occults (closed spina bifida)
where does spina bifida most commonly occur in the spine?
lumbosacral region (90%)
cervical region (2-3%)
what are clinical symptoms for spina bifida?
back swelling
lower limb motor defecit
sensory deficit
sphincteric disturbance
associated back deformities / lower limb deformities
describe the site, sac coverings, sac contents, trans illumination, neurologicsl deficit, sphincters and hydrocephalis of meningocele?
commonly lumbosacral
common to be covered with normal skin and less to be membranous
CSF
no deficit
ussually intact
uncommon association
describe the site, sac coverings, sac contents, trans illumination, neurologicsl deficit, sphincters and hydrocephalis of myelomeningocele?
commonly lumbosacral
ussuallt sac covering is membranous
CSF and neural tissue
transopaque
neurological deficit
double incontinence
associated with 85% of cases
what is the treatment for spina bifida?
primary surgical closure
if infant has other abnormalities which disallow general anaestethic then closure can be delayed with broad spectrum antibiotics
how should spina bifida patients be assessed post operatively?
infants should be assessed regularly for hydrocephalus and placement of VP shunt if needed
what is tethered cord syndrome?
inelastic anchoring of the cqaudal spinal cord by an abnormally thick or fatty filum terminale
what results from tethered cord syndrome?
lumbosacral spinal cord abnormally stretched and elongated so it cannot mobe in a cephalad direction during spinal movements
how may patients with tethered cord syndrome typically present?
neurological, urolofical and orthopaedic symptoms
what are four causes of spine infection?
pyogenic vertebral osteomyelitis and discitis
granulomatous infection
epidural infection
post operative infection
what is pyogenic vertebral osteomyelitis and discitis?
represents a spectrum of spinal infections including discitis, vertebral osteomyelitis, and epidural abscess
how many skeletal infections are due to vertebral osteomyelitis?
1%
how does discitis typicallt arise?
due to hematogenous spread
what parts of the spine does pyogenic infections most frequently involve?
lumbar spine (58%)
thoracic spine (30%)
cervical spine (11%)
which gram positive organisms most commonly present in pyogenic vertebral osteomyelitis and discitis?
staph aureus
steptoccocus species
how does pyogenic vertebral osteomyelitis and discitis present clinically?
axial pain
fever
radicular numbness
muscle weakness
what should you ask in a patient suspected of pyogenic vertebral osteomyelitis and discitis in their history?
travel history
recent procedures
what are the lab findings for pyogenic vertebral osteomyelitis and discitis?
wbc - increased/normal
erythrocyte sedimentation rate - more senstive
crp - elevated
blood culture - reveal causative pathogen
urinalysis - rule out UTI
what neuroimaging is done for pyogenic vertebral osteomyelitis and discitis?
X-ray
CT
MRI
what is treatment for PVOD?
broad spectrum intravenous antibiotics for at least 6-8 weeks until pathogen identified through biopsy, blood culture
why may immobilisation be beneficial for reducing pain in PVOD?
reducing pain and stabilising the spine
when may surgery be needed for PVOD?
appropriate medical mamagement fails
patients develops neurologic deterioration
spinal instability/deformity
what are the goals of surgery in PVOD?
debridement of infected tissue
decompression of the neural structures
stabalisation of the spine
what do post operative infections arise following?
following direct inoculation of the wound with normal skin flora
what are risk factors for post-operative infections?
increased age
obesity
diabetes
tobacco use
poor nutritional status
prolonged surgical time
placement of instrumentation
what are post-operatie infections commonly associated with?
longer hospital stays
high complication rates
increased mortality
what are preventative measures for post -operative infections?
prophalactic antibiotics administered 60 mins before a spinal procedure
additional doses of intraoperative antibiotics for prolonged surgical procedures
what is the treatment for post-operative infections?
open irrigation and debridement
IV antibiotics continued for minimum of 6 weeks, patients may be switched to oral antibiotics
how are spinal cord tumour classified?
intradural
intramedullary
extramedullary
extradural
metastases
cancers of bone
what imaging is done for spinal cord tumours?
plain Xray and CT
MRI
what is the treatment for spinal tumours?
surgical excision, biopsy, radio and chemo
what are ecamples of spinal emergencies?
spinal epidural compression (hematomas/abscess)
cauda equina and conus syndromes
whay is the site of spinal hematomas?
subdural
epidural
subarachnoid
intramedullary
where are spinal haematomas typically localised to?
spinal cord
where can subarachnoid haematomas extend to?
along entire legnth of the subarachnoid space
what is the etiolofy of spinal hematomas?
trauma
anticoagulant therapy
how do spinal hematomas present clinically?
symptoms depend on location and extent of haemorrage
epidural/ subdural haematomas present with intrense knife like pain in location of haemorrage
subarachnoid haemorrage associated with meningitis like symptoms
what imaging is done for spinal hematomas?
MRI
what is treatment fdor a spinal haematoma?
correction of coagulopathy
emergent surgical decompression
laminectomy
what is cauda equina syndrome?
surgical emergency that results from compressive ichaemic and inflammatory neuropathy of multiple lumbar and sacral nevr roots in lumbar spinal canal?
what is the aetiology for cauda equina syndrome?
trauma
haemorrhage
inflammtory diseases
infectioon
degenerative spine disease
spine tumours
how does cauda equina syndrome clinically present?
leg pain
saddle anaethesia
bladder bowel and sexual dysfunction
abscens of ankle reflec
what are types of cauda equina syndrome?
incomplete
complete
what is incomplete cauda equina syndrome?
loss of urgency or decreased urinary sensation without incontinence
what is complete cauda equina syndrome?
urinary and bowel retention or incontincence
what imaging is done for cauda equina syndrome?
MRI
what is the treatment for cauda equina syndrome?
surgical decompression with 24 H
what is the epidemiology of spinal cord injury?
mortality risk dependent on cervical level
descibe primary SCI?
trauma results in the immediate death of local cells
direct damage to cell bodies and neuronal processes (die and not replaced)
damage to spinal axoms (wallerian degeration)
describe secondary SCI?
inflammation
account for up to 70% of the final outcome ad include 4 overlapping events
which vascular events can cause secondary SCI?
damage to endothelial cells of local blood vessels result in diminished flow at site of injury
blood supply is compromised near impact site partly because of impaired autoregulation and vasospasm resulting in ischemia
SCI causes neurogenic shock, bradycardia, hypotension contributing to cord tissue ischaemia
breakdown of blood-sponal cord barrier causes an influx of inflammatory cells resultinf in more inflammation and secondary tissue damage
what four overlapping events cause secondary spinal cord injury?
inflammation
vascular events
chronic phase of injury
what does chronic phase of injury include?
demylination
scar formation
what is the definition of spinal cord (spinal shock) injury?
transient loss of all neurologic function below the level of the spinal cord injury - flaccid paralysis and areflexia
hypotension
duration: 72H, typically persists 1-2 weeks
what are multiple factors that cause spinal shock?
interuption of sympathetics (spinal cord inkuery above T1
loss of vascular tone, below level of injury leaves parasympathetics relatively unopossed causing bradycardia
relative hypovolemia
true hypovolemia
what is relative hypovolemia?
skeletal muscle paralysis below level of injury resulting in venous pooling
what is true hypovolemia?
blood loss from associated wounds
what is complete spinal cord injury?
complete loss of motor and/or sensory function below level of the injury in the absence of spinal shock
3% of patients dvelop some recovery within 24 H
poor prognosis
what is incomplete spinal cord injury?
any residual motor or sensory function below the level of the injury
- sacral sparing
- voluntary anal sphincter contraction
- voluntary toe flexion
what are different types of SCI?
central cord syndrome
brown-sequard syndrome
anterior cord syndrome
posterior cord syndrome
what is central cord syndrome?
most common type of incomplete spinal cord injury
results from hyperextension injury in older patients with pre-existing stenosis
can result in cord contusion
what may spinal cord injury be associated with?
cervical fracture / dislocation
acute traumatic cervical disc herniation
how does central cord syndrome present clinically?
motor: weakness in UL more than LL
sensory: loss below level of the injury
sphincter: urine retention
what is the recovery for spinal cord injury?
lower limbs early to recover upper limbs recover later
recovery usually incomplete
what is anterior cord syndrome (anterior spinal artery syndrome)
cord infection in the territory supplied by the anterior spinal artery
what may result in anterior cord syndrome (anterior spinal artery syndrome)?
occlusion of the anterior spinal artery
anterior cord compression e.g by dislocated bone fragment or by traumatic herniated disc
how does anterior cord syndrome present?
paraplegia or quadriplegia
dissociated senosry loss below lesion - loss of pain and temperature sensation (spinothalmic tract lesion) with preservation of two point discrimination, joint position sense, deep pressure sensation
what does brown sequard syndrome manifest with?
ipsilaterak loss of joint position sense vibration sense and discrimination
ipsilaterak spastic paresis below level of lesion
contralateral loss of pain and tempeerature one level below the lesion
what is involves in primary assessment of spinal cord injury?
airway
breathing
circulation
immobalization
what are components of secondary assessment assessing?
assessment of GCS
identifying:
axial skeleton fractures
appendicular skeleton
pelvic fractures
how is spinal cord injury managed?
xray
CT
MRI
what are indications for incomplete spinal cord injury?
incomplete spinal cord injury
patients with progressive neurological deterioration
what are examples of cervical spine injuries?
occipital condyle fracture
atlantooccipital dislocation
fracture of atlas
fracture of axis
atlantoaxial instability
subaxial cervical spine fractures
what is an occipital condyle fracture?
rare
ussually stable fractures
mostly due to blow to the head
what is the most common cause of occipital condyle fracture?
blow to the head?
what may patients present with in an occipital condyle fracture?
loss of conciousness
cranio-cervical pain
rarely with lower cranial nerve deficits
who does atlanto-occpiral disclocation most commonly affect?
children due to smaller occipital condyles and soft tissue laxity
how does atlanto-occipital dislocation resent clinically?
typically instntly fatal
80% surviors have neurological dedecits
what are 3 different types of fractures of fractures of the atlas?
anterior or posterior arch
&/- intact / disrupted transvere ligament
lateral mass fractures
isolated transverse process fractures
why are patients with fractures of the atlas usually neurologically stable?
canal is capacious C0-C1
fracture tens to explode away from canal
what are the three categoried of axis fractures?
fractures of the odontoid process
traumatic spondylosthesis of the axus
fractures of the body of the axis
what are subaxial cervical fractures divided into?
ligamentous (facet dislocation)
osseous (tear drop/ burst fracture)
what are ligamentous subaxial cervical spine fractures?
unilateral and bilateral dislocation
what are osseous subaxial cervical spine fractures?
tear drop fractures
burst fractures
what are thorco lumbar spine injuries classified into?
compression
burst
seat belt
fracture - dislocation
what are zone 1 sacral spine injuries?
rare
produce neurological injuries
either L5 nerve root or sciatic N damaged
what are zone 2 sacral spine injuries?
higher incidence of neurological defecits ussually no sphincter invlvement
what are zone 3 sacral spine injuries?
involve area medial to te foramina and possibly central canal - highest rate of profound neurolofical defecits
bowel and bladder disfunction may also result
what are general indications for surgical treaatment in spine fractures?
occpital condyle avulasion fractures
atlanto occipital dislocation
more than 5mm C1-C2 displacement
neurological deficits
bimechanical instability
non union after 12 weeks immobalisation
