Clinical Anatomy of the Spine Flashcards
Back pain
- Low back pain affects 70-90% of people at some time in their lives
- 2nd most common reason for visits to a primary care physician
- 2nd most common cause of missed work
- Most common cause of disability in patients <45 yo and third leading cause of disability for >45 yo
What are some neurologic symptoms related to spinal nerve root(s) or cord compression?
Extremity pain
Numbness
Tingling
Weakness
Bowel/bladder urgency/incontinence
What are the components of the musculoskeletal spine examination?
- Inspection
- Palpation
- Range of motion
- Neuromuscular exam: muscle testing, sensory testing, reflexes
- Special tests
- Examination of related areas: shoulder (cervical spine) and hip (lumbar spine)
What parts of the spine are most prone to disc herniation? Why?
Cervical – increased motion
Lumbar – increased weight bearing
Seperate the gray matter of the spinal cord into the three different sections and their functions.
Ventral horn: cell bodies of motor neurons
Lateral horn: cell bodies of autonomic neuons
Dorsal horn: sensory input
Is the ventral rami sensory or motor?
Both – has fibers from both sensory and motor components.
A collection of muscle fibers innervated by the motor axons within each segmental nerve (root)
Myotome
Area of skin innervated by the sensory axons within each segmental nerve (root)
Dermatome
A patient presents with flaccid paralysis of the right arm. No pain, paresthesias or sensory loss noted. Lab reveals polio virus infection. What is the target of the virus?
Ventral horn of spinal cord gray matter
Motor system is affected
Which dermatome supplies the thumb?
What about the ulnar side of the hand?
Nipple?
Umbilicus?
Thumb: C6
Ulnar hand: C8
Nipple: T4
Umbilicus: T10
Most common infection of the peripheral nervous system. Acute nerualgia confined to the dermatome distribution of a specific spinal or cranial sensory nerve root.
Herpes Zoster (shingles)
What are some anterior and posterior landmarks for palpation in the cervial spine exam?
Anterior:
- Hyoid bone: C3
- Thyroid cartilage: C4-5
- First cricoid ring: C6
- Carotid tubercle: C6
Posterior:
- Occiput
- Cervical spinous processes: C7 largest
- Facet joints
Manual muscle testing: rated 5 to 1
5: Normal strength – complete ROM against gravity with maximal resistance (examiner cannot overcome)
4: Active movement against gravity and moderate resistance through full ROM (examiner can overcome)
3: Active movement through full range of motion against gravity (no resistance)
2: Active movement through full ROM with gravity eliminated (no resistance)
1: Flicker or trace of contraction, but no joint motion (no palpable muscle action)
0: No contraction palpated (complete paralysis)
What are some causes of muscle weakness?
- Muscle strain
- Pain/reflex inhibition
- Peripheral nerve injury
- Nerve root lesion (myotome)
- Upper motor neuron lesion
- Tendon pathology
- Avulsion
- Psychologic overlay
How do you test myotome C5?
Biceps flexion
How do you test myotome C6?
Extensor carpi radialis–extension of wrist
How do you test myotome C7?
Triceps – elbow extension
How do you test myotome C8?
Flexor digitorum profundus– 3rd distal finger flexion
How do you test myotome T1?
Abductor digiti minimi– little finger abduction
How do you test root level L2?
Iliopsoas – hip flexion
How do you test root level L3?
Quadriceps – Knee extension
How do you test root level L4?
Tibialis anterior–ankle dorsiflexion
How do you test root level L5?
Extensor hallicus longus–big toe extensor
How do you test root level S1?
Gastrocnemius–ankle plantarflexion
What is the scale for reflex testing?
0: absent
1: slight or less than normal (trace response, includes response only brought out with reinforcement)
2: lower half of normal range
3: upper half of normal range
4: enhanced and more than normal (including clonus)
What root levels does biceps reflex test? Brachioradialis? Triceps?
Biceps: C5
Brachioradialis: C6
Triceps: C7
What root level does the Patellar reflex test? Hamstring? Achilles?
**Patellar: **L4
**Hamstring: **L5
**Achilles: **S1
Passive anterior cervical flexion elicits “electric-like” sensation down the spine or extremities.
What does it imply?
Lhermitte’s sign
Cervical spinal cord pathology
Reproduction of radicular symptoms with cervical spine extension, rotation, and lateral flexion.
What does it imply?
Spurling’s neck compression test
Implies cervical nerve root pathology
Flick the patient’s middle finger.
What is a positive test?
What does it imply?
Hoffman’s sign
Positive: flexion-adduction of ipsilateral thumb and index finger
Implies upper motor neuron process affecting cervical spine or brain
What test implies lumbar nerve root pathology (L5 or S1)??
Straight-leg raising test: patient lies supine while the leg is raised with the knee extended. Examiner stops raising the leg when patient reports pain.
Positive test: leg pain reproduced at 30-70 degree angle
Which test implies an upper lumbar nerve root pathology (L2-L4)?
What is a positive test?
Femoral nerve stretch test (upper lumbar disc): patient is placed in prone position while the knee is flexed
Positive test: reproduction of patient’s pain in anterior thigh
What signs are associated with an upper motor neuron injury?
- Spasticity/hypertonicity
- Increased reflexes (hyperreflexia)
- Positive pathological reflexes
- Extensor plantar response
Think: spinal cord injury, brain injury/stroke, myelopathy, CNS lesion
What signs are associated with lower motor neuron injury?
- Flaccid weakness
- Loss of reflexes (hyporeflexia)
- Muscle wasting and atrophy
Think: Peripheral nerve entrapment, radiculopathy
What are some red flags for malignancy to watch out for?
- H/o cancer
- Unexplained weight loss
- Age > 50
What are some red flags for a spinal fracture to watch out for?
- Major trauma (MVA, fall)
- Minor trauma or strenuous lifting in an older or potentially osteoporotic individual
- Prolonged corticosteroid use
- Osteoporosis
- Advanced age >70 yrs
What are some red flags for infection to watch out for?
- Constitutional symptoms (fevers, chills)
- Recent bacterial infection (UTI, skin, pneumonia)
- Immunosuppressin
- IV drug abuse
Case: 28 yo male with right sided low back pain x3 days after putting his toddler into his car seat. Otherwise healthy. No radiation of pain, numbness/tingling/weakness. Tender and hypertonic lumbar paraspinals, limited (painful) lumbar ROM, normal neuro exam.
Lumbar strain
Hx: axial low back pain after acute injury (lifting or twisting), pain worse with movement, better with rest
Etiology: muscle disruption from excessive stretch or tension
Exam: Localized muscle tenderness, reduced ROM, normal neuro exam
Treatment: Relative reset, pain control (NSAIDs, muscle relaxants), physical therapy if >4 wks or recurring, majority self limited
Case: 37 yo painter wiht 2 weeks of progressive pain in the neck and right scapular and arm pain. Past 1 wk with shooting pain and numbness down the arm to the hand more severe. Notes numbness downt he arm into the hand and his arm feels weak.
Exam: postitive spurling, weak elbow extension, decreased pain over middle finger
Herniated disc
This man would also have absent triceps reflex – LMN injury, hyporeflexia, C7 herniation is triceps
Posterolateral herniation most common
Which ligament in vertebral canal forces herniated discs to slip posterolaterally?
Posterior longitudinal ligament
Which cervical spine levels are most affect by disc herniation? What about lumbar levels?
Cervical: C6, C7 most affected
Lumbar: L5, S1 most affected
What motor weakness would you expect with a disc herniation that affects C7?
Elbow extension; wrist flexion
What motor weakness would you expect with a disc herniation that affects L4?
Knee extension, ankle dorsiflexion
What motor weakness would you expect with a disc herniation that affects C8?
Finger flexion and abduction
What motor weakness would you expect with a disc herniation that affects L5?
Ankle dorsiflexion; great toe extension
What different things can cause radiculopathy?
Mechanical compression of nerve root:
- Neural ischemia, increased intraneural pressure
- Dura is mechanically sensitive
- Edema of nerve root, DRG
Biochemical irritation of nerve root:
- Nucleus pulposis contains cytokines, leukotrienes, Cox-2, interleukin-1, TNF-a
- Can cause apoptosis of DRG cells
What does the classical history of a cervical disc herniation look like?
- Numbness, tingling, weakness
- Worse with motion towards affected side
- Better lying down
What does the classical history of a lumbar disc herniation look like?
- Numbness/tingling/weakness
- Worse sitting, bending, coughing/sneezing
- Better standing, walking
Is disc herniation an upper or lower motor neuron deficit?
Lower – decreased or absent reflex of affected nerve
What is the treatment for disc herniation?
Activity modification - avoid bedrest
Pain meds: NSAIDs, neuromodulators (gabapentin, pregabalin), possible short course oral prednisone, limited opioids
Physical therapy
Epidural steroid injection – pain control
What are some indications for surgical treatment of disc herniation?
Progressive (or profound) weakness
Refractory symptoms
Bowel/bladder dysfunction
Myelopathy
What percentage of disc herniations improve without surgery?
70-85%
If there is a disc herniation at C6-C7, what level of spinal nerve is affected?
C7 – the spinal nerve associated is always the LOWER vertebrae
Case: 34 yo man with chronic back stiffness and pain that has been getting progressively worse over the past few years. Stiffness is worse in the morning and loosens up somewhat by mid-day, but he has difficulty getting up from a chair after prolonged sitting. Feels better when he exercises.
On examination reveals decreased range of back motion without any neurological deficits.
Ankylosing spondylitis
Earliest sign on lumbar x-ray would be sacroiliitis – see changes in SI joint, becomes sclerotic and somewaht irregular
Later on you start to see SI joint fusion (this is one of the only conditions that can fuse the SI joints)
Eventually see “Bamboo spine” – symmetric syndesmophytes bridging all vertebral bodies
Also ossification of the anterior, posterior and interspinous longitudinal ligaments
What is ankylosing spondylitis?
Does it effect males or females more?
What are some systemic effects?
It is a chronic inflammatory disease with progressive invovlement of sacroiliac and axial skeleton joints. Can get enthesitis, as well as chondritis and osteitis.
Affects more males than females in 3:1 ratio
Systemic effects: upper lobe interstitial lung fibrosis, iritis, CV abnormalities (aortitis, aortic insufficiency, cardiomegaly, conduction defects)
What are some lab test to run for ankylosing spondylitis?
Elevated C-reactive protein, sedimentation rate.
90% HLA-B27 positive (but just because you have this doesn’t mean you WILL get ankylosing spondylitis)
What are some treatment options for ankylosing spondylitis?
- NSAIDs: often provide marked relief
- Physical therapy: emphasis on ROM, spine exercises
- Anti-TNF-a agents if severe, refractory to NSAIDs
What is the difference between spondylolysis and spondylolisthesis?
Spondylolysis: can be congenital or acquired, stress fx of lamina with NO slippage of adjacent articulating vertebrae (commonly at L5-S1 site). Radiographic appearance of “Scottie dog” with collar
Spondylolisthesis: is a bilateral defect with anterior displacement of the L5 body and transverse process, the posterior fragment remains in proper alignment over the sacrum (S1). Radiographic appearance of Scottie dog with broken neck.
Case: 59 yo female with low back ache for several months limiting standing and walking. No injury or trauma. No pain sitting.
Central, low midline lumbar pain
No lower extremitiy referral, numbness/tingling, weakness
Facet joint arthropathy
Hx: axial low back pain, gradual onset
Cervial: worse with cervical extension
Lumbar: worse standing/walking, better sitting/lying
What causes facet joint arthropathy?
Gradual degenerative changes/osteoarthritis to zygoapophyseal facet joints
More common > 55 yo
What is the treatment for facet joint arthropathy?
Imaging: NONE or plain lumbar x-rays
NSAIDs, mild analgesics
Physical therapy (flexion bias)
Consider facent joint steroid injections if refractory
Case: 77 yo male with 1 year of low back pain.
Pain is intermittent, with pain down both legs to the ankles walking more than 1/4 mile. Pain resolves with sitting, and no pain in bed.
No numbness/tingling or weakness.
Exam normal, except for reduced lumbar ROM (painfree) and mildly decresed achilles reflex bilaterally
Most likely lumbar stenosis
History: slowly progressive pain in back – unilateral or bilateral legs
Worse: standing/walking
Relieved with lumbar flexion, sitting (different from peripheral vascular disease – must flex lumbar spine, cycling OK)
In exam: check pulses to R/O PVD
What caues lumbar stenosis?
Narrowing of the spinal canal by disc, osseous thickening of bone, facet joints, spondylolisthesis, lickening of ligamentum flavum
What is the treatment for lumbar stenosis?
- Physical therapy
- Gait aid – walker facilitates mild flexion (shopping cart sign)
- NSAIDs, neuromodulators
- Epidural steroids
- Surgical txt if intolerable pain and lifestye restriction despite non-operative treatment
- Lumbar laminectomy can decompress and open up the canal
Case: 65 yo healthy female with 2 weeks of severe low back pain after playing vigorously with her grandchildren.
No leg papin or numbness/tingling
Other than her age, no red flags
Exam with local tenderness in upper lumbar region
X rays show compression fracture – vertebral body loses height
What is the most common underlying condition that predisposes to developing a compression fracture?
Osteoporosis
What causes compression fractures?
Majority in people with osteoporosis
Assoc with prolonged corticosteroid use
In younger patients (<55 yo), consider underlying malignancy such as multiple myeloma
At least 1/3 asymptomatic
How do compression fractures usually present?
Usually sudden onset of thoracic or lumbar pain
Can be related to trauma, fall or heavy exertion
Often little or no trauma
Worse with flexion, movement
Better with rest
Usually no leg pain
On exam: local tenderness, painful lumbar ROM (especially flexion), normal neuro exam unless nerve affected
What is the treatment for compression fracture?
Imaging: plain x-rays, consider MRI or CT
If malignancy suspected: get CBC, SPEP (multiple myeloma), alk phos, ESR
NSAIDs, acetaminophen, calcitonin, mild opioids
Consider bracing for 6 wks
Osteoporosis workup if no prior diagnosis
Case: 36 yo executive chef with a h/o chronic low back pain. 1 wk ago with increased LBP and new right > left posterior thigh and calf pain after a long flight
4 day sago awoke on return flight wtih escalation of back and leg pain, saddle anesthesia which persists
He reports 1 episode of bowel incontinence, difficulty emptying his bladder, and leg weakness
Cauda equina syndrome
Caused by large herniated disc compressing cauda equina (could also be epidural tumor, abscess or hematoma)
On exam: reduced or absent reflexes, weakness, decreased rectal tone
Treament: surgical emergency
Case: 74 yo with gradual progression of walking funny
Notes 4 falls in the past month d/t losing balance, difficulty with buttoning his shirt and pants
Exam: hyperreflexia at triceps, patellas, and Achilles, positive Hoffman’s and Babinski, mild weakness of hand intrinsics and diffuse in legs, wide based gait with poor balance
Cervical Myelopathy
Typically > 50 yo
Subtle and varied presentation which requires a high index of suspicion
Loss of fine motor skills/hand clumsiness
Gait disturbance
B/B dysfunction
Motor weakness
LE numbness, weakness, pain
Symptoms may be attributed to old age
What causes cervical myelopathy?
Spinal cord compression, usually gradual progression due to posterior osteophyte formation, spinal stenosis
Can also occur d/t tumor, abscess, hematoma, or other cord compression
What is the treatment for cervical myelopathy?
Surgical treatment almost always indicated – cervical decompression (laminectomy); May not correct the neuro deficies, but will prevent progression
Typically no role for non-operative treatment unless not a surgical candidate d/t comorbidities
