Levin - Myelopathy Flashcards
What is a myelopathy?
Any disease that affects the spinal cord
Briefly describe the anatomy of the spinal cord. You should be esp. worried if pt points where in the spinal cord when asked where it hurts?
- Spinal cord ends at L1-L2; spinal taps done between L4 and S1
- More back pain is lumbar; if pt points to thoracic area, you should be worred bc bad things happen there
What are the 5 divisions within the spinal cord Dr. Levin wants us to know? What happens in case of a lesion to these areas?
- Lancinating = piercing, stabbing
- REMEMBER: spinothalamic tract crosses w/in spinal cord; all other tracts stay ipsilateral until brainstem
Describe the structure of the spinal cord from most interior to most exterior. Terms?
- Spinal cord itself: parenchyma = intramedullary
- Pia mater
- Subarachnoid space = leptomeningeal (pia + subA space)
- Subdural space (aka, intradural)
- Dura
- Epidural space: fat is in here (aka, extradural)
- Bone: vertebral body
How do the spinal cord and CSF appear on MRI?
- CSF is white
- Spinal cord gray/black
- NOTE: attached image shows cervical spinal cord
What part of the spine is this?
Thoracic
What part of the spine is this?
Lumbar (conus usually ends at L1-2)
What is a sensory level? List some common sensory dermatomes in spinal cord lesions.
- Sensory level = pt cannot feel at or below this level
- T4 = nipple line
- T10 = umbilicus
How might a spinal cord lesion affect the bladder?
- Sphincter dysfunction is COMMON in spinal cord lesions
- Micturition is a complex process, ultimately controlled by the CNS (brain + spinal cord) -> long axons from frontal lobe of brain synapse in thoracic and sacral cord
1. These tracts are very vulnerable to injury in severe spinal cord lesions
How is bladder dysfunction different acutely vs. chronically in spinal cord lesions?
- ACUTE: urinary retention with some overflow incontinence
- CHRONIC: small, spastic bladder that does not completely empty with spasms and urge incontinence
How should you approach the pt with acute/subacute myelopathy?
- Acute and subacute myelopathies are NEURO EMERGENCIES that require IMMEDIATE ATTENTION:
1. Recognize signs and symptoms
2. Immediate neuro-radiologic testing
3. Other dx tests, depending on clinical picture
4. LP may be needed, esp. if neuro-radiologic testing is negative
5. Therapy is usually IV STEROIDS
How should you approach the pt with chronic myelopathy?
- Recognize signs and symptoms
- Neuroradiologic testing almost always done to rule out compressive myelopathies
- Other dx tests, depending on clinical picture
- LP may be needed, esp. if neuroradiologic testings is negative
- Therapy directly related to cause of the myelopathy
What are the important elements of the hx and PE for a pt presenting with myelopathy?
- HISTORY: other illnesses, fever, location of pain, neuro symptoms, pace of symptoms (pt can become paralyzed in matter of minutes)
- PHYSICAL EXAM:
1. GENERAL: fever, “show me where it hurts,” check for vertebral body tenderness - NEURO: motor strength and tone, sensory pain and vibration, reflexes (incl. Babinski), and gait (make pt get out of chair w/o using arms and walk)
What is the first step in the progression of an epidural spinal cord lesion?
- Early symptoms include:
1. Numbness or allodynia (hyper-sensitivity to touch) ipsilateral (dorsal root compression); band or girdle-like sensation in abdomen
2. Subtle changes in sensory symptoms on the contralateral lower extremity (spinothalamic)
3. Motor symptoms (compression of corticospinal tract): pt may not be weak early on, but there will be neuro signs, incl. hyper-reflexia, (+) Babinski, and difficulty walking
4. Urinary urgency is COMMON (don’t forget to ask, even though pt may be embarrassed and lie)
What is the second step in the progression of an epidural spinal cord lesion?
- MOTOR: in addition to spasticity, hyper-reflexia (brisk reflexes), and Babinski, legs are weak
- SENSORY: worse -> numbness shown in image (root area totally numb), pain in contralateral LE DEC
- BLADDER: definite sphincter dysfunction and may include bowel dysfunction
- NOTE: may appear as partial Brown-Sequard hemi-cord syndrome w/weakness and numbness to touch and vibration on ipsilateral side AND loss of pain on contralateral side (spinothalamic tract crosses over)
What is the third step in the progression of an epidural spinal cord lesion?
- Full-blown spinal cord compression
- If slow and CHRONIC, there will be spastic paresis with a definite sensory level to all modalities
- If ACUTE or hyper-acute, so much damage that spinal cord shock occurs -> flaccid, areflexic paraplegia (trunk, legs, pelvis) w/complete sensory level to all modalities
- REMEMBER: all of this may occur over hours - days
What are some causes of myelopathy in the extradural, intradural extramedullary, and intramedullary spaces?
- EXTRADURAL: disc disease, metastatic tumor, abscess
- INTRADURAL EXTRAMEDULLARY: neurinoma, meningioma
- INTRAMEDULLARY: syringomyelia, glioma, myelitis
What is disc disease? Tx?
- Severe disc disease (i.e., herniated or degenerative disc) in cervical or thoracic cord can cause epidural cord compression and myelopathy
- TX: steroids and surgery
- IMAGE: arrows show multiple discs compressing spinal cord and arrowheads show hyper-intense lesions in spinal cord parenchyma -> this is edema associated w/compression
What kind of damage can spinal cord trauma cause?
- Paraparesis (partial)/paraplegia (complete)
- Quadriparesis/quadriplegia
- Vertebral body compression
- Hematoma
- Spinal cord infarct
- Cord transection
- IMAGE: vertebral body fracture w/acute spinal cord compression -> pt may present w/spinal cord shock due to acuity of lesion
1. This may result in spinal cord infarct or cord transection
What are the common cancers that met to the spine? Presentation?
- Epidural compression: cancer enters vertebral body, weakens it, expands, then compresses spinal cord
- Most common are LUNG, BREAST, PROSTATE
How should you approach the cancer pt with back pain (flow chart)?
- Most docs no longer use plain spine x-rays
- If clinically suspicious of spinal cord compression, tx with steroids (dexamethasone) first, arrange for spinal MRI with gadolinium, and follow pt slowly
1. Neurosurgical consult required in case surgical decompression needed - If work-up negative, cancer cells can still enter sub-arachnoid space and cause meningitis or spinal cord injury -> spinal tap necessary if no evidence of spinal cord compression by imaging
- CT myelograms rarely done bc MRI sensitive and non-invasive
- NOTE: particularly for back pain in thoracic region; ESCC = epidural spinal cord compression
Where do most spinal abscesses occur? Most common infection? Test of choice?
- Most spinal abscesses begin in DISC SPACE, then devo into abscess and expand to cause spinal compression
1. Contrast this to metastatic cancer, most of which begins in the vertebral body - Most common infection is S. AUREUS
- MRI of the spine is test of choice
What are the signs, symptoms, risk factors, and sources of infection in pts w/epidural abscesses?
- SIGNS/SYMPTOMS: fever, pain on percussion
1. Elevated white count
2. Elevated ESR - RISK FACTORS: IV drug use, HIV, immunosuppression
- SOURCES: hematogenous or direct (see image)
What is osteomyelitis? Sequelae? What might it look like on an MRI?
- Osteomyelitis = infarction of vertebral bodies
- Causes weakness of bones, collapse of vertebral body, and subsequent cord compression as shown in the attached image
1. Note the irregular vertebral body end plates on the left (large arrow); marrow also enhanced on right image (small arrows)
What is Pott’s disease?
- Neuro syndrome of osteomyelitis resulting from TB infection
What is a spinal meningioma? Where is it? Imaging findings? Clinical clue?
- 90% are intradural, extramedullary; most commonly in thoracic spine
- Most typical benign meningiomas (2nd most common cause of spinal tumor)
- Classic pt is middle-aged woman
- IMAGING: bone erosion (calcification rare), most isointense w/cord on T1 and T2WI, moderate contrast enhancement, +/- dural “tail” (thickening, enhancement of dura)
- CLINICAL CLUE: while occasional benign herniated disc can occur in thoracic spine, most diseases of THORACIC SPINE are BAD
What are nerve sheath tumors? Types? Symptoms? Imaging?
- Most common intradural extramedullary mass
- TYPES: schwannoma, neurofibroma (multiple lesions common), ganglioneuroma, neurofibrosarcoma (rare)
- 1o seen in middle-aged adults
- Variable LOCATION: intradural extramedullary (75%), dumbbell (15%), extradural (15%), intramedullary (<1%)
1. While dumbbell shape is not very common, it is CLASSIC -> usually one of these tumors - Clinical SYMPTOMS can mimic disc herniation
- IMAGING: enlarged neural foramen common (Ca rare), 75% isointense, 25% hyper on T1WI, >95% hyperintense on T2WI (“target” appearance” common)
1. Virtually 100% enhance
What is the first step in the progression of a central cord lesion?
- Begins w/pain in shoulders (cervical lesion)
- Loss of pain and temp are EARLY signs bc spinothalamic fibers cross in center of cord
- Loss of sensation across torso shown in image is common
- NOTE: most of these syndromes are not perfect; you will see partial syndroems that indicate intramedullary (w/in spinal parenchyma) lesion/disease process
What is the second step in the progression of a central cord lesion?
- Interruption of dorsal root entry zone of afferent arc of reflexes = loss of reflex in arms at area of lesion
- Continued loss of pain and temp
- Involvement of SYM pathways = Horner’s syndrome (ptosis + miosis)
- Posterior columns spared until late, so vibration and joint position sense preserved compared to pain/temp
1. DISSOCIATED SENSORY LEVEL - Below lesion, involvement of corticospinal pathways results in paraparesis, hyper-reflexia, Babinski
What is the third step in the progression of a central cord lesion?
- All features worsen
- There may be SACRAL SPARING bc these fibers are most lateral = furthest away from central cord and thus not damaged
1. Sacral dermatomes will maintain normal sensation - May involve face due to sensory (spinal) nucleus of trigeminal
What is the classic lesion that presents with central cord syndrome?
- Syringomyelia: syrinx (large, expanding space in spinal cord)
1. Can be result of trauma or tumor (astrocytoma in attached image -> multisegmental enlargement characteristic) - Note how each tract results in pt’s symptoms
What do you see here?
- ASTROCYTOMA: large arrows indicate tumor (lobulated, somewhat heterogeneous hyperintense mass)
1. Enhancement with gadolinium in image on left, and large amt of edema on right
How can vascular disease affect the spinal cord (table)?
- Aneurysm, AVM, infarcts less common than in brain
- REMEMBER: Adamkiewicz and spinal aa provide most blood supply
What are the features of anterior spinal artery syndrome?
- Anterior 2/3 of spinal cord supplied by artery of Adamkiewicz = great radicular artery (mid-thoracic region)
- These pts will have symptoms referable to spinothalamic (loss of pain/temp, sensory level), corticospinal function (weakness), but INTACT POSTERIOR COLUMN FUNCTION (vibration and joint/position sense)
One more time: features of anterior spinal artery syndrome (image).
What are the features of Brown-Sequard hemi-section syndrome?
- Rare: stab wound, sometimes seen in myelitis (more common to see these in a partial form, i.e., only weakness + loss of pain/temp)
- Ipsilateral (to lesion) spastic paralysis (after spinal shock) below level of lesion, hyper-reflexia, and Babinski signs
- Ipsilateral loss of vibration and position sense
- Contralateral loss of pain and temp
- NOTE: if you see this at the bedside, you can be 100% certain you are dealing w/a spinal cord lesion, which may be a neuro emergency
What are the features of subacute combined degeneration of the spinal cord?
- B12 deficiency, pernicious anemia
- Spastic weakness of lower extremities (corticospinal) + DEC sensation to vibration and position (post column) -> subacute combined (2 tract systems)
- (+) Romberg’s sign, Babinski signs, hyperreflexia
- Non-cerebellar ataxia
- May also cause peripheral neuropathy (mixed signs) and dementia
- TX is IM B12 injections
- NOTE: this myelopathy is neither infiltrative nor compressive (and many of these are reversible) -> part of DDc for spinal cord disease
One more time: features of subacute combined degeneration syndrome (image).
What is this? Features?
- Vacuolar myelopathy: neuro complication of HIV infection -> usually late with AIDS
- Progressive spastic paraparesis: hyperreflexia, extensor plantar responses
- Sensory ataxia and incontinence
- Vacuolation and myelin pallor (posterior and lateral columns; see attached MRI hyperintensity in post column)
- Resembles B12 deficiency
What is tabes dorsalis?
- One complication of neurosyphilis
- Posterior column dysfunction = loss of vibration and joint position sense
- (+) Romberg sign
What is Horner’s syndrome (image)?
