Spinal Cord Syndromes B&B

Question 1

what type of virus is polio, and to which part of the spinal cord does it cause destruction?

Answer 1

ssRNA virus

destruction of anterior horn —> LMN lesion —> flaccid paralysis

Question 2

unvaccinated child with febrile illness presenting with neuro symptoms 4-5 days later as weakness preferentially in legs>arms and flaccid muscle tone

what are you thinking

Answer 2

polio: ssRNA virus, destruction of anterior horn (LMN) —> flaccid paralysis

Question 3

Werdnig-Hoffman Disease

Answer 3

spinal muscle atrophy disease presenting with hypotonia/weakness in newborn (“floppy baby”) and tongue fasciculations

genetic condition with similar lesion to polio (anterior horn - LMN lesion), death within a few months

Question 4

genetic spinal muscle atrophy disease presenting with hypotonia/weakness in newborn (“floppy baby”) and tongue fasciculations

Answer 4

Werdnig-Hoffman Disease

similar lesion to polio (anterior horn - LMN lesion), death within a few months

Question 5

polio vs Werdnig-Hoffman Disease

Answer 5

polio: ssRNA virus, destruction of anterior horn —> LMN lesion —> flaccid paralysis

Werdnig-Hoffman Disease: genetic spinal muscle atrophy disease presenting with hypotonia/weakness in newborn (“floppy baby”) and tongue fasciculations, similar lesion to polio (anterior horn - LMN lesion), death within a few months

Question 6

how does multiple sclerosis affect the spinal cord?

Answer 6

random, asymmetrical lesions of cervical white matter (demyelinating disease)

relapsing, remitting pattern, most often affects women

Question 7

how does amyotrophic lateral sclerosis (ALS) affect the spinal cord? (aka Lou Gehrig’s disease)

Answer 7

combined UMN and LMN disease of unknown cause - lesions of anterior horns (LMN) and lateral corticospinal/corticobulbar tracts (UMN) - degeneration, but NOT demyelination

upper symptoms: spasticity, hyperreflexia
lower symptoms: wasting, fasciculations

no sensory symptoms

Question 8

describe the symptoms of amyotrophic lateral sclerosis (ALS, aka Lou Gehrig’s disease)

Answer 8

combined UMN and LMN disease of unknown cause - lesions of anterior horns (LMN) and lateral corticospinal tracts (UMN)

upper symptoms: spasticity, hyperreflexia
lower symptoms: wasting, fasciculations

cranial nerves may be involved —> dysphagia (may lead to need for feeding tube)

no sensory symptoms

initial symptoms usually in limbs, asymmetric distribution

Question 9

describe the prognosis of amyotrophic lateral sclerosis (ALS). what is the most common cause of death in patients with ALS?

Answer 9

ALS: combined UMN and LMN disease of unknown cause - lesions of anterior horns (LMN) and lateral corticospinal tracts (UMN)

most common 40-60yo, fatal 3-5 years most commonly by aspiration pneumonia (respiratory dysfunction)

Question 10

what are the only 2 FDA approved drug for amyotrophic lateral sclerosis (ALS)?

Answer 10

ALS: combined UMN and LMN disease of unknown cause - lesions of anterior horns (LMN) and lateral corticospinal tracts (UMN)

1. riluzole: decreases glutamate release from neurons, but only increases survival by a few months
2. edaravone: free-radical scavenger, prevents functional deterioration

Question 11

what is the cause of familial amyotrophic lateral sclerosis (ALS)?

Answer 11

ALS: combined UMN and LMN disease of unknown cause - lesions of anterior horns (LMN) and lateral corticospinal tracts (UMN)

familial ALS - autosomal dominant, due to zinc copper superoxide dismutase deficiency, SOD1 (free radical scavenger)

Question 12

Pt is a 50yo M presenting with slowly worsening arm weakness and dysphagia to solids and liquids. On PE, some muscles appear flaccid while others appear spastic. However, sensation is intact. What is the diagnosis?

Answer 12

amyotrophic lateral sclerosis (ALS): combined UMN and LMN disease of unknown cause - lesions of anterior horns (LMN) and lateral corticospinal tracts (UMN)

upper symptoms: spasticity, hyperreflexia
lower symptoms: wasting, fasciculations

no sensory symptoms

Question 13

what occurs in ASA occlusion?

Answer 13

anterior spinal artery occlusion = stroke of the spinal cord —> loss of all but posterior columns (these have separate blood supply)

acute onset (stroke) of flaccid or spastic bilateral paralysis (loss of LMN) below the lesion

vibration and proprioception remain intact (posterior columns)

Question 14

what type of nerve function remains INTACT following ASA occlusion?

Answer 14

anterior spinal artery occlusion = stroke of the spinal cord —> loss of all but posterior columns (these have separate blood supply)

acute onset (stroke) of flaccid or spastic bilateral paralysis (loss of LMN) below the lesion

vibration and proprioception remain intact (posterior columns)

Question 15

Pt presents to ED with acute onset of flaccid bilateral paralysis. Vibration and proprioception remain intact. What is the most likely cause?

Answer 15

anterior spinal artery (ASA) occlusion = stroke of the spinal cord —> loss of all but posterior columns (these have separate blood supply)

acute onset (stroke) of flaccid or spastic bilateral paralysis (loss of LMN) below the lesion

vibration and proprioception remain intact (posterior columns)

Question 16

what is the cause of tabes dorsalis?

Answer 16

tertiary syphilis —> demyelination of the posterior columns of spinal cord + loss of dorsal roots

ataxia (loss of posterior column) + loss of reflexes (dorsal roots)

motor function is not affected

Question 17

demyelination of the posterior columns of the spinal cord + loss of dorsal roots caused by tertiary syphilis

Answer 17

tabes dorsalis: ataxia (loss of posterior column) + loss of reflexes (dorsal roots)

motor function is not affected

Question 18

Pt is a 37yo F with PMH of STD presenting with difficulty walking and fleeting, recurrent shooting pains in the legs. PE reveals a wide-based gait, loss of ankle and knee reflexes, positive Romberg sign, and Argyll Robertson pupils. However, strength in arms and legs is 5/5. What is the most likely cause?

Answer 18

tabes dorsalis: tertiary syphilis —> demyelination of the posterior columns of spinal cord + loss of dorsal roots

ataxia (loss of posterior column) + loss of reflexes (dorsal roots)

motor function is not affected

+Romberg = no proprioception
Argyll Robertson pupils: don’t react to light but can follow finger

Question 19

syringomyelia

Answer 19

fluid-filled space in spinal canal, which compresses/damages spinothalamic nerves crossing through the center —> bilateral loss of pain/temp (only at the level of the syrinx)

can expand to anterior horn (LMN), lateral (sympathetics —> Horner’s), and can cause kyphoscoliosis (spine curve)

usually C8-T1 (arms/hands)

Question 20

which nerves of the spinal cord are primarily involved in syringomyelia?

Answer 20

fluid-filled space in spinal canal, which compresses/damages spinothalamic nerves crossing through the center —> bilateral loss of pain/temp (only at the level of the syrinx)

can expand to anterior horn (LMN), lateral (sympathetics —> Horner’s), and can cause kyphoscoliosis (spine curve)

usually C8-T1 (arms/hands)

Question 21

what segment of the spinal cord is most often involved in syringomyelia?

Answer 21

fluid-filled space in spinal canal, which compresses/damages spinothalamic nerves crossing through the center —> bilateral loss of pain/temp (only at the level of the syrinx)

can expand to anterior horn (LMN), lateral (sympathetics —> Horner’s), and can cause kyphoscoliosis (spine curve)

usually C8-T1 (arms/hands)

Question 22

with what congenital malformations is syringomyelia strongly associated?

Answer 22

Chiari malformations: lower part of brain presses on and through an opening in the base of the skull and cerebellum into the spinal canal

fluid-filled space in spinal canal, which compresses/damages spinothalamic nerves crossing through the center —> bilateral loss of pain/temp

usually C8-T1 (arms/hands)

Question 23

Pt is presenting to their GP with complaint of numbness in their arms and hands. PMH is significant for a spinal cord injury 5y ago. They have cuts and burns on their hands that they report they did not feel. PE reveals loss of pinprick and temp in back, shoulders, and arms. What is the most likely diagnosis?

Answer 23

syringomyelia: fluid-filled space in spinal canal, which compresses/damages spinothalamic nerves crossing through the center —> bilateral loss of pain/temp (only at level of syrinx)

can expand to anterior horn (LMN), lateral (sympathetics —> Horner’s), and can cause kyphoscoliosis (spine curve)

usually C8-T1 (arms/hands)

Question 24

what is the cause of subacute combined demyelination (SCD)?

Answer 24

B12 deficiency

causes demyelination of the posterior columns (vibr/proprio) + loss of lateral motor tracts

—> slowly progressive weakness + ataxia

Question 25

demyelination of the posterior spinal columns + loss of lateral motor tracts caused by B12 deficiency

Answer 25

subacute combined demyelination (SCD): causes demyelination of the posterior columns (vibr/proprio) + loss of lateral motor tracts

—> slowly progressive weakness + ataxia

Question 26

which spinal tracts are affected by subacute combined demyelination (SCD)?

Answer 26

B12 deficiency causes demyelination of the posterior columns (vibr/proprio) + loss of lateral motor tracts

—> slowly progressive weakness + ataxia

Question 27

Pt presents to their GP with complaint of trouble walking and spastic paresis in their legs that has slowly gotten worse. PE reveals a positive Romberg sign, lower extremity hyperreflexia, and a positive Babinski sign. What is the most likely diagnosis?

Answer 27

subacute combined demyelination (SCD): B12 deficiency causes demyelination of the posterior columns (vibr/proprio) + loss of lateral motor tracts

—> slowly progressive weakness + ataxia

Question 28

Brown-Sequard Syndrome

Answer 28

loss of half of spinal cord due to trauma (gunshot) or tumor, symptoms below lesion:

—> loss of pain/temp on contralateral side (cannot cross)
—> loss of position/vibration on ipsilateral side (cannot ascend)
—> loss of motor on ipsilateral side that presents with LMN symptoms at the level of lesion, but UMN below the level of lesion

Question 29

how are the spinal column tracts affected by Brown-Sequard Syndrome? (3)

Answer 29

loss of half of spinal cord due to trauma (gunshot) or tumor, symptoms below lesion:

1. loss of pain/temp on contralateral side (cannot cross)
2. loss of position/vibration on ipsilateral side (cannot ascend)
3. loss of motor on ipsilateral side that presents with LMN symptoms at the level of lesion, but UMN below the level of lesion

Question 30

describe how motor innervation is disrupted at the level of lesion and below the level of lesion in Brown-Sequard syndrome

Answer 30

loss of half of spinal cord due to trauma (gunshot) or tumor

—> loss of pain/temp on contralateral side (cannot cross)
—> loss of position/vibration on ipsilateral side (cannot ascend)

—> loss of motor on ipsilateral side that presents with LMN symptoms at the level of lesion, but UMN below the level of lesion

Question 31

Pt presents to the ED following gunshot wound and it is determined he has Brown-Sequard syndrome. If weakness is felt on the left side of the body, which side of the spinal cord is lesioned?

Answer 31

loss of half of spinal cord due to trauma (gunshot) or tumor

—> loss of pain/temp on contralateral side below lesion (cannot cross)
—> loss of position/vibration on ipsilateral side below lesion (cannot ascend)
—> loss of motor on ipsilateral side that presents with LMN symptoms at the level of lesion, but UMN below the level of lesion

so, weak side = side with lesion

Question 32

what are 3 potential causes of cauda equina syndrome?

Answer 32

aka compression of cauda equina

1. massive disk rupture
2. trauma
3. tumor

Question 33

how does cauda equina syndrome present?

Answer 33

aka compression of cauda equina

presents with severe low back pain, “saddle anesthesia” (numb over butt and posterior inner thighs), loss of anocutaneous reflex, bowel/bladder dysfunction

normal Babinski sign bc cauda equina is technically peripheral nerves —> LMN findings (not UMN)

Question 34

describe the common presentations of multiple sclerosis (4)

Answer 34

1. optic neuritis: unilateral blurred vision, eye pain, color desaturation
2. transverse myelitis: weakness, numbness, urinary difficulty
3. cerebellar: ataxia, dysmetria, nystagmus, scanning speech
4. brainstem: diplopia, facial weakness/numbness, hearing loss

symptoms may be worse with heat (Uhtoff’s phenomenon), shooting pains with neck flexion (Lhermitte’s sign), tonic spasms throughout the day

Question 35

Pt presents to your neurology clinic complaining of new onset of recurrent brief spasms throughout the day. They also report shooting pain when flexing their neck forward. By mid-afternoon, they feel exhausted despite plenty of sleep. They state the symptoms have been worse on hot days. What are you concerned about, and what other clinical findings are you on the lookout for? (4)

Answer 35

multiple sclerosis

1. optic neuritis: unilateral blurred vision, eye pain, color desaturation
2. transverse myelitis: weakness, numbness, urinary difficulty
3. cerebellar: ataxia, dysmetria, nystagmus, scanning speech
4. brainstem: diplopia, facial weakness/numbness, hearing loss

symptoms may be worse with heat (Uhtoff’s phenomenon), shooting pains with neck flexion (Lhermitte’s sign), tonic spasms throughout the day

Question 36

what are the 4 subtypes of multiple sclerosis?

Answer 36

1. relapsing-remitting
2. relapsing-remitting followed by secondary-progressive
3. progressive-relapsing
4. primary-progressive (linear increase in symptoms)

Question 37

describe the [hypothesis of] pathophysiology of multiple sclerosis

Answer 37

“outside-in hypothesis”: auto reactive T cells cross into CNS, trigger immune-mediated destruction of myelin

biopsy shows white matter plaques

Question 38

what does biopsy and histology show, respectively, in multiple sclerosis?

Answer 38

biopsy: white matter plaques

histology: perivascular lymphocytes in active MS plaques

Question 39

how is multiple sclerosis diagnosed (aside from clinical presentation/ history)?

Answer 39

contrast enhanced MRI: distinctive lesion pattern, enhancing lesions = recent/active, 3+ lesions = 80% relapse risk

CSF tap: presence of oligoclonal bands (OCB) doubles attack risk

serum studies: evaluate for mimicking disorders (of which there are many!)

Question 40

how are acute multiple sclerosis relapses typically treated? (4)

Answer 40

1. high dose IV steroids: methylprednisolone IV for 5 days
2. intramuscular ACTH
3. IV immunoglobin
4. plasma exchange

these do not prevent future attacks or disease progression, only treat current symptoms

Question 41

what is the mechanism and clinical use of natalizumab?

Answer 41

infusion disease-modifying therapy for multiple sclerosis (very effective!!)

mAb against alpha-4 integrin, preventing its interaction with VCAM-1 and subsequent T-cells from entering CNS

note: progressive multifocal leukoencephalopathy (PML) is rare but devastating side effect

Question 42

Acute Disseminated Encephalomyelitis (ADEM)

Answer 42

often a monophasic post-viral demyelinating disease, treated with steroids

mimics MS, could be first (presenting) attack of multiple sclerosis

Question 43

Neuromyelitis optica spectrum disorder (NMOSD)

Answer 43

Recurrent episodes of optic neuritis and/or transverse myelitis

labs show specific anti-aquaporin 4 antibody

can mimic multiple sclerosis