CHAPTER 8

Question 1

Neuropathologic examination of the spinal
cord reveals two lesions labeled A and B. Lesion A is restricted to five segments.

1. The result of lesion A is best described as
   (A) bilateral arm dystaxia with dysdiado-chokinesia
   (B) spastic paresis of the legs
   (C) flaccid paralysis of the upper extremities
   (D) loss of pain and temperature sensation
   below the lesion
   (E) urinary and fecal incontinence

Answer 1

1- C. Lesion A involves degeneration of the ventral horns bilaterally at midcervical levels, re-
sulting in flaccid paralysis in the upper extremities.

Question 2

2. The result of lesion B is best described as

(A) dyssynergia of movements affecting both
arms and legs
(B) flaccid paralysis of the upper extremities
(C) impaired two-point tactile discrimination
in both arms
(D) spastic paresis affecting primarily the
muscles distal to the knee joint
(E) bilateral appallesthesia

Answer 2

2- D. Lesion B involves degeneration of the lateral corticospinal tracts bilaterally, resulting in
spastic paresis of the lower extremities and primarily affecting the muscles distal to the knee.
Spastic paresis of the upper extremities is masked by flaccid paralysis resulting from lesion A.
Apallesthesia is the inability to perceive a vibrating tuning fork.

Question 3

3. Lesions A and B result from

(A) an intramedullary tumor
(B) an extramedullary tumor
(C) thrombosis of a spinal artery
(D) multiple sclerosis
(E) amyotrophic lateral sclerosis (ALS)

Answer 3

3- E. Lesions A and B are the result of amyotrophic lateral sclerosis (ALS), a pure motor disease

Question 4

4. Neurologic examination reveals an extensor
   plantar reflex on the left side, hyperreflexia on
   the left side, a loss of pain and temperature
   sensation on the right side, and ptosis and mio-
   sis on the left side. A lesion that causes this
   constellation of deficits would most likely be
   found in the

(A) paracentral lobule, left side
(B) crus cerebri, right side
(C) dorsolateral medulla, left side
(D) cervical spinal cord
(E) lumbar spinal cord

Answer 4

4- D. A lesion of the cervical spinal cord could result in ipsilateral Horner syndrome, ipsilateral
spastic paresis, and contralateral loss of pain and temperature sensation. Horner syndrome is
always manifested on the ipsilateral side. This lesion represents a classic Brown-Sequard syn-
drome.

Question 5

5. A 50-year-old woman complains of clumsi-
   ness in her hands while working in the
   kitchen; she recently burnt her hands on the
   stove without experiencing any pain. Neuro-
   logic examination reveals bilateral weakness
   of the shoulder girdles, arms, and hands, as
   well as a loss of pain and temperature sensa-
   tion covering the shoulder and upper extrem-
   ity in a cape-like distribution. Severe atrophy
   is present in the intrinsic muscles of the hands.
   The most likely diagnosis is

(A) amyotrophic lateral sclerosis (ALS)
(B) subacute combined degeneration
(C) Werdnig-Hoffmann disease
(D) syringomyelia
(E) tabes dorsalis

Answer 5

5- D. Syringomyelia is a cavitation of the spinal cord most commonly seen in the cervicothoracic
segments. This condition results in bilateral loss of pain and temperature sensation in a cape-
like distribution as well as wasting of the intrinsic muscles of the hands. Amyotrophic lateral
sclerosis (ALS) is a pure motor syndrome, subacute combined degeneration includes both sen-
sory and motor deficits, Werdnig-Hoffmann disease is a pure motor disease, and tabes dorsalis
is a pure sensory syndrome (neurosyphilis).

Question 6

6. A 50-year-old man has a 2-year history of
   progressive muscle weakness in all extremi-
   ties, with severe muscle atrophy and reduced
   muscle stretch reflexes (MSRs) in both legs. In
   his arms, the muscle atrophy is less pro-
   nounced and the MSRs are exaggerated. Post-
   mortem examination would most likely show
   which of the following areas of neuronal de-
   generation?

(A) Loss of Purkinje cells
(B) Loss of neurons from the globus pallidus
(C) Loss of neurons from the paracentral lob-
ule and from the anterior horns of the
spinal cord
(D) Demyelination of axons in the posterior
and lateral columns
(E) Demyelination of axons in the posterior
limb of the internal capsule

Answer 6

6- C. Amyotrophic lateral sclerosis (ALS) affects both the upper and lower motor neurons. It is
also referred to as motor systems disease. A loss of Purkinje cells as seen in cerebellar cortical
atrophy (cerebello-olivary atrophy) results in cerebellar signs. Cell loss in the globus pallidus and putamen is seen in Wilson disease (hepatolenticular degeneration). Demyelination of axons in
the posterior and lateral columns is seen in subacute combined degeneration. Demyelination of
axons in the posterior limb of the internal capsule results in contralateral spastic hemiparesis.

Question 7

7. All of the following statements concerning
   syringomyelia are correct EXCEPT

(A) it is a central cavitation of the spinal cord
(B) it usually is found at lumbosacral levels
(C) it usually includes a lower motor neuron
(LMN) lesion
(D) it usually results in a bilateral loss of pain
and temperature sensation
(E) it may result in Horner syndrome

Answer 7

7- B. Syringomyelia is a central cavitation of the cervical spinal cord and is of unknown etiology.
Expansion of the syrinx typically affects the ventral white commissure, interrupting the decus-
sating fibers of the spinothalamic tracts and resulting in a bilateral loss of pain and temperature sensation at the level of involvement. Lateral extension involves one or both of the ventral horns and results in a lower motor neuron (LMN) lesion with muscle wasting and flaccid paralysis. Caudal extension to (C8) T1-T2 may involve the lateral horn (ciliospinal center of Budge) and produce Horner syndrome.

Question 8

8. Hemisection of the spinal cord at Tl on the
   left side results in all of the following signs or
   symptoms EXCEPT

(A) plantar response flexor on the left side
(B) loss of vibration sensation in the left leg
(C) leg dystaxia on the right side
(D) exaggerated knee jerk reflex on the left
side
(E) normal pain and temperature sensation
on the left side

Answer 8

8- A. Hemisection of the spinal cord is known as Brown-Sequard syndrome. Transection of the
left lateral corticospinal tract would result in an extensor plantar response on the left side
(Babinski sign). Leg dystaxia on the right side results from interruption of the crossed ventral
spinocerebellar tract.

Question 9

9. Lower motor neuron (LMN) lesions result in
   all of the following deficits or signs EXCEPT
   (A) loss of muscle stretch reflexes (MSRs)
   (B) loss of superficial reflexes
   (C) fasciculations
   (D) muscle wasting
   (E) plantar reflex extensor

Answer 9

9- E. Lower motor neuron (LMN) lesions result from destruction of ventral horn (or cranial
nerve) motor neurons or transection of their axons. LMN lesions interrupt the final common
pathway to skeletal muscles; they result in flaccid paralysis and atrophy (muscle wasting) and a
loss of all reflex action (areflexia). Fasciculations (visible muscle twitching) and fibrillations [seen on an electromyogram (EMG)] are signs of LMN disease. The Babinski sign, an extensor plantar reflex, is not seen in LMN lesions.

Question 10

10. All of the following statements concerning
    upper motor neuron (UMN) lesions are correct
    EXCEPT

(A) they are found above the pyramidal de-
cussation
(B) they result in the presence of the Babin-
ski sign
(C) they result in the absence of the knee jerk
reflex
(D) they are commonly caused by cerebrovas-
cular accidents
(E) they frequently involve the internal cap-
sule

Answer 10

10- C. Upper motor neuron (UMN) lesions result from destruction of cortical neurons (or their
axons) that give rise to the corticospinal and corticobulbar tracts. UMNs are found in the cere-
bral cortex and in the brainstem. UMN lesions result in spastic paralysis (hyperreflexia, hyper-
tonia, clasp-knife phenomenon, clonus, muscle weakness, and the Babinski sign). UMN lesions
are commonly caused by cerebrovascular accidents and frequently damage the internal capsule

Question 11

11. All of the following statements concerning
    Horner syndrome are correct EXCEPT
    (A) it is seen in spinal cord lesions above Tl
    (B) it is ipsilateral to the lesion
    (C) it results from interruption of descending
    autonomic pathways
    (D) it results in mydriasis and mild ptosis
    (E) it results in facial hemianhidrosis

Answer 11

11- D. Interruption of descending autonomic pathways found in the lateral funiculi of the spinal
cord results in Horner syndrome. Horner syndrome is ipsilateral to the lesion and consists of miosis, ptosis, facial hemianhidrosis, and apparent enophthalmos.

Question 12

12. All of the following statements concerning
    intervertebral disk herniation are correct EXCEPT

(A) it results from prolapse of the nucleus pul-
posus through a defective annulus fibro-
sus into the vertebral canal
(B) it may involve the cauda equina
(C) it usually involves a single nerve root
(D) it most frequently appears in the L4-L5
interspace
(E) it usually results in urinary incontinence

Answer 12

12- E. Intervertebral disk herniation results from the prolapse of the nucleus pulposus through
a defective annulus fibrosus into the vertebral canal. In 90% of cases, it appears at the L4-L5 or
the L5—Si interspace. In 10% of cases, it appears at the cervical region, usually at the C5-C6 or
C6-C7 interspace. Intervertebral disk herniation may involve the cauda equina; usually it in-
volves a single nerve root. Urinary incontinence is not seen with unilateral root lesions.

Question 13

13. A pure lower motor neuron disease

(A) Amyotrophic lateral sclerosis (ALS)
(B) Cauda equina syndrome
(C) Cervical spondylosis
(D) Friedreich ataxia
(E) Guillain-Barre syndrome
(F) Multiple sclerosis
(G) Subacute combined degeneration
(H) Tabes dorsalis
(I) Werdnig-Hoffmann disease

Answer 13

13-I. Werdnig-Hoffmann disease is a heredofamilial degenerative disease of infants that affects
only lower motor neurons (LMNs).

Question 14

14. Elevated cerebrospinal fluid (CSF) protein
    with a normal CSF cell count

(A) Amyotrophic lateral sclerosis (ALS)
(B) Cauda equina syndrome
(C) Cervical spondylosis
(D) Friedreich ataxia
(E) Guillain-Barre syndrome
(F) Multiple sclerosis
(G) Subacute combined degeneration
(H) Tabes dorsalis
(I) Werdnig-Hoffmann disease

Answer 14

14- E. Guillain-Barre syndrome is characterized by an elevated cerebrospinal fluid (CSF) pro-
tein with normal CSF cell count (albuminocytologic dissociation).

Question 15

15. Characterized by asymmetric lesions found in the white matter of cervical segments

(A) Amyotrophic lateral sclerosis (ALS)
(B) Cauda equina syndrome
(C) Cervical spondylosis
(D) Friedreich ataxia
(E) Guillain-Barre syndrome
(F) Multiple sclerosis
(G) Subacute combined degeneration
(H) Tabes dorsalis
(I) Werdnig-Hoffmann disease

Answer 15

15- F. Multiple sclerosis is characterized by asymmetric lesions frequently found in the white
matter of cervical segments.

Question 16

16. May result from intervertebral disk herniation

(A) Amyotrophic lateral sclerosis (ALS)
(B) Cauda equina syndrome
(C) Cervical spondylosis
(D) Friedreich ataxia
(E) Guillain-Barre syndrome
(F) Multiple sclerosis
(G) Subacute combined degeneration
(H) Tabes dorsalis
(I) Werdnig-Hoffmann disease

Answer 16

16- B. The cauda equina syndrome frequently results from intervertebral disk herniation; se-
vere spontaneous radicular pain is common.

Question 17

17. Symptoms include a painful stiff neck,
    arm pain and weakness, spastic leg weakness
    with dystaxia; sensory disorders are frequent

(A) Amyotrophic lateral sclerosis (ALS)
(B) Cauda equina syndrome
(C) Cervical spondylosis
(D) Friedreich ataxia
(E) Guillain-Barre syndrome
(F) Multiple sclerosis
(G) Subacute combined degeneration
(H) Tabes dorsalis
(I) Werdnig-Hoffmann disease

Answer 17

17 -C. Cervical spondylosis is the most commonly observed myelopathy. Its symptoms include a
painful stiff neck, arm pain and weakness, and spastic leg weakness with dystaxia; sensory dis-
orders are frequent.

Question 18

18. Associated with a loss of Purkinje cells

(A) Amyotrophic lateral sclerosis (ALS)
(B) Cauda equina syndrome
(C) Cervical spondylosis
(D) Friedreich ataxia
(E) Guillain-Barre syndrome
(F) Multiple sclerosis
(G) Subacute combined degeneration
(H) Tabes dorsalis
(I) Werdnig-Hoffmann disease

Answer 18

18- D. Friedreich ataxia is the most common hereditary ataxia with autosomal recessive inher-
itance. Dorsal columns, spinocerebellar tracts, and the corticospinal tracts show demyelination.
Friedreich ataxia results in a loss of Purkinje cells in the cerebellar cortex and a loss of neurons
in the dentate nucleus.

Question 19

Questions 19-26
Match the statement in items 19—26 with the
lesion shown in the figure below that corre-
sponds best to it.

19. Neurologic manifestation of vitamin B12
    deficiency

Answer 19

19- C. A neurologic manifestation of vitamin B12 deficiency is subacute combined degeneration.
There is no involvement of LMNs.

Question 20

20. Lesion due to vascular occlusion

Answer 20

20- A. Lesion A shows the territory of infarction resulting from occlusion of the ventral (anterior)
spinal artery.

Question 21

21. Loss of vibration sensation on the right
    side; loss of pain and temperature sensation on
    the left side

Answer 21

21- D. A spinal cord hemisection (Brown-Sequard syndrome) on the right side results in a loss
of vibration sensation on the right side and a loss of pain and temperature sensation on the left
side (dissociated sensory loss).

Question 22

22. Bilateral loss of pain and temperature sen-
    sation in the legs

Answer 22

22- A. Total occlusion of the ventral spinal artery, involving five cervical segments, results in in-
farction of the ventral two-thirds of the spinal cord and interrupts both lateral spinothalamic
tracts. The patient would have a loss of pain and temperature sensation caudal to the lesion.

Question 23

23. Bilateral loss of pain and temperature sen-
    sation in the hands; muscle atrophy in both
    hands; spastic paresis on the right side only

Answer 23

23- B. Lesion B shows a cervical syringomyelic lesion involving the ventral white commissure,
both ventral horns, and the right corticospinal tract. The patient would have a bilateral loss of
pain and temperature sensation in the hands, muscle wasting in both hands, and a spastic pare-
sis on the right side.

Question 24

24. Urinary incontinence and quadriplegic

Answer 24

24- A. In lesion A, both lateral and ventral funiculi have been infarcted by arterial occlusion. Bi-
lateral destruction of the lateral corticospinal tracts at upper cervical levels results in quadri-
plegia (spastic paresis in upper and lower extremities). Bilateral destruction of the ventrolateral
quadrants results in urinary and fecal incontinence.

Question 25

25. No muscle atrophy or fasciculations

Answer 25

25- C. In lesion C, subacute combined degeneration, there is no involvement of lower motor neu- rons (LMNs), hence no flaccid paralysis, muscle atrophy, or fasciculations.

Question 26

26. Demyelinating disease

Answer 26

26- C. In lesion C, subacute combined degeneration, there is symmetric degeneration of the white matter, both in the dorsal columns (fasciculi gracilis) and in the lateral funiculi (corti- cospinal tracts). In this degenerative disease, both the myelin sheaths and the axis cylinders are involved. Subacute combined degeneration is classified under nutritional diseases (in this case a vitamin B12 neuropathy). In true demyelinative diseases (e.g., multiple sclerosis), the myelin sheaths are involved but the axis cylinders and nerve cells are relatively spared.