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to limit spinal flexion. The ligamentum flavum is the con-
necting ligament between the laminae of vertebrae. The
nuchal ligament is an extension of the supraspinous liga-
ments from the cervical vertebrae to the occiput. The
transverse ligament of the atlas functions to limit posterior
translation of the odontoid process.
22. In the thoracolumbar spine, the posterior radicular
arteries branch directly off of which vessels?
a. Posterior spinal arteries
b. Anterior spinal artery
c. Segmental spinal arteries
d. Posterior intercostal arteries
e. Aorta
Preferred Response: (c) Segmental spinal arteries. The
spinal cord is supplied by both longitudinal and segmental
vessels. The anterior and posterior spinal arteries are longi-
tudinal vessels that originate within the cranial cavity. Fee-
der arteries, or segmental spinal arteries, enter the
intervertebral foramina at each level. After entering the
intervertebral foramina, the segmental spinal arteries branch
into anterior and posterior radicular arteries. At various
vertebral levels, these segmental spinal arteries also branch
into segmental medullary arteries that course longitudinally.
23. Which of the following statements regarding the artery
of Adamkiewicz is false?
a. It joins the anterior spinal artery
b. It is the largest anterior segmental artery
c. It arises from the right side of the aorta in most
individuals
d. It arises between T8 and L2 in most individuals
e. It shares collateral circulation with the lumbar
arteries
Preferred Response: (c) It arises from the right side of the
aorta in most individuals. The artery of Adamkiewicz arises
from the left side in 75% of individuals. It is known as the
largest anterior segmental artery and joins the anterior spinal
artery. This vessel supplies the “watershed” zone between
T8 and L2 in most individuals, but in up to 25% of indi-
viduals it can arise above T8. Caudal collateral circulation
with the lumbar arteries are common.
24. At how many years of age does the secondary ossifi-
cation center of the odontoid process (ossiculum ter-
minale) normally fuse?
a. 1 year
b. 3 years
c. 6 years
d. 12 years
e. 18 years
Preferred Response: (d) 12 years. The axis has severa l
secondary ossification centers, the latest of which to mature
in normal humans being that of the odontoid process. In some
patients, the ossiculum terminale fails to fuse by 12 years—
this is known as “ossiculum terminale persistens” or “Berg-
man’s ossicle.” This is typically a benign condition that is
incidentally noted on imaging; rarely, it may present with
symptoms such as neck pain and neurological signs [14].
25. How many primary ossification centers are typically
present in the subaxial spine in a developing human?
a. One
b. Two
c. Three
d. Four
e. Five
Preferred Response: (c) Three. The C3-L5 vertebrae have
three primary ossification centers that appear in the 9th or
10th week in utero and finish primary ossification by one
year. One of these ossification centers is in the center of the
vertebral body; the other two are located on either half of the
neural arch. These ossification centers hold clinical rele-
vance in that they may be mistaken for fractures on radio-
logic studies in young individuals.
26. In the evaluation of a patient with spinal trauma, what is
the imaging modality of choice to evaluate the integrity
of the ligamentous complex?
a. Plain radiographs
b. Flexion–extension radiographs
c. CT
d. MRI
Preferred Response: (d) MRI. In a patient with questioned
or suspected soft tissue damage or ligamentous injury, MRI
is the imaging study of choice. Radiographs and CT scans
are useful in the evaluation of bony injury and are relatively
quick imaging methods that can rule out various acute
neurosurgical indications. Flexion–extension radiographs
may provide evidence of spinal instability, but direct eval-
uation of the ligaments is best a chieved with MRI.
27. What is the MRI imaging sequence of choice in eval-
uating a patient with suspected spinal cord hemorrhage?
a. T1 weighted
b. T2 weighted
c. Short tau inversion recovery (STIR)
d. Gradient recalled echo (GRE)
6 Z. Almadidy et al.
Preferred Response: (d) Gradient recalled echo (GRE).
GRE sequences carry the most specificity in identifying
blood products as a result of spinal cord hemorrhage, com-
pared to the T1, T2, and STIR sequences [15].
28. What is the MRI sequence of choice in evaluating a
patient with suspected spinal cord ligamentous injury?
a. T1 weighted
b. T2 weighted
c. Short tau inversion recovery (STIR)
d. Gradient recalled echo (GRE)
Preferred Response: (c) Short tau inversion recovery.
Presence of significant edema or obvious disruption of the
ligamentous complex on STIR is sensitive for injury to the
ligaments. In patients with suspected injury to the odontoid
process, STIR sequence is commonly used to evaluate the
integrity of the transverse atlantal ligament [15].
29. The presence of which of the following on imaging of
the spine is most indicative of poor prognosis in a
patient with spinal cord trauma?
a. Presence of cord hemorrhage on MRI
b. Acute fracture of the lumbar transverse process
c. Disruption of the anterior longitudinal ligament
d. Paraspinal muscle hyperintensity on MRI STIR
sequence
Preferred Response: (a) Presence of cord hemorrhage.
Presence of cord hemorrhage is the most important prog-
nostic indicator in a patient with spinal cord injury18.
30. What is the diagnostic study of choice to distinguish an
acute from chronic fracture of the vertebrae?
a. CT scan without contrast
b. CT scan with contrast
c. MRI
d. Lumbar puncture
e. Plain radiograph
Preferred Response: (c) MRI. Presence of marrow edema
on MRI is associated with acute fracture and can be of
particular use when CT or plain radiograph identifies an
age-indeterminate fracture [15].
31. A 4-month-old boy is admitted to the hospital with
E. Coli meningitis. During workup for underlying
causes, the patient undergoes MRI of the lumbosacral
spine which demonstrates a hypointense tract with
communication between the spinal canal and the skin.
This finding most likely attributable to which of the
following?
a. Incomplete separation of endoderm and ectoderm
during gastrulation
b. Incomplete closure of the caudal neuropore without
herniation of neural tissue
c. Incomplete closure of the caudal neuropore with
herniation of neural tissue
d. Premature separation of the neural tube prior to
complete closure
e. Failure of surface ectoderm to separate from
neuroectoderm
Preferred Response: (e) Failure of surface ectoderm to
separate from neuroectoderm. The patient in the vignette
described has a dermal sinus tract, an abnormal
epithelium-lined communication between the spinal canal
and the skin, resulting from a primary defect in neurulation.
This condition affects an estimated 1 in 2500 live births and
clinical presentation can range from lack of symptoms to
significant disease, including infectious complications.
Incomplete separation of the endoderm and ectoderm during
gastrulation results in diastematomyelia, a rare condition
marked by sagittal splitting of the notochord. Incomplete
closure of the caudal neuropore with/without herniation of
neural tissue describes spina bifida occulta or
myelomeningocele, in which tracts between the skin and
spinal canal are not present. Premature separation of the
neural tube prior to closure results in intradural lipoma,
which appears on MRI as fat-appearing tissue [16].
32. A 6-year-old child exhibits progressive bladder incon-
tinence, bilateral lower extremity weakness, and
paresthesias. MRI of the lumbosacral spine reveals a
thickened filum with low-lying conus medullaris.
Which of the following are potential causes of tethered
cord syndrome?
a. Prior infection
b. Impaired neural canalization
c. Lipoma
d. Meningocele
e. All of the above
f. (b) and (c)
g. (b) and (d)
h. (a), (c), and (d)
Preferred Response: (e) All of the above. Tethered cord
syndrome most commonly presents in the first months of life
up until the teenage years. Causes of tethered cord syndrome
1 Anatomy, Embryology, Examination and Imaging of the Spine 7
can be primary (resulting from defect s in neurulation) or can
be secondary (acquired). Impaired neural canalization and
defects such as meningocele are developmental causes of
tethered cord syndrome, whereas scarring from prior infec-
tion, or the presence of lipomatous masses can result in
tethering [17].
33. Which of the following landmarks is commonly used
for the administration of caudal epidural anesthesia?
a. Intervertebral foramina
b. Median sacral crest
c. Superior iliac crest
d. Cornua of the sacral hiatus
e. Posterior sacral foramina
Preferred Response: (d) Cornua of the sacral hiatus. Caudal
anesthesia is used to anesthetize the sensory nerves from the
perineum. It is frequently used in surgical anesthesia for
children as well as for chronic pain management in adults.
The objective is to deliver local anesthetic to the epidural
space via the sacral hiatus. The cornua of the sacral hiatus
provides an opening through which a needle may be direc-
ted. The superior iliac crest and median sacral crest are both
located cranial to the sacral hiatus. The intervertebral
foramina and posterior sacral foramina are not palpable
external landmarks [18].
34. At which of the following spinal levels does the spinal
cord of a newborn end?
a. L1
b. L2
c. L3
d. L4
e. L5
f. S1
Preferred Response : (c) L3. In the newborn, the spinal cord
ends at L3. During development, the spinal cord “ascends”
to the lower border of L1 as an adult, as the vertebral column
lengthens in relation to the neural elements. In some
pathologic states, the cord may become “tethered,” pre-
cluding normal ascent and resulting in a low-lying conus
medullaris on subsequent imaging [19].
35. Manual stereognosis is dependent upon the integrity of
which of the following pathways?
a. Dorsal column medial lemniscus tract
b. Lateral spinothalamic tract
c. Ventral spinothalamic tract
d. Vestibulospinal tract
e. Rubrospinal tract
Preferred Response: (a) Dorsal column medial lemniscus
tract. Manual stereognosis is the ability to distinguish the
identity of an unseen object placed in one’s hand based on
3-dimensional form and texture. This is a function of the
dorsal column. The lateral spinothalamic tract mediates itch,
pain, and temperature sensation. The ventral spinothalamic
tract is concerned with light touch. The vestibulospinal tract
is coordinates maintenance of extensor tone. The rubrospinal
tract is important in the maintenance of flexor tone.
36. Which of the following changes does not occur at the
spinomedullary junction?
a. Decussation of the pyramids
b. Synapse between hypothalamic radiations and
sympathetic trunk
c. Replacement of Lissauer’s tract by spinal trigeminal
tract
d. Replacement of the spinal gray by the cranial nerve
nuclei
e. Termination of the fasciculi cuneatus and gracilis
Preferred Response: (b) Synapse between hypothalamic
radiations and sympathetic trunk. The synapse between the
hypothalamic radiations and the sympathetic trunk occurs at
the level of C8-T1 at the ciliospinal center. This is the first
synapse in the oculosympathetic chain, the second being the
synapse at the superior cervical ganglion. The decussation of
the pyramids, replacement of Lissauer’s tract by spinal
trigeminal tract, spinal gray by cranial nerve nuclei, and
termination of the fasciculi cuneatus and gracilis all occur at
the spinomedullary junction.
37. Which of the following tracts is responsible for con-
veying unconscious proprioceptive input from the
upper extremity?
a. Dorsal spinocerebellar tract
b. Cuneocerebellar tract
c. Vestibulospinal tract
d. Ventral spinocerebellar tract
e. Lateral corticospinal tract
Preferred Response
: (b) Cuneocerebellar tract. The
cuneocerebellar tract transmits proprioception, touch, and
pressure from the upper extremity to the cerebellum. The
dorsal spinocerebellar tract is analogous to the cuneocere-
bellar tract for the lower extremities. The vestibulospinal
tract is involved in the maintenance of extensor tone. The
8 Z. Almadidy et al.
ventral spinocerebellar tract conveys information regarding
lower limb posture and coordination. The lateral corti-
cospinal tract coordinates voluntary skilled movements.
38. An isolated lesion to the cell bodies of which of the
following structures would be most likely to cause
Horner’s syndrome?
a. Anterior gray horn of the spinal cord
b. Spinal ganglia
c. Lateral gray horn of the spinal cord
d. Posterior gray horn of the spinal cord
e. Anterior commissure of the spinal cord
Preferred Response: (c) Lateral gray horn of the spinal
cord. Horner’s syndrome is characterized by dysfunction of
the sympathetic pathway. Symptoms include miosis, ptosis,
and anhidrosis, among others. The cell bodies of the sym-
pathetic nerves are found within the lateral gray horn of the
spinal cord, therefore a lesion in this area would be most
likely to generate Horner ’ s syndrome. The anterior gray horn
contains cell bodies for somatic efferent fibers, while the
posterior gray horn contains sensory fibers from the spinal
ganglia cell bodies. The anterior commissure is a white
matter tract that does not contain neuronal cell bodies.
39. A 38-year-old male with a several month history of
gradually progressive low back/buttock pain, worse on
the right side, presents to the office for evaluation. As
part of the examination, the patient lies supine, and the
physician flexes the right hip and leg, abducts the leg,
places the patient’s right ankle on the left knee, and
allows the patient’s right knee to drop parallel to the
floor. Which of the following findings would be most
suggestive of a sacroiliac source of pain?
a. Ipsilateral buttock pain
b. Ipsilateral groin pain
c. Restriction of movement
d. Ipsilateral anterior hip pain
e. Ipsilateral lateral hip tenderness
Preferred Response: (a) Ipsilateral buttock pain.
The FABER (Flexion, ABduction, and External Rotation)
test is a provocative test that can aid in identifying the hip as
a pain generator in an individual with buttock pain. Pain in
the groin or anterior/lateral hip is more suggestive of a pri-
mary hip disorder, while pain in the low back/buttock region
is more suggestive of a sacroiliac source. This test has a
sensitivity of 71% and specificity of 75% in the identifica-
tion of sacroiliac joint inflammation [20].
40. In addition to the capsule of the zygapophyseal joint,
which of the following structures forms the posterior
border of the lumbar intervertebral foramen?
a. Posterolateral vertebral body
b. Intervertebral disc
c. Ligamentum flavum
d. Pedicle of the superior vertebrae
e. Pedicle of the inferior vertebrae
Preferred Response (c) Ligamentum flavum. The ventral
border of the intervertebral foramen is formed by the inter-
vertebral disc and posterolateral aspect of the vertebral body,
the superior and inferior borders formed by the pedicles, and
the posterior border formed by the ventral aspect of the
zygapophyseal joint capsule and the ligamentum flavum.
41. A patient with history of brachial plexus avulsion sec-
ondary to motor vehicle collision is being evaluated for
persistent upper extremity pain. As one of his treatment
options, his surgeon discusses spinal cord Dorsal Root
Entry Zone (DREZ) lesioning. The spinal DREZ
underlies which of the following structures?
a. Posterolateral sulcus
b. Posteromedian sulcus
c. Posterior gray commissure
d. Anterior median fissure
e. Dorsal root ganglion
Preferred Response : (a) Posterolateral sulcus. The DREZ is
the region of the spinal cord at which the dorsal roots (car-
rying nociceptive and somatosensory information) of the
upper limb terminate. The DREZ is a surgical term thought to
encompass both Lissauer’s tract and superficial layers of the
dorsal horn gray matter. The DREZ is located lateral to the
posteromedian sulcus. The anterior median fissure, posterior
gray commissure, and dorsal root ganglion are not on the
surface of the spinal cord at which the fibers enter [21].
42. The corticospinal tract is responsible for the coordina-
tion of voluntary motor movements. The origin of the
corticospinal tract originates from the primary motor
cortex within the precentral gyrus. Through which of
the following structures does the corticospinal tract pass
prior to entering the spinal cord?
a. Anterior limb of the internal capsule
b. Retrolenticular part of the internal capsule
c. Sublenticular part of the internal capsule
d. Posterior limb of the internal capsule
Preferred Response: (d) Posterior part of the posterior limb
of the internal capsule. The corticospinal tract occupies the
posterior half of the posterior limb of the internal capsule.
The anterior limb contains the anterior thalamic peduncle,
1 Anatomy, Embryology, Examination and Imaging of the Spine 9
the retrolenticular part contains the visual projects, and the
sublenticular contains auditory projections. Lesions to this
area (e.g. lacunar infarctions) can cause neurological deficits
consistent with upper motor neuron dysfunction with an
otherwise intact spinal cord.
43. A patient is undergoing elective repair of an abdominal
aortic aneurysm. Intraoperatively, his aorta is tem-
porarily clamped. Anastomoses from which of the fol-
lowing arteries will likely be responsible for preventing
ischemia of the spinal cord in this patient?
a. Anterior spinal artery
b. Posterior spinal arteries
c. Radicular branches of the intercostal arteries and
artery of Adamkiewicz
d. Segmental arteries from the vertebral, intercostal,
superficial epigastric, lumbar, and medial sacral
arteries
e. Segmental arteries from the vertebral, intercostal,
lumbar, spinal anterior, and posterior and lateral
sacral arteries
Preferred Response: (e) Segmental arteries from the ver-
tebral, intercostal, lumbar, spinal anterior, and posterior and
lateral sacral arteries. In the presence of abdominal aortic
clamping, the anterior and posterior spinal arteries will not
provide adequate blood flow to maintain the demand of the
spinal cord. At various vertebral levels, the segmental spinal
arteries arise predominantly from the vertebral and deep
cervical arteries, which will provide the additional supply
along the course of the spinal cord. The radicular branches of
the intercostal arteries branch from the aorta and will likely
not have sufficient blood flow if the aorta is clamped.
44. Which of the following is true regarding first-order
neurons of the ventral spinocerebellar tract?
a. They are responsible for the afferent limb of muscle
stretch reflexes
b. These neurons are located within the dorsal root
ganglia of the thoracic spine
c. They project axons onto the medial root entry zone
d. Their axons decussate in the anterior white
commissure
e. They enter the fasciculus gracilis
Preferred Response: (a) They are responsible for the afferent
limb of muscle stretch reflexes. The first-order neurons of the
ventral spinocerebellar tract receive input from muscle
spindles, golgi tendon organs, and pressure receptors. They
are located within the dorsal root ganglia from L1 to S2, not
the thoracic spine. The ventral spinothalamic tract and dorsal
spinocerebellar tracts project axons onto the medial root entry
zone. The second-order neurons of the ventral spinocere-
bellar tract decussate within the anterior white commissure of
the spinal cord. The fasciculus gracilis and cuneatus are
associated with the dorsal column medial lemniscus tract, not
the ventral spinocerebellar tract [22].
45. A pregnan t woman in labor elects for epidural anes-
thesia prior to delivery. Which of the following struc-
tures is not perforated by the needle to access the
epidural space?
a. Subcutaneous tissue
b. Ligamentum flavum
c. Posterior longitudinal ligament
d. Interspinous ligament
e. Supraspinous ligament
Preferred Response: (c) Posterior longitudinal liga ment.
The order of structures pierced in epidural anesthesia
administration is skin, subcutaneous tissue, muscle, supras-
pinous ligament, interspinous ligament, and ligamentum
flavum. The posterior longitudinal ligament is located pos-
terior to the vertebral body and anterior to the cord; it cannot
be reached by epidural anesthesia [23].
46. A patient is being evaluated in the emergency depart-
ment for severe low-back pain following a fall from a
ladder. Initial radiographs of the lumbar spine reveal
bilateral fractures of the pars interarticularis at L5.
Which of the following radiographic views would
provide the best visualization of these fractures?
a. Anteroposterior
b. Oblique
c. Lateral
d. Posteroanterior
Preferred Response: (b) Oblique. In the anteroposterior or
posteroanterior views, the vertebral bodies obscure the view
of the pars interarticularis. In the lateral view, the pedicles
may be superimposed on the pars interarticularis and there-
fore preclude complete visualization. The oblique is the ideal
radiographic view for suspected pars interarticularis fracture.
47. A 33-year-old female is being evaluated in the emer-
gency department following a motor vehicle collision in
which she was the restrained driver. MRI of the cervical
spine revealed a unilateral tear of the alar ligament
without injury to any other ligaments. Upon physical
10 Z. Almadidy et al.
exam, the range of motion of which of the following
cervical spine movements is most likely present as a
result of this tear?
a. Increased flexion
b. Decreased flexion
c. Increased extension
d. Decreased extension
e. Increased lateral flexion
f. Decreased lateral flexion
g. Increased rotation
h. Decreased rotation
Preferred Response: (g) Increased rotation. The alar liga-
ment attaches the odontoid process to the medial surface of the
occipital condyles and functions to limit excessive
atlantoaxial rotation. Disruption of this ligament would
therefore result in increased range of motion upon cervical
spine rotation. Flexion and extension occur at the atlantooc-
cipital joints and zygapophyseal joints. Lateral flexion occurs
as a combination of movements at the uncovertebral joints.
The alar ligament has no influence on these movements.
48. Which of the following reflexes is the fifth lumbar nerve
associated with?
a. Patellar
b. Achilles
c. Cremasteric
d. Anal wink
e. All of the above
f. None of the above
Preferred Response: (e) None of the above. The L5 nerve
root is not associated with a known reflex. Primary associ-
ations for the other named reflexes are as follows: patellar,
L4; Achilles, S1, cremasteric, L1-L2; anal wink, S3-S4 [24].
49. Upon exiting its respective intervertebral foramen,
which of the following nerve roots is oriented most
obliquely?
a. T4
b. T8
c. T12
d. L3
e. L5
f. S1
Preferred Response: (f) S1. Because the vertebral column is
longer than the spinal cord itself, spinal nerve roots become
longer and increasingly more obliquely oriented from the
cervical to coccygeal region.
50. In the operating room, a patient undergoing elective
spinal fusion surgery is positioned prone. Prior to
draping, the attending physician draws a horizontal line
connecting the inferior aspects of the scapula. What
vertebral level does this line traverse?
a. T5
b. T6
c. T7
d. T8
e. T9
Preferred Response: (c) T7. The T7 vertebrae can be
readily identified by a line across the inferior tip of the
scapula to the other. Because the presence of the scapula can
render this level difficult to identify on a lateral radiograph,
this tip is useful for identifying T7 in the operating room.
51. Which of the following external landmarks can be uti-
lized to identify the level of C3?
a. Hyoid bone
b. Thyroid cartilage
c. Cricoid cartilage
d. Carotid bifurcation
Preferred Response: (a) Hyoid bone. In most humans, C3
can be identified by the presence of the hyoid bone anteri-
orly. The thyroid cartilage is typically located at the level of
C4-C5. The cricoid is typically located opposite of C6. The
carotid bifurcation typically occurs around the level of
C4-C5 but is not a reliably identifi
able external landmark.
52. On what imaging modality is acute transverse myelitis
most readily identified?
a. X-ray
b. CT without contrast
c. CT with contrast
d. T1-weighted MRI
e. T2-weighted MRI
Preferred Response: (e) T2-weighted MRI. Although
imaging is frequently normal, transverse myelitis can
sometimes be identified on MRI as high T2 signal involving
gray and adjacent white matter. Plain radiography and CT
scan can be used to rule out several acute neurosurgical
indications but are unrevealing in transverse myelitis
specifically [25].
53. A patient with a history of progressive neck and left arm
pain with numbness presents to the office for evalua-
tion. As part of the physical exam, the physician places
downward pressure on the vertex and tilts the patient’s
1 Anatomy, Embryology, Examination and Imaging of the Spine 11
head towards the left. The patient’s left arm pain is
reproduced. What is the name of this finding?
a. Positive Lhermitte’s sign
b. Positive Hoffman’s sign
c. Positive Spurling’s test
d. Positive Adson’s test
e. Positive neck distraction test
Preferred Response: (c) Positive Spurling’s test. Spurling’ s
test is a provocative maneuver in which the patient’s head is
flexed laterally towards the symptomatic side, and down-
ward axial force is applied. This narrows the intervertebral
foramen and can provoke radicular symptoms, analogous to
the straight leg raise for the lumbar spine [26].
54. A 65-year-old man presents to the office with progres-
sive hand clumsiness, difficulty typing quickly, balance
difficulties, and neck stiffness. As part of the physical
exam, the physician provides passive snapping flexion
to the distal phalanx of the patient’s middle finger. The
patient’s ipsilateral thumb and index finger flex and
adduct in response. What is the name of this finding?
a. Positive Lhermitte’s sign
b. Positive Hoffman’s sign
c. Positive Spurling’s test
d. Positive Adson’s test
e. Positive neck distraction test
Preferred Response: (b) Positive Hoffman’s sign. Hoff-
man’s sign is a provocative maneuver first described in the
early 1900s, in which flicking the middle finger of a patient
with cervical myelopathy provokes a flexion/adduction
response in the ipsilateral thumb/index finger [26].
55. Which of the following conditions is least likely to
present with a positive Lhermitte’s sign?
a. Amyotrophic lateral sclerosis
b. Multiple sclerosis
c. Cervical myelopathy
d. Subacute combined degeneration
e. Transverse myelitis
Preferred Response: (a) Amyotrophic lateral sclerosis.
Lhermitte’s sign is most classically associated with multiple
sclerosis but can also be seen in other conditions such as
cervical myelopathy, subacute combined degeneration, trans-
verse myelitis, and cervical disc herniation. Lhermitte’ssignis
not reported to occur in amyotrophic lateral sclerosis [27].
56. Autonomic hyperreflexia occurs with spinal cord
lesions above which vertebral level?
a. C3
b. C7
c. T1
d. T6
e. T10
Preferred Response: (d) T6. Symptoms of autonomic
hyperreflexia include cutaneous vasodilation, hyperhidrosis,
and headache, among others. Mechanistic understanding of
autonomic hyperreflexia following spinal cord injury
remains poor, although early recognition of these symptoms
is paramount as appropriate management can minimize
long-term sequelae 28.
57. Which of the following is not a common characteristic
of conus medullaris syndrome?
a. Preserved patellar re flex
b. Flaccid bladder with overflow incontinence
c. Asymmetric motor deficits
d. Hyperreflexia
e. Low back pain
Preferred Response: (c) Asymmetric motor deficits. Conus
medullaris syndrome typically presents with symmetric
neurological deficits, as opposed to cauda equina syndrome,
which is typically asymmetric. Preserved patellar re flex,
flaccid bladder, hyperreflexia, and low back pain are all
common features of conus medullaris syndrome [29].
58. A patient comes to the office for evaluation of gait
ataxia. During the physical examination, the patient is
asked to place his feet together and stand up straight. He
is able to do this with his eyes open, but with closed
eyes, he falls over. Dysfunction of which pathway is
most likely responsible for this finding?
a. Dorsal spinocerebellar tract
b. Dorsal column medial lemniscus
c. Lateral spinothalamic tract
d. Lateral corticospinal tract
Preferred Response: (b) Dorsal column medial lemniscus.
This patient is able to stand up without falling when their
eyes are open, but not with their eyes closed, indicating
sensory dystaxia, or Romberg sign. This is a manifestation
of dorsal column dysfunction. The dorsal spinocerebellar
tract is analogous to the cuneocerebellar tract for the lower
extremities in transmitting proprioceptive input. The lateral
spinothalamic tract mediates itch, pain, and temperature
sensation. The lateral corticospinal tract coordinates volun-
tary skilled movements.
59. An adolescent male with mid-back pain is evaluated in
the office for abnormal findings on recent radiographs.
12 Z. Almadidy et al.
The radiologist reports a hemivertebra of the thoracic
spine. Which of the following findings is also most
likely present on imaging?
a. Scoliosis
b. Osteoporosis
c. Thoracolumbar spondylolisthesis
d. Sacralization of L5
e. Hyperlordosis of the lumbar spine
Preferred Response: (a) Scoliosis. A hemivertebra is a
condition in which part of one or more vertebrae does not
develop. This generates an abnormal lateral bend towards
the side of the developmental deficit and is thus a nidus for
scoliotic deformity. Rotational deformity may also be pre-
sent. Osteoporosis is a condition in which the cortical bone
loses its normal density and may predispose to fracture.
Spondylolisthesis is anterior displacement of a portion of the
vertebra upon another, usually secondary to a fracture of the
pars interarticularis. Lumbar hyperlordosis is characterized
by increased anterior curvature of the lumbar spine.
Sacralization of the L5 vertebrae is a congenital fusion of the
L5 verte bra to the sacrum.
60. A patient is being evaluated in the emergency depart-
ment for acute onset of severe back pain. CT of the
thoracolumbar spine reveals a fracture of the pars
interarticularis of L5 with normal alignment of the
vertebral body over the sacrum. Based on this infor-
mation, which of the following is the most likely
diagnosis?
a. Spondylosis
b. Spondylolysis
c. Spondylolisthesis
d. Spondylitis
Preferred Response: (b) Spondylolysis. Spondylolysis is a
fracture of the pars interarticularis. Spondylosis is a non-
specific term used to describe degenerative conditions of the
spine. Spondylolisthesis is anterior displacement of the
vertebral body after fracture of the pars interarticularis.
Spondylitis is a nonspecific term used to describe inflam-
matory conditions of the spine.
61. Which of the following statements is not true regarding
the vestibulospinal tract?
a. It arises from the giant cells of Deiters in the ipsi-
lateral vestibular nucleus
b. Plays a role in maintenance of extensor tone
c. It is located ventral to the rubrospinal tract
d. It is located medial to the ventral corticospinal tract
Preferred Response: (d) It is located medial to the ventral
corticospinal tract. The vestibulospinal tract arises from the
giant cells of Deiters in the ipsilateral vestibular nucleus and
is an important tract in the maintenance of extensor tone. It is
located in the ventral funiculus, lateral to the ventral corti-
cospinal tract, and ventral to the ventral horn of the spinal
gray matter. Decerebrate posturing is a tonic, static reflex
that is maintained by the reticular formation and vestibu-
lospinal system.
62. Which of the following spinal tracts is concerned with
the control of trunk muscles?
a. Dorsal spinocerebellar
b. Vestibulospinal
c. Ventral corticospinal
d. Lateral corticospinal
e. Lateral spinothalamic
Preferred Response: (c) Ventral corticospinal. The ventral
corticospinal tract is involved in the control of the axial
muscles, including those of the trunk and head. The dorsal
spinocerebellar tract is analogous to the cuneocerebellar tract
for the lower extremities in transmitting proprioceptive
input. The lateral spinothalamic tract mediates itch, pain, and
temperature sensation. The lateral corticospinal tract coor-
dinates voluntary skilled movements.
63. A 44-year-old male presents to the emergency depart-
ment after the sudden onset of pain while lifting a heavy
box. He states that the pain originates in the right but-
tock, travels down the lateral aspect of the thigh to the
front of the leg, and through the dorsum of the foot. His
anterior thigh is unaffected. Which of the following
nerve roots is most likely affected?
a. L3
b. L4
c. L5
d. S1
Preferred Response: (c) L5. The pain described in the
vignette follows an L5 dermatomal distribution. The L3 and
L4 distributions involve the anterior thigh. The S1 der-
matome involves posterior thigh pain that radiates to the
lateral aspect of the leg.
64. An epidural abscess is most commonly encountered in
which segment of the spine?
a. Cervical
b. Thoracic
c. Lumbar
1 Anatomy, Embryology, Examination and Imaging of the Spine 13
Preferred Response (b) Thoracic . Spinal epidural abscesses
are infectious processes that most commonly occur in indi-
viduals with history of intravenous drug abuse. These should
be suspected in patients presenting with focal pain, signs of
infection, and elevated inflammatory markers. These infec-
tions are distinct from vertebral osteomyelitis, which most
commonly occurs in the lumbar spine.
65. In the normal anatomical state, what percentage of the
total area of the lumbar intervertebral foramen is
occupied by the neurovascular bundle?
a. 10–20%
b. 20–50%
c. 40–70%
d. 60–90%
Preferred Response: (b) 20–50%. In the lumbar spine, in
the absence of significant degenerative processes and/or
foraminal stenosis, the neurovascular bundle (nerve root,
paired arteries/veins, fat) occupies approxi mately 20–50% of
the total cross sectional foraminal area. Significant narrow-
ing of foraminal area can cause radicular symptoms [30].
66. On which of the following days of development do the
anterior and posterior neuropore close, respectively?
a. 21 and 23
b. 23 and 25
c. 25 and 27
d. 27 and 25
e. 25 and 23
Preferred Response: (c) 25 and 27. A key concept of spinal
development is the closure of the neuropores during week 4.
The anterior neuropore closes prior to the posterior neuro-
pore. Disruption or failure of either of these processes can
lead to pathologies such as myelomeningocele, meningocele
and anencephaly [31].
67. Normal lordotic curvature of the cervical spine is within
which of the following ranges?
a. 10–15°
b. 15–20°
c. 20–25°
d. 25–30°
Preferred Response: (b) 15–20°. Under normal conditions,
the cervical and lumbar spine are lordotic, and the thoracic
spine is kyphotic. In some pathological states, the cervical
spine may develop a kyphotic deformity. Recognition of
normal cervical lordosis on lateral spine radiographs is
essential in the management of cervical spine disorders.
68. Which of the following is not true regarding the
uncovertebral joints of the cervical spine?
a. They are formed by the articulation between the
uncinate process and vertebral body
b. They define the lateral borders for discectomy
c. They define the midline for cervical plate placement
d. They have a distinct synovial membrane with syn-
ovial fluid
e. They have a distinct joint capsule
Preferred Response (e) They have a distinct joint capsule.
The uncovertebral joints of the cervical spine are an
important intraoperative landmark at the lateral aspects of
the upper surfaces of typical vertebrae. They define the lat-
eral borders for corpectomy and discectomy, as well as the
midline for implant placement. Although the uncovertebral
joints have a synovial membrane with fl
uid, they do not have
their own joint capsule.
69. At which vertebral level is the apex of thoracic kyphosis
typically located?
a. T4
b. T5
c. T6
d. T7
e. T8
f. T9
Preferred Response: (d) T7. The normal kyphosis of the
thoracic spine ranges from 10 to 40°. The apex of kyphosis
occurs at T7 in most individuals. Some surgeons choose to
avoid ending spinal constructs at the thoracic kyphotic apex
and the thoracolumbar junction in order to prevent instru-
mentation failures and progressive deformity.
70. A patient with suspected L5 radiculopathy undergoes
an electromyography (EMG) approximately 4 weeks
after onset of symptoms. What are the most likely
findings?
a. Normal insertion but very long-duration, rapid-firing
motor units
b. Prolonged latencies on both motor and sensory
nerve conduction studies
c. Abnormal insertion with fibrillations and positive
waves
14 Z. Almadidy et al.
d. Normal insertion, but poor activation of muscles in
the L5 myotome
Preferred Response: (c) Abnormal insertion with fibrilla-
tions and positive waves. These reflect denervation changes
(axonal injury). These changes are evident 3 to 4 weeks
following initial insult; until then, it is more common to see
normal insertion with poor muscle activation (d).
71. Which of the following ligaments is not responsible for
suspending the sacrum between the ilia?
a. Anterior sacroiliac
b. Posterior sacroiliac
c. Sacrotuberous
d. Interosseous
Preferred Response: (c) Sacrotuberous. The anterior and
posterior sacroiliac together with the interosseous ligaments
limit motion at the sacroiliac joint. The most important
ligaments in this function are the posterior sacroiliac and the
interosseous. The sacrotuberous ligament attaches the
sacrum to the ischial tuberosity but does not function to
suspend the sacrum within the ilia.
72. Which of the following nerves is at greatest risk during
dissection of the anterior surface of the psoas major
muscle?
a. Genitofemoral nerve
b. Ilioinguinal nerve
c. L5 nerve root
d. S1 nerve root
Preferred Res ponse (a) Genitofemoral nerve. The gen-
itofemoral nerve is formed within the belly of the psoas
muscle by union of the anterior rami of L1 and L2. The
nerve courses within the muscle and then emerges on its
anterior surface distally. This is of significance in
anterior/lateral approaches to the thoracolumbar spine.
73. Which of the following is true regarding the denticulate
ligament?
a. It is a type of pia mater
b. Is present between all dorsal and ventral roots
c. Is continuous with the dural sac
d. Tethers the radicular arteries in place
Preferred Response: (a) It is a type of pia mater. The
denticulate ligaments are specialized portions of pia mater
extending from the lateral surface of the pia, which aids in
suspending the spinal cord within the subarachnoid space.
These ligaments are not present between all of the dorsal and
ventral rootlets of the spine, are not continuous with the
dural sac, and are not related to the radicular arteries.
74. Which of the following veins/venous systems are
anatomically predisposed to permit the spread of
metastases throughout the vertebral column?
a. Basilic veins
b. Cephalic veins
c. Dorsal scapular veins
d. Batson’s venous plexus
e. Transverse cervical
Preferred Response: (d) Batson’s venous plexus. Batson’s
venous plexus is valveless and thus is clinically important in
the spread of metastatic disease. All other veins listed above
have valves.
75. The dural sac and subarachnoid space end at which
vertebral level?
a. L4
b. L5
c. S1
d. S2
e. S4
Preferred Response: (d) S2. The dural sac and subarach-
noid space end at S2. The filum terminale extends from the
caudal end of the dural sac to attach to the coccyx inferiorly.
76. At which of the following levels is a patient most likely
to develop a cervical disc herniation?
a. C4-C5
b. C5-C6
c. C6-C7
d. C7-T1
Preferred Response: (c) C6-C7. A cervical disc herniation
at C6-C7, which results in compression of the C7 nerve root,
accounts for approximately 69% of all cervical disc syn-
dromes. The next most commonly affected level is C5-C6,
accounting for approximately 19% of all cervical disc her-
niations. Of the above options, C4-C5 is the least common.
77. In early development, which of the following structures
forms the boundary between the ventral mantle layer
and the dorsal mantle layer?
1 Anatomy, Embryology, Examination and Imaging of the Spine 15