Pediatric Neurology xxx (2015) 1e4

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Pediatric Neurology
journal homepage: www.elsevier.com/locate/pnu

Clinical Observations

Spinal Cord Stroke Presenting With Acute Monoplegia
in a 17-Year-Old Tennis Player
Julie A. Nelson BA a, Chang Y. Ho MD b, Meredith R. Golomb MD, MSc a, *
a
Division of Pediatric Neurology, Department of Neurology, Indiana University School of Medicine and Riley Hospital for Children
at Indiana University Health, Indianapolis, Indiana
b
Division of Pediatric Neuroradiology, Department of Radiology, Indiana University School of Medicine and Riley Hospital for
Children at Indiana University Health, Indianapolis, Indiana

abstract
BACKGROUND: Acute monoplegia is a rare presentation for spinal cord stroke, which usually presents with
paraplegia or paraparesis. PATIENT DESCRIPTION: We describe an athletic girl who presented after a week of heavy
athletic activity complaining of back and left leg pain, followed by flaccid left leg paralysis. RESULTS: The pro-

thrombotic evaluation was unremarkable. Cerebrospinal fluid studies demonstrated elevated myelin basic protein
but no oligoclonal bands. Magnetic resonance imaging revealed a lesion in the anterior cord from T9 to T11 with T2
hyperintensity, contrast enhancement, and diffusion restriction, suggesting infarction. There was a herniated disc
at T10-T11 contacting the spinal cord and Schmorl’s nodes at T11 and T12. Magnetic resonance angiography of the
spinal cord was limited by movement artifact. CONCLUSIONS: The combination of our patient’s clinical presentation,
imaging studies, and laboratory evaluation suggests that our patient had a spinal cord infarct. A fibrocartilaginous
embolism was the likely mechanism of infarct due to the presence of Schmorl’s nodes and disc herniation on
imaging. In addition to spinal cord stroke, other possible mechanisms leading to presentation with monoplegia,
such as transverse myelitis, neuromyelitis optica, and multiple sclerosis, are discussed.
Keywords: stroke, spinal cord, monoplegia, fibrocartilaginous embolism, Brown-Séquard syndrome

Pediatr Neurol 2015; -: 1-4
Ó 2015 Elsevier Inc. All rights reserved.

Introduction

Patient Description

Spinal cord infarction in children and adults usually
presents with paraparesis or hemiplegia.1 The artery of
Adamkiewicz supplies most of the spinal cord2; ischemia of
this artery usually leads to bilateral symptoms.1 Presentation with monoplegia is rare. We describe a teenage athlete
who presented with pain and flaccid paralysis of her left leg.
Imaging was consistent with spinal cord stroke. The differential diagnoses, the difficulty in making the diagnosis,
and the likely pathogenesis of this infarct are discussed.

A 17-year-old athletic girl with no significant personal or family
medical history presented at an outside emergency department, complaining of left hip pain and weakness that had evolved from pain and
limited mobility of the left knee the previous evening. She was a high
school tennis player who had played in four matches the week before
presentation and had gone running the day before symptoms started.
She came to the emergency department because that morning, she had
fallen when getting out of bed because her left leg would not support her
weight. Her physical examination demonstrated sensitivity to palpation
on the lateral left hip and increased hip pain with movement. Her left
knee and foot had decreased range of motion. Strength in the lower left
leg was 3/5. Sensation in both legs was preserved. She was discharged
home after a normal X-ray of the hip and told the diagnosis was likely hip
strain.
The next day (symptom day 3), she complained of bilateral lumbar
pain and left leg paresthesias that did not respond to ibuprofen. She saw
a neurologist, who noted that she could not move her left leg except for
slight ankle plantarflexion and dorsiflexion. She had decreased pinprick
sensation in her left leg in a patchy distribution but intact vibration
sensation. Left knee jerk and both ankle jerks were decreased at 1þ, right

Article History:
Received July 22, 2015; Accepted in final form November 7, 2015
* Communications should be addressed to: Dr. Golomb; Division of
Pediatric Neurology; Department of Neurology; Indiana University
School of Medicine; RI1340, 705 Riley Hospital Drive; Indianapolis,
IN 46202.
E-mail address: mgolomb@iupui.edu
0887-8994/$ e see front matter Ó 2015 Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.pediatrneurol.2015.11.007

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J.A. Nelson et al. / Pediatric Neurology xxx (2015) 1e4

knee jerk was normal, and Babinski reflexes were negative. Magnetic
resonance imaging (MRI) without contrast of her thoracic spine revealed
a small disc extrusion with superior migration at T10-T11 causing mild
anterior cord compression. There was an adjacent lesion within the
anterior spinal cord with abnormal T2-weighted signal from spinal levels
T9-T11 concerning for anterior cord ischemia caused by anterior spinal
artery occlusion or stenosis possibly caused by disc extrusion (Fig 1). She
was administered prednisone 20 mg twice daily, tapering by 5 mg every
other day.
Her left leg weakness did not improve with prednisone. She developed urinary incontinence on symptom day 5 and was referred to our
emergency department. She had flaccid paralysis of the left leg. Her right
leg strength was 4þ/5 with normal tone. Several examiners noted
decreased temperature sensation in the right leg, but proprioception and
vibration were intact in both legs; there was some variation among examiners. Her left knee jerk was 1-2þ and her right knee jerk was 2-3þ,
with no Babinski signs. Lumbar spine MRI without contrast that day
(symptom day 5) demonstrated increased T2 signal in the anterior cord
along with Schmorl’s nodes at the T11-12 and T12-L1 levels. The next day
(symptom day 6) a third whole spine MRI was performed with threedimensional T2 images, postcontrast, and diffusion-weighted images.
The disk extrusion at T10-T11 with associated spinal cord lesion was
redemonstrated. Axial T2 images showed the lesion enhanced with
contrast and was confined to the anterior half of the spinal cord, more on
the left. There was focal restricted diffusion within the spinal cord. Small
Schmorl’s nodes were noted at the inferior end plates of T11 and T12 as
well as another disk herniation at T8-T9 (Fig 2). Magnetic resonance
angiography was attempted, but the anterior spinal artery could not be
evaluated due to movement artifact. Brain MRI was unremarkable.
Echocardiogram was unremarkable. Serum testing was unremarkable and included complete blood cell count, sedimentation rate, international normalized ratio, activated partial thromboplastin time, protein
C and S activity, functional antithrombin, homocysteine, antiphospholipid antibody screen, lipid panel, lipoprotein a, and genetic
screen for the factor V Leiden, Prothrombin 20210, and methylene tetrahydrofolate reductase gene abnormalities. Vitamin B12 was in the low
normal range. Urinalysis demonstrated nitrites. Cerebrospinal fluid
demonstrated glucose of 80 mg/dL (normal 40-70 mg/dL); protein
31 mg/dL (normal 15-45 mg/dL); white blood cell count 2/mm3; red
blood cell count 249/mm3; myelin basic protein 74.7 ng/mL (normal 05.5 ng/mL); and negative oligoclonal bands. Both serum and cerebrospinal fluid were negative for aquaporin-4 immunoglobulin G.

She was admitted and given prophylactic cephalexin and a Foley
catheter for bladder decompression. She initially received both steroids and aspirin because of the difficulty in determining whether she
had transverse myelitis or stroke. She was administered intravenous
dexamethasone 4 mg every 6 hours for four doses, then switched to
1 g of intravenous methylprednisolone a day for 5 days due to concern
for cord compression then transverse myelitis. She was given 81 mg of
aspirin the second day of admission as spinal stroke was a possibility.
She was administered sublingual vitamin B12 1000 mg daily on the
third day of admission. A fourth spine MRI with and without contrast
and diffusion-weighted imaging on symptom day 10 demonstrated
stable T2 hyperintensity and the earlier noted disc extrusions. Plain
lateral radiograph of the thoracic spine demonstrated mild kyphosis
and anterior wedging of T9, T10, and T11 of greater than 5 degrees
(Fig 3).
She slowly regained strength in her left leg with physical therapy and
was transferred to inpatient rehabilitation on hospital day seven. She
could ambulate using crutches with strength of 3þ/5 in the left lower
extremity by the time of her discharge, 14 days after admission.
She was able to walk without crutches five weeks after her stroke,
and her gait was only mildly hemiplegic. She had difficulty running and
would tire easily. At 3-month follow-up, she was noted to have 5-/5
strength for left hip flexion and extension. Left knee flexion was 4/5 and
extension was 5/5. She complained of right hip pain and said her right leg
tired easily. This condition was attributed to her right leg doing more
work than her left leg.
Thirteen months later, she was seen at the emergency department,
complaining of back pain. She had bilateral paraspinal spasms in the
thoracic and lumbar spine on physical examination. She complained of
slight persistent difficulties with gait on her left side, including a mild
foot drop, although her left leg strength was rated at almost a 5/5, which
was an improvement since discharge. She reported numbness in her
right leg in a stocking-glove distribution up to her right hip, which had
started approximately 5 months earlier. MRI with and without contrast
and diffusion-weighted imaging showed gliosis in the previous region of
spinal cord abnormality and no new evidence of stroke. Her back pain
was attributed to either spasticity from her spinal cord stroke the previous year or from musculoskeletal strain due to her changed gait since
the stroke. Eighteen months later, she reported ongoing decreased pain,
temperature, and pressure sensation in her right leg, and nearly baseline
strength of her left leg. She returned to modified athletic activity and
started college.

FIGURE 1.
Patient’s third day of symptoms. Sagittal T2 image of the thoracic spine (A) shows a disk herniation with cranial migration at T10-T11 (white arrow) with
associated anterior spinal cord lesion spanning T9-T11 levels (black arrows). Axial T2 image just above the T10-T11 disk level (B) shows the disk extrusion
(white arrow) and the anterior involvement of the spinal cord lesion (black arrow). Just below the disk level (C) there is asymmetric involvement of the
spinal cord on the left (black arrow).

J.A. Nelson et al. / Pediatric Neurology xxx (2015) 1e4

3

FIGURE 2.
Patient’s fifth day of symptoms. Sagittal postcontrast image (A) of the thoracic spine again shows the disk herniation at T10-T11 (white arrow) with
enhancement of the anterior spinal cord lesion (black arrow). There is also improved visualization of Schmorl’s nodes of the inferior end plates of T11 and
T12 (arrowheads). Axial postcontrast image (B) below the T10-T11 disk level confirms the asymmetric left anterior involvement of the spinal cord (white
arrow) at this level. There is a focal area of increased signal on diffusion-weighted images (C, white arrow), consistent with diffusion restriction suggesting
cytotoxic edema. High-resolution sagittal T2 image (D) also shows an additional disk extrusion at T8-T9 in addition to T10-T11 (white arrows). The anterior
cord lesion is again noted (black arrow).

Discussion

Spinal cord stroke in children may be difficult to recognize and diagnose appropriately.3 This teenager presented
with progressive flaccid monoplegia, sensory changes, and
urinary retention suggestive of myelopathy; MRI confirmed
a thoracic cord lesion. The differential diagnoses for acute
myelopathy include acute transverse myelitis, early multiple sclerosis, neuromyelitis optica, and spinal stroke.
The presentations of acute transverse myelitis and early
multiple sclerosis can be difficult to differentiate from earlystage stroke. Many patients with acute transverse myelitis
present with pain4; our patient’s initial complaint was left
knee pain, which progressed to hip and back pain. However,
neck and back pain are presenting symptoms in 59% of
patients with spinal cord stroke.4 Most patients with acute
transverse myelitis present after a prodromal illness or
vaccination,4 and our patient had been healthy, with no
recent vaccinations. Presentation with bilateral weakness is
considered a diagnostic criterion for transverse myelitis.4
Our patient presented with acute monoplegia. Our patient’s sensory examinations suggested a partial BrownSéquard syndrome, which is rare in children with spinal
infarct.1 She presented with flaccid left leg paralysis and
decreased right leg temperature sensation, but intact proprioception. By the time of her admission, she had taken
multiple doses of steroids, which may have decreased the
accuracy of her sensory examination.5 Sensory examinations in patients with spinal cord injury are challenging and
less reliable than the motor examination.6

The radiographic appearance of acute transverse myelitis
and acute spinal stroke can be similar. Children with acute
transverse myelitis have involvement of multiple spinal
cord levels on MRI,4 similar to our patient. However,
transverse myelitis typically involves at least two thirds of
the cross-section of the spinal cord, whereas in our patient
only the anterior cord was involved.7 On axial images, the
lesion was confined to the anterior cord and asymmetric,
more on the left, corresponding with her left monoplegia.
Diffusion restriction also supported the diagnosis of an
anterior spinal artery infarct. Given the disk herniation
associated with the cord abnormality, and no other explanation for spinal stroke, fibrocartilaginous embolism was
suspected. Spine radiography suggested Scheuermann disease, or spinal kyphosis, which has been linked to increased
thoracic disk herniations.8 Schmorl’s nodes, which are also
thought to be a source of fibrocartilaginous emboli,3 were
present at T11 and T12.
Our patient’s laboratory results supported a diagnosis of
spinal stroke. Most children with acute myelitis have a
lymphocytic pleocytosis and elevated protein level in cerebrospinal fluid4; our patient did not. The presence of
oligoclonal bands is a predictor for development of multiple
sclerosis9; our patient had no oligoclonal bands. Our patient
was negative for serum and cerebrospinal fluid aquaporin-4
immunoglobulin G, ruling out neuromyelitis optica. Her
cerebrospinal fluid showed early elevated level of myelin
basic protein, which initially raised suspicion for acute
transverse myelitis.10 Myelin basic protein level is
frequently elevated in inflammatory central nervous system

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J.A. Nelson et al. / Pediatric Neurology xxx (2015) 1e4

Given the lack of prodromal illness, history of recent
strenuous physical activity, negative thrombotic evaluation,
and MRI findings, the most likely etiology of our patient’s
spinal cord infarct was a fibrocartilaginous embolism. There
are several proposed mechanisms for fibrocartilaginous embolism. One theory proposes that lateral rupture of the
annulus fibrosis allows fragments of nucleus pulposis to enter
into the circulation of the anterior spinal artery.3 Another
theory suggests that a vascular malformation of the radicular
arteries supplying the intervertebral disks allows abnormal
passage of an embolus.3 Fibrocartilaginous emboli may also
originate from Schmorl’s nodes.3 One retrospective antemortem study found that fibrocartilaginous emboli caused
5.5% of acute spinal cord infarct cases, suggesting that fibrocartilaginous embolism is likely the underlying cause for
some unexplained cases of spinal cord infarcts.13
This young woman with monoplegia and probable partial
Brown-Séquard syndrome most likely suffered a spinal cord
infarct from a fibrocartilaginous embolism due to a herniated
disc or Schmorl’s node. Her infarct may have been precipitated by the fact that she was very physically active and had
underlying Scheuermann disease. Obtaining accurate
vascular imaging would have been extremely helpful in her
diagnosis. As our patient was unable to lie still for a diagnostic
magnetic resonance angiogram, further advances in pediatric
imaging techniques will play an important role in clarifying
the diagnosis and causes of spinal cord infarction.
References

FIGURE 3.
Patient’s tenth day of symptoms. Standing lateral plain film of the thoracic
spine shows mild kyphosis and 5 degrees or more of anterior wedging at
three consecutive levels, T9, T10, and T11.

disorders;10 it is also elevated in almost 40% of patients with
acute ischemic stroke.11
A lesion producing a partial Brown-Séquard syndrome
implies involvement of the left corticospinal tract and right
spinothalamic tract after decussation. These tracts are
supplied by the anterior spinal artery, which is fed by the
artery of Adamkiewicz. Artery of Adamkiewicz compression
in the intervertebral foramen from left-sided thoracic disc
herniation can cause Brown-Séquard syndrome.12 Unfortunately, our patient moved during the magnetic resonance
angiogram, and neither the anterior spinal artery nor the
artery of Adamkiewicz was well visualized. The team felt
that repeating magnetic resonance angiography was not
worth the risk of additional anesthesia.

1. Stettler S, El-Koussy M, Ritter B, et al. Non-traumatic spinal cord
ischaemia in childhood - clinical manifestation, neuroimaging and
outcome. Eur J Paediatric Neurol. 2013;17:176-184.
2. Koshino T, Murakami G, Morishita K, Mawatari T, Abe T. Does the
Adamkiewicz artery originate from the larger segmental arteries?
J Thorac Cardiovasc Surg. 1999;117:898-905.
3. Davis GA, Klug GL. Acute-onset nontraumatic paraplegia in childhood: fibrocartilaginous embolism or acute myelitis? Childs Nerv
Syst. 2000;16:551-554.
4. Yiu EM, Kornberg AJ, Ryan MM, Coleman LT, Mackay MT. Acute transverse myelitis and acute disseminated encephalomyelitis in childhood:
spectrum or separate entities? J Child Neurol. 2009;24:287-296.
5. Kiwerski JE. Application of dexamethasone in the treatment of acute
spinal cord injury. Injury. 1993;24:457-460.
6. Marino RJ, Jones L, Kirshblum S, Tal J, Dasgupta A. Reliability and
repeatability of the motor and sensory examination of the international standards for neurological classification of spinal cord
injury. J Spinal Cord Med. 2008;31:166-170.
7. DeSanto J, Ross JS. Spine infection/inflammation. Radiol Clin North
Am. 2011;49:105-127.
8. Kapetanos GA, Hantzidis PT, Anagnostidis KS, Kirkos JM. Thoracic
cord compression caused by disk herniation in Scheuermann’s disease: a case report and review of the literature. Eur Spine J. 2006;15
Suppl 5:553-558.
9. Perumal J, Zabad R, Caon C, et al. Acute transverse myelitis with
normal brain MRI: long-term risk of MS. J Neurol. 2008;255:89-93.
10. Miyazawa R, Ikeuchi Y, Tomomasa T, Ushiku H, Ogawa T,
Morikawa A. Determinants of prognosis of acute transverse myelitis
in children. Pediatr Int. 2003;45:512-516.
11. Hill MD, Jackowski G, Bayer N, Lawrence M, Jaeschke R. Biochemical
markers in acute ischemic stroke. CMAJ. 2000;162:1139-1140.
12. Mansour H, Hammoud F, Vlahovitch B Brown-Sequard syndrome
caused by foramen and calcified disk herniation, responsible for
direct compression of Adamkiewicz’s artery. Neurochirurgie. 1987;
33:478-481. [Article in French].
13. Mateen FJ, Monrad PA, Hunderfund AN, Robertson CE, Sorenson EJ.
Clinically suspected fibrocartilaginous embolism: clinical characteristics, treatments, and outcomes. Eur J Neurol. 2011;18:218-225.