Clinical and radiological profile
Sobue disease
Dynamic MRI study of neck in upper limb weakness and
atrophy
No. IRIA - 1210
AIM
The role of flexion magnetic resonance (MR) imaging can
help differentiate Sobue/Hirayama disease by depicting
forward displacement of the posterior dural sac from
others.
Introduction
• Hirayama disease (HD) /sobue is benign focal amyotrophy of the
distal upper limbs, often misdiagnosed as motor neuron disease.
Routine magnetic resonance imaging (MRI) is often reported
normal.
• Most of these patients may undergo only nonflexion cervical MR
examination because most clinicians are not familiar with this
disorder and do not request a flexion cervical MR examination.
• Purpose of our study was to investigate the sensitivity and
specificity of dynamic MR imaging findings in the diagnosis of
Hirayama flexion myelopathy.
Materials and methods.
• It’s a retrospective ,cases were collected at medical college and
hospital in tamilnadu. during period of november 2013 to
november 2014.
• 12 patients with a clinical suspicion of HD. One patient after initial
evaluation was lost to follow-up and has not been included in the
final analysis, along with 10 controls.
• The pre- and post contrast MRI were done in neutral and flexion
positions of cervical spine and imaging findings were correlated
with the clinical presentation and electrophysiology findings.
• Another patient (patient number 12) declined to undergo dynamic
contrast study.
criteria for patient selection
• Weakness and wasting
predominantly in one upper limb
or asymmetrically in both upper
limbs,
• Insidious onset in the teens or in
the early 15 -35 yrs,
• Progression for 1–3 years
followed by arrest of disease or
relatively benign course,
• EMG evidence of chronic
denervation in the clinically or
subclinically affected muscles ,
• Absence of substantial sensory
loss/reflex abnormalities, cranial
nerve, pyramidal tract signs in
lower limbs, sphincter or
cerebellar deficits.
• all of the control subjects gave written informed consent.
• The control subjects underwent cervical MR imaging to provide a
diagnosis for
posterior neck pain,
weakness or numbness of hands, and
gait disturbance;
to screen for cerebrospinal seeding; or
to rule out multiple sclerosis.
Exclusion criteria
• Associated with any co-morbiditys.
• Other than age group 15-35 yrs.
• Previous history of any trauma to neck.
• Any previous history to surgery.
Technical aspects.
The MR imaging was done by superconducting 1.5-T machine.
neutral position
•
•
•
•
Sagittal SE T1W,
TSE T2,
Gradient Echo T2,
MR myelogram in
sagittal and coronal planes
In hyperflexion of
cervical spine
• Sagittal SE T1W with and
without fat saturation,
•
TSE T2,
•
Gradient Echo T2 and
• MR myelogram in sagittal and
coronal planes
Postcontrast SE T1W was done in
transverse plane.
• Cervical curvature was measured according to the relationship of the dorsal
aspect of the vertebral bodies C3 through C6 to a line drawn from the
dorsocaudal aspect of the vertebral body C2 to the dorsocaudal aspect of the
vertebral body C7.
• The degree of separation between the posterior dural sac and its subjacent
lamina was evaluated within a range defined medially by the point of
junction with the lamina and laterally by a tangential line along the medial
aspect of the pedicle.
• A separation of less than 33.3% at all of the observed segments was
considered normal, while a separation of more than 33.3% at any of the
observed segments was considered positive for LOA.
Following features were evaluated
(a) Localized lower cervical cord atrophy,
(b) Asymmetric cord flattening,
(c) Abnormal cervical curvature,
(d) Loss of attachment between the posterior dural sac and subjacent
lamina,
(e) Anterior shifting of the posterior wall of the cervical dural canal,
(f) Enhancing epidural component with flow voids and
(g) Intramedullary signal hyperintensity.
Statistics
• Data were analyzed with software (SPSS, version 10.0; SPSS,). The power
for the current study was calculated retrospectively by means of the formula
of Fleiss.
• Ratio of the control group to patient group of 1:1, and sample size of 20 for
both groups. The resultant power was 100%.
• The independent t test was used to examine the difference between
patients and control subjects with regard to age.
• The χ2 test was used to examine the difference between patients and control
subjects with regard to sex, abnormal cervical curvature, LOA between the
posterior dural sac and subjacent lamina, localized lower cervical cord
atrophy, asymmetric cord flattening, and noncompressed intramedullary
high signal intensity.
• Differences with a P value of less than .05 were considered to be statistically
significant
Master chart
for cases and
controls
Master sheet for cases
Results ..
Loss of lardosis
10
8
Total
number
of
hirayama
cases
Sobue
with loss
of
lardosis
Sobue
without
loss of
lardosis
7(100%)
7(100%)
0
6
HIRAYAMA
4
2
100%
0
with
HIRAYAMA
loss of lardosis
WITHOUT
TOTAL
loss of lardosis
90%
80%
70%
60%
50%
HIRAYAMA
40%
30%
20%
10%
0%
with
without
lardosis
Intensity
of cord
9(100%)
Sobue
with HI
cord
Only HI
of cord
7(77%)
2(33%)
INTENSITY OF CORD
Flattenin
g of cord
With
sobue
disease
without
7(100%)
7(100%)
0
Flattening cord
9
8
7
8
6
6
5
INTENSITY OF
CORD
4
4
flattening cord
2
3
0
2
flattening cord
without
total hirayama
1
0
1
2
3
Sobue cases
Males
females
7(100%)
6(85.71%)
1(14.28%)
Saboe disease
7
6
5
4
saboe disease
3
2
1
0
males
females
total
Total
hirayama
Neutral mri
Flexion mri
15%
100%
120%
100%
80%
60%
Series1
40%
20%
0%
TOTAL HIRAYAMA
NEUTRAL MRI
FLEXION MRI
RESULTS
• No significant difference in age was found between the control and patient
groups (P > .05).
• The difference between the groups was significant (P < .001).
other findings
• OPLL
1/10
• Disc bulge 2/10
• Osteophytes
• Haemangioma
2/10
1/10
Findings
straightening of cervical cord with focal
atrophy at C5–C7 level.
Symmetric anterior cord flattening.
anterior displacement of posterior epidural
sheath with flow voids
Post-contrast shows posterior epidural venous
congestion.
OPLL
Disc bulge with hyper intensity of card
Loss of attachment of dorsal dural sac, anterior displacement of
the dorsal dura on flexion (from C3 to D2) and a prominent
posterior epidural space
discussion
• HD/Sobue disease, a rare disease affecting young men in the
second to third decades of life, is characterized by insidious onset
and slowly progressive course followed few years later by static
phase of unilateral or asymmetric atrophy of the hand(s) and
forearm(s) with sparing of the brachioradialis, characterized as
oblique amyotrophy.
• It is thought to be a cervical flexion myelopathy related to repeated
movements of the neck causing chronic microcirculatory changes in
the territory of the anterior spinal artery supplying the anterior
horns of the lower cervical cord.
• In normal patients, the dural slack compensates for the increased
length in flexion
• Patients with Hirayama dz may have an imbalance in growth of
vertebrae and dura, and the short dural canal cannot compensate;
therefore, the dural canal becomes tight when the neck is flexed.
▫ Results in an anterior shift of the posterior dural wall, causing
spinal cord compression
• Spinal cord flattening is asymmetric in majority of cases.
▫ This is an important finding on routine nonflexion MR images
and should raise the suspicion.
• Spinal cord atrophy limited to the anterior horn cells found in later
stages of the disease.
• Morphologic changes on MR images correlate well with clinical and
electromyographic data
• The pathogenesis of cervical myelopathy may be ischemic changes
or chronic trauma with repeated neck flexion.
▫ Compression may cause microcirculatory disturbances in
anterior portion of the cord, leading to necrosis of anterior horns
• Changes are often greatest at C6 vertebral level
• Primarily affects the anterior horn cells, and in later stages of the
disease, spinal cord atrophy ensues.
• Some autopsy studies report ischemic changes in the anterior horn
cells, with asymmetric cord thinning.
• Physiologically, the cervical cord starts to enlarge at C3, reaches its
maximum at C5, and tapers thereafter to T2; thus, for a lower
cervical cord lesion, a larger cord below the suspected atrophy
confirms atrophy at the suspected level.
DIFFERENTIAL DIAGNOSIS
Localized amyotrophy of the distal arm
•
•
•
•
syringomyelia,
amyotrophic lateral sclerosis,
cervical spondylotic myelopathy, and
Spinal cord tumor
should be differentiated from Hirayama disease.
Management
• Avoidance of neck flexion can stop the progression of the disease
• Some advocate application of a cervical collar for 3 to 4 years since
the progressive stage usually ceases in a few years.
• Surgical intervention, including cervical decompression and/or
fusion with or without duraplasty, may be an option
Refferences
• 1.Hirayama K. Non-progressive juvenile spinal muscular atrophy of the distal upper limb
(Hirayama’s disease). In: De Jong JM, eds. Handbook of clinical neurology. Vol 15.
Amsterdam, the Netherlands: Elsevier, 1991; 107-120.
• 2.Hirayama K, Toyokura Y, Tsubaki T. Juvenile muscular atrophy of unilateral upper
extremity: a new clinical entity. Psychiatr Neurol Jpn 1959; 61:2190-2197.
• 3.Hirayama K. Juvenile non-progressive muscular atrophy localized in hand and
forearm: observation in 38 cases. Rinsho Shinkeigaku 1972; 12:313-324. 4.Hirayama K,
Tomonaga M, Kitano K, Yamada T, Kojima S, Arai K. Focal cervical poliopathy causing
juvenile muscular atrophy of distal upper extremity: a pathological study. J Neurol
Neurosurg Psychiatry 1987;
• 50:285-290. 5.Sobue I, Saito N, Iida M, Ando K. Juvenile type of distal and segmental
muscular atrophy of upper extremities. Ann Neurol 1978; 3:429-432.
• 6.Kikuchi S, Tashiro K, Kitagawa K, Iwasaki Y, Abe H. A mechanism of juvenile muscular
atrophy localized in the hand and forearm (Hirayama’s disease): flexion myelopathy
with tight dural canal in flexion. Rinsho Shinkeigaku 1987; 27:412-419. [Medline]
Thank you////////
• Thanks to my Prof..
and my friends….
without them its incomplete…..