|
Multiple
Sclerosis |
|
Donna
Plecha, M.D. |
|
| Clinical
History : This is a 39-year-old white female with a 15 year
history of multiple sclerosis. At diag- |
| nosis
the patient had weakness and numbness in the lower extremities. Currently,
the patient has m- |
| yoclonus. |
| Findings
: On the axial (Image1) proton density (TE 30/TR
2500) and (image 2) and (image 3) T2 weight |
|
images (TE 90/TR 2500) there are rounded areas of increased signal
intensity perpendicular to the lat- |
| eral
ventricles. There is a single lesion see on the ( image4) T1 weighted
images (TE 20/TR 750) in the |
| right
parieto-occipital region in the periventricular white matter which
enhances after the administra- |
| tion
of intravenous contrast. |
| Diagnosis
: Multiple Sclerosis |
| Discussion
: Multiple sclerosis
is a chronic inflammatory disease of myelin that is of unknown etiology.
|
| It has
a remitting course and is most commonly seen in female patients with
peak age between 20 and |
| 40 years.
It is a relapsing-remitting disease which usually presents with weakness
and/or numbness in |
| one or
more extremities. Another common presentation is visual loss secondary
to optic neuritis. |
| Magnetic
resonance imaging is the most sensitive radiographic technique for
imaging multiple sclero- |
| sis, with
sensitivity of nearly 85%. Commonly, foci identified on MRI imaging
are clinically silent. A com- |
| bination
of history, physical exam, laboratory tests such as CSF oligoclonal
banding and imaging findi- |
| ngs are
used to diagnose multiple scle. |
| Multiple
sclerosis plaques are typically isointense to hypointense on T1 weighted
scans . On proton |
| density
and T2 weighted images, the plaques are hyperintense compared to brain.
The lesions adja- |
| cent to
the ependymal surface are best seen on proton density weighted images,
contrasted against |
| the lower
signal intensity to the CSF within the lateral ventricles . |
| Multiple
sclerosis plaques are commonly seen as round or void discrete lesions
in the periventricular |
| white matter.
The characteristics Dawson's fingers are the periventricular white
matter lesions |
| situated
perpendicular to the ventricles as seen in this patient's images.
Other common locations for |
| multiple
sclerosis plaques include the corpus callosum, corona radiata, internal
capsule and centrum |
| semiovale. |
| Enhancement
of M.S. lesions indicate blood brain barrier disruption. This indicates
an active demyeli- |
| nating
stage, this is seen in this patient in the right parieto-occipital
region. Enhancement can persist |
|
up to eight weeks following acute demyelination. Both nodular or ring-like
enhancement can be seen
|
|
after contrast administration. Immediate post contrast scans are most
sensitive for detecting active |
| M.S.
lesions. Edema and hemorrhage are not characteristics of multiple
sclerosis. |
| References: |
|
Wallace CJ, Seland TP, Fong TC. Multiple Sclerosis:
The Impact of Mr Imaging. ARJ 1992; 158:849-257 |
|
Osborne
AG. Diagnostic Neuroradiology. Mosby 1994; 755-761. |
|
Lee
KH, Hashimoto SA, Hooge JP et al. Magnetic Resonance Imaging of
the Head in the Diagnosis of M- |
|
ultiple
Sclerosis: A perspective 2-year follow-up with comparison of clinical
evaluation, evoked poten- |
|
tials,
oligoclonal banding, and CT . Neurol 1991; 41:657-660 |
|
Hesselink
JR, Hicks RT. Brain: Periventricular White Matter Abnormalities.
In Edelman and Hesselink, |
|
editor,
MRI Clinical Magnetic
Resonance Imaging. WB Saunders Company 1990; 549-552. |
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Image1 |
Image2 |
Image3 |
Image4 |
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