Multiple foci of white matter signal abnormality are identified
involving the left centrum semiovale as well as the subcortical
white matter of the right temporal lobe. Small foci of signal
abnormality are identified bilaterally, medially within the
cerebellar peduncles. There is abnormal enhancement, without
enlargement, of the right optic nerve.
Multiple sclerosis is a disease process characterized by the
formation of demyelination plaques within the white matter of the
brain and spinal cord. There is a 60:40 female predominance, with
most cases occurring between the ages of 18 and 50. There are a
number of theories regarding the causation of multiple sclerosis.
Some of these include post-traumatic, post-viral and genetic
susceptibility resulting in immune mediated white matter disease.
The course of multiple sclerosis is typically relapsing and
remitting. In rare cases, also known as Marburg type multiple
sclerosis, the disease is rapidly progressive and debilitating.
Visual problems and eye pain are frequent presenting symptoms due
to optic neuritis. MRI is the best imaging study to evaluate for
multiple sclerosis with a sensitivity of 85%. Abnormal
periventricular foci of signal abnormality are identified with
enhancement seen in active plaques. Three such lesions measuring
greater than 5mm each is suggestive of the diagnosis. Lesions that
appear ovoid, located at the callosal-septal interface are known as
"Dawson's Fingers", and are also suggestive.
Orrison Jr, William. Neuroimaging. W.B. Saunders Company,