Imaging
Features
MRI features show selective hypointensity / hyperintensity of the putamen
on T1/T2,
extensive bilateral frontal white matter gliosis with frontal atrophy, and
hypointensity of
subcortical white matter with cortical atrophy.
Diagnosis
Wilson’s disease
Discussion
Wilson’s disease is a disorder that causes the body to absorb and retain
excessive
amounts of copper. This disorder is an inherited autosomal recessive
trait, and is rare,
affecting about 1 in 30,000 people. It is caused by the ATP7B gene found
on
chromosome 13, and is most common in Europeans, and Southern Italians.
It usually occurs in people between the age of 4-40, but is commonly found
in teenagers.
Wilson’s disease is usually discovered as a result of liver
disease symptoms.
Pathology
The result of the genetic defect is a failure of the liver to get rid of
copper. This copper is
then deposited in the liver, brain, kidneys and the eyes. Copper
deposition in the liver
causes cirrhosis, necrosis, hepatosplenomegaly, and abdominal enlargement.
Deposits in
the brain, usually the basal ganglia cause CNS damage, resulting in loss
of motor
function, muscular control, tremors, loss of memory and intellectual
function,
accompanied by increasing confusion and dementia if left untreated.
Deposits in the eye
result in restriction of eye movement, as well as build-up of brown
pigment in the cornea
called Kayser-Fleischer rings. Other symptoms include jaundice, weakness,
and
symptoms due to hemolytic anemia due to RBC damage.
Diagnosis
The diagnosis is based on
1)
A decreased ceruloplasmin level
2)
An increase in the urine copper excretion
3)
Presence of corneal Kayser-Fleischer ring
4)
Large amounts of copper deposited in the liver (liver biopsy)
MRI - Imaging
Findings
Most MRI reports reveal low signal
intensities on T1WI and high signal intensity on
T2WI in the basal ganglia, due to copper deposits. Few unusual findings
have been
mentioned in case reports: high signal intensities in the basal
ganglia on T1 (in a patient
with a porto-systemic shunt + encephalopathy) and enhancement of the
cerebral cortex
and cortico-medullary junction on MRI contrast study.
Dr. Deepak
Patkar, MRI Center, Nanavati Hospital, Mumbai
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