Q. A 60 yrs old patient presents with rapidly progressive
dementia, myoclonic jerks, and periodic sharp-wave EEG tracing.CJD is
suspected.MR of brain was advised as MR
is highly sensitive and specific for the detection of CJD abnormalities.All are
true regarding CJD except
a. Lesions do not enhance and do not demonstrate mass
effect
b. DWIs is superior to over any T2-weighted images in the
assessment of CJD
c. DWI changes have been observed as early as 1 month after
the onset of symptoms
d. hyperintensity on DWI found in the cortex and basal
ganglia
e. primary sensorimotor cortex is almost always involved
ANS.----e
CJD patient shows symmetric increased signal in
T2-weighted images in the caudate nuclei , putamen, thalamus and cortex , basal
ganglia , periventricular white matter , and occipital lobes .In CJD.primary sensorimotor cortex
is almost always spared, even when extensive abnormalities are found in the
frontal and parietal cortex.
The mechanism of hyperintensity on
DWI found in the cortex and basal ganglia is poorly understood, although it
correlates with deposition of abnormal prion protein, vacuolation, neuronal
loss, and gliosis.
DWI changes have been observed as early as 1 month after the
onset of symptoms and may show modifications 6 months prior to T2-weighted
images and 4 months prior to FLAIR images
