martedì 28 ottobre 2008
Vanderknaap disease - Megaloencephalic leukoencephalopathy with subcortical cysts (MLC)
Figure 1: Subcortical CSF intensity cyst in superior frontal and parietal lobe. Normal cerebellum.
Figure 2: CSF intensity subcortical cyst in superior parietal and anterior temporal lobe.
Figure 3: Diffusely swollen white matter (blue arrow). Preserved gray matter. CSF intensity subcortical cyst in anterior temporal lobe.
Figure 4: Diffusely swollen white matter. Preserved gray matter.
Figure 5: Cavum septum pellucidum. CSF intensity subcortical cyst in superior frontal and anterior temporal lobe. Normal basal ganglia.
Figure 6: Cavum septum pellucidum. CSF intensity subcortical cyst in superior frontal and anterior temporal lobe. Normal basal ganglia.
Diagnosis: Vanderknaap disease - Megaloencephalic leukoencephalopathy with subcortical cysts (MLC)
Vanderknaap disease is newly described rare leukoencephalopathies includes:
- 1. MLC - Megaloencephalic leukoencephalopathy with subcortical cysts
- 2. VWM - Leukoencephalopathy with vanishing white matter
- 3. WML - White matter disease with lactate
- 4. H-ABC- Hypomyelination with atrophy of the basal ganglia(BG) and cerebellum
Megaloencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukoencephalopathy with an autosomal recessive mode of inheritance. The disease is relatively prevalent among Turkish people and in a certain Asian-Indian community, the Agarwal ethnic group.
In MLC the cerebral hemispheric white matter is diffusely abnormal and swollen. There are almost invariably subcortical cysts in the anterior temporal region, often also in the frontal and parietal subcortical regions The cysts are bilateral. The cysts tend to become larger with age and may increase in number. In some patients they become very large, The signal intensity of the contents of the cysts is always similar to that of CSF. Cortical gray matter structures,corpus callosum and basal nuclei are always normal. A patent and enlarged cavum septi pellucidum and cavum vergae are often present.
Similar white matter changes with swelling have been reported in Canavan disease, Alexander disease, L-2-hydroxyglutaric aciduria, and merosin-deficient congenital muscular dystrophy. However, in Canavan disease, as a rule, MRI demonstrates additional involvement of the thalamus and globus pallidus, not found in MLC patients. Special MRI findings in Alexander disease are a more prominent sparing of parieto-occipital white matter and often also sparing of the U fibers throughout. Basal ganglia and brain stem structures are typically involved. Cavitation starts in the deep frontal white matter. None of these features is present in MLC. In L-2-hydroxyglutaric aciduria MRI shows additional involvement of caudate nuclei, putamen, dentate nuclei, and severe atrophy of the cerebellar vermis, not observed in MLC. The MRI abnormalities observed in merosin-deficient congenital muscular dystrophy are very similar to those observed in MLC.