Hemimegalencephaly: A Study of Abnormalities Occurring Outside the Involved Hemisphere
N. Satoa,
A. Yagishitac,
H. Obad,
Y. Mikie,
Y. Nakataa,
F. Yamashitaf,
K. Nemotog,
K. Sugaib and
M. Sasakib
a Department of Radiology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
b Department of Child Neurology, National Center Hospital for Mental, Nervous, and Muscular Disorders, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
c Department of Neuroradiology, Tokyo Metropolitan Neurological Hospital, Kokubunji, Tokyo, Japan
d Department of Radiology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
e Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University School of Medicine, Kyoto, Kyoto, Japan
f Clinical Neuroscience, Medical Sciences for Control of Pathological Processes, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
g Department of Psychiatry, Ibaraki Prefectural Tomobe Hospital, Ibaraki, Japan
View larger version (133K):
[in this window]
[in a new window]
|
Fig 1. A 3-month-old boy with right hemimegalencephaly.
A and B, Coronal T2-weighted images demonstrate a diffusely enlarged right olfactory nerve from the exit to the distal portion (arrows). The left nerve is not enlarged.
B, Superficial cortical veins are asymmetrically dilated on the right (arrowheads).
| |
View larger version (61K):
[in this window]
[in a new window]
|
Fig 2. A 7-month-old boy with left hemimegalencephaly.
A, Axial FLAIR image shows an asymmetrically enlarged left optic nerve (arrow).
B, Coronal T1-weighted image reveals findings similar to those in A (arrow).
C, Coronal T2-weighted image reveals asymmetry of the olfactory nerves (arrow), as well, with the left one slightly larger than the right at the exit zone (arrowhead).
| |
View larger version (107K):
[in this window]
[in a new window]
|
Fig 3. An 8-month-old girl with right hemimegalencephaly. Axial T2-weighted image shows an asymmetrically dilated right internal cerebral vein (arrow).
| |
View larger version (161K):
[in this window]
[in a new window]
|
Fig 4. A 4-month-old boy with right hemimegalencephaly. Coronal T2-weighted image shows markedly dilated superficial cerebral cortical vessels (arrows) and subependymal veins (arrowhead) on the ipsilateral side.
| |
View larger version (77K):
[in this window]
[in a new window]
|
Fig 5. A 4-month-old girl with right hemimegalencephaly.
A, Axial T2-weighted image demonstrates asymmetry of the medulla oblongata and hemicerebellum with abnormal folia.
B, Axial T2-weighted image shows asymmetry of the pons and hemicerebellum.
C, Axial T2-weighted image also shows an asymmetric midbrain. The findings for this case are compatible with total hemimegalencephaly.
| |
View larger version (122K):
[in this window]
[in a new window]
|
Fig 6. A 4-month-old boy with left hemimegalencephaly.
A, Axial T2-weighted image shows an asymmetrically enlarged left hemicerebellum. No asymmetry of the brain stem is noted.
B, Coronal FLAIR image also shows asymmetry of both the left hemicerebrum and hemicerebellum.
| |
View larger version (84K):
[in this window]
[in a new window]
|
Fig 7. A 6-month-old boy with right hemimegalencephaly.
A and B, Coronal T2-weighted images demonstrate abnormal folia in both ipsilateral and contralateral cerebellar hemispheres.
| |
