MRI, volumetry, 1H spectroscopy, and cerebropetal blood flowmetry in childhood idiopathic anatomic megalencephaly.
OBJECTIVE
To evaluate cerebral abnormalities in childhood idiopathic anatomic megalencephaly (MC) by means of different magnetic resonance (MR) modalities.


METHODS
MRI, volumetry, spectroscopy, and cerebropetal blood flowmetry were performed in six children with idiopathic anatomic MC, and seven volunteers.


RESULTS
MRI revealed an increased ventricular system in five of six patients. A thalamic hamartoma was found in one patient and a Chiari I malformation was found in two. Volumetric analysis showed a disproportional increase of ventricular volume but normal subarachnoid cerebrospinal fluid (CSF) volume. Supratentorial volume was disproportionally increased compared to cerebellar volume. Intracranial volume correlated significantly with skull circumference. MR spectroscopy (MRS) N-acetyl aspartate/choline (NAA/Cho) peak ratios in WM were significantly higher in patients than in controls. Choline/creatine (Cho/Cr) peak ratios in WM were significantly lower in patients. Cortical gray matter (GM) MRS ratios were unaltered. Cerebropetal flow was increased in MC, possibly related to increased brain volume.


CONCLUSIONS
This study reveals associated developmental anomalies for idiopathic anatomic MC. A relative ventriculomegaly was found, which should not be misinterpreted as true hydrocephalus. In contrast to metabolic MC, MRS showed no severe disturbances. Total intracranial volume is correlated to skull circumference and cerebropetal blood flow.
Koudijs
Suzanne M
SM
Department of Child Neurology, University Medical Centre Utrecht, Utrecht, The Netherlands. s.m.koudijs@umcutrecht.nl
van der Grond
Jeroen
J
Hoogendoorn
Mechteld L C
ML
Hulshoff Pol
Hilleke E
HE
Schnack
Hugo G
HG
Witkamp
Theo D
TD
Gooskens
Rob H J M
RH
van Nieuwenhuizen
Onno
O
Braun
Kees P J
KP
D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001783:Blood Flow Velocity; D001921:Brain / Q000002:abnormalities*; D001927:Brain Diseases / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D002648:Child; D002675:Child, Preschool; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D006984:Hypertrophy; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D009929:Organ Size; D018709:Statistics, Nonparametric
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline