Proton MR spectroscopy in connatal Pelizaeus-Merzbacher disease.
BACKGROUND
Pelizaeus-Merzbacher disease (PMD) is a rare dysmyelinating disorder characterised by early pendular nystagmus, often rotatory and muscular hypotonia with subsequent ataxia, spasticity and mental retardation. Various point mutations or duplications in the PLP gene on the X chromosome are responsible for PMD in the majority of patients. Autosomal recessive inheritance, particularly in the connatal form, cannot be excluded. Three different forms of the disease have been identified based on their onset, progression and severity of myelin pathology indicated by MRI features. Objective. To determine if MR spectroscopy is useful in the diagnosis of the connatal form of PMD.


METHODS
Proton MR spectroscopy was performed on two children with connatal PMD.


RESULTS
Our patients showed a markedly decreased peak of Cho. This alteration is well represented by quantitative analysis of the NAA-to-Cho ratio, which is the most important ratio affected. A significant decrease of the Cho-to-Cr ratio is also present. In the connatal form of PMD, global lack of myelination may be relevant, as demonstrated by a significant Cho peak reduction.


CONCLUSIONS
Proton MR spectroscopy may be of diagnostic value in metabolic and destructive disorders of the brain. A greater number of patients with connatal PMD is needed in order to elucidate the significance of reduction of the Cho peak.
Spalice
A
A
Paediatric Department, University La Sapienza, Rome, Italy.
Popolizio
T
T
Parisi
P
P
Scarabino
T
T
Iannetti
P
P
D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D002648:Child; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D020371:Pelizaeus-Merzbacher Disease / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology