This poster was originally presented at the RANZCR Annual Scientific Meeting 2011, October 6-9, in Melbourne/AU.
Congress:
RANZCR ASM 2011
Keywords:
Paediatric, Neuroradiology brain, MR physics, MR, MR-Diffusion/Perfusion, Congenital, Genetic defects
Authors:
S. Bhuta, C. Hsu, G. Kwan; Gold Coast/AU
DOI:
10.1594/ranzcr2011/R-0109
Purpose
The aim of our study was to extend the previously reported phenotypic-neuroradiologic correlation by studying three patients with JS.
To evaluate the white matter tracts by using diffusion tensor imaging (DTI)and demonstrate abnormal white matter tracts a step beyond well described "Molar Tooth Sign".
These findings were compared with normal age matched control subjects.
INTRODUCTION
Joubert syndrome (JS) is a rare disorder with an incidence of 1/80,000 to 1/100,000 live births.1,2 It is characterized by complex malformation of the midbrain-hindbrain,
with the so-called molar tooth sign on axial imaging.3 This results from vermis hypoplasia,
a deep interpeduncular fossa,
and thickened,
elongated,
and abnormally horizontal superior cerebellar peduncles.3 JS is clinically characterized by hypotonia evolving into ataxia and developmental delays.4 The term "Joubert Syndrome and Related Disorders" (JSRD) represents the pathognomonic neuroradiological features of the molar tooth sign associated with the variable involvement of other organs and systems,
mainly the eyes and kidneys.5 Genetic heterogeneity mirrors the clinical heterogeneity of JSRDs,
with several genes involved identified (Fig 1 and Fig 2).
Common features associated with all subgroups of JSRDs include oculomotor apraxia,
nystagmus,
mental retardation of variable severity,
neonatal respiratory abnormalities and dysmorphic features.5