High-Resolution Diffusion Tensor Imaging and Tractography in Joubert Syndrome: Beyond Molar Tooth Sign

Review of Ocular Manifestations of Joubert Syndrome

“…Additionally observed symptoms include frequent cyclic deviations of the eyes, including periodic alternating gaze deviation, periodic alternating skew deviation, periodic alternating torsional deviation, and a lateral alternating skew deviation that produces an alternating hyperdeviation of the abducting eye. [8,36,43,57,60,63,67,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90]. Wheel rolling torsional eye movements from extreme excyclodeviation to extreme incyclodeviation have also been observed in patients with periodic alternating skew deviation and paroxysmal skew deviation [91].…”

Tractography of the Cerebellar Peduncles in Second- and Third-Trimester Fetuses

“…The lack of decussation of the SCP, a characteristic feature of Joubert syndrome, results in a unique parallel configuration on postnatal tractography that could help the radiologist identify the disorder with greater certainty in fetal MR imaging. 32,33 Tractography of the cerebellar peduncles and other posterior fossa tracts could also help in the identification of a variety of axonal guidance disorders (eg, tubulinopathies, pontine tegmental cap dysplasia), which are known to harbor aberrations in white matter connections. 34,35 Tractography could also improve our understanding of the emerging abnormalities in the fetal cerebellum in disorders such as congenital heart disease and intrauterine growth restriction, which are known to impact cerebellar development.…”

Radiological Features of Joubert's Syndrome

“…Recently, diffusion tensor imaging (DTI) technique has given an insight into the underlying complex radiological findings in JS, especially on fiber tract abnormalities including absence and/or thinning of the dorsal pontocerebellar tract, abnormal thickening of the ventral pontocerebellar tract, abnormal decussation of superior cerebellar peduncles, and finally, the absence of red dot sign. 67 The Principal Ultrasound Findings of Joubert Syndrome The shepherd's crook sign must be also considered when evaluating patients for suspected JS. The arc of the crook is made by abnormal superior cerebellar peduncle and cerebellar hemisphere.…”

“…Recently, diffusion tensor imaging (DTI) technique has given an insight into the underlying complex radiological findings in JS, especially on fiber tract abnormalities including absence and/or thinning of the dorsal pontocerebellar tract, abnormal thickening of the ventral pontocerebellar tract, abnormal decussation of superior cerebellar peduncles, and finally, the absence of red dot sign. 67…”