Further diffusion tensor imaging contribution in horizontal gaze palsy and progressive scoliosis

Abstract

-In two siblings with clinical diagnosis of horizontal gaze palsy associated with progressive scoliosis (HGPPS) we could demonstrate by diffusion tensor imaging: (1) An anterior displacement of the transverse pontine fibers; (2) Posterior clumping of the corticospinal, medial lemniscus and central tegmental tracts and of the medial and dorsal longitudinal fasciculi complex; (3) Absent decussation of superior cerebellar peduncle. Those findings can contribute as surrogate markers for the diagnosis.Key wordS: diffusion, scoliosis, palsy, MrI.contribuição adicional das imagens por tensores de difusão em paralisia do olhar conjugado horizontal associada a escoliose progressiva resumo -em dois irmãos com diagnóstico clínico de paralisia do olhar conjugado horizontal associada a escoliose progressiva, foi possível determinar através de imagens por tensores de difusão: (1) deslocamento anterior das fibras pontinas transversas; (2) Agrupamento posterior do trato córtico-espinhal, lemnisco medial e trato tegmentar central e complexos dos fascículos longitudinais medial e dorsal; (3) Ausência da decussação dos pedúnculos cerebelares superiores. Tais achados podem contribuir como marcadores para o diagnóstico.

Human disorders of axon guidance

“…Cerebellar neuronal migration, axonal and neuronal midline crossing, and nucleus cytoarchitecture are abnormal in Robo3 −/− mice, which further substantiates abnormal cerebellar tracts noted in DTI of HGPPS patients [12,14,15,25]. Interestingly, mouse precerebellar neurons require a translational regulatory protein, Musashi1, for protein expression of Robo3.1 and 3.2 in order to permit proper cerebellar neuron and axonal midline crossing events [26].…”

“…Sensorimotor evoked potential studies in a second patient revealed ipsilateral CST but partial crossing of the dorsal column tracts, suggesting there may be some variability in midline crossing defects within and between patients [4]. DTI of HGPPS patients revealed that cerebellar tracts are also uncrossed or abnormally located, which may contribute to progressive scoliosis [12,14,15]. FMRI and brainstem auditory evoked potential (BAEP) studies indicate that HGPPS patients also have abnormal activation of auditory pathways [4,13].…”

Lissencephalies and Axon Guidance Disorders

“…Clinical findings characteristic of HGPPS include absence of all horizontal gaze reflexes, conjugate pendular nystagmus, and progressive scoliosis (Bomfim et al, 2009;Engle, 2010;Otaduy et al, 2009). Affected individuals are born with restricted horizontal gaze and develop scoliosis within the first decade of life (Engle, 2010;Otaduy et al, 2009).…”

“…The differential diagnosis of HGPPS embraces several genetic disorders of eye movement, such as Duane retraction syndrome (DRS), Möbius syndrome, and others (Bomfim et al, 2009;Otaduy et al, 2009). Clinical and neuroimaging findings can differentiate these entities from HGPPS (Bomfim et al, 2009).…”

“…nlm.nih.gov/omim) (Amouri et al, 2009;Avadhani et al, 2010;Bomfim et al, 2009;Engle, 2010;Otaduy et al, 2009). nlm.nih.gov/omim) (Amouri et al, 2009;Avadhani et al, 2010;Bomfim et al, 2009;Engle, 2010;Otaduy et al, 2009).…”