title: Degeneration and plasticity of the optic pathway in Alström syndrome.
abstract: OBJECTIVE
  Alström syndrome is a rare inherited ciliopathy in which early progressive cone-rod dystrophy leads to childhood blindness. We investigated functional and structural changes of the optic pathway in Alström syndrome by using MR imaging to provide insight into the underlying pathogenic mechanisms.
  
  
  METHODS
  Eleven patients with genetically proved Alström syndrome (mean age, 23 years; range, 6-45 years; 5 females) and 19 age- and sex-matched controls underwent brain MR imaging. The study protocol included conventional sequences, resting-state functional MR imaging, and diffusion tensor imaging.
  
  
  RESULTS
  In patients with Alström syndrome, the evaluation of the occipital regions showed the following: 1) diffuse white matter volume decrease while gray matter volume decrease spared the occipital poles (voxel-based morphometry), 2) diffuse fractional anisotropy decrease and radial diffusivity increase while mean and axial diffusivities were normal (tract-based spatial statistics), and 3) reduced connectivity in the medial visual network strikingly sparing the occipital poles (independent component analysis). After we placed seeds in both occipital poles, the seed-based analysis revealed significantly increased connectivity in patients with Alström syndrome toward the left frontal operculum, inferior and middle frontal gyri, and the medial portion of both thalami (left seed) and toward the anterior portion of the left insula (right and left seeds).
  
  
  CONCLUSIONS
  The protean occipital brain changes in patients with Alström syndrome likely reflect the coexistence of diffuse primary myelin derangement, anterograde trans-synaptic degeneration, and complex cortical reorganization affecting the anterior and posterior visual cortex to different degrees.
authors.affiliation: From the Department of Medicine and Surgery (R.M., A.V., F.D.S.), Neuroradiology, University of Salerno, Salerno, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Manara
authors.affiliation: Department of Radiology (V.C.), Neuroradiology Unit, IRCCS San Camillo Hospital, Venezia, Italy valentinacitton@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Citton
authors.affiliation: Department of Internal Medicine (P.M., G.M., R.V.), University Hospital of Padova, Padova, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Maffei
authors.affiliation: Jackson Laboratory (J.D.M., J.K.N.), Bar Harbor, Maine.
authors.forename: J D
authors.initials: JD
authors.lastname: Marshall
authors.affiliation: Jackson Laboratory (J.D.M., J.K.N.), Bar Harbor, Maine.
authors.forename: J K
authors.initials: JK
authors.lastname: Naggert
authors.affiliation: Department of Internal Medicine (P.M., G.M., R.V.), University Hospital of Padova, Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Milan
authors.affiliation: Department of Internal Medicine (P.M., G.M., R.V.), University Hospital of Padova, Padova, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Vettor
authors.affiliation: Department of Neurosciences (A.B., C.B., A.F.), University of Padua, Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Baglione
authors.affiliation: From the Department of Medicine and Surgery (R.M., A.V., F.D.S.), Neuroradiology, University of Salerno, Salerno, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Vitale
authors.affiliation: Department of Neurosciences (A.B., C.B., A.F.), University of Padua, Padova, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Briani
authors.affiliation: From the Department of Medicine and Surgery (R.M., A.V., F.D.S.), Neuroradiology, University of Salerno, Salerno, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Di Salle
authors.affiliation: Department of Neurosciences (A.B., C.B., A.F.), University of Padua, Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Favaro
mesh_terms: D000293:Adolescent; D000328:Adult; D056769:Alstrom Syndrome / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D002648:Child; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009473:Neuronal Plasticity / Q000502:physiology; D014795:Visual Pathways / Q000473:pathology*; D055815:Young Adult