Maria Camilla Rossi-Espagnet1,2, Martina Lucignani3, Luca Pasquini4,5, Antonio Napolitano3, Stefano Pro6, Andrea Romano5,7, Daria Diodato8, Diego Martinelli9, Daniela Longo4. 1. Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Piazza Sant'Onofrio 4, 00100, Rome, Italy. mcamilla.rossi@opbg.net. 2. NESMOS Department, Sant'Andrea Hospital, Sapienza University, Rome, Italy. mcamilla.rossi@opbg.net. 3. Medical Physics Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. 4. Neuroradiology Unit, Imaging Department, Bambino Gesù Children's Hospital, IRCCS, Piazza Sant'Onofrio 4, 00100, Rome, Italy. 5. NESMOS Department, Sant'Andrea Hospital, Sapienza University, Rome, Italy. 6. Neurology Unity, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. 7. Department of Odontostomatological and Maxillo-Facial Sciences, Umberto I Hospital, Sapienza University, Rome, Italy. 8. Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. 9. Division of Metabolism and Research Unit of Metabolic Biochemistry, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
Abstract
PURPOSE: Kearns Sayre syndrome (KSS) is a mitochondrial disorder characterized by development of visual impairment. Electroretinogram (ERG) and visual evoked potentials are not able to provide topographical information of optic damage. The purpose of this study was to explore retrochiasmatic optic pathway alteration in KSS with diffusion tractographic analysis and to compare it with different tracts. METHODS: DTI from 8 KSS subjects (14.7 years) and 10 healthy controls (HC) were acquired on a 3T scanner. Optic radiations (OR), optic tracts (OT), inferior frontooccipital fasciculus (IFOF) and corticospinal tract (CST) were reconstructed with probabilistic tractography. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial (RD), and axial diffusivity (AD) were calculated, evaluating group differences. T test on diffusion parameters identified significantly different track portions among cohorts. RESULTS: All patients had optic pathway alterations at electrophysiological examination. Significant lower FA were found in OT, IFOF, and CST of KSS group. RD was significantly higher in bilateral OR, IFOF, CST, and right OT, while ADC was higher in bilateral OR and CST. RD values were higher in the proximal and distal portion of OR bilaterally and in the distal portion of right OT, while widespread differences were found in IFOF and CST. No significant differences were found for AD. FA profiles analysis demonstrated significant differences between groups in several regions of OT, IFOF, and CST, while ADC assessment revealed spread differences in OR and CST. CONCLUSIONS: DTI evaluation of retrochiasmatic tracks may represent a useful tool to topographically investigate retrochiasmatic visual impairment in KSS.
PURPOSE:Kearns Sayre syndrome (KSS) is a mitochondrial disorder characterized by development of visual impairment. Electroretinogram (ERG) and visual evoked potentials are not able to provide topographical information of optic damage. The purpose of this study was to explore retrochiasmatic optic pathway alteration in KSS with diffusion tractographic analysis and to compare it with different tracts. METHODS: DTI from 8 KSS subjects (14.7 years) and 10 healthy controls (HC) were acquired on a 3T scanner. Optic radiations (OR), optic tracts (OT), inferior frontooccipital fasciculus (IFOF) and corticospinal tract (CST) were reconstructed with probabilistic tractography. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial (RD), and axial diffusivity (AD) were calculated, evaluating group differences. T test on diffusion parameters identified significantly different track portions among cohorts. RESULTS: All patients had optic pathway alterations at electrophysiological examination. Significant lower FA were found in OT, IFOF, and CST of KSS group. RD was significantly higher in bilateral OR, IFOF, CST, and right OT, while ADC was higher in bilateral OR and CST. RD values were higher in the proximal and distal portion of OR bilaterally and in the distal portion of right OT, while widespread differences were found in IFOF and CST. No significant differences were found for AD. FA profiles analysis demonstrated significant differences between groups in several regions of OT, IFOF, and CST, while ADC assessment revealed spread differences in OR and CST. CONCLUSIONS: DTI evaluation of retrochiasmatic tracks may represent a useful tool to topographically investigate retrochiasmatic visual impairment in KSS.
Authors: Nichola Z Lax; Graham R Campbell; Amy K Reeve; Nobuhiko Ohno; Jessica Zambonin; Emma L Blakely; Robert W Taylor; Eduardo Bonilla; Kurenai Tanji; Salvatore DiMauro; Evelyn Jaros; Hans Lassmann; Doug M Turnbull; Don J Mahad Journal: Arch Neurol Date: 2012-04
Authors: Klaus Schmierer; Claudia A M Wheeler-Kingshott; Daniel J Tozer; Phil A Boulby; Harold G Parkes; Tarek A Yousry; Francesco Scaravilli; Gareth J Barker; Paul S Tofts; David H Miller Journal: Magn Reson Med Date: 2008-02 Impact factor: 4.668