Neurovisual Assessment in Children with Ataxia Telangiectasia

Abstract

Aim Visual impairment is present in almost all patients with ataxia telangiectasia (AT) and, due to their early onset, constitute an important disabling aspect of the syndrome: the quality of vision is limited by dyspraxia and oculomotor abnormal movements. The purpose of this observational study was to describe visual disorders, notably oculomotor impairment, in a sample of children with AT.

Methods Fifteen AT patients (mean age 12 years and 4 months) underwent a neurovisual evaluation, particularly focused on oculomotor functions (fixation, smooth pursuit, saccades, and abnormal ocular movements). We compared the visual profile obtained with that described using the International Cooperative Ataxia Rating Scale (ICARS) subscale of oculomotor dysfunction.

Results Refractive errors were seen in eight patients and strabismus in three. Major oculomotor findings were fixation abnormalities (6/15), saccadic impairment (15/15), and abnormal smooth pursuit (14/15). Abnormal ocular movements were seen in 13/15 (saccadic intrusion in 8 and nystagmus in 5). Using ICARS scale, 13/15 children presented gaze-evoked nystagmus, 4/15 a clearly saccadic pursuit, and 11/15 dysmetria of saccades.

Discussion We propose a clinical neurovisual evaluation, which could be integrated with ICARS scores in the study of oculomotor involvement in AT pediatric patients. We strongly recommend the empowerment of visual functions to slow down progressive global disability of these patients.

Keywords

ataxia telangiectasia - neurovisual disorders - oculomotor dyspraxia - International Cooperative Ataxia Rating Scale

• References

• 1 Nissenkorn A, Ben-Zeev B. Ataxia telangiectasia. Handb Clin Neurol 2015; 132: 199-214
• 2 Baloh RW, Yee RD, Boder E. Eye movements in ataxia-telangiectasia. Neurology 1978; 28 (11) 1099-1104
• 3 Stell R, Bronstein AM, Plant GT, Harding AE. Ataxia telangiectasia: a reappraisal of the ocular motor features and their value in the diagnosis of atypical cases. Mov Disord 1989; 4 (04) 320-329
• 4 Smith JL, Cogan DG. Ataxia-telangiectasia. Arch Ophthalmol 1959; 62: 364-369
• 5 Lewis RF, Lederman HM, Crawford TO. Ocular motor abnormalities in ataxia telangiectasia. Ann Neurol 1999; 46 (03) 287-295
• 6 Chun HH, Gatti RA. Ataxia-telangiectasia, an evolving phenotype. DNA Repair (Amst) 2004; 3 (8-9): 1187-1196
• 7 Nissenkorn A, Levi YB, Vilozni D. , et al. Neurologic presentation in children with ataxia-telangiectasia: is small head circumference a hallmark of the disease?. J Pediatr 2011; 159 (03) 466-471.e1
• 8 Cogan DG. A type of congenital ocular motor apraxia presenting jerky head movements. Am J Ophthalmol 1953; 36 (04) 433-441
• 9 Farr AK, Shalev B, Crawford TO, Lederman HM, Winkelstein JA, Repka MX. Ocular manifestations of ataxia-telangiectasia. Am J Ophthalmol 2002; 134 (06) 891-896
• 10 Shaikh AG, Marti S, Tarnutzer AA. , et al. Ataxia telangiectasia: a “disease model” to understand the cerebellar control of vestibular reflexes. J Neurophysiol 2011; 105 (06) 3034-3041
• 11 Shaikh AG, Marti S, Tarnutzer AA. , et al. Gaze fixation deficits and their implication in ataxia-telangiectasia. J Neurol Neurosurg Psychiatry 2009; 80 (08) 858-864
• 12 Nissenkorn A, Borgohain R, Micheli R. , et al. Development of global rating instruments for pediatric patients with ataxia telangiectasia. Eur J Paediatr Neurol 2016; 20 (01) 140-146
• 13 Fazzi E, Signorini SG, Bova SM. , et al. Spectrum of visual disorders in children with cerebral visual impairment. J Child Neurol 2007; 22 (03) 294-301
• 14 Fazzi E, Signorini SG, LA Piana R. , et al. Neuro-ophthalmological disorders in cerebral palsy: ophthalmological, oculomotor, and visual aspects. Dev Med Child Neurol 2012; 54 (08) 730-736
• 15 Krippendorff K. Agreement and information in the reliability of coding. Commun Methods Meas 2011; 5: 93-112
• 16 Panouillères M, Frismand S, Sillan O. , et al. Saccades and eye-head coordination in ataxia with oculomotor apraxia type 2. Cerebellum 2013; 12 (04) 557-567
• 17 Yang Q, Bucci MP, Kapoula Z. The latency of saccades, vergence, and combined eye movements in children and in adults. Invest Ophthalmol Vis Sci 2002; 43 (09) 2939-2949
• 18 Brecht M, Singer W, Engel AK. Amplitude and direction of saccadic eye movements depend on the synchronicity of collicular population activity. J Neurophysiol 2004; 92 (01) 424-432
• 19 Marple-Horvat DE, Crowdy KA. Direct visualisation of gaze and hypometric saccades in cerebellar patients during visually guided stepping. Gait Posture 2005; 21 (01) 39-47
• 20 Leuzzi V, Micheli R, D'Agnano D. , et al. Positive effect of erythrocyte-delivered dexamethasone in ataxia-telangiectasia. Neurol Neuroimmunol Neuroinflamm 2015; 2 (03) e98
• 21 Moncayo J, Bogousslavsky J. Eye movement abnormalities. Front Neurol Neurosci 2012; 30: 13-16
• 22 Thurtell MJ, Leigh RJ. Nystagmus and saccadic intrusions. Handb Clin Neurol 2011; 102: 333-378
• 23 Nyström M, Andersson R, Holmqvist K, van de Weijer J. The influence of calibration method and eye physiology on eyetracking data quality. Behav Res Methods 2013; 45 (01) 272-288
• 24 Bodranghien F, Bastian A, Casali C. , et al. Consensus paper: revisiting the symptoms and signs of Cerebellar Syndrome. Cerebellum 2016; 15 (03) 369-391
• 25 Guo Z, Kozlov S, Lavin MF, Person MD, Paull TT. ATM activation by oxidative stress. Science 2010; 330 (6003): 517-521
• 26 Sahama I, Sinclair K, Pannek K, Lavin M, Rose S. Radiological imaging in ataxia telangiectasia: a review. Cerebellum 2014; 13 (04) 521-530