Spectrum Disorder; mailing address: 675 Valley- illustrate the possibility of a shared neurode- wood Drive SE, Salem, OR 97306; e-mail: velopmental origin. Comparing the similari- Ͻ[email protected]Ͼ. D. Jay Gense, Ed.S., di- rector, National Consortium on Deaf-Blindness, ties in these conditions may lead to a greater Teaching Research Institute, Western Oregon Uni- understanding of the risk factors contributing versity; mailing address: NCDB, Western Oregon to either condition, as well as potential clini- University, 345 N, Monmouth, OR 97361; e-mail: Ͻ[email protected]Ͼ. cal outcomes, as the relationship is further explored. Optic Nerve Hypoplasia and ASD AND BLINDNESS Autism: Common Features It is not surprising that ASDs are prevalent in of Spectrum Diseases children with ONH when one considers that Cassandra Fink and Mark Borchert published data indicate ASDs are overrepre- Autism is a developmental disorder charac- sented in the visually impaired population, terized by impaired social interaction, prob- with prevalence estimates as high as 1 case of lems in verbal and nonverbal communication, autism in every 4 visually impaired persons and stereotyped or repetitive activities and (Brown, Hobson, Lee, & Stevenson, 1997), interests. Rather than a single condition, au- compared to 1 out of 110 in the general pop- tism is today generally regarded as consisting ulation (Rice, 2009). The behaviors and char- of a spectrum of pervasive developmental dis- acteristics of children with vision impairment orders that together are known as autism that resemble those of children with ASDs, spectrum disorders (ASDs). including echolalia, pronoun reversal, stereo- Optic nerve hypoplasia (ONH) is a congenital typic motor movements, and delays in devel- condition characterized by underdeveloped op- oping pretend play, are often attributed to the tic nerves and neurological impairment involv- vision impairment itself (Andrews & Wyver, ing endocrine dysfunction and developmental 2005). These behaviors may be termed delay, with or without brain malformations that “blindisms,” since they are explainable in the are visible by way of neuroimaging tools. In- context of vision impairment. (For example, creasing in prevalence, ONH is now the leading rocking or spinning may provide needed ves- single ocular cause of blindness in children in tibular stimulation in a child with limited mo- the developed world, affecting 10.9 per 100,000 bility due to lack of vision; language devel- births (Patel, McNally, Harrison, Lloyd, & opment and social interactions may be Clayton, 2006; Hatton, Schwietz, Boyer, & Ry- impaired in congenitally blind children due to chwalski, 2007). their lack of concrete experiences and visual Clinical observations and recent reports in- models.) The similarity of these “blindisms” dicate a high frequency of ASDs in children to “autistic-like” behaviors, coupled with the with ONH (Ek, Fernell, & Jacobson, 2005; absence of autism diagnostic measures de- Parr, Dale, Shaffer, & Salt, 2010). In children signed for use with people who are blind or with ONH, there are additional characteristics visually impaired, complicates the diagnosis of ASD beyond those attributable to visual of ASDs in children who are visually im- impairment alone, such as echolalia and ste- paired.” Thus, the debate concerning whether reotypic motor movements. We argue that “true” autism is prevalent in children who are ONH, like ASDs, should be considered a visually impaired remains unresolved. spectrum disorder to account for the range of severity in outcomes and symptoms associ- ASDS AND ONH ated with this condition. In addition, we be- Most reports of ASDs in children with vision lieve the similarities in the two conditions impairment (ASDVI) are limited to children 334 Journal of Visual Impairment & Blindness, June 2011 ©2011 AFB, All Rights Reserved who have severe congenital blindness regard- of ASDs reported by Parr and colleagues less of any cause (Brown, Hobson, Lee, & (2010), all of which have demonstrated high Stevenson 1977; Ek, Fernell, Jacobson, & levels of autism characteristics in children Gillberg, 1998). There are a few reports fo- with ONH. This finding lends support to the cused specifically on children with ONH. In a concept of there being a neurological basis, group of 13 Swedish children with ONH and rather than a visual reason, for these behav- blindness, 6 had ASDs and 3 had “autistic- iors and impaired social interaction and com- like” conditions. The remaining 4 children did munication since the study on ONH included not fall on the autism spectrum (Ek, Fernell, children of varying levels of vision, including & Jacobson, 2005). Parr and colleagues re- those with unilateral ONH. Therefore, the ported in a sample of 83 children with ONH ASD behaviors cannot be attributed solely to and severe vision impairment (with acuities the vision impairment. Both autism and ONH of worse than 6/30), 31 (37%) had social, are neurological conditions, thus the ASD be- communicative, and repetitive or restricted haviors are likely neurological in origin. behavioral difficulties. The majority of those Although making an accurate diagnosis of (26 out of 31) were clinically diagnosed with autism is a problem in evaluating children autism (Parr, Dale, Shaffer, & Salt, 2010). with ONH, the similarities between ASDs and Unlike the previous studies of ASDs and ONH extend beyond the characteristics and ONH that focused only on children with se- behaviors assessed with measures for ASDs, vere visual impairment, a prospective study of and the overlap is striking. Characteristics of children with ONH (Garcia-Filion, Epport, autism that have been observed clinically in Nelson, Azen, Geffner, Fink et al., 2008) children with ONH include: repetitive behav- studied children with a range of visual im- ior; echolalia; “sing-song” language tone; dif- pairment from mild to severe. A modified ficulty engaging in the give and take of version of the Social Responsiveness Scale interactions; obsessions; nonocular self- was implemented at age 5 years with a subset stimulatory behaviors; hypersensitivity to cer- of 46 children from the original cohort to tain sounds, textures, tastes, and smells; and screen for ASDs. In this pilot study, based on other behaviors that are qualitatively different parent reports, 21 (46%) of the participants and result in more functional impairment than demonstrated deficiencies in reciprocal social the behaviors seen in children with other behavior (social awareness and the ability to types of visual impairments. Other character- participate in give and take communication), istics shared by children with ONH and those and more than half of that group (12) scored with ASDs that are not diagnostic features of in the severe range on the scale. In a typical ASDs, include neuro-radiographic findings, population, the severe range of reciprocal so- seizures, gastrointestinal (GI) disturbances, cial behavior is associated with a clinical di- and sleep dysfunctions. agnosis of autism. This screening measure, An example of comparable impairment in however, has not been validated for children central nervous system connectivity is the re- with visual impairment; therefore, the associ- duction in the size of the corpus callosum as ation of the scores on the Social Responsive- illustrated on magnetic resonance imaging ness Scale with a diagnosis of autism cannot (MRI) for children with both conditions. Cor- be confirmed. Despite including children with pus callosum is the structure in the brain that a range of visual acuities, including those connects the two hemispheres, accounting for with unilateral ONH, among the sample, the much of the inter-hemispheric communica- findings from this prospective study of chil- tion in the brain. In a sample of children with dren with ONH are consistent with the rates ASDs, Vidal and colleagues detected signifi- ©2011 AFB, All Rights Reserved Journal of Visual Impairment & Blindness, June 2011 335 cant reductions in the genu and splenium re- (41%) than in their siblings without autism gion of the corpus, where fibers from the (9%) or their parents (24%) (Campbell, Buie, orbitofrontal cortex, the parahippocampal Winter, Bauman, Sutcliffe, Perrin et al., gyrus, and the visual association cortex, re- 2009). Constipation was the most commonly spectively, cross the midline (Vidal, Nicol- reported GI problem (Valicenti-McDermott, son, DeVito, Hayashi, Geaga, Drost et al., McVicar, Rapin, Wershil, Cohen, & Shinnar, 2006). This finding is important, because the 2006). orbitofrontal cortex may play a role in the Rates of reported sleep disturbances in indi- interpretation of social and emotional cues, a viduals with ASDs are variable, but are often skill many children with ASD lack. Likewise, more than 50%. For example, in a study of 59 in the prospective study of children with children with an ASD and 40 typically devel- ONH, 39% had corpus callosum hypoplasia, oping control subjects, parent-reported sleep and this was significantly associated with in- disturbances using the Children’s Sleep Habits creased risk for impaired personal-social and Questionnaire, as well as actigraphic data, dem- adaptive skills (Garcia-Filion et al., 2007). In onstrated that 66% of subjects with ASDs and children with ONH, the rates of corpus cal- 45% of control subjects had sleep disturbances losum hypoplasia between those with and (Souders, Mason, Valladares, Bucan, Levy, without autism have not yet been examined. Mandell et al., 2009). Rivkees and colleagues