Tourette Syndrome and Learning Disabilities Larry Burd, David W. Kauffman, and Jacob Kerbeshian

We reviewed the records of 42 consecutive cases of children with Tourette Syndrome (TS) who had IQs above 70, and contrasted the reading, reading comprehension, math, and spelling quotients with IQ scores to determine how many would meet criteria for a learning disability. The mean IQ of the 35 males and 7 females was 94.4 and was higher than the mean math score (82.8), spelling score (90.4), reading score (87.4), and reading comprehension score (85.3). Using a 1.5 standard deviation discrepancy, 51% met criteria for learning disability in at least one academic area; 21% had a 2-standard-deviation discrepancy. Children with TS frequently have learning disabilities, and assessment of academic achievement should be a routine aspect in the evaluation of such children.

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n the past decade, major strides have been made in the conceptualization of developmental disorders. Recent findings suggest that the putative gene for Tourette Syndrome (TS) may be expressed as tics, multiple tics, TS, or obsessivecompulsive disorder (Pauls & Leckman, 1986; Pauls, Towbin, Leckman, Zahner, & Cohen, 1986). There is disagreement over the inclusion of obsessive-compulsive disorder as part of the TS phenotype (Shapiro, Shapiro, Young, & Feinberg, 1988). Other researchers have suggested that the expression of the TS phenotype can be expanded to include an even wider range of neuropsychiatric conditions (Comings, 1990); this issue has been extensively discussed elsewhere (Comings & Comings, 1988; Pauls et a l , 1988). Although the defining boundaries of TS are as yet unknown, what is clear is that TS is an extremely complex disorder that is very frequently associated with conditions such as obsessive-compulsive disorder (OCD)

and attention deficit-hyperactivity disorder (ADHD). The interaction of genetic, behavioral, and environmental factors in the emergence and expression of TS has been discussed elsewhere (Cohen, Detlor, Shaywitz, & Leckman, 1982). Previous reports have suggested that approximately 50% of children with TS also have a learning disability (Burd, Kerbeshian, Cook, Bornhoeft, & Fisher, 1988; Golden, 1984; Hagin, Beecher, Pagano, & Kreeger, 1982; Hagin & Kugler, 1988). Interpretation of these data is difficult because investigators have relied on various sources, such as questionnaire data (Burd et al., 1988; Comings & Comings, 1987; Jagger et al., 1982) or histories supplied by parents (Erenberg, Cruse, & Rothner, 1986), to determine the prevalence of learning disabilities in populations of children with TS. Previous studies have found that in some children, the onset of learning problems coincides with the onset of the tics (Burd et al., 1988). A small number of children

were doing well in school but, with the onset of tics, also saw the onset of significant learning problems. Interestingly, in some cases, those problems included letter and number reversals that had not been present previously. This specific finding occurred as late as the end of the third grade (Burd et al., 1988). Other studies have utilized neuropsychological testing and have found a wide range of neuropsychological impairments in children with TS (Ferrari, Mathews, & Barabas, 1984; Incagnoli & Kane, 1982; Lucas, Kauffman, & Morris, 1967; Shapiro, Shapiro, Young, & Feinberg, 1988; Sand, 1972). Such tests may not directly assess the core element in learning disabilities, which in many definitions is a discrepancy between ability (IQ) and academic achievement (Siegel, 1989). Studies that have directly assessed the relationship between IQ and academic achievement have found learning disabilities to occur in about 50% of children with TS (Bornstein, Carroll, & King, 1985; Hagin & Kugler, 1988; Joschko & Rourke, 1982). However, those studies relied on small samples and confirmation of their results are needed. In our practice, we see the majority of children with TS in North Dakota. In the present study, we sought to determine the proportion of children from our TS clinic population who meet North Dakota educational criteria for a learning disability.

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Three specific questions were posed: 1. How many children in the authors' TS clinic have a 1.5- and a 2.0standard-deviation discrepancy between academic achievement and intellectual potential in reading recognition, reading comprehension, math, or spelling? (Several other aspects of achievement were assessed, including written language, memory, and retention, but were not included because the measures used in assessment are too varied to allow for pooling of scores.) 2. How many of these children had received a diagnosis of LD in their school system? 3. How many children had a learning disability in more than one area?

Method Subjects This study reviews consecutive cases of TS seen since 1986. All patients met criteria for TS by DSM-III (American Psychiatric Association, 1980) or DSMIII-R (American Psychiatric Association, 1985) criteria. Records for all (104) children seen by the authors with a diagnosis of TS were reviewed. Patients were excluded from this frequency study if they were not between 84 months and 204 months of age (n = 16), if they had IQs below 70 (n=26), if they had severe sensory impairment (e.g., blindness, n = 9, or deafness, n=3), if they were nonverbal (n = 10), if they had such severe school phobia that their opportunities for traditional academic instruction had been severely limited (n = 8), or if they had an additional diagnosis of bipolar disorder (n=2) or schizophrenia (n=3). There were then 42 children (35 males and 7^ females) remaining from the original pool of 104. A number of children met more than one exclusion criterion. Because the authors care for most children from North Dakota with severe TS or children with TS and other developmental disorders, the patients

who were excluded may have had more severe developmental disorders than would typically be found in a population of children with TS. The exclusionary criteria were utilized to identify children who might not be appropriately classified as learning disabled even if a severe discrepancy between IQ and achievement were present. All children had English as a primary language. All evaluations and testing were usually accomplished in 1 or 2 months, but for a few children, the learning disability testing was delayed for up to 5 months. The age range (84 to 204 months) was selected to represent the age range that schools typically serve. The male to female ratio of children in this study was 5:1. When we completed the first prevalence study of TS in a defined population, a male to female ratio of 9 to 1 was found (Burd et al., 1988). Similar ratios have been consistently found in other prevalence studies of TS and appear to be a feature of the disorder (Caine, McBride, Chiverton, & Bamford, 1988; Comings, Himes, & Comings, 1990). The group mean age was 139 months (SD = 32.7 months) with a range of 84 to 204 months. The mean age was 137 months for males and 150 months for females.

Procedure The charts of the 42 children with a diagnosis of TS were then reviewed for the presence of learning disabilities. Data from a questionnaire completed by the teacher provided information about the child's class rank in each subject area and about several areas of behavior. Information was reviewed on previous intervention strategies attempted by the school and parents, including modifications of teaching strategies, tutoring sessions, curricular changes, and workload adjustments. The information on class rank and on modifications made by the teacher was supplemented with interviews of the child and the child's parents to determine their opinions of his or her problems. Assessments using the child's

current school materials and a review of attached samples of work provided by the teacher were also included. Specific testing to determine achievement in each of the academic areas and follow-up evaluations using curriculum-based procedures and other measures deemed appropriate were also reviewed. We utilized data on the academic scores obtained from the Wide Range Achievement Test (WRAT) (Jastak & Jastak, 1978) and the Peabody Individual Achievement Test (PIAT) (Dunn & Markwardt, 1970). The revised editions of both tests were also used as they became available. In order to keep our data comparable, we utilized only the subject areas of reading, reading comprehension, math, and spelling. The IQ data were obtained from the Wechsler Intelligence Scale for Children-Revised (Wechsler, 1974) and the Stanford-Binet Intelligence Scale (Thorndyke, Hagen, Stattler, & Merrill, 1985). Additional information was obtained from an extensive data base completed by the child's teachers, principal, and parents. When available, representative samples of the child's daily work and school tests were reviewed. The parents were interviewed before the assessment and, when warranted, the teachers were contacted by telephone to address specific questions. Copies of all school records, including any previous IQ or achievement testing, were also obtained and reviewed. To be considered to have a learning disability, children had to have met the following criteria: 1. Show achievement that was believed to be below their potential. This discrepancy must be 1.5 standard deviations or more below measured IQ on a normed measure of achievement. In the present study, we used primarily the PIAT or PIAT-R (Markwardt, 1989). For math and spelling, either the WRAT or the PIAT scores were used. 2. Have a disrepancy on testing confirmed by a supplemental assessment using the child's school mate-

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rials and class rank in a subject, or by competency-based assessment of skills and class rank in an individual academic area. 3. Have any ability-achievement discrepancy judged not to be due to a sensory deficit, cultural or language differences, or a lack of opportunity to learn (e.g., school phobia causing a child to miss the majority of the school year). 4. Have the results reviewed by a multidisciplinary team and the appropriate diagnosis believed to be a learning disability. The team consisted of a clinical psychologist, a speech-language pathologist, an occupational therapist, a social worker, a nurse, a child psychiatrist, and an educational specialist. During this review the child's developmental and medical history was discussed. If a family history of a developmental disorder was noted, this was also discussed. The team paid careful attention to the presence of familial problems with attention, concentration, or achievement during this review. The individual disciplines that either evaluated the child or had information presented their findings. At the conclusion of this discussion, the team formulated a diagnosis and discussed recommendations. This information was then conveyed to the parents and school, with written reports by each discipline provided to parents, school, family physician, and other relevant entities. Statistical

Methods

This procedure allowed us to operationalize the state of North Dakota's definition of a learning disability. The data analysis consisted of development of group means and standard deviations for age and sex. T tests were used to compare the ages of the two genders. A one-way analysis of variance was completed on IQ-achievement scores and followed by post hoc comparisons of mean scores for the in-

dividual academic areas using the Tukeys HSD procedure. Confidence intervals were calculated at the 95% level. The IQ-achievement discrepancy scores were calculated for each child in each subject area using the z-score discrepancy method (Telzrow, 1985). The adequacy of the discrepancy model has been criticized on both operational and theoretical grounds (Rispens, van Yperen, & van Duijn, 1991). Although the formula may also be criticized because it does not correct for test reliability or regression toward the mean, it is still the most widely used in public education in North Dakota and thus is useful for defining this population.

Results Table 1 lists the individual IQ and academic scores of the children in this study. The females' mean age was 150 months but was not statistically different from the males' mean age of 137 months. A one-way, within-subjects ANOVA was conducted and found to be significant, F(3,108) = 6.15, p< .001. Subsequent post hoc comparisons between individual means were done using the Tukey's HSD procedure and are reported at the .05 level. The IQ scores were significantly higher than the math quotients or the spelling quotients. In addition, the mean reading quotient was significantly higher than the mean math quotient. The ranges, means, and standard deviations and 95% confidence intervals for age, IQ, and achievement scores are presented in Table 2. From our population of 42 children with TS whose IQs were above 70, we found that 51% met criteria for a 1.5 standard deviation IQ-specific academic skill discrepancy in one subject area, 21% met criteria in two or more areas, and 11% in three or more areas. Using a 2.0 standard deviation discrepancy, 21% met criteria for a learning disability in one area, 9.5% in two areas, and 2.4% in all three areas. Table 3 demonstrates the frequency of 1.5

and 2.0 standard deviation discrepancies. As can be seen, learning disabilities in math and spelling are the most frequent.

Discussion The findings reported here are from the largest sample of children with TS to have ever been evaluated for the presence of a learning disability. The children came from a rural area and most have been followed for a period of years. Hagin and Kugler (1988) reported that in a population of 26 children with TS, 16% were below expectancy in reading, 40% in reading comprehension, 52% in spelling, and 56% in math. In another study (Erenberg et al., 1986), parents reported that 22% of 200 TS pediatric patients had a learning disability. Our data showed that in a rural population of clinicascertained children with TS, 51% evidenced a learning disability in at least one subject and 21% exhibited disabilities in two or more areas. In our experience, the severity of the learning disabilities in children with TS tends to lessen over time. This improvement over time is consistent with the notion that TS represents a marker for improvement in other developmental conditions, such as the pervasive developmental disorders (Burd, Fisher, Kerbeshian, & Arnold, 1987; Fisher, Burd, & Kerbeshian, 1988). The presence of learning disabilities across the age groups in this study suggests that evaluation of children with TS for a learning disability is appropriate regardless of the age of onset or recognition of the TS. In North Dakota the diagnosis of learning disability in a public school setting requires evidence of a severe discrepancy between ability and achievement that cannot be explained by any of the exclusionary factors, that is, poor vision, hearing impairment, cultural and linguistic factors, or poor school attendance. We applied these same criteria in our study. We did utilize behavioral observations from the

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children's teachers and other school personnel but did not involve them in our diagnostic team discussions about the children. In our experience, less than 25% of children with TS have their learning disabilities diagnosed in a school setting. Given the results of recent reports that learning disabilities are frequently underdiagnosed, some of these evaluations may need to be done in a center apart from the school (Shaywitz, Shaywitz, Fletcher, & Escobar, 1990). A model program for the educational evaluation of children with TS has been suggested wherein a wider range of staff familiar with TS can be utilized (Burd, 1992; Burd & Kerbeshian, in press). As noted elsewhere, the tics and other symptoms of TS, coupled with poor academic achievement, are often attributed to disruptive behavior (Burd et al., 1988). This attribution appears even more likely to occur in children who have ADHD in addition to TS, as their academic performance tends to fluctuate widely, especially in math and handwriting (Burd et al., 1988). In many cases this fluctuation is felt to represent poor motivation ("I know he can do the work because he did it once") or resistance ("If he would quit trying to impress his classmates he could finish his work").

Management Suggestions The single most important element of a successful remediation program is accommodation of the child's individual needs. Strategies that have been successful in our experience are briefly reviewed here. Such remediation efforts are primarily focused on development of appropriate compensation skills for the child, teacher, and the child's peers. Successful management strategies in school also include the use of a longterm positive reinforcement, rewardoriented behavior management program targeting primarily behaviors we wish to see increase in frequency. This method has been utilized in our intervention strategies because for a

TABLE 1 Ages, Sex, IQ,and Academic Achievement Standard Scores (A/ == 42) Subject number

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 Means

Age

Full scale

(months)

IQ

110 150 111 204 122 125 187 150 122 90 192 93 89 175 126 105 173 157 140 167 173 148 153 195 149 117 192 121 178 95 127 170 120 124 174 144 129 120 120 116 84 106 139

119 100 118 90 104 81 117 84 72 105 96 79 80 91 104 93 89 113 90 112 76 101 109 71 78 118 78 109 95 99 80 91 103 96 82 91 93 102 89 113 82 71 95.7

Reading decoding

Reading comprehension

98 75 107 87 98 88 112 86 55 80 — 10 105 94 102 88 47 49 97 93 — 99 103 89 100 98 102 111 88 — 91 94 98 89 58 105 82 98 73 100 88 73

95 — 104 73 88 11

111 84 59 89 69 60 93 78 86 105 84 53 103 81 — 95 100 50 89 95 89 90 — — 92 — 93 82 88 100 — 91 74 100 82 70 97.7

90.4

small but significant number of children, cost-response or punishmentdependent behavioral programs have resulted in an exacerbation of tics and related behavior problems (Burd & Kerbeshian, 1987). Each year a child's new teachers should attend an inservice on TS, to demonstrate recognition and management of behavior problems

Math

69 52 95 28 101 82 111 42 — 80 69 — 93 102 105 93 88 74 65 78 __ 82 75 72 51 99 90 99 88 — 98 102 92 112 60 98 85 83 63 125 83 61 87.7

Spelling

96 83 95 — 97 89 118 33 — — 71 — 93 — — 106 — — 98 — — 110 — — — — 112 81 — — 81 — 85 97 — — — — — — 82 — 83.1

or different tics that may have emerged as the symptoms of TS change over time. We have utilized a standard homework plan that begins by taking a baseline on the average amount of homework the child can do successfully and then gradually increasing the amount (Burd, 1992). For example, rather than

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TABLE 2 Means and Standard Deviations on IQ and Achievement Scores Used in the Analysis of Variance3

Range Mean Standard deviation 95% confidence intervals

IQ

Reading decoding quotient

Reading comprehension quotient

Spelling quotient

Math quotient

71-119 95.7 13.82 91.1-100.3

10-112 90.4 15.25 85.3-95.5

50-111 87.7 20.1 75.6-89.6

33-118 83.13 20.64 76.3-90.0

42-115 87.76 16.25 82.3-93.1

Note. The mean IQ is significantly higher (at p

Tourette syndrome and learning disabilities.

We reviewed the records of 42 consecutive cases of children with Tourette Syndrome (TS) who had IQs above 70, and contrasted the reading, reading comp...
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