Current Status of Treatments for Dyslexia: Critical Review

Ann W. Alexander, MD; Anne-Marie Slinger-Constant, MD

Disclosures

J Child Neurol. 2004;19(10):744-758. 

In This Article

Research Relating to Linguistically Based Commercial Programs

When classroom-based programs are not sufficient, clinicians and teachers can turn to commercial treatment programs. Many commercial programs (Alphabetic Phonics, Project Read, the Herman Approach, Slingerland Approach, the Spalding Approach, the Wilson Approach, LANGUAGE! [see Appendix]) are based on the Orton-Gillingham approach.[32] This is a multisensory explicit phonics method with emphasis on visual and auditory feedback for sounds and the tactile-kinesthetic input of letter formation. This evidence-based treatment is the only method offering a complete intervention, including writing instruction, and has been the forerunner in the field. Unfortunately, there are few methodologically sound studies in peer-reviewed journals to validate its efficacy. Quasiexperimental studies were published by the International Multisensory Structured Language Education Council in 1995.[33] Many of the studies were hampered by either large, diverse groups of subjects or by inadequate numbers of subjects, by gains being reported in grade equivalents and not standard scores, by no long-term follow-up, and by the absence of control groups.

A study by Guyer and colleagues using the Wilson Reading System to treat the spelling deficits of college students is of interest, although the sample size was small.[34] There were three groups of 10 subjects.a no-treatment control group, a group receiving intervention via the Wilson Reading System spelling approach, and a third group receiving treatment via a nonphonetic spelling approach. After 2 hours/week for 16 weeks, the students receiving the Wilson Reading System manifested significant gains in contrast to the other groups; spelling scores on the Wide Range Achievement Test-Revised[35] improved from a standard score of 76.7 to a score of 91, reaching the 30th percentile benchmark. The other groups did not show this level of improvement.

The results of Project Read interventions with young at-risk children and matched control groups in three school districts, using standard score gain measures to monitor gains, were described by Greene.[36] The treatment groups gained an annual mean of 12.7 standard score points (almost 1 SD) in 1 year, in contrast to the nonsignificant mean loss of 1.50 standard score points by matched-pair subjects in the control group. First-graders made the greatest gains in comparison with second- and third-graders.

In another study using the Orton-Gillingham method, Maskel and Felton evaluated the response of 230 older reading-disabled children (elementary through high school age) in a school for learning disabilities.[37] Subjects were instructed in small-group (3:1 or 4:1), daily (3 hours) sessions over 1 to 3 years, and the response was monitored over a 5-year period. The mean Wechsler Full-Scale IQ was 108. The subjects fell into the mildly impaired range.reading comprehension scores for all three groups were in the 100 to 104 range, and word reading skills were in the low 90s, based on the Woodcock Reading Mastery Test-Revised[38] and the Woodcock Johnson Tests of Achievement-Revised.[13] Based on the Wide Range Achievement Test-Revised,[35] pretest spelling scores were in the mid- to upper 80s. Significant gains were noted for all groups in comprehension and word-level reading. The subjects who made the greatest gains were those who required only 1 or 2 years of treatment. Spelling gains were significant for all except the middle and high school students who required 2 years of intervention, even though their baseline spelling scores were in the 35th to 40th percentile. The students requiring 3 years of intervention did not achieve significant gains in word identification or spelling despite beginning with relatively mild impairments. Their resistance to treatment would suggest that other factors were involved in their lack of response, but no other measures were available in the study. There was no control group.

These studies support the use of the Orton-Gillingham method, but future research using methodologically sound designs is badly needed. Two Orton-Gillingham interventions have been reported in peer-reviewed journals. Oakland et al. reported on a scientifically controlled study of the effectiveness of Alphabetic Phonics.[39,40] Their study measured word identification and comprehension ability after 350 hours of small-group treatment. There were moderate gains in word reading (standard score 72 to 82) and comprehension (13th to 22nd percentile; no standard scores were given), but the 30th percentile benchmark was not achieved. A study by Hook et al. revealed that an Orton-Gillingham approach resulted in significant gains in phonologic decoding after 6 weeks, in contrast to a group receiving FastForWord.[41]

The Lindamood Phoneme Sequencing program[12] has been described above and has been scientifically validated in a series of well-designed research studies.[8,11] The Phono-Graphix program also involves a systematic and explicit phonologic intervention but has less multisensory mediation.[42] It was used in the study by Simos and colleagues described above and resulted in significant behavioral and physiologic gains in the six patients who were treated.[25] However, no other scientifically controlled studies on this program have been reported. A word of caution is necessary.the Simos et al. study delivered the intervention in a one-to-one daily intensive manner using a trained teacher. However, the program was designed to be carried out by parents at home, with 1 to 2 hours per week of teacher support, making the intensity considerably less. No reliable study has validated this form of delivery. Intensity is a key ingredient to successful remediation, and the intensity needs to increase when the deficit is severe. Home programs in this day and age in families in which both parents are working are not realistic if intensity is required.

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