Virginia W. Berninger University of Washington Director, - PowerPoint PPT Presentation

Tier 3 Differential Diagnosis of Specific Learning Disabilities Virginia W. Berninger University of Washington Director, Multidisciplinary Learning Disabilities Research Center, Literacy Trek Longitudinal Study, and The Write Stuff Intervention Project, and School Psychology Internship Program vwb@u.washington.edu CASP March 4, 2005 Riverside, CA

Making the Case for Tier 3 Ø Special education placement decisions and differential diagnosis are not the same. Diagnosis should be made even if student is not given services. Ø For efficiency, use differential diagnosis for identifying disorder and branching diagnosis for planning treatment: Ø Implications for etiology, treatment, and prognosis

What Is Dyslexia? Ø Not all learning disabilities involve reading. Ø Not all reading disabilities are dyslexia, but dyslexia exists and is one specific learning disability Ø Dyslexia has genetic basis, neuroanatomical signatures, and changing phenotype (observable behavioral signs) across development as curriculum requirements change.

Neuroanatomical Differences between Good Readers (left) and Dyslexics (right)

What Is Dyslexia? Ø First signs in kindergarten : Unusual difficulty in learning to name letters and attach phonemes to letters. (Orthographic- Phonological Mapping Relationships) 1 st grade —Unusual difficulty learning to read single words out of sentence context (sight words and/or phonological decoding).

What Is Dyslexia? 2 nd – 3 rd grades May learn to read single words accurately but reading rate (automaticity of single word reading and/or fluency of oral reading of text) impaired 4 th grade and thereafter Spelling problems typically persist and may interfere with writing development. Silent reading comprehension tends to be better than oral reading accuracy and fluency.

What Is Dyslexia? Ø Does not go away with maturation alone: Systematic and explicit instruction improves accuracy of single word reading. Ø Assessing reading only in context may mask the difficulty dyslexics have in reading single words. Ø Assessing only real word reading may mask unusual difficulty in reading pseudowords (translating the orthographic word form into the phonological word form) . Ø Assessing only accuracy of word reading and decoding may mask reading rate problems (accuracy vs rate disability, Lovett, 1987)

Etiology of Dyslexia Genetic Constraints in UW Family Study : Ø preciseness of the phonological word form and phonological short- term memory, CTOPP Nonword Repetition Ø accuracy and rate of phonological decoding (orthographic- phonological-morphological mapping), TOWRE Phonemic Reading Efficiency; WIAT II pseudoword reading or WJ III Word Attack Ø written spelling, WRAT 3 or 4 or WIAT II Spelling and Ø executive function for inhibition and self-regulation of attention during processing of written word forms or their parts. Delis Kaplan Inhibition; Delis Kaplan Verbal Fluency Letters; Rapid Alternating Switching (Wolf letter and number switching attention)

Etiology of Dyslexia Dyslexia is a Language (Not Perceptual) Disorder Ø Problem in preciseness of phonological word form, phonological short-term/working memory, orthographic- phonological mapping, inhibition,and executive support of language functions that manifests itself in written language at the word level. Ø Language markers in phenotype: Deficits in orthographic, phonological, and rapid naming skills. Ø Relative strengths in morphological and syntactic skills Ø May occur with or without ADHD (inattention more common), specific arithmetic disability, handwriting problem

Research-Supported Diagnosis of Dyslexia Ø Discrepancy of at least 15 standard score points between WISC III or IV Verbal Comprehension Factor and a measure of single word reading (WRMT-R or WJ III Word Identification and/or Word Attack, WIAT II Word Reading and/or Pseudoword Reading, TOWRE sight word efficiency and/or phonemic reading efficiency), oral reading (GORT-3 accuracy or rate), and/or spelling (WRAT 3 or 4, WIAT II Spelling); the measures of single word reading, oral reading, or spelling must be below the population mean . Ø Deficits in one or more of the language markers for dyslexia that interfere with word reading and spelling: orthographic coding (PAL receptive coding, expressive coding, word choice), phonological coding (CTOPP elision, nonword repetition, phoneme reversal or PAL Syllables, Phonemes, Rimes), and/or rapid automatic naming (RAN) (Wolf Letters, Letters and Digits; PAL Letters, Words, Letters and Numbers) + or – executive dysfunction (DK Inhibition, Repetitions)

What Is Dysgraphia? Ø Developmental dissociation between transcription and text generation skills in writing development Ø Dysgraphia = Impaired + Hand (Language by Hand Produced by the Grapho-Motor System) or Letter Ø Transcription Skills affected are handwriting and/or spelling.

Relationship between Dyslexia and Dysgraphia Ø All dyslexics have dysgraphia (spelling is always affected, handwriting may or may not be affected). Ø Not all dysgraphics have dyslexia Only handwriting may be affected (IQ irrelevant as long as in the normal range). Only spelling may be affected (underdeveloped for vocabulary knowledge, VIQ) Both handwriting and spelling may be affected—if so, worst prognosis for writing.

What is Language Learning Disability (LLD)? (Wallach & Butler, 1994) Ø Deficits in morphological and syntactic processing and executive functions for language (e.g. CELF Sentence Formulation) Ø Persisting profile of expressive < receptive even if language development in normal range; may have subtle to severe word retrieval and/or oral motor planning problems Ø Deficits in reading comprehension and word decoding— deficits in reading comprehension may be greater than those in word decoding Ø Typically no VIQ-achievement discrepancy (because of morphological and syntactic impairment that lowers VIQ)

What is Language Learning Disability (LLD)? (Wallach & Butler, 1994) Ø Learn language but have difficulty using language to learn despite normal intelligence—analogy to Chall ’ s learning to read and reading to learn Ø can learn well using nonverbal strategies see research by Elaine Silliman University of Florida Tampa Ø Need explicit instruction in (a) processing instructional language across the curriculum, (b) using language to learn, and (c) reading comprehension (PAL Lesson Set 6)

Early Preschool Signs of LLD vs Dyslexia In contrast to children with primary language disability or specific language impairment who have significant developmental delays in acquiring language milestones, Ø Language learning disabled acquire language-- slowly but within the lower limits of the normal range—fast responders to early language intervention Ø Dyslexics show normal early language development (words and sentences) until written language introduced.

Differential Diagnosis Ø To diagnose dyslexia, dysgraphia, or language learning disability must rule out mental retardation, pervasive developmental disorder, autism, primary language disorder, and slow(er) learner. Ø Need to assess these domains of development : gross and fine motor, cognitive (memory and abstract reasoning), language and communication, attention and executive function, and social/ emotional.

Differential Diagnosis Mental Retardation = all domains of development are delayed (outside normal range) Pervasive Developmental Disorder= delays in two or more domains of development Autism = Impaired Language and Communication, Social/Emotional (+ or – Mental Retardation)

Differential Diagnosis Primary Language Disorder = Language development outside the normal range and significantly underdeveloped compared to nonverbal reasoning in normal range. Slow(er) Learner = Developmental profile consistently at the lower end of the normal range but does not meet criteria for LLD.

Conditions for Which Dyslexia Is Inappropriate Diagnosis Ø Trauma to mother or child during gestation or labor or adverse drug or vaccine reaction Ø Significant Prematurity (Low Birth Weight) Ø Disease (e.g. menegitis) or injury (e.g. cerebral palsy) Ø Fetal Alcohol or Effect or Substance Abuse Ø Other neurogenetic disorders (fragile X, Down Syndrome etc.

Importance of Differential Diagnosis The nature of the diagnosis has implications for treatment planning, for example Ø Dyslexics benefit from explicit and intensive phonological, morphological, and orthographic training for word learning; they do not need intensive work in comprehension. Ø Language learning disabled need the same training for word learning plus more intensive morphological and syntactic treatment and very explicit comprehension instruction. Ø Dysgraphics need and benefit from explicit handwriting and keyboarding instruction rather than merely accommodation; delivery of this instruction depends on whether they also have dyslexia or language learning disability.

Importance of Differential Diagnosis The nature of the diagnosis has implications for prognosis (determining when a student has reached an expected level of achievement and no longer needs specialized instruction), for example, Ø Students with language learning disability may need specialized instruction longer than do those with only dyslexia Ø Students whose cognitive development falls outside the normal range cannot be expected to read and write at grade level.