Clinical Experience in (C)APD (Screening, Diagnosis, Intervention)

Teri James Bellis, Ph.D.The University of South DakotaVermillion, SD, USA

Screening for (C)APD

Principles of (C)APD Screening

• Purpose of Screening: To determine need for comprehensive central auditory assessment

• Global or pan-sensory disorders (i.e., MR, ADHD, autism) must ALWAYS be addressed prior to evaluation for (C)APD

Bellis Screening Method

Screening involves review of multidisciplinary assessment results:

• Cognitive• Psychoeducational/

academic• Speech/language• Medical/neurologic• Other (e.g., questionnaires,

auditory tests, other)

Screening is designed to answer four questions:

1. Are the current evaluations sufficient in scope?

2. Is there a likelihood of (C)APD?3. Can the individual participate in

the testing?4. Will a diagnosis of (C)APD add

significantly to the management/ treatment plan?

Outcomes of Screening

• Referral for comprehensive assessment

• Referral for other testing/follow-up

• Interim Recommendations

• Other

Screening tools should never be used for

diagnostic purposes, even if the term

“auditory processing” is included in their titles!!!

Diagnosis of

(C)APD

Principles of (C)APD Diagnosis

• Purpose of Diagnostic Testing: To

identify presence and delineate

characteristics/nature of central

auditory deficit

• Requires audiologist-administered

diagnostic tests of central

auditory function

• Provides information regarding

integrity of left-hemisphere, right-

hemisphere, interhemispheric,

and brainstem auditory structures

• May include psychophysical

and/or neuro(electro)physiologic

tests of central auditory integrity

• Leads directly to development of

deficit-specific treatment and

management plans

Diagnostic Tests for (C)APD

• Must employ a test battery approach that assesses various levels/loci within the CNS, as well as different perceptual processes

• The tests chosen should meet accepted psychophysical and scientific standards , should control for higher-order confounds, and should be appropriate to the individual being tested!

Most importantly:

The tests used should have been demonstrated to be sensitive, reliable, and efficient for identification of CANS dysfunction

Categories of Diagnostic Tests

•Dichotic Speech Tests•Monaural Low-Redundancy

Speech Tests•Temporal Patterning/

Processing Tests•Auditory Discrimination

Tests

•Binaural Interaction Tests•Electroacoustic Tests•Electrophysiologic Tests

• Electrophysiologic and related measures may play an important role in the objective demonstration of neural deficits in the auditory system in many cases, as well as in the documentation of treatment efficacy

Test Battery Interpretation

• Norm-referenced criteria

• Using the patient as his/her own control (pattern analysis using neurophysiologic tenets):

• Intra-test analysis (including ear differences)

• Inter-test analysis

• Cross-discipline analysis

Differential Diagnosis

• Requires examination of multidisciplinary findings and functional sequelae

• Diagnosis of (C)APD enabled ONLY when clear pattern of auditory deficits exists along with auditory-specific complaints

• OR• Pronounced deficit exists in one

process accompanied by functional difficulties in that process

• Lack of a pattern (e.g., poor performance on all measures) argues for more global or motivational deficit, not (C)APD

• Multimodal (multidisciplinary) input is critical to fully explore functional deficits and confirm differential diagnosis

(C)APD should NEVER be

diagnosed in a vacuum!!!

The key to interpretation and differential diagnosis:

Analysis of findings for neurophysiologically tenable PATTERNS consistent with CANS dysfunction

Relating Auditory Deficits to Functional

Difficulties and Sequelae

Integrating Multidisciplinary Assessment Results

•Examination of multidisciplinary findings for neurophysiologically tenable patterns•Subprofiling Methods

Utility of Subprofiling Methods

• Useful guides to analysis of central auditory and multidisciplinary test findings for neurophysiologically tenable patterns

• Not designed to be a catch-all, cookie-cutter approach to APD diagnosis and categorization

ONE Subprofiling Method:The Bellis/Ferre Model

•Involves integration and pattern analysis of auditory and multidisciplinary findings•Three primary profiles:

Auditory Decoding Deficit

• Auditory deficits indicate left-hemisphere (primary auditory cortex) pattern:

– Bilateral or right-ear deficit on dichotic speech tasks

– Poor performance on auditory closure tasks

– Poor phoneme discrimination– Reduced LH electrophysiologic

responses (MLR, cortical)– Elevated gap detection thresholds

• Associated difficulties in left-hemisphere functions:

– Phonological decoding (word attack) difficulties

– Speech-in-noise problems– Better performance with

visual/multimodality cues– Other phonological and language-

based concerns– Better Performance than Verbal IQ

Prosodic Deficit

• Auditory deficits indicate right-hemisphere pattern:

– Left-ear deficit on dichotic speech tasks

– Poor temporal patterning performance (BOTH humming and labeling)

– Reduced RH electrophysiologic responses (MLR, cortical)

– Elevated frequency, intensity, duration difference limens

• Associated difficulties in right-hemisphere functions:

– Sight word reading and other Gestalt patterning difficulties

– Problems with prosody perception– Poor pragmatic skills– Sequencing difficulties– Other RH difficulties (e.g., visual-

spatial skills, math calculation, better verbal than performance IQ)

Integration Deficit

• Auditory deficits indicate inefficient interhemispheric transfer:

– Left-ear deficit on dichotic speech tasks (opposite for nonspeech)

– Poor temporal patterning performance (labeling ONLY)

– Traditional electrophysiologic responses (MLR, cortical) often normal; may see reduced hemispheric asymmetry to speech stimuli

• Associated interhemispheric difficulties:

– Poorer performance with multimodality or visual cues

– Sound-symbol association difficulties

– Speech-in-noise and localization difficulties

– May have subtle difficulties in other interhemispheric tasks (bimanual/bipedal activites, etc.) but not “true” sensory integration dysfunction

Interventionfor

(C)APD

Basic Principles

• Intervention for (C)APD is a multidisciplinary endeavor

• Treatment/intervention should be ecologically valid and based on the individual’s unique needs

The key to effective

treatment is accurate

diagnosis!

• Intervention should employ “bottom-up” (e.g., auditory training, signal enhancement) and “top-down” (e.g., compensatory strategies, instructional modifications) approaches

• Should include three components:

1. Environmental Modifications (bottom-up and top-down)

• To enhance access to and acoustic clarity of auditory information

• To increase opportunity for effective listening/learning

2. Compensatory Strategies (top-down)

• To strengthen higher-order top-down processing skills (metacognition, metamemory, metalinguistic)

• To overcome secondary/associated motivational and related deficits

3. Direct Remediation Techniques (bottom-up)

• To improve auditory performance by altering the way the brain processes sound

• Involves targeted activities that maximize neuroplasticity

Maximizing Neuroplasticity

Auditory training activities must :

• Be– Frequent– Intense– Challenging

• Involve active participation• Include salient reinforcement

Computer-Assisted Therapies

• Allow for multisensory stimulation, sustained interest, reinforcement, and intense/frequent stimulation

• BUT

• Each program MUST BE analyzed for appropriateness of task demands targeted and adherence to principles of maximizing neuroplasticity

There is NO one-size-fits-all intervention/ treatment approach or program that is

appropriate for ALL individuals with

(C)APD!

Communicating Results and

Recommendations

General Principles

• View patient counseling sessions and reports (both screening and diagnostic) as educational opportunities

• Focus on what (C)APD is AND what it is not

• Make sure communications are individualized and appropriate to the patient in question

Elements of a “good” (C)APD Report

• Clearly explains what was done and what was found

• Delineates how findings relate (or do not relate) to reported symptoms and complaints

• Provides comprehensive, individualized recommendations for intervention and/or follow-up

• Assists reader in understanding why recommendations were made

• Can be understood by anyone from any discipline

Questions???