Diagnosis of Asperger Syndrome - Procedure

Procedure

Developmental screening during a routine check-up by a general practitioner or pediatrician may identify signs that warrant further investigation. This will require a comprehensive team evaluation to either confirm or exclude a diagnosis of AS. This team usually includes a psychologist, neurologist, psychiatrist, speech and language pathologist, occupational therapist and other professionals with expertise in diagnosing children with AS. Observation occurs across multiple settings; the social disability in AS may be more evident during periods when social expectations are unclear and children are free of adult direction. A comprehensive evaluation includes neurological and genetic assessment, with in-depth cognitive and language testing to establish IQ and evaluate psychomotor function, verbal and nonverbal strengths and weaknesses, style of learning, and skills for independent living. An assessment of communication strengths and weaknesses includes the evaluation of nonverbal forms of communication (gaze and gestures); the use of non-literal language (metaphor, irony, absurdities and humor); patterns of speech inflection, stress and volume; pragmatics (turn-taking and sensitivity to verbal cues); and the content, clarity and coherence of conversation. Testing may include an audiological referral to exclude hearing impairment. The determination of whether there is a family history of autism spectrum conditions is important. A medical practitioner will diagnose on the basis of the test results and the child’s developmental history and current symptoms. Because multiple domains of functioning are involved, a multidisciplinary team approach is critical; an accurate assessment of the individual's strengths and weaknesses is more useful than a diagnostic label. Delayed or mistaken diagnosis is a serious problem that can be traumatic for individuals and families; diagnosis based solely on a neurological, speech and language, or educational attainment may yield only a partial diagnosis.

Advances in genetic technology allow clinical geneticists to link an estimated 40% of ASD cases to genetic causes; in one study the diagnostic yield for AS, PDD-NOS and atypical autism was similar to that for classic autism. Genetic diagnosis is relatively expensive, and genetic screening is generally impractical. As genetic tests are developed several ethical, legal, and social issues will emerge. Commercial availability of tests may precede adequate understanding of how to use test results, given the complexity of the genetics.