Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by differences in social communication and interaction, together with repetitive behaviors and restricted interests. The word “spectrum” is not accidental: the signs vary widely from child to child. International pediatric guidelines recommend a standard screening questionnaire for every child at 18 and 24 months, because the outcome of early intervention is better than that of late intervention.
A neurologist does not diagnose autism spectrum disorder alone — the assessment is a team effort. The role of a pediatric neurologist is to recognize early signs, check for related neurological conditions (epilepsy, developmental delay, sleep disorders, genetic syndromes) and guide the family toward the right support.
Signs to watch for at 12–24 months
- At 9–12 months: doesn't turn to their name, doesn't follow your gaze, makes few babbling sounds
- At 12 months: doesn't point, doesn't wave goodbye, doesn't imitate adults' actions
- At 16 months: no meaningful words; at 24 months: no two-word phrases
- Eye contact is rare and brief; doesn't smile back when you smile
- Doesn't look at an object you point to, doesn't show you something interesting (“look!”)
- Repetitive movements: hand flapping, spinning, lining up objects, spinning wheels
- Unusual reactions to sounds, touch or bright light; strong refusal of certain foods and clothing
- At any age: loss of speech or social skills the child had already gained — a reason for urgent evaluation
Screening
The M-CHAT-R/F questionnaire, completed by a parent at 18 and 24 months, is a widely used screening tool. In a study of 16,071 children, among those who scored high on the questionnaire and were confirmed on follow-up, 47.5% were found to have autism spectrum disorder and 94.6% had some developmental concern; children identified through screening were diagnosed on average 2 years earlier. Screening is not a diagnosis — a “positive” result is a referral for a detailed evaluation.
What the neurological exam looks at
- Developmental history: speech, social and motor milestones; whether any skills have been lost
- Neurological status: muscle tone, coordination, head circumference (sometimes larger in autism), skin findings
- Hearing — checked in every child with delayed speech
- Seizures or “zoning out” episodes: epilepsy is more common in autism spectrum disorder than in the general population; if suspected, an EEG
- Sleep, feeding, constipation, iron deficiency
- Genetic testing when indicated; a routine MRI is not indicated
Diagnosis and early intervention
Diagnosis is made with standard observation tools and a developmental assessment, with input from a child psychiatrist, psychologist, speech-language therapist and neurologist. Intervention can and should begin while you wait for a diagnosis: early developmental-behavioral programs, speech-language support, and learning how to strengthen communication at home. The plan is individual for every child; the goal is to help your child build communication, learning and independence skills as fully as possible.
The neurologist treats related conditions: epilepsy, serious sleep problems, movement disorders. This helps your child benefit more from the program.
Frequently asked questions
My child isn't talking at 2 but is very bright — is this autism?
Delayed speech does not mean autism. The difference is in social communication: if your child makes eye contact, points and shares play with you, the picture is different. In any case, no speech at age 2 calls for an evaluation.
Can autism be diagnosed with an EEG or MRI?
No. Autism is a clinical diagnosis. An EEG is needed only when seizures are suspected, and an MRI only when there is a neurological reason for it.
Do vaccines cause autism?
No. This has been disproved by large studies.
How much does early intervention help?
Structured programs started early significantly improve communication and adaptive skills. The result depends on your child's profile and on how consistent the program is; the sooner support begins, the better.
Scientific sources
The medical information on this page is based on the following peer-reviewed publications (PubMed).
- Hyman SL və b. (2020). Identification, Evaluation, and Management of Children With Autism Spectrum Disorder Pediatrics. PMID 31843864
- Robins DL və b. (2014). Validation of the Modified Checklist for Autism in Toddlers, Revised With Follow-up (M-CHAT-R/F) Pediatrics. PMID 24366990
- Lipkin PH, Macias MM (2020). Promoting Optimal Development: Identifying Infants and Young Children With Developmental Disorders Through Developmental Surveillance and Screening Pediatrics. PMID 31843861
Medically reviewed by: Dr. Aynura IbrahimovaLast updated:
The information on this page is for education only and does not replace an examination by a doctor. If you are worried about your child, book an appointment. In an emergency, call 103.