Neuro Bio Of Disease (ASD)


Autism Spectrum Disorder

Dr. Katie Dabrowski, PT, DPT




• ASD is a developmental disorder that affects communication and behavior • Symptoms generally appear in the first 2 years of life • According to DSM-5, people with ASD have:

• Difficulty with communication and interaction with other people • Restricted interests and repetitive behaviors • Symptoms that hurt the person’s ability to function properly in school, work, and

other areas of life

• Autism is a “spectrum” disorder because there is great variation in type and severity of symptoms




Signs and Symptoms

• Social communication/interaction behaviors: • Making little or inconsistent eye contact • Tending not to look at or listen to people • Rarely sharing enjoyment of objects or activities by pointing or showing things to others • Failing to, or being slow to, respond to someone calling their name or to other verbal attempts

to gain attention

• Having difficulties with the back and forth of conversation • Often talking at length about a favorite subject without noticing that others are not interested

or without giving others a chance to respond

• Having facial expressions, movements, and gestures that do not match what is being said • Having an unusual tone of voice that may sound sing-song or flat and robot-like • Having trouble understanding another person’s point of view or being unable to predict or

understand other people’s actions




Signs and Symptoms

• Restrictive/repetitive behaviors • Repeating certain behaviors or having unusual behaviors. For

example, repeating words or phrases, a behavior called echolalia • Having a lasting intense interest in certain topics, such as numbers,

details, or facts • Having overly focused interests, such as with moving objects or

parts of objects • Getting upset by slight changes in a routine • Being more or less sensitive than other people to sensory input,

such as light, noise, clothing, or temperature NIMH



Signs and Symptoms

• But there are strengths, too! • Being able to learn things in detail and remember information for

long periods of time

• Being strong visual and auditory learners • Excelling in math, science, music, or art




Neuroanatomical and Neurodevelopmental Basis of ASD



Altered brain growth

• One consistent finding in ASD is altered brain growth • The clinical onset of autism appears to occur after two phases of brain growth abnormalities:

1. Reduced head size at birth 2. Then a sudden and excessive increase between 1-2 months and 6-14 months of age

• In addition to these initial two phases, it is also shown that an abnormal pattern of brain growth also occurs in areas of the frontal lobe, cerebellum, and limbic structures between 2-4 years of age • An abnormal slowness in brain growth then follows this initial growth • We know that these regions are intimately involved with developing social, communication, and motor

abilities that are impaired in ASD