Investigations for Autism
What are the Investigations conducted for Autism?
Prior to Diagnosis based on clinical observations and Standardized assessment tools, you may be requested to perform one or more of the following investigative procedures for your child. These will help in ruling out other possible problems.
Neuro-imaging studies (MRI/CT/PET-CT):
Neuro-imaging procedures are painless, non-surgical methods which provide a view of the brain structure and sometimes function in two or three-dimensions. A Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) of the brain reveal its gross structure in different views as well as any gross defects. However, most children with autism have a near-normal MRI and CT scan. In recent times a new investigative modality called Positron Emission Tomography (PET) is being explored to identify functional problems in the various brain areas. While computed tomography of brain (CT) and MRI of brain predominantly show the anatomical pictures of the brain such as size, shape, structure, location etc., PET-CT scan tells us how it is functioning and measures the chemical and biological processes at the cellular and molecular level.
An EEG is a test that records the electrical activity of the brain by the use of sensors across many different areas on the scalp. This was one of the earliest methods used to study the neurobiology in autism. In some cases of autism associated with a high frequency of epileptiform seizures (convulsions), the EEG will be abnormal. Approximately 30% of ASD patients without clinical seizures are found to have epileptiform abnormalities.
Brain Stem Evoked Response Audiometry (BERA):
Also called Auditory brain-stem Response (ABR) or Brainstem auditory evoked response (BAER), this is an objective method of picking up brain stem (part that connects brain and spine) potentials in response to audiological click sounds. These waves are recorded by electrodes placed over the scalp. Often in autism, there is delayed speech or failure to respond to name-call. It is then that your doctor may recommend a BERA test to rule out any hearing problems.