Interactive Autism Network at Kennedy Krieger Institute
Date Published: December 9, 2016
Pediatric Neurologist Deepa Menon Answers Common Questions
To help educate patients and families, Dr. Deepa U. Menon answered questions from the Interactive Autism Network (IAN) about the role of neurologists in treating children and youth with autism. Dr. Menon is assistant professor of Neurology and Neurodevelopmental Medicine, and assistant medical director of the Center for Autism and Related Disorders, at Kennedy Krieger Institute in Baltimore. Her research interests include metabolic and mitochondrial disorders associated with autism, regression in autism, and early identification and treatment of autism and communication disorders.
IAN: When should the parents of a child with autism spectrum disorder consider taking him or her to a neurologist?
Dr. Menon: Child neurologists specialize in identifying and treating disorders of the nervous system and brain. Parents may consider consulting a neurologist if they notice:
- Their child is not developing at the same rate or pace as other children the same age,
- If there are delays in motor skills, speech and language, and social and play skills,
- If they notice red flags for autism including delays in social communication and play, and an increase in repetitive behaviors and behavioral disruption,
- If there is a loss of previously-acquired developmental milestones, like speech or eye contact or play. Parents may say, "My child was doing very well, and all of a sudden he's not progressing, or he's losing skills." About 30 percent of children with autism do lose skills between 18 months and 2 years of age, and a small fraction of them have seizures as an underlying cause.
- If there is a history of seizure-like jerking movements or staring spells indicating a possible seizure,
- If there are concerns of hyperactivity, sleep issues, feeding problems,
- If there's a concern about hypotonia [low muscle tone] or motor abnormalities – if the child is a very floppy baby or one side of his body is stronger than the other.
Other reasons that someone might see a neurologist are a history of prematurity, a concern that the child has a large head or a small head, or anything that makes you think there's a medical cause for the child's autism, such as a mitochondrial disorder.
IAN: Are seizures more common in people with autism?
Dr. Menon: Seizures are slightly more common in children with autism than in the typically-developing population. In the general population, the incidence of seizures is 1 to 5 percent. In autism the chances of having seizures are 10 to 20 percent.
IAN: How can families recognize the different types of seizures that can occur in autism?
Dr. Menon: A seizure is a sudden surge of electrical activity in the brain. The two types of seizures are focal seizures – seizures occurring in part of the brain – and generalized seizures, which occur over the entire brain. Focal seizures can occur with or without a loss of consciousness.
A petit mal or absence seizure is a type of generalized seizure. It looks like a staring spell and lasts less than 10 to 15 seconds. A child might be playing, then he will stop and stare or appear blank, and then go back to what he was doing without any obvious delay or change.
Another kind of generalized seizure is the grand mal or tonic-clonic seizure. The arms, legs, and body may stiffen and shake uncontrollably during this kind of seizure. After this seizure, most children will have a period of being tired or confused, and may go into a deep sleep.
Children with a genetic syndrome, such as tuberous sclerosis, and autism might have more complicated or longer seizures.
Landau-Kleffner Syndrome is a rare disorder of night-time seizures over the temporal regions of the brain that are involved in the use of language. These children lose language. The symptoms are very similar to autism but occur in a slightly older age. They will develop typically until five to seven years of age, when they start losing language. Landau-Kleffner can be treated with medication such as corticosteroids.
IAN: Can it be difficult for parents or teachers to distinguish the behavioral symptoms of autism – such as not responding to one's name and staring into space – from signs of an absence seizure?
Dr. Menon: It is often hard, even for a neurologist, to detect brief seizures. Often when a child is being sent for an EEG [electroencephalogram, a test for seizures], it's because they have had a staring spell. Often a single EEG may not pick up on a seizure disorder.
IAN: What are the types of tests a neurologist might perform?
Dr. Menon: First you start with a patient history and a good physical exam. You're also looking for marks on the skin that might be a sign of syndromes or genetic causes of autism, like tuberous sclerosis. In terms of testing, the main one would be an EEG. [In an EEG, electrodes are placed on the head to measure electrical activity in the brain. The test can detect seizures.] There are different kinds of EEGs. We usually try to have an extended EEG because we would be more likely to detect a seizure. In children with a history of regression, we try to get an overnight EEG that will capture a longer period of time (six to eight hours). Seizures are frequently associated with the sleep cycle. You tend to have a higher frequency of seizure activity when the child is falling asleep, asleep, or coming out of sleep.
In the past, you always had to come into the hospital to get this test done, but for a certain group of children who cannot stay in the hospital, there is an ambulatory EEG. These are portable machines that can be used in the home. But I think the results are better if EEGs are done in the hospital, where you can monitor them and record a video EEG. The video EEG records both the brain waves via the electrodes, and a video film of the child's activity while the EEG is being recorded.
An additional test that might be done is a brain MRI. [Magnetic Resonance Imaging uses a magnetic field and radio waves to take pictures of the brain]. If a child has a focal seizure, which means he always has a seizure involving just one arm or leg, for example, you might do an MRI to see if there is any abnormality in the region of the brain that controls that limb.
In rare cases of seizures that occur in the setting of a fever or infection, a lumbar puncture may be done to see if there is an abnormality of electrolytes, or if there is an infection or inflammation, that is causing the seizure. [In a lumbar puncture, a doctor uses a needle to collect spinal fluid for testing].
IAN: Are sleep problems a sign of a neurological disorder?
Dr. Menon: Sleep problems are very common in typically-developing preschool and school-aged kids, too, and it can be a behavioral issue. However, in children with autism the incidence of sleep disorders is higher, both in falling asleep and in maintaining sleep. If behavioral strategies have been tried, and the child is still having significant sleep issues, then a neurologist may consider doing a sleep study to study the sleep patterns of the brain. A majority of children with autism spectrum disorder have low levels of melatonin, as per research. [Melatonin is a hormone that regulates sleep.] Some of them have difficulty falling asleep. Or if they do go to sleep, they have difficulty maintaining sleep and wake up frequently or very early in the morning. That does affect the child's and family's quality of life.
IAN: What's a seizure threshold, and do people with autism have lower thresholds?
Dr. Menon: A seizure threshold is the level at which the brain will have a seizure. There are certain triggers for a seizure, even in people who don't have autism, such as an infection or a high fever, or if someone is on medication for seizures and misses a dose of the medication, or if there's a sleep abnormality and the person has had decreased sleep. All of those things may make it more likely the person will have a seizure. A child who doesn't have autism may only have a seizure when he has three or four of these factors, but a child with autism might have a seizure when he only has one of these factors. That is a lower threshold. Some children with autism are on medication for management of behavior, and some of those medications, as a side effect, can cause seizures.
IAN: When are children most likely to develop seizures?
Dr. Menon: There are two peaks that occur, one during the toddler years from ages 1 to 4, and again, during the teenage years.
IAN: Do children who take seizure medications have to take them for many years?
Dr. Menon: Some children have absence seizures in early childhood, and have been on antiseizure medication for two to three years and completely seizure-free. In those cases, we might try to wean them from seizure medication. But it's also important to be careful around the teenage years. A teenager might not sleep at the right times, be exhausted, and not eat well. If a teenager had seizures when he was younger, it's something for parents to keep in the back of their minds, to monitor him to make sure there's no reoccurrence of seizures in the teen years.
IAN: What happens if an EEG reveals an unusual pattern, but it does not reveal a seizure disorder? Do you treat that?
Dr. Menon: The jury is out on that question. You wonder, "Should you treat the child or not?" You might monitor the child, and if he starts showing signs of not progressing or losing skills, you might benefit the child by treating him with anti-seizure medication. Some neurologists believe that you should treat any EEG abnormality, but others say you shouldn't because seizure medications have side effects. If you start seizure medication treatment, you are committing the child to a minimum of two to three years of treatment. You have to consider what are you treating, what is your end point of treatment, and how will it affect the development of the child.
- More about Dr. Deepa Menon, MBBS
- To learn more about seizure disorder, also called epilepsy, download the brochure, "If Your Child Has Seizures," by Johns Hopkins Medicine and Kennedy Krieger Institute.
- The American Academy of Neurology has a "Find a Neurologist" search page to locate neurologists throughout the U.S.
- U.S. National Institutes of Health Epilepsy Information Page answers more questions about seizures.
- U.S. National Institutes of Health Landau-Kleffner Syndrome Information Page