New York -- It's not all in their heads.
Parents who suspected their child's strep throat caused subsequent development of obsessive compulsive (OC) or tic disorders can rest easy now that research finally confirms this relationship.
The mounting evidence pointing to a link between group A Beta-hemolytic streptococci and these disorders could eventually lead to a means of identifying children at risk and the use of preventive therapy.
The research is so convincing that Dr. Susan Swedo, acting scientific director at the National Institute of Mental Health (NIMH) and head of the NIMH's section on behavioral pediatrics, said she believes a throat culture is in order for both the child and family members when a child presents with acute onset or exacerbation of OC or tic symptoms.
"Our studies and others on obsessive compulsive disorder are truly proof that these are neurobiological illnesses, that what was previously thought to be due to punitive toilet training is now known to be associated with changes in your brain chemicals, patterns of responsiveness of glucose metabolism, and now perhaps to be triggered by an autoimmune reaction."
The evidence shows in susceptible children, the strep infection triggers the autoimmune response, which affects the basal ganglia and can lead to symptoms of OC or tic disorder including Tourette's syndrome.
About 1% of children suffer from OCD and up to 15% of grade-school children have some sort of tic disorder, although true Tourette's is very rare, said Dr. Swedo.
Several studies involving antibiotics and immunological treatments in these children were described by Dr. Swedo during the American Psychiatric Association annual meeting here. She called some treatment responses "miraculous".
The studies involve children with PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections). To be included in the studies, these kids must have had at least one strep infection, abrupt onset of symptoms or frequent symptom exacerbations, and onset before puberty.
These children can display obsessive symptoms including washing, checking, hoarding, arranging, symmetry rituals and various compulsive movements. They usually are "squirmy, fidgety" and unable to sit still, said Dr. Swedo.
One of the red flags for PANDAS is sudden onset, she said. "Nearly all the patients tell us that the symptoms have exploded in severity on a specific day or week ... They say they went to bed fine and woke up the next morning and had (a compulsion) to check."
It's sometimes difficult to make the connection between strep and onset of OC symptoms because the "dramatic explosion of symptoms" may not occur until one or two weeks after their strep throat, said Dr. Swedo.
She described a "classic example" of one little girl whose compulsive fear of AIDS began when she saw a wrapped hypodermic needle while visiting the doctor; when her medical records were examined, it turned out that the reason she was at the pediatrician's in the first place was because of a strep throat.
Dr. Swedo said she and colleagues have studied over 50 children (36 boys and 14 girls) who fit the PANDAS profile. The mean age of onset of symptoms for these children was 6-1/2 years for tics and 7-1/2 years for OCD, and their mean age at presentation was about 9-1/2 years, said Dr. Swedo.
The rate of comorbidity in these 50 children was high: 82% met criteria for tic disorder at some point in time, about three-quarters met criteria for OCD, and 42% met criteria for attention deficit hyperactivity disorder (ADHD).
The researchers are taking a number of steps to try to piece together the puzzle of PANDAS. One step involves a study of penicillin prophylaxis. "If you can keep the child from getting a strep infection then you should be able to keep them from getting exacerbations," said Dr. Swedo.
Preliminary data on 27 children who completed an eight-month, double-blind crossover trial of penicillin prophylaxis are encouraging in improving symptom severity. "Nineteen of the 27 parents chose the penicillin as their favorite (treatment over placebo), and asked that their child remain on the penicillin following treatment," said Dr. Swedo.
Not only were OC and tic symptoms curtailed with treatment, but their hyperactivity symptomatology also improved, said Dr. Swedo. These symptoms went from being "almost intolerable" to having only some inattention and some impulsivity.
The research group is also conducting a randomized controlled trial of immunoglobulin treatments in seriously affected children to study the effect of this treatment on the autoimmune reaction affecting the basal ganglia. The treatment involves plasma exchange or intravenous immunoglobulin (IVIG).
At the end of a year, all seven of the children who received either IVIG or plasma exchange had a greater than 80% reduction in symptom severity. The average length of remission was 42 weeks.
These children were also treated prophylactically with penicillin. "These treatments are so invasive that we don't want to take a chance that they would get another strep infection," said Dr. Swedo.
Parents of these children were also encouraged. Four rated their children as very much improved, one as much improved and only two rated it as minimally improved after one year. All said they would go through the treatment again if their child had serious symptoms.
Dr. Swedo said the determination of at risk status for OC following strep infections may involve several factors. These may include genetics (about 17% of the parents of children with PANDAS had one or both parents with OCD), neurodevelopment (a birth trauma that makes the basal ganglia more susceptible to another insult), immunological factors, or even a "mutated" strep bacteria.
The PANDAS research is intricately related to that of Sydenham's chorea, a form of rheumatic fever which has also been linked to strep infections and immunological responses. Dr. Swedo said children with PANDAS perhaps have a "dual vulnerability" in that they inherited a genetic propensity towards rheumatic fever and a propensity towards OCD which is manifested early on as PANDAS.
Dr. Swedo said the biological marker for rheumatic fever may be useful in determining a "broader scale" of at risk status for these other children.
"In an ideal world, you would identify the child at risk before they ever got their first strep infection, prophylax them against it and keep them from having onset of symptoms," said Dr. Swedo. "We're not there yet (but) ... our data suggest that it may be possible within the next few years."
Dr. Swedo said she welcomes Canadian patients who fit the PANDAS profile. For more information, call (301) 496-5323.
Copyright © 1996 Maclean Hunter Publishing Limited
Reprinted with permission.
Internet Mental Health (www.mentalhealth.com) copyright © 1995-2011 by Phillip W. Long, M.D.