|
SUDDEN UNSET OF OBSESSIVE–COMPULSIVE DISORDER MAY POINT TO PANDAS
CHICAGO—Between September and April, if a boy age 5 to 11 presents with a new, explosive onset of an obsessive-compulsive, tic, or anxiety disorder, consider adding group A beta hemolytic streptococcal (GABHS) tonsillopharyngitis to the differential diagnosis, even in the absence of symptoms.
That is the conclusion of the first prospective study to confirm the association between acute GABHS tonsillopharyngitis and the Pediatric Autoimmune Neuropsychiatric Disorder Associated with Group A Streptococci, or PANDAS. The results of the study, which also confirmed the response of PANDAS to appropriate antibiotic therapy at the sentinel episode, were presented at the 41st Interscience Conference on Antimicrobial Agents and Chemotherapy.
PANDAS PRESENTATION
Between 1998 and 2000, Marie Lynd Murphy, MD, and Michael E. Pichichero, MD, of the Elmwood Pediatric Group and the University of Rochester Medical Center, Rochester, New York, identified 12 children with new-onset PANDAS using current diagnostic criteria: pediatric onset; neuropsychiatric disorder (obsessive-compulsive) and/or tic disorder; abrupt onset and/or episodic course of symptoms; association with GABHS infections; and association with neurologic abnormalities (motoric hyperactivity or adventitious movements, including choreiform movements or tics).
In their study, the mean age at presentation was 7, and PANDAS occurred predominantly in males (1:4.1). All patients had an abrupt onset of a significant new behavioral problem (62% could state the day symptoms began) and obsessive thought patterns that were “accompanied by mild symptoms and signs of acute GABHS tonsillopharyngitis,” they noted. Compulsions were germ-related in 75% of children (hand-washing, toilet hygiene rituals, hoarding), and more than half (58%) had compulsive patterns of excessive daytime urinary urgency and frequency without fever, dysuria, or urinary tract infection. Separation anxiety and fear of illness, death, or harm to self or a loved one was also noted.
PANDAS PREVENTION
After 10 days of treatment with penicillin or a cephalosporin, GABHS was eradicated, as confirmed by negative follow-up throat culture. Symptoms of obsessive-compulsive disorder abated in an average of 14 days (range, five to 60 days). Throat swabs tested positive for GABHS by rapid antigen detection and/or culture. In three children, GABHS serology showed very high anti-DNase B and/or anti-streptolysin titers. Six patients experienced 16 recurrences of sudden-onset obsessive-compulsive disorder symptoms or tic, each of whom had “a preceding negative throat culture followed by a positive throat culture at the onset of obsessive-compulsive disorder symptoms,” Dr. Murphy noted. “In most, antibiotic treatment again eradicated the GABHS, and the obsessive-compulsive disorder or tic resolved. Two patients experienced a greater number of previous episodes of GABHS, had more frequent recurrences of PANDAS, and became less responsive to antibiotic treatment.”
Sudden onset of obsessive-compulsive disorder symptoms (eg, within 48 hours)—as opposed to those that emerge over time—is key to PANDAS, Dr. Murphy said. The first indication “was generally a phone call about a sudden and rather bizarre behavior that had started at a particular time,” she said. “For many of the children, it was an obsessive need to urinate, and they had this elaborate cleaning ritual afterwards. It would seem to peak if they were going to leave the house. These are continent children who had no issues with that before.”
A child presenting with complaints of frequent urination might be worked up for a bladder infection or, in the absence of symptoms, urinary frequency. Instead, Dr. Murphy advised, the question that should be asked is whether the throat should be examined and cultured during a visit that doesn’t really seem to be a strep throat visit. “We’re seeing plenty of strep throat in all the other rooms, but these are kids who are coming in specifically because of the behavior change, so you have to add the strep in yourself.” Those children with a sentinel episode of GABHS tonsillopharyngitis that seemed to trigger PANDAS were identified as previously having experienced persistent such episodes.
“What I generally would recommend is a throat culture,” Dr. Murphy added. “If a child has a sore throat and a positive throat culture, then you can debate if you need to go further than that. Where it becomes important—because this is a secondary effect, a week or two after the strep infection—is if the throat culture is not positive. The child may remember that he or she had a sore throat and a low-grade fever and then present with the behaviors. In that instance, an antibody titer is helpful to show that that was strep; it just wasn’t significant enough to get you to the doctor’s office.”
PANDAS PROGNOSIS
Given that only 12 children were diagnosed with PANDAS in three years, Dr. Murphy said it is difficult to make “sweeping statements” regarding how often the entity might be seen in clinical practice; they estimate one to three new cases annually. Most of what is known about PANDAS has resulted from studying children with long-standing obsessive-compulsive disorder or a known tic disorder, such as Tourette’s syndrome, in research and referral centers. Dr. Murphy said a question they tried to answer is whether such children can be identified “when they’re just starting up with these behaviors,” adding that their large community-based pediatric practice offers “an opportunity to possibly see the very first episode” of PANDAS, allowing early intervention and prevention of full-blown obsessive-compulsive disorder and tic disorders. “If there is any chance that treating a strep throat would prevent you from moving on into obsessive-compulsive disorder or Tourette’s syndrome, you’d want to do it,” she said.
More than likely genetics and the environment may ultimately be found to play a role in disorders such as obsessive-compulsive disorder, Tourette’s syndrome, and PANDAS. “The mechanism of how we’re thinking PANDAS works is very similar to the mechanisms of how streptococcal antibody in Sydenham’s chorea works,” Dr. Murphy said. One major hope is to determine if there is “a way to intervene early in this process.” Currently, Dr. Murphy’s group is examining standardized behavioral assessments in all children throughout the winter months, both to demonstrate a link with GABHS infection and to determine the effect of treatment.
NR
—Debra Hughes
Suggested Reading
Garvey MA, Giedd J, Swedo SE. PANDAS: the search for environmental triggers of pediatric neuropsychiatric disorders: lessons from rheumatic fever. J Child Neurol. 1998;13:413-423.
Leonard HL, Swedo SE. Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). Int J Neuropsychopharmacol. 2001;4:191-198.
Swedo SE, Leonard HL, Garvey M, et al. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections: clinical description of the first 50 cases. Am J Psychiatry. 1998;155:264-271.
Return to table of contents
|
|
