CHICAGO — A new study suggests that three of the five criteria for inclusion in the pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS, subgroup could be narrowed and still provide clinically useful benchmarks.
The first criterion for this subgroup is that the children must meet a lifetime diagnostic criterion for obsessive-compulsive disorder (OCD) or a tic disorder, Lisa Snider, M.D., said at the annual meeting of the Society for Developmental and Behavioral Pediatrics.
“Some people are suggesting that anorexia nervosa, attention-deficit hyperactivity disorder, possibly even bipolar disorder could be triggered by infections like streptococcal infection,” Dr. Snider said. “Our research came out of a predisposition to thinking that OCD and tics are secondary to a dysfunction within the basal ganglia.
“Our original research was on patients with Sydenham's chorea, which is triggered by streptococcal infection, and felt to be a basal ganglia disorder.”
The criteria were defined in 1998 by colleague Susan Swedo, M.D., of the National Institute of Mental Health, Bethesda, Md., and have been used successfully to study the pathophysiology and clinical course of the PANDAS subgroup. But, they also have been criticized as being too broad.
PANDAS is now defined by the presence of OCD and/or tic disorder, prepubertal onset, unique clinical course, association of neuropsychiatric symptoms with group A β-hemolytic streptococcal infections, and association with neurologic abnormalities during symptomatic periods.
Dr. Snider and her colleagues suggested the three new criteria should be:
▸ A primary diagnosis of OCD or prominent obsessive-compulsive features (criterion 1).
▸ Abrupt onset of neuropsychiatric symptoms reaching clinical impairment in less than 48 hours or a period of complete neuropsychiatric symptom remission (criterion 2).
▸ A positive throat culture in the 2 months prior to or elevated antistreptococcal titers drawn between 3 weeks and 3 months after neuropsychiatric symptom onset or exacerbation (criterion 3).
“The criteria haven't radically changed, but they are tighter and much more specific, which should help clinicians and researchers,” Dr. Snider told this publication. “If you see someone for the first time, you have a better chance now of saying if this is PANDAS or not, because we don't have a blood test for this disorder.” The study included 30 boys and 20 girls, mean age 8.2 years, who met the original PANDAS criteria. Thirty-eight (76%) had a primary diagnosis of OCD and 12 patients (24%) had a primary diagnosis of tic disorder.
Of the 12 patients with a primary tic disorder, 9 (75%) had comorbid OCD or significant obsessive-compulsive symptoms. Only three patients had a tic disorder without obsessive-compulsive features.
The results were equally clear in regard to criterion 2, Dr. Snider said. Forty-four of the 50 patients (88%) had an abrupt onset of symptoms reaching clinical impairment in less than 48 hours. Of the remaining six patients, four had at least one period of complete symptom remission.
All 50 patients had a group A β-hemolytic streptococcal infection associated with onset or exacerbation. Infection was found in 23% of patients at presentation.