Can Strep Infections Cause Neuropsychiatric Disorders?
Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS), is a controversial and confusing syndrome. PANDAS is diagnosed in children who get a streptococcal infection and later develop tics and severe OCD. The treatment of PANDAS and its legitimacy as an actual disorder are highly contested among doctors.
Picture a normal, happy-go-lucky eight-year-old recently recovered from a strep throat infection who wakes up one morning screaming that she does not want to go to school. She puts on her clothes but starts shouting that her pants, socks, and shirt are squeezing her too much. A change of clothes provides no relief. She refuses to eat any breakfast, claiming that all the food is unhealthy and poisonous. She next runs laps around the driveway and then bursts into tears alternating with temper tantrums of screaming rage. She is too frightened to get into the family car and first needs to close the house door multiple times and then wash her hands repeatedly. At school she makes simple mistakes and erases her paper over and over again until the paper tears. This transformation overnight from a regular kid and good student into a child who is withdrawn, obsessive, and terrified fits the clinical picture of a child with PANDAS.
Doctors who believe in PANDAS state that the diagnosis requires a specific set of clinical criteria, including pre-pubertal, acute onset of tics or ritualistic, obsessive compulsive behaviors, such as frequent hand-washing or severely restricted food intake. These symptoms cannot be explained by a known medical or neurological disorder and must have an association with a prior streptococcal infection. To meet the diagnostic criteria for PANDAS, two or more severe neuropsychiatric symptoms must accompany the new change in behavior, such as developmental regression or temper tantrums, vocal or motor tics, extreme anxiety, separation difficulties, bedwetting or daytime urinary accidents, and sudden deterioration in school performance. The symptoms follow a relapsing and remitting course.
The transformation overnight from a regular kid and good student into one who is withdrawn, obsessive, and terrified fits the clinical picture of a child with PANDAS.
PANDAS was first described in 1998 at the National Institute for Mental Health by pediatrician Dr. Susan Swedo. After studying Sydenham’s chorea (SC), a neurological disease consisting of jerking movements that occurred in some children with acute rheumatic fever caused by a streptococcal infection, Swedo hypothesized that if strep infections could trigger a neurological manifestation similar to Sydenham’s chorea, strep may also cause other neurological diseases. When Swedo began studying the sudden onset of more general obsessive-compulsive behaviors without the jerking movements seen in SC, she recognized that many of the children had recently had a strep infection.
Swedo believes that PANDAS is caused by an autoimmune response to a streptococcal infection. The streptococcus bacteria, which mimics human cells to avoid detection by the immune system, is known to initiate various immune-related disorders in rheumatic fever and kidney disease. Because strep mimics human cells so closely, antibodies created by patients to attack the strep cells may also begin to target the host’s own cells, especially the basal ganglia in the brain, which control behavior, emotions, and physical movements. Damage to this brain region may explain the tics and OCD-like behavior of PANDAS patients.
The symptoms of PANDAS start suddenly. PANDAS case studies have shown that these “symptoms literally begin overnight,” as opposed to OCD which typically develops over months or years, according to Dr. Swedo. One parent said, “It’s like my child was possessed.”
Not all physicians are on-board with the diagnosis of PANDAS, however. Many consider PANDAS to be a hypothesis and not a proven disease. Doctors complain of a high rate of misdiagnosis with the application of the criteria of tics and obsessive-compulsive behavior in children. Furthermore, streptococcal infections are common, as are tics, which also have a “sudden” onset. How can one prove a temporal relationship to a strep infection?
Neurologist Dr. Roger Kurlan, Director of the Movement Disorders Program at Overlook Medical Center in New Jersey, believes that studies linking strep and PANDAS are based mainly on anecdotal evidence. He states, “It’s not uncommon for tics and OCD to wax and wane.” Parents probably take their children to the pediatrician when their symptoms are severe, so the observation that the symptoms get better after antibiotics may not be relevant. Dr. Kurlan contends that strep can be linked to “almost anything…because strep is extremely common.”
Many children diagnosed with PANDAS have had prior tics or OCD behaviors for months or years. Studies trying to identify cognitive or clinical features that could distinguish between PANDAS and other neuropsychiatric disorders have not been successful. Two prospective longitudinal studies provided no evidence for a temporal association between streptococcal infections and tic/OCD symptoms in children who met the diagnostic criteria for PANDAS.
Despite the failure to establish PANDAS as a real disorder, roughly two-dozen PANDAS experts across the country offer treatment for PANDAS. A first line treatment for many PANDAS specialists is antibiotics to eradicate streptococcus.
But the length of treatment for PANDAS has also been disputed. For a typical strep infection, pediatricians treat with antibiotics such as amoxicillin for ten days. Some PANDAS doctors, on the other hand, prescribe a month’s supply and observe their patients’ improvement, while others write prescriptions for an entire year. People worry about excess antibiotic use and long-term resistance to these medications.
Another common treatment involves prescribing Prozac or other selective serotonin re-uptake inhibitors (SSRIs) to control the OCD symptoms, along with cognitive behavioral therapy. Parents and physicians both are concerned about the effects of SSRIs on the young, developing brain. For severe symptoms that do not respond to antibiotics, SSRIs, and therapy, other treatments have been tried with limited success.
These experimental treatments for PANDAS include the use of high-dose steroids, intravenous immunoglobulin (IVIG), and plasma electrophoresis. IVIG is believed to boost the immune system by providing concentrated doses of antibodies from healthy donors. However, IVIG is extremely costly — within the thousands for a single treatment — and is not covered by insurance. Like antibiotics, IVIG is also at risk for overuse without clear guidelines for treatment. Additionally, plasmapheresis involves drawing blood from a patient, removing the harmful bacteria, and then transfusing the cleaned blood back into the patient. All of these immune-modulating remedies require further investigation.
Almost two decades after its initial characterization, PANDAS remains controversial. Evidence is mounting that this is not a real disorder. Treatment plans are neither clear nor effective. Yet parents, desperate for a cure for their child’s unusual behavior, continue to travel great distances to seek out PANDAS experts.
Unfortunately, it’s hard to treat an illness that may not even exist.