PANDAS

No, today’s column is not about those adorable bamboo-eating bears from China.  PANDAS is an abbreviation for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections.  The term is used to describe a set of children who often have a dramatic “overnight” onset of symptoms, including motor or vocal tics (such as Tourette’s Syndrome), obsessions, and/or compulsions (Obsessive Compulsive Disorder). In addition to these symptoms children may have other symptoms such as emotional moodiness, irritability, enuresis (bed-wetting), anxiety, and deterioration in handwriting. This abrupt presentation of symptoms is generally preceded by streptococcal infections such as “Strep throat” or Scarlet Fever.

It should be noted that this diagnosis/disorder is still controversial within the medical profession with some medical research scientists believing this is only a subset of patients that really do not differ significantly from the rest of the patient population, and that there is not significant increase in risk of developing OCD or Tourette’s symptoms as a result of streptococcal infections.  As a result, PANDAS is a rapidly evolving area of ongoing medical research.

Although still in question the hypothesized mechanism behind this phenomenon, which the NIMH (National Institute of Mental Health) is aggressively pursuing, is an autoimmune reaction.  In a typical bacterial infection the body produces antibodies against the assaulting bacteria, and the antibodies help eliminate the bacteria from the body.  However, in certain infections, the antibodies mistakenly recognize and go after normal parts of the body and/or certain parts of the brain.  The antigens on the cell wall of the streptococcal bacteria are similar in some ways to the proteins of these parts of the body or brain. The antibodies then set off an immune reaction which damages those particular tissues.  In PANDAS it is thought that the tics and OCD symptoms are produced in a similar way.  The basal ganglia, a part of the brain believed to control movement and behavior, may be involved in the PANDAS process.  It is thought that the antibodies cross-react with brain tissue in the basal ganglia to cause the tics and OCD that characterize PANDAS.

According to the NIMH children with PANDAS are clinically identified by five criteria:

  1. Presence of Obsessive-compulsive disorder and/or a tic disorder
  2. Childhood onset of symptoms (age 3 years to puberty)
  3. Sporadic severity of symptoms
  4. Association with group A Beta-hemolytic streptococcal (GABHS) infection (a positive throat culture for strep or history of Scarlet Fever.)
  5. Association with neurological abnormalities (motor hyperactivity, or tic and/or other abnormal movements)

Currently there are no lab tests for PANDAS.  Rather, the diagnosis is a clinical one based upon the use of these five diagnostic criteria.  At present these clinical features of the illness are the only means of determining whether or not a child might have PANDAS.

 

Ongoing NIMH research is looking at whether there may be a limited group of genetically predisposed children who, when exposed to a particular strain of streptococcus, demonstrate the clinical signs and symptoms of PANDAS.  For now the best we can do is watch for changes in a child’s behavior that are out of character and unable to be explained as a result of other significant stressors.  Be mindful of such things as:

  • Obsessive thoughts
  • Repeated “checking” behaviors
  • Severe mood changes
  • Hyperactivity
  • Inattentiveness
  • Repetitive vocalization (such as verbal ‘clicks’)
  • Increased clinginess (separation anxiety)
  • Sudden onset of diminished coordination and muscle control
  • New onset bed-wetting
  • Joint pains
  • Nighttime enuresis (bed-wetting) and/or daytime urinary frequency

 

Although children with PANDAS will have ups and downs in the presentation of their tics and/or OCD symptoms, these symptoms are almost always present.  This is in contrast to many children with actual OCD or tic disorders who oftentimes have a much more periodic course.  Patients with PANDAS typically have a very sudden onset and worsening of their symptoms, followed by a slow, gradual improvement. If they suffer another streptococcal infection their symptoms will suddenly worsen again.  The severity of symptoms of the follow-on infection will usually last for several weeks, or even months.  The OCD and tics then once again gradually diminish and almost always completely go away.

To be clear, almost all school-aged children will suffer from strep throat at some point during their childhood.  And, many children have OCD and/or tics.  It is the close relationship between the rapid onset or worsening of OCD and/or tics, and an earlier streptococcal infection that delineates the likelihood of PANDAS.
Oftentimes a child with undiagnosed PANDAS will end up being taken to a psychologist or psychiatrist as a result of the abrupt onset or worsening of signs and symptoms of OCD, oppositional behaviors, or ADHD.  These children will frequently be treated with antidepressant medication and/or stimulants, as well as undergoing behavioral intervention and counseling.  As the streptococcus antibodies generated by the body in response to the infection diminish, the symptoms, as expected, will gradually subside leaving clinicians and parents believing the interventions were a success.  Then, after a subsequent strep infection the signs and symptoms re-emerge, and the treatment process is once again implemented.  The problem with this, of course, is that the basal ganglia is being repeatedly injured by streptococcus antibodies created to fight off the infections.  After each subsequent event recovery may not be as complete which may lead to a more chronic presentation of a psychiatric disorder.It has been asked if adults can suffer from PANDAS.  By definition the answer is ‘No’.  PANDAS is a childhood disorder.  However, there are several reported cases in the medical literature of adolescent and adult onset of OCD and tic disorders following streptococcal infections.  So, although it is possible that teenagers and adults may experience such autoimmune mediated disorder, current NIMH research studies areonly being conducted in children.Penicillin and other antibiotics do effectively treat streptococcus and other types of bacterial infections.  They treat the pharyngitis (sore throat) caused by the infection by directly destroying the bacteria.  In PANDAS, however, the current theory is that it is the antibodies produced by the body in response to the infection that cause the signs and symptoms of the disorder, not the bacteria themselves.  As such, it would not be expected that antibiotics would be helpful in treating the symptoms of PANDAS.  Interestingly, NIMH researchers are investigating the administration of antibiotics as a form of prophylaxis or prevention of future problems.  At this point, however, there is not nearly enough research evidence to recommend the long-term use of antibiotics as a preventative intervention.  As such, until their usefulness is clearly determined antibiotics should probably not be used as a long-term treatment intervention for OCD or tic behaviors.

The treatment options for children with PANDAS are exactly the same as if they were suffering from other types of OCD or tic disorders.  Whether or not signs and symptoms are brought on by the body’s response to a streptococcal infection, as described in my prior Healthy Mind – Healthy Future column on OCD, patients will benefit from the combination of anti-OCD medications (SSRI’s in particular) and cognitive behavioral therapy (CBT).  Studies have demonstrated that the combination of an SSRI and CBT was clearly the most effective treatment intervention for OCD, while an SSRI alone, or CBT alone were better than no treatment or placebo.  As it often takes time for these treatment modalities to work, the sooner they can be initiated the better.