PANDAS: THE OCD/STREP CONNECTION
By Marc W. Reitman, MD
Western Suffolk Psychological Services, Inc.
Huntington, New York
(Published with the kind permission of the author. For more
information about Dr. Reitman and WSPS, click
here)
Over the last ten years, there has
appeared a mounting body of evidence that suggests there is a small subgroup
of individuals whose childhood onset Obsessive-Compulsive Disorders may have
been triggered by streptococcal throat infections. This association of an
infectious cause with a neurobiological disorder may also be true for tic
disorders, such as Tourette's Disorder, Trichotillomania (compulsive hair
pulling), and possibly Attention Deficit Hyperactivity Disorder.
These conclusions were drawn from
research conducted by Drs. Susan Swedo, Judith Rappaport, and their associates
at The National Institute of Mental Health. During the late 1980's, they
observed that children with Sydenham's Chorea, the neurobiological
manifestation that follows bouts of Rheumatic Fever, had an unusually high
percentage of OCD symptoms, including both obsessions and compulsions.
Rheumatic Fever is caused by Group A Beta hemolytic streptococcal bacteria,
commonly known as strep throat. In a vulnerable subgroup of children, the
immune response to the bacteria goes awry, causing the antibodies to
mistakenly identify the basal ganglia (an area deep within the brain) as
foreign bodies. The basal ganglia then become inflamed as a result of this
"mistaken identification." This chain reaction is what is known as an
autoimmune response, when the immune system misidentifies an individual's own
cells as foreign.
Noting that 70% of Sydenham's Chorea
patients have OCD symptoms, Drs. Swedo and Rappaport conducted research of
children with sudden onset of OCD, looking for a casual relationship between a
strep infection and OCD symptoms. To identify this group of children, the
acronym PANDAS was proposed representing Pediatric Autoimmune Neuropsychiatric
Disorders Associated with Streptococcal Infections. The proposed working
criteria that has been developed to make a diagnosis of PANDAS include:
* The presence of OCD and/or a tic disorder
* Childhood onset (between the age of 3 and puberty)
* Episodic course (sudden burst of symptoms followed by a gradual decline,
then absence of symptoms until the next sudden burst of symptoms)
* The presence of a group A Beta hemolytic streptococcal infection
(established by a positive throat culture and/or elevated titer of
anti-streptococcal antibodies)
* The presence of abnormal neurological signs
The National Institute of Mental Health
group has recently published their findings of 50 children, following them
over a 2-year course. The results indicate that these children have typical
OCD symptoms but atypical associated features, which would include:
* The onset of symptoms is sudden and dramatic such that parents can
frequently recall the date of onset. The usual onset of OCD is more gradual.
* This group of children has an earlier age of onset of symptoms than compared
to the usual onset.
* PANDAS children are seen to have complete remissions of symptoms between
episodes of symptoms. The non-PANDAS OCD symptoms usually follow a waxing and
waning course.
* The presence of accompanying neurological signs such as tics, hyperactivity,
or choreiform movements (irregular spasmodic involuntary movements of the
limbs or facial muscles) further distinguishes this subgroup of children with
OCD.
* Other symptoms can include emotional lability (over reactions to minor
events), separation anxiety, nighttime fears and oppositional behaviors.
* Symptoms worsen following a strep infection.
The identification of this subgroup of
OCD has advanced our understanding of this disorder by providing evidence
through neuroimaging studies of a specific location in the brain and possible
causes. Genetic vulnerability in those who develop these symptoms is also
being explored. There is a biological marker in certain blood cells that
appears to have a higher frequency of expression among children with PANDAS.
However, this test is only available in research laboratories and is not
commonly used as a diagnostic tool.
Treatments for this type of OCD have
included plasma exchange (a filtering of the plasma eliminating
antigen/antibody complexes), intravenous immunoglobulin (IVIG), steroids or
antibiotics. There is an ongoing study exploring the chronic use of
antibiotics to prevent re-infection by strep, which could theoretically avoid
further episodes of OCD. The results of this study could help guide
clinicians in the treatment of this subgroup of OCD. However, these are no
current recommendations that antibiotics should routinely be administered as a
formal treatment.
Until more is learned about the outcome
of these experimental treatments, it is wise to follow these suggestions for
children who may be vulnerable to have PANDAS:
* Treat all strep infection aggressively with antibiotics.
* Be sure to complete the course of antibiotic treatment to avoid development
of resistant strains of bacteria.
* Make use of proven therapies such as cognitive/behavioral therapy and
serotonin medication (SSRI's) as are utilized to treat the more usual forms of
OCD.
* The "quick" strep throat culture is not accurate enough for demonstrating
the presence of streptococcal infection. The older method of incubation of a
throat swab on agar for 48 hours is far more accurate.
* In addition to throat cultures, there are blood tests that the pediatrician
can request to help identify the association of strep infection and
exacerbation of symptoms. These include anti-streptolysin O titer and
anti-streptococcal DNase B titer.
The current interest about the role of
the immune system in neuropsychiatric disorders will increase our
understanding of brain functioning and potential treatments for these
disorders in children and adults.
Copyright © 2008 OCD
Resource Center of Florida. All Rights Reserved
