|PANDAS: The OCD - Strep Connection|
|Written by Administrator|
|Friday, 15 April 2011 17:38|
PANDAS THE OCD/STREP CONNECTION
By Marc W. Reitman, MD
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 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 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:
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.