Publications by authors named "Lisa Snider"

Background: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus (PANDAS) research is based on the hypothesis that infections trigger changes in behavior and movement in children.

Methods: We enrolled 693 children (ages 3 to 12 years) into a systematic, longitudinal study. Data were collected monthly for 8 months (October-May) to determine point prevalence of Group A Streptococcal (GAS) infections, tics, behavior, and choreiform movements.

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Behavioral and movement disorders may have antibody responses where mimicry and signal transduction may lead to neuropsychiatric abnormalities. In our study, antibodies in pediatric autoimmune neuropsychiatric disorders associated with streptococci (PANDAS) reacted with the neuronal cell surface and caudate-putamen and induced calcium-calmodulin dependent protein (CaM) kinase II activity in neuronal cells. Depletion of serum IgG abrogated CaM kinase II cell signaling and reactivity of CSF was blocked by streptococcal antigen N-acetyl-beta-d-glucosamine (GlcNAc).

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Background: H. Szechtman and E. Woody (2004) hypothesized that obsessive-compulsive disorder results from a deficit in the feeling of knowing that normally terminates thoughts or actions elicited by security motivation.

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Sydenham's chorea has been established as a postinfectious autoimmune neuropsychiatric disorder. Corticosteroids have been used to treat patients with severe disease but are not always effective, and relapses are frequent after cessation. Eighteen subjects were entered into this randomized-entry controlled trial designed to determine if intravenous immunoglobulin or plasma exchange would be superior to prednisone in decreasing the severity of chorea.

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Background: Among patients with tic disorders, a distinctive clinical profile of obsessive-compulsive symptomatology has been described. The present investigation was designed to document the phenomenology of obsessive-compulsive symptoms (OCS) among patients with Sydenham chorea (SC), the neurologic variant of rheumatic fever. We hypothesized that OCS occurring in association with SC would be similar to those among patients with tic disorders.

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Background: The acronym PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) describes a subgroup of children with obsessive-compulsive disorder and/or tic disorder that experience symptom exacerbations following streptococcal infections. We hypothesized that the prevention of streptococcal infections among children in the PANDAS subgroup would decrease neuropsychiatric symptom exacerbations.

Methods: Twenty-three subjects with PANDAS were enrolled in a double blind, randomized controlled trial.

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Background: Sydenham's chorea is the neurologic manifestation of rheumatic fever and is a diagnosis of exclusion requiring only the presence of frank chorea in the absence of another neurologic disorder. Two thirds of children with Sydenham's chorea also have rheumatic carditis (pathologic mitral valve regurgitation). Although there are similar neuropsychiatric symptoms and preceding group A beta-hemolytic streptococcal infection associated with both Sydenham's chorea and the PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections) subgroup, it is unknown whether patients in the PANDAS subgroup have any cardiac involvement.

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Objective: To determine whether group A beta-hemolytic streptococcal infections increase the risk of developing symptoms characteristic of the diagnosis pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS).

Design: Prospective cohort study.

Methods: Children (N = 814) aged 4 to 11 years seen for sore throat or well-child care in a large pediatric practice in Rochester, NY, were enrolled from October 2001 to June 2002 (group A beta-hemolytic streptococcal [GAS] infected, n = 411; GAS uninfected, n = 403, of whom 207 had a sore throat of presumed viral etiology and 196 were well children).

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A subgroup of childhood-onset obsessive-compulsive disorder (OCD) and tic disorders has been found to have a postinfectious autoimmune-mediated etiology. Clinical observations and systematic investigations have shown that a subgroup of children with OCD and/or tic disorders have the onset and subsequent exacerbations of their symptoms following infections with group A beta-hemolytic streptococci (GABHS). This subgroup has been designated by the acronym PANDAS: pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections.

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Purpose Of Review: Autoimmune disease has long been intertwined with investigations of infectious causes. Antibodies that are formed against an infectious agent can, through the process of molecular mimicry, also recognize healthy cells. When this occurs, the immune system erroneously destroys the healthy cells causing autoimmune disease in addition to appropriately destroying the offending infectious agent and attenuating the infectious process.

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Objective: Tic disorders are the most common movement disorder diagnosed in children and have symptoms that fluctuate in frequency and intensity over time. We conducted an 8-month longitudinal observational study to determine the variations in frequency of motor tics and associated problem behaviors.

Methods: A total of 553 children, kindergarten through sixth grade, were observed monthly from November 1999 to June 2000 by 3 raters.

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