MIND ON THE RUN:
PANDAS: Strep’s Enduring Threat To The Brain
By Kristi Wees, MSc Chemistry
Chief Patient Advocacy Officer
Pediatric Alliance — Arcadia
“And therefore as a stranger give it welcome.
There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.”
— “Hamlet” by William Shakespeare
For those who are new to the table, PANDAS is an acronym for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections and PANS is short for Pediatric Acute-onset Neuropsychiatric Syndrome. According to the National Institute for Mental Health’s website:
“A child may be diagnosed with PANDAS when:
> Obsessive compulsive disorder (OCD) and/or tic disorders suddenly appear following a strep infection (such as strep throat or scarlet fever);
> The symptoms of OCD or tic symptoms suddenly become worse following a strep infection.”
The symptoms are usually dramatic, happen “overnight” and “out of the blue,” and can include MOTOR and/or VOCAL TICS, OBSESSIONS, and/or COMPULSIONS. In addition to these symptoms, “children may also become moody, irritable, experience ANXIETY attacks, or show concerns about separating from parents or loved ones.” However, it is this abrupt “thunderclap” presentation which differentiates PANDAS/PANS from the corresponding primary neuropsychiatric conditions; therefore, it is essential that the evaluating provider pay strict attention to one of the cardinal rules of pediatric practice: listen intently to the details of the history provided in turn by the parents and child without prejudice and subconscious bias.
Obsessions can be manifested by refusal to eat or severe food aversion (leading to emaciation), or by a disabling habitual focus on urination which leads to a frequency typical of diabetes mellitus. A classic and, importantly, a documentable finding is deterioration in handwriting and other fine motor skills (similar to adults with dementia). Although strep infections most commonly affect elementary school children, no age is exempt (this pediatrician has diagnosed the disorder in a child as young as three years of age).
The term PANDAS first appeared in the medical literature in 1996 and 1997 through case studies and government-funded research done at the National Institute of Mental Health by Dr. Susan Swedo and others. The term PANS was coined in 2012, also by Dr. Swedo, in her paper, “From Research Subgroup to Clinical Syndrome: Modifying the PANDAS Criteria to Describe PANS (Pediatric Acute-onset Neuropsychiatric Syndrome).”
The crucial difference between the two conditions is that PANDAS has a strep connection, and PANS can be triggered by either infectious or non-infectious (environmental) factors as is stated in the paper:
“PANS is postulated to be much broader than PANDAS, including not only disorders potentially associated with a preceding infection, but also acute-onset neuropsychiatric disorders without an apparent environmental precipitant or immune dysfunction.”
From a historical and clinical perspective, rheumatic fever established the precedent for a post-infectious immunologic complication associated with simple strep infections. Seen primarily in geographic clusters in this day and age, rheumatic fever involves auto-antibodies which attack the heart, the joints, and the skin. However, it is the development of autoantibodies to the basal ganglia of the brain (the center which controls involuntary movements) which produces Sydenham’s chorea — a self-limited, but protracted feature of rheumatic fever. The malady, also known as “Saint Vitus Dance,” is characterized by widespread uncontrollable jerking — purposeless movements of the body. By a phenomenon known as “molecular mimicry,” antibodies to the strep surface membrane (which in certain strains can mimic that of human biomolecules) can direct their attention to the basal ganglion of the developing brain. Vulnerable children appear to have a compromised blood-brain barrier, allowing these auto-antibodies to leak into and attack the selected areas of the brain which are the executors of tics, anxiety, obsessions, mood, etc. This pathogenesis will be the keystone in future discussions of therapy.
Tomorrow on The PediaBlog: More than 20 years after it was first described in the medical literature, PANDAS remains a misunderstood and underappreciated condition.