The Short Answer

PANDAS and PANS are autoimmune neuropsychiatric conditions triggered by strep infections or other pathogens, causing sudden-onset OCD, tics, and behavioral changes in children. New research shows these conditions involve autoimmune attacks on brain cells called cholinergic interneurons in the basal ganglia, as well as a “leaky blood-brain barrier” that allows antibodies to cross into the brain. Genetic susceptibility and inflammatory immune responses determine who develops these conditions after infection.

What Are PANDAS and PANS?

Some children develop sudden-onset neurological and psychiatric symptoms after a strep infection: obsessive-compulsive disorder (OCD), Tourette’s, tics, odd behaviors, emotional instability, and other psychiatric and neurological disorders. This condition is called PANDAS — Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections.

A similar disorder called PANS (Pediatric Acute-Onset Neuropsychiatric Syndrome) results from environmental factors or other infections triggering the same spectrum of symptoms. Both conditions are believed to involve an autoimmune attack against the brain, explaining the rapid onset of neurological and psychiatric symptoms.

Many mainstream doctors and researchers have historically dismissed PANDAS/PANS as credible because the condition can’t be measured by a single lab test and has limited research backing. However, parents recognize the reality: their previously healthy child changed drastically and permanently after exposure to strep or another pathogenic trigger. New research is now validating these observations and explaining the biological mechanisms at work.

How Autoimmune Attack on Brain Cells Causes Symptoms

Recent research reveals that PANDAS/PANS results from inflammation in the basal ganglia, an area of the brain that controls emotions and motor function. When autoimmunity is triggered by strep infection in genetically susceptible children, the immune system attacks and damages this critical brain region.

In 2018, researchers isolated specific cells called cholinergic interneurons in the basal ganglia — these cells were identified as the target of autoimmune attack. Previous studies showed that these same cells are depleted in Tourette’s syndrome, explaining the motor symptoms. The autoimmune attack causes these cholinergic interneurons to fire less effectively when strep antibodies attach to them, directly causing PANDAS/PANS symptoms.

The Leaky Blood-Brain Barrier: Why Some Children Are Vulnerable

A key question researchers have addressed: why does strep infection trigger autoimmune brain attack in some children but not others? One critical explanation is a compromised blood-brain barrier.

In a healthy brain, the blood-brain barrier protects the brain by preventing strep antibodies from crossing into brain tissue. However, in susceptible children, inflammatory TH-17 immune cells released during a strep infection can damage the blood-brain barrier, making it overly permeable, a condition called “leaky blood-brain barrier.” This allows strep antibodies and other harmful compounds to enter the brain and trigger the autoimmune attack.

Research shows most of these TH-17 immune cells pool in the olfactory bulb, the brain’s “smelling” center that receives signals from the nasal passages. This anatomical pathway provides direct access for antibodies to enter the brain, especially after repeated strep infections or prolonged exposure.

Genetic Susceptibility and Individual Risk

Genetic susceptibility has been identified as a key factor determining who develops PANDAS/PANS after exposure to infection. Not all children with strep infections develop the condition; those with specific genetic variations in immune regulation are at higher risk. Understanding these genetic factors helps explain why identical environmental exposures produce different outcomes in different children.

PANDAS Diagnosis Criteria

A PANDAS diagnosis requires all of the following:

• Significant obsessions, compulsions, or tics
• Abrupt onset of these symptoms or relapsing and remitting symptom severity
• Symptom onset prior to puberty
• Clear association with strep infection
• Association with neuropsychiatric symptoms

PANS Diagnosis Criteria

PANS diagnosis requires an abrupt, dramatic onset of OCD or severely limited food intake, plus at least two of the following:

• Anxiety
• Emotional swings and/or depression
• Irritability, anger, or oppositional behavior
• Behavioral regression
• Sudden decline in school performance
• Sensory or motor abnormalities
• Sleep disturbances, urinary frequency, or bedwetting

Functional Medicine Support for PANDAS/PANS

Functional medicine approaches can help reduce inflammation and autoimmune activation in PANDAS/PANS while supporting brain and immune health. Treatment strategies may include:

• Removing inflammatory triggers from diet and environment
• Nutritional supplements targeted at lowering inflammation and supporting brain healing
• Stabilizing blood sugar and optimizing gut health
• Addressing environmental toxin exposures
• Supporting neurotransmitter balance and production
• Repairing mitochondrial function and blood-brain barrier integrity

Early, swift action often significantly improves outcomes in PANDAS/PANS. While some physicians may question the validity of these conditions, parents and functional medicine doctors recognize the reality of rapid neuropsychiatric changes following infection in susceptible children.

Contact RedRiver Health and Wellness to work with a functional medicine doctor experienced in autoimmune neuropsychiatric conditions like PANDAS/PANS.