PANS & Autoimmune Encephalitis: When Infection and Immune Dysfunction Present as Psychiatric Illness

By: Jen Milau, APRN, PMHNP-BC

When I started my career as a nurse practitioner in 2017, I couldn’t have guessed that I’d end up where I am today – a psychiatric provider treating children, adolescents, and adults with a largely misunderstood and relatively controversial diagnosis that causes severe neuropsychiatric symptoms due to a misdirected immune response.

Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS), considered by expert consortiums to be a type of Autoimmune Encephalitis (AE), is characterized by a dramatic onset of severe obsessive-compulsive symptoms or food restriction that presents along with two or more of the following which cause impairment to functioning:

  • Behavioral/developmental regression (immature play, “baby talk,” afraid of the dark, wanting to sleep in parents’ bed, etc)
  • Abnormal movements such as tics, jerking/involuntary muscle spasms, stereotyped movements
  • Severe mood swings and depression
  • Out of character rage, aggression, tantrums with or without self-injurious behavior or suicidal/homicidal ideation or gestures
  • Changes to executive functioning (poor memory, impaired concentration/focus, slowed processing speed)
  • Separation anxiety and panic attacks
  • Psychosis
  • Sensory amplification (aversion to certain textures, sensitivity to noise, lights, or repetitive sounds)
  • Insomnia or other sleep disturbance (nightmares/night terrors)
  • Changes to fine motor skills or muscle strength (for example, difficulty opening doors, using utensils or holding a pencil; changes to handwriting or drawing abilities)
  • Urinary changes (bedwetting, daytime accidents, urgency/frequency of urination)

So what causes this?

While originally believed to be an unusual response to a Group A Strep infection (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus, or PANDAS), we now understand that in susceptible individuals, PANS can be triggered by anything that activates the immune response – this can include infection, allergies, certain cancers, inflammatory conditions or injuries, and exposure to toxins. Like other autoimmune diseases, PANS occurs when the immune system mistakes our own cells and healthy tissue as foreign pathogens that need to be eradicated. More commonly-identified autoimmune diseases, such as rheumatoid arthritis, lupus, hashimoto’s thyroiditis, etc., present with primary physical symptoms that are associated with the type of cell that is mistakenly targeted by the inflammatory response. In the case of PANS/Autoimmune Encephalitis, however, it’s healthy tissue in certain areas of the brain that is the target of this autoimmune attack – the result being the array of severe neuropsychiatric symptoms described above.

Interestingly, since the start of the COVID19 pandemic, PANS/AE clinicians across the country have seen a significant increase in cases. In some instances, this is clearly related to infection with the COVID19 virus, itself; however, often the trigger is not straightforward, and while many theories currently center around the impact of extreme stress (which subsequently can increase inflammation and suppress the immune response which elevates the risk of reactivation of latent infection or acquiring illness from exposure), the overall etiology is not clear.

How is it diagnosed & treated?

PANS symptoms exist on a spectrum of severity that impacts the approach to a diagnostic work-up and treatment recommendations. For individuals with mild to moderate symptoms who are otherwise functioning fairly well overall, I often recommend “traditional” psychiatric treatment with the appropriate psychotherapy interventions along with low-dose medications to target their psychiatric symptoms, with the plan to keep PANS on my differential should their presentation abruptly change in the future.

Typically, however, the patients that I see have a much more severe and impairing set of neurological and psychiatric symptoms that warrants a diagnostic assessment to look for underlying infectious, inflammatory, or immunological abnormalities that might be impacting their clinical presentation. This typically consists of blood work and urine studies though can sometimes include imaging when clinically indicated. In rare and severe cases, a lumbar puncture might be considered. Collaboration with clinicians in other specialty areas such as immunology, rheumatology, and neurology, is necessary in more complex case presentations.

In general, the treatment of PANS entails a three-pronged approach:

  • Initiate appropriate psychiatric interventions including psychotherapy and medications to target specific symptoms (SSRIs/SNRIs, Non-stimulant ADHD medication, Antipsychotics).
  • Treat any underlying infection with appropriate antimicrobial medication, keeping in mind the importance of balancing this with pre/probiotics to ensure that gut flora is adequately maintained during therapy.
  • Treat immune system dysregulation with anti-inflammatory medication and/or immunomodulatory therapy if indicated.

Once someone has gotten through the most severe part of their flare-up, we often transition to a “maintenance” phase of treatment which includes lifestyle and dietary changes along with selective use of supplements to support immune health and manage systemic inflammation. Psychiatric treatment is also maintained for as long as clinically indicated. These efforts, along with quick identification and treatment of signs/symptoms of future flare-ups, help to minimize the frequency/intensity of subsequent flares and can ultimately improve long-term prognosis.

What makes this such a controversial diagnosis?

Our understanding of PANS and other neuroinflammatory conditions is still somewhat in its infancy. This means that much of the existing literature is based on empirical evidence gathered by expert consensus groups and clinicians with experience in assessing, diagnosing, and treating this special patient population. As with any emerging field of science or medicine, new research and expanded awareness of the disease have led to modifications to the original diagnostic criteria and theories associated with PANS/PANDAS – however, these updates (namely, that PANS/AE may not present as “acute” onset, but rather, as sub-acute or insidious; not limited to pediatrics – can also occur in adolescence and adulthood) are largely underrecognized, and as a result, the condition is prematurely “ruled out” in individuals who otherwise meet criteria based on their clinical presentation.

The complex and variable presentation of symptoms and potential triggers associated with PANS leads many clinicians to refute the connection between infection/immune dysfunction and psychiatric symptoms. Unfortunately, when seeking care, families often face judgment and experience repeated invalidation when they attempt to bring up their concerns for possible PANS/AE, as individual providers and occasionally even entire organizations maintain a firm stance against the assessment/diagnosis and treatment of PANS/PANDAS as a whole.

Final thoughts and resources:

PANS/AE can be a significant source of suffering not only for the individual impacted by the illness, but the entire family who is involved with their care. It’s important to strengthen your own support systems and build in time for self-care when faced with a loved one’s intense cognitive and behavioral manifestations of the disease.

Regardless of the underlying etiology, psychiatric treatment with psychotherapy and appropriate medication management is imperative for individuals with this diagnosis.

Below are a few of my favorite resources for patients, families, and clinicians who want to learn more about PANS/PANDAS/AE: