How Do Children with Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS) Progress Over Time?

What you need to know

• Most children with PANS showed significant improvement in symptoms over a 2-5 year follow-up period
• Full remission was rare, with only 6% of patients having no symptoms at follow-up
• About one-third of patients developed a chronic course with ongoing symptoms requiring treatment
• Many patients were diagnosed with additional neuropsychiatric conditions like ADHD during follow-up
• The study proposes new definitions for classifying disease flares and clinical course in PANS

What is PANS?

Pediatric acute-onset neuropsychiatric syndrome (PANS) is a condition characterized by the sudden onset of obsessive-compulsive symptoms and/or eating restrictions, along with other neuropsychiatric symptoms. These may include anxiety, emotional instability, irritability, hyperactivity, sleep disturbances, and more. PANS is thought to be triggered by infections or other inflammatory processes, though the exact cause is unknown.

The sudden, severe onset of symptoms can be very distressing for children and families affected by PANS. However, little is known about how the condition progresses over time. This study aimed to follow up with a group of children diagnosed with PANS to better understand the long-term outcomes.

How the study was conducted

The researchers followed up with 34 children who had been previously diagnosed with PANS at a specialty clinic in Sweden. The children were evaluated 2-5 years after their initial diagnosis (average of 3.3 years later).

At the follow-up visit, the children and their parents were interviewed about current symptoms, treatments received, school attendance, and overall functioning. The children also underwent a medical exam and laboratory tests.

The researchers used standardized rating scales to assess symptom severity and overall functioning at both the initial diagnosis and follow-up time points. This allowed them to track changes over time.

Most children showed improvement over time

The good news is that the majority of children showed significant improvement in their PANS symptoms over the follow-up period:

• 85% were rated as “much improved” or “very much improved” compared to their initial presentation
• Average scores on measures of symptom severity and overall functioning showed statistically significant improvement
• Only 15% still had clinically significant obsessive-compulsive symptoms at follow-up
• Only 6% had clinically significant tic symptoms at follow-up

While full remission (no symptoms for at least 12 months) was rare, occurring in only 6% of patients, most children were doing much better than when they were first diagnosed.

But some developed a chronic course

Despite the overall positive trend, about one-third of the children (35%) were classified as having a “chronic-static/progressive” course. This meant they were experiencing significant PANS symptoms more than half the time over the past year.

Compared to children with a non-chronic course, those with a chronic course:

• Had an earlier age of onset
• Had lower overall functioning scores at both initial diagnosis and follow-up
• Were more likely to have received additional psychiatric diagnoses like ADHD
• Required more ongoing medication and psychological treatments
• Had more school absences

This suggests that while many children with PANS improve over time, a significant subset develop an ongoing chronic condition requiring continued treatment and support.

New neuropsychiatric diagnoses were common

An interesting finding was that 38% of the children received new neuropsychiatric diagnoses during the follow-up period. The most common was ADHD, diagnosed in 26% of patients.

This highlights the complex nature of PANS and the overlap with other neurodevelopmental conditions. It also emphasizes the importance of comprehensive psychiatric evaluations in these patients over time, rather than focusing solely on PANS symptoms.

Proposed definitions for flares and clinical course

One challenge in PANS research has been the lack of standardized definitions for concepts like symptom “flares” or clinical course patterns. To address this, the researchers proposed the following definitions:

Flare: Worsening of PANS symptoms and/or loss of function lasting longer than 4 days

Clinical course categories:

• Remitting: No symptoms for at least 12 months
• Relapsing-remitting: At least one flare in past 12 months, but in remission >50% of the time
• Chronic-static/progressive: Meeting flare criteria >50% of the time over past 12 months

These definitions appeared to meaningfully distinguish between patient subgroups in terms of impairment levels and healthcare needs. The authors suggest they could be useful for future research and clinical practice.

Physical exam and lab tests had limited utility at follow-up

At the initial PANS diagnosis, comprehensive physical exams and laboratory tests are typically performed to rule out other medical conditions. However, this study found that abnormal physical exam findings were much less common at the follow-up assessment.

Similarly, while some lab tests showed differences between chronic and non-chronic patients, most did not require any specific medical intervention. The authors suggest that extensive testing may not be necessary at follow-up visits for most patients.

Limitations of the study

Some limitations to keep in mind when interpreting these results:

• The sample size was relatively small at 34 patients
• Some patients were lost to follow-up, which could bias the results
• The study was conducted at a single specialty clinic, so may not be representative of all children with PANS
• Some measures used at follow-up were not available from the initial assessment, limiting certain comparisons

Conclusions

• While full remission is rare, most children with PANS show significant symptom improvement over a 2-5 year period
• About one-third develop a chronic course requiring ongoing treatment and support
• New neuropsychiatric diagnoses like ADHD are common during follow-up
• Early age of onset and low functioning at diagnosis may predict a more chronic course
• The proposed definitions of flares and clinical course patterns may be useful for future PANS research and clinical care

This study provides important information on the long-term outcomes of PANS, which can help guide treatment approaches and set realistic expectations for families. More research is still needed to better understand what factors influence prognosis and to develop targeted treatments for those with a chronic course.