What minor criteria or contextual features accompany the ESSTS 2022 FTLB criteria and how are they defined in source documents?

1. What the consensus says about “minor” or contextual features

The ESSTS statement proposes three major criteria and two minor criteria to support an FTLB diagnosis, and explicitly allows a clinically probable diagnosis to be confirmed by fulfilling two major criteria and one minor criterion, indicating that minor features are meant as supportive/contextual rather than determinative elements of the diagnosis ^{[1] [2]}.

2. Which minor/contextual items are named in the ESSTS sources

Across the publicly available summaries and the ResearchGate abstract, the minor criteria are listed as the patient’s co‑morbidity profile and the presence of other functional neurological symptoms or somatic symptom disorders; reviewers and summaries repeat this triage—major clinical phenomenology plus these ancillary features—when explaining how some patients reach a “probable” but not “definite” FTLB diagnosis ^{[2] [1]}.

3. How “co‑morbidity profile” is framed in the literature

The documents and associated reporting link co‑morbidity to higher rates of anxiety and depression and a broader burden of functional neurological disorder (FND) symptoms in patients with rapid‑onset tic‑like presentations, using co‑morbid psychiatric diagnoses as contextual clues that favor a functional aetiology; however, ESSTS acknowledges this as a supportive profile rather than a standalone diagnostic test ^[2].

4. How “other functional neurological symptoms / somatic symptom disorders” are framed

The consensus uses the occurrence of other FND manifestations or somatic symptom disorder as a minor criterion—i.e., additional functional signs elsewhere in the neurological or somatic domain that co‑occur with tic‑like behaviours strengthen the likelihood of FTLBs—again as contextual evidence rather than a primary diagnostic item ^{[2] [1]}.

5. Evidence testing and specificity caveats

Independent testing of the ESSTS phenomenological criteria has focused on the three major criteria—age at onset ≥12 years, rapid evolution and specific phenomenology—with reported good specificity for some phenomenological items (for example, complex‑over‑simple tic predominance showed specificity near 90% in one study), but the minor/contextual features have not been subject to the same prospective sensitivity/specificity validation and the ESSTS authors themselves note the lack of prospective testing as a limitation ^{[3] [4] [1]}.

6. Process, implicit agendas and practical implication

The criteria arose from a Delphi consensus among ESSTS experts, reflecting expert clinical experience during a surge of rapid‑onset cases; that provenance explains why the guidance emphasizes pragmatism and clinical context (minor features) over biomarker thresholds, but it also introduces the implicit agenda of codifying clinical impressions rapidly during a public‑health‑relevant wave of referrals—an approach helpful for clinicians yet dependent on future empirical validation ^{[1] [2]}.

7. What remains unclear or under‑defined in source documents

While sources name the two minor criteria, they do not publish tightly operationalized cutoffs or structured instruments for “co‑morbidity profile” or for grading other FND symptoms within the ESSTS 2022 paper summaries; therefore clinicians must interpret these minors within broader psychiatric and neurology assessments and await prospective studies for formal measurement properties ^{[2] [1]}.