What are the ESSTS 2022 diagnostic criteria for functional tic‑like behaviours, and how are they applied in clinic?
Executive summary
The ESSTS 2022 consensus defines functional tic‑like behaviours (FTLBs) using a small set of phenomenological “red flags” — three major criteria (age at onset ≥12 years, rapid evolution of symptoms, and characteristic phenomenology) plus additional minor features — and operationalises a diagnostic threshold in which all three major criteria give a clinically definite diagnosis and two major plus one minor a clinically probable one [1] [2]. These criteria were developed by Delphi consensus to help clinicians distinguish FTLBs from primary tic disorders and to guide different treatment pathways, but they remain chiefly consensus‑based and lack prospective validation of sensitivity [3] [2].
1. What the ESSTS 2022 criteria actually are: the three major anchors
The guideline sets out three major diagnostic anchors: first, symptom onset at or after age 12; second, a rapid evolution of tic‑like behaviours (often abrupt emergence of numerous, complex movements and vocalisations); and third, a specific phenomenology that differs from typical primary tics — for example complex arm/hand movements, blocking, self‑injury, copropraxia, and complex vocalisations such as words, phrases, disinhibited speech or coprolalia — features explicitly named in the ESSTS criteria and subsequent specificity testing [1] [4] [3].
2. How clinicians convert the anchors into a diagnosis (probable vs definite)
The working group recommended a pragmatic threshold: a clinically definite diagnosis of FTLBs is supported when all three major criteria are present, while a clinically probable diagnosis can be made when two major criteria plus at least one minor criterion are present [2] [5]. The minor criteria concept is included as part of the consensus schema to capture contextual and supportive features, but the consensus paper and many follow‑up reports focus on the three major phenomenological items as the decisive elements in day‑to‑day clinical triage [3] [2].
3. How the criteria are applied in clinic: assessment, tools and workflow
In practice clinicians use the ESSTS criteria alongside structured interviews, tic severity instruments (for example Yale Global Tic Severity Scale in validation studies) and collateral history to check age at onset, tempo of symptom escalation and the precise phenomenology; clinicians then weigh the presence of minor/contextual features to reach probable versus definite labels [4] [1]. The criteria were designed to be pragmatic for neurologists, paediatricians, psychiatrists and psychologists confronted with the rapid‑onset presentations that surged during the COVID‑19 era, and to support early diversion from tic‑directed pharmacotherapy when an FTLB phenotype is more likely [3] [6].
4. Evidence for performance and known limitations
Retrospective testing indicates high specificity for several phenomenological items: one study found specificity of 100% for combined specified complex motor and phonic tics and 92–89.7% for “more complex than simple tics,” supporting clinical utility in distinguishing FTLBs from primary tic disorders [4] [7]. However, the ESSTS authors and subsequent commentators emphasise that the criteria were consensus‑derived and have limited prospective sensitivity/specificity data; prospective validation and longer‑term outcome studies remain lacking [2] [3].
5. Clinical caveats: comorbidity, functional overlay and treatment implications
The ESSTS framework is explicit that FTLBs can co‑exist with neurodevelopmental tic disorders, producing diagnostic complexity and the risk of mislabelling treatment‑resistant Tourette syndrome when a functional overlay exists; systematic use of the criteria can highlight “red flags” and prompt psychosocial and functional‑neurology approaches rather than routine escalation of tic pharmacotherapy [5] [3]. Because the criteria emphasise phenomenology and course, careful collateral history and longitudinal follow‑up remain essential — the consensus paper itself cautions against overreliance on single‑visit impressions [3] [2].
6. Bottom line for clinicians and researchers
The ESSTS 2022 criteria give clinicians a concise, consensus‑based checklist to identify FTLBs — anchored to age ≥12, rapid onset, and specific complex phenomenology — and a pragmatic diagnostic threshold (three majors = definite; two majors + one minor = probable) that has shown promising specificity in retrospective cohorts but still needs prospective validation and richer guidance on the minor/supportive features and longitudinal application [1] [4] [2].