Prognosis of rapid onset functional tic‐like behaviors: Prospective follow‐up over 6 months

Abstract Background and Purpose The prognosis of rapid onset functional tic‐like behaviors (FTLBs) is unknown. This prospective cohort study describes the course and treatment of rapid onset FTLBs in adolescents (n = 20) and adults (n = 9) previously reported in two case series. Methods Yale Global Tic Severity Scale (YGTSS) scores were compared between first clinical presentation and 6‐month follow‐up assessment. All treatments used for FTLBs and any psychiatric comorbidities were recorded. Results In adolescents with FTLBs, motor tics, vocal tics, total tics, impairment, and global scores on the YGTSS significantly improved at 6 months, with a mean decrease in the YGTSS global score of 31.9 points, 95% confidence interval (CI) 15.4, 48.4, p = .0005. In adults with FTLBs, only impairment and global scores significantly improved, with a mean decrease in the YGTSS global score of 19.6 points, 95% CI −3.2, 42.3, p = .04. Selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT) for anxiety and depression were the most used treatment in both age groups. Conclusions This prospective study suggests that adolescents have a better prognosis than adults with FTLBs. Management of comorbidities with SSRIs and CBT seems effective.

escalation to peak severity within hours to days) (Buts et al., 2021;Müller-Vahl et al., 2021;, later age of onset, and complex motor and vocal tic-like behaviors that do not follow the expected rostrocaudal nor simple to complex progression typically seen in TS (Buts et al., 2021;Müller-Vahl et al., 2021;.
Patients with FTLBs present with higher Yale Global Tic Severity Scale (YGTSS) total tic and impairment scores than patients with TS and are more likely to meet the clinical threshold for an anxiety disorder or major depressive disorder (Müller-Vahl et al., 2021;. Many of the young people when initially studied were unable to attend school or work nor perform some of their activities of daily living . Theories for such magnification of FTLBs in clinical settings include the possibility of social contagion illnesses spread through the medium of social media (Buts et al., 2021;Müller-Vahl et al., 2021;. For example, many individuals presented with complex vocalizations, including the common expressions and coprolalia displayed by social media influencers, which is concerning for an aspect of social contagion (Müller-Vahl et al., 2021;. Additional stressors through the pandemic, including school and extracurricular activity closures, "virtual schooling" and associated academic pressures, and increased tensions at home during lockdown measures are also thought to contribute to this clinical phenomenon (Buts et al., 2021;Canadian Mental Health Association, 2020;. For adults, job insecurity, heightened substance use, social isolation, and increased domestic violence may be implicated in experienced mental health symptoms throughout the pandemic (Canadian Mental Health Association, 2020). The COVID-19 pandemic has heightened mental health symptoms, such as anxiety, and the demand for associated services (Canadian Mental Health Association, 2020; Daly & Robinson, 2021;Rossi et al., 2021;Vigo et al., 2021;Wong et al., 2021).
In 2021, we published two case series of 20 adolescents and nine adults with rapid onset FTLBs seen in Calgary before the end of June 2021 . The purpose of this prospective cohort study is to report the trajectory and course of illness after 6 months of follow-up of these originally reported cases, as well as their response to medical and behavioral interventions. It was hypothesized that patients with FTLBs would improve at 6-month follow-up with behavioral interventions and treatment of comorbid mental health concerns.

METHODS
All 29 patients reported in our two case series were diagnosed by one of two movement disorders neurologists (Tamara Pringsheim or Davide Martino), and were offered continuing care at our center. Our overall treatment approach for FTLBs included medical and behavioral treatment for co-occurring anxiety and depression, in addition to the Comprehensive Behavioral Intervention for Tics (CBIT). At the ini-tial consultation, the Yale Global Tic Severity Scale (YGTSS) was completed, and this was repeated in all patients returning at 6 months.
At the 6-month assessment, all treatments used for FTLBs and any psychiatric comorbidities were recorded. A paired t-test was used to compare YGTSS scores at initial presentation and follow-up. This project received ethical approval from the University of Calgary Conjoint Health Research Ethics Board. Subjects gave informed consent for participation.

Adolescent sample
Of the 20 adolescent cases, 19 were assigned female at birth and one was assigned male at birth. Eleven identified as cis-gender, nine iden- The most used treatments were selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT) for anxiety or depression (Table 2). One adolescent was taking an antipsychotic medication (aripiprazole) for treatment augmentation for depression.
Both adolescents with YGTSS global scores of zero were receiving an SSRI (sertraline, fluoxetine) and CBT for anxiety or depression. Two adolescents developed psychogenic nonepileptic seizures (PNES) during the follow-up period. No other functional neurological symptoms were seen at follow-up.

Adult sample
Of the original reported nine adult cases, eight were assigned female at birth and one was assigned male at birth. Seven identified as cis-gender, and two identified as trans. Abbreviation: SSRIs, selective serotonin reuptake inhibitors.
All nine adults returned for follow-up at 6 months. While there was a decrease in motor tics, vocal tics, and total tics on the YGTSS from initial consultation to 6-month follow-up, the change was not statistically significant (Table 1). Impairment and global scores on the YGTSS were significantly lower at 6 months, with a mean decrease on the global score of 19.6 points (95% CI −3.2, 42.3, p = .04). Three adults had YGTSS impairment scores of zero at follow-up, and one had a YGTSS global score of zero.
The most commonly used treatments over the 6-month period of follow-up were antipsychotics, SSRIs, and CBT for anxiety or depression (Table 2). Of the three adults taking antipsychotics, two were taking quetiapine and one was taking aripiprazole, all for augmentation for depression. One adult with a YGTSS global score of zero at followup was receiving sertraline and quetiapine, and CBT for anxiety. Two adults developed PNES during the follow-up period. No other functional neurological symptoms were seen at follow-up.

DISCUSSION
Adolescents had a better outcome than adults with FTLBs, which is consistent with previous literature in FNDs. In one study, forty adolescents with FND assessed and treated at a child psychiatry referral center were re-evaluated 4 years after their initial presentation.
Children received treatment for FND symptoms and comorbid psychiatric disorders. Eighty-five percent were found to have completely recovered, 5% had improved, and only 10% were unchanged. Mood and anxiety symptoms continued to occur at a considerable rate despite recovery from FND symptoms (Pehlivantürk & Unal, 2002). Similarly, a study documenting the 12-month outcome of FND in 147 under 16 years old found that symptoms were improved in over 90% of children with motor weakness, abnormal movements, paralysis, and nonepileptic seizures (Ani et al., 2013). Twenty-eight percent were diagnosed with a new psychiatric disorder during the follow-up period, suggesting progress away from somatic to emotional expression of distress in some children. Psychological interventions were offered and accepted by the majority of patients, including psychoeducation, supportive counselling, anxiety management, family therapy, and cognitive behavioral therapy. In contrast, adult studies suggest a lower rate of symptom resolution. Persistence of FND was found in 90% of adults at an average follow-up of 3.2 years (Feinstein et al., 2001) in a Canadian study, despite 74% of patients receiving psychiatric care after the FND diagnosis was made. Another study reported resolution or improvement in 58% of adults with medically unexplained motor symptoms after 6 years of follow-up (Crimlisk et al., 1998). Medical and psychological treatment for this sample was not described.
In children and adolescents, FNDs have shown improvement with multidisciplinary cognitive and behavioral treatment, with greater efficacy in those with a shorter time from symptom onset to diagnosis