Comorbid Tics, Stereotypies Common in Typically Developing Patients, Review Finds
Tics and stereotypies often co-occur in otherwise typically developing pediatric patients, according to a systematic literature review published in Neurological Sciences.
“Specifically, we found that up to 1 in 4 patients diagnosed with stereotypic movement disorder present with comorbid tics, and up to 1 in 12 patients with Tourette syndrome presents with both tics and stereotypies,” wrote corresponding author Andrea E. Cavanna, MD, PhD, of the University of Birmingham in the United Kingdom, and study coauthors.
Tics are sudden, rapid, nonrhythmic movements or vocalizations, such as blinking, shrugging, or grunting, the authors explained. Stereotypies are repetitive and driven but apparently purposeless motor behaviors, such as hand flapping, rocking, and head banging.
The literature review included 6 studies in patients without autism or severe learning disability. Four studies of 231 children focused on tics in the context of stereotypic movement disorder, and two studies of 344 adults focused on stereotypes in the contest of Tourette syndrome.
On the whole, 23% of patients with stereotypic movement disorder presented with comorbid tics. The prevalence of tics across the 4 studies ranged from 18% to 43%, according to the study. Some 38% of patients in the studies also had attention-deficit/hyperactivity disorder (ADHD) and 16% had obsessive-compulsive symptoms.
About 8% of patients with Tourette syndrome had comorbid stereotypies, the review found. The prevalence of stereotypes in the 2 studies ranged from 6% to 12%. Nearly a quarter of patients in the studies also had ADHD, and almost half had obsessive-compulsive symptoms.
Between 65% and 70% of patients with both tics and stereotypies across all 6 studies were male, researchers noted.
“The association of tics and stereotypies in the same patient has practical implications, in consideration of the different treatment approaches,” researchers wrote. “Future research should focus on the assessment and management of both conditions, particularly in special populations (eg, patients with pervasive developmental disorders).”
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