Severe Tourette syndrome, tics increase cervical spine disorder risk

People with severe Tourette syndrome or chronic tic disorders had a higher risk for cervical spine disorders than people without them, though it was a “relatively rare” outcome, according to a population-based, matched cohort study.

“Motor tics involving the neck region (eg, neck stretches/movements, head jerk movements, complex head/shoulder/neck movements) are common, occurring in up to 58% of children and adults with [Tourette syndrome (TS)/chronic tic disorder (CTD)] and also are reported to be among the most bothersome tics,” Josef Isung, MD, PhD, of Karolinska Institutet’s Centre for Psychiatry Research in Stockholm, Sweden, and colleagues wrote in JAMA Neurology. “The neck is particularly vulnerable to severe damage owing to repeated trauma.”

Isung and colleagues used Sweden’s National Patient Register to analyze 6,791 people (77.1% men) born in Sweden between 1973 and 2013 and living there between 1997 and 2013 diagnosed with TS or CTD when they were at least 3 years old. Investigators matched these patients to 67,910 individuals in the general population without TS/CTD. On average, follow-up for all participants was 17 years.

According to the analysis, those in the TS/CTD group carried a 39% higher rate of having at least one cervical spine disorder than persons in the control group (237 [3.5%] vs. 1,483 [2.2%]; adjusted HR = 1.39; 95% CI, 1.22-1.59). Further, the TS/CTD group had a higher risk for vascular (aHR = 1.57; 95% CI, 1.16-2.13) and nonvascular cervical disorders (aHR = 1.38; 95% CI, 1.19-1.6).

There was no significant risk for men or women in either group.

Though Isung and colleagues determined cervical spine disorders were rare in the TS/CTD group and even rarer in the control group, they suggested diagnosing TS/CTD early and carefully monitoring those with TS/CTD to prevent long-term disability.

“Individuals with TS/CTD presenting with severe repetitive neck extension tics (so-called whiplash tics) and/or those who are in need of emergency care or even hospitalization (referred to as malignant TS) should be monitored in collaboration with movement disorder experts because they will likely require highly specialized interventions other than conventional behavioral therapy or medication, such as botulinum toxin injections, spinal surgery, or deep brain stimulation in selected cases,” they wrote.

The study was strengthened by large TS/CTD cohort, long follow-up period, prospective design and minimized selection and recall bias. However, it was limited by possible misdiagnosis in the original data, specificity to severe tic disorders, surveillance bias and lack of information on tic topography or severity.