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Clinical and electrophysiological aspects of tics in children
Insights
Children with tics exhibit signs of minimal brain dysfunction and neuromuscular system hypersensitivity. This study highlights the multifactorial origin of tics and suggests dysfunction in descending inhibitory control as a key mechanism.
Area of Science:
- Neurology
- Pediatrics
- Clinical Electrophysiology
Background:
- Tics are involuntary movements or vocalizations significantly impacting children's quality of life, social interactions, and learning.
- The prevalence of tics in children ranges from 4% to 24%, underscoring the clinical relevance of this condition.
Purpose of the Study:
- To investigate the clinical and electrophysiological characteristics of tics in pediatric patients.
- To explore potential new treatment strategies for childhood tics.
Main Methods:
- Comprehensive clinical and electrophysiological assessment of 50 children (5-15 years) with tics and 20 healthy controls.
- Included neurological examination, manual muscle testing, psychological evaluation, and electrophysiological studies of the corticospinal tract (CST) via magnetic stimulation (MS) and polysynaptic reflex excitability (PRE) using the blink reflex (BR).
Main Results:
- All patients displayed signs of minimal brain dysfunction (MBD) with complex medical histories.
- Electrophysiological findings revealed decreased excitation propagation velocity (PVE) in the CST, negatively correlating with tic severity (r = -0.38).
- Ninety percent of patients showed hyper-excited blink reflex (BR) responses, with 10% exhibiting decreased PVE, identifying two subgroups with distinct neuro-motor disturbances and myofascial trigger points (MFTPs) in one subgroup.
Conclusions:
- The pediatric neuromuscular system demonstrates heightened sensitivity to various stimuli, contributing to the multifactorial origin of tics.
- Dysfunction of descending inhibitory control appears to be a primary mechanism in tic development.
- Individualized therapeutic approaches based on polysynaptic reflex excitability patterns are recommended.
Background:
Tics are diverse in nature inappropriate movements or vocalizations. They significantly degrade patients' quality of life, lead to social difficulties, and disturbance of learning especially during exacerbations. The prevalence of tics among children ranges from 4% to 24%, thus emphasizing the relevance of the problem.
Objective:
To study clinical and electrophysiological features of tics in children with development of new treatment methods.
Methods:
We conducted a comprehensive clinical and electrophysiological examination of 50 patients with tics, aged 5 to 15 years. The control group consisted of 20 healthy children. The research included a thorough study of the history, neurological examination, manual testing of skeletal muscles, psychological testing. Electrophysiological examination included a review of the functional state of corticospinal tract (CST) by the method of magnetic stimulation (MS), study of polysynaptic reflex excitability (PRE) according to a late component of the blink reflex (BR). Statistical analysis included parametric and nonparametric methods of data processing.
Results:
All children of the study group showed signs of minimal brain dysfunction (MBD), they had complicated antenatal and postnatal history (trauma, disease, occurring with intoxication). There was a trend towards the increase of MBD signs with worsening of tics. Manual diagnosis in patients identified functional blockade at different levels of the vertebral column, sacroiliac joints, we identified latent myofascial trigger points (MFTP) mainly in the cervical-collar zone, in the area of the paravertebral muscles, periosteal triggers in the area of the sacroiliac joints.The research allowed determining decrease in propagation velocity of excitation (PVE) throughout CST in patients with tics. Correlation analysis revealed a negative correlation between the severity of tics and PVE (r = -0.38; p < 0.001).When studying polysynaptic reflex excitability (PRE) a significant predominance of hyper-excited types of blink reflex (BR) (90% of cases) was revealed. However, in 10% of patients there was a moderate decrease in propagation velocity of excitation (PVE), which allowed us to identify two subgroups of patients with tics: I - low and moderate type of reflex responses; and II - high type of reflex responses. Collation of data of MS and BR revealed a significant decrease of PVE in patients of the subgroup I, which probably reflects a deeper disturbance of the neuro-motor apparatus. The presence of numerous myofascial trigger points (MFTP) in patients of the subgroup I with moderately low polysynaptic reflex excitability (p < 0.05) was characteristic.
Conclusions:
The data show extraordinary sensitivity of neuromuscular system of children to various physiological and pathological stimuli, occurring in the body in the ontogenesis or diseases, and multifactorial origin of the pain syndrome in tics.The results suggest that one of the main mechanisms of development of pathological process is dysfunction of descending inhibitory control. However, further clarification of the type of polysynaptic reflex excitability in a certain patient is needed, that will allow to develop individualized approach to the choice of therapeutic interventions.
