Correspondence Address: Dr. Pramod Kumar Pal Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bengaluru, Karnataka. India
Source of Support: None, Conflict of Interest: None
The practice of yoga is based on the traditional Indian philosophy. Children during their development show adaptive neuroplasticity which is due to long-term potentiation that causes changes in the synaptic transmission. Excessive plasticity in the developing brain can lead to maladaptive neuronal circuits which can cause hyperkinetic movement disorders. It is not clear at what age yoga should be started and whether certain yogas or yogas done improperly can lead to maladaptive plasticity. We report here an unusual case of tic disorder which was precipitated by yoga.
Keywords: Motor control, plasticity, tic disorder, yoga
How to cite this article: Kamble N, Jhunjhunwala K, Yadav R, Bhattacharya A, Pal PK. Can yoga lead to maladaptive plasticity resulting in disorder of motor control?. Ann Mov Disord 2020;3:178-80
How to cite this URL: Kamble N, Jhunjhunwala K, Yadav R, Bhattacharya A, Pal PK. Can yoga lead to maladaptive plasticity resulting in disorder of motor control?. Ann Mov Disord [serial online] 2020 [cited 2021 Apr 12];3:178-80. Available from: https://www.aomd.in/text.asp?2020/3/3/178/300257
The practice of yoga is based on the traditional Indian philosophy. It incorporates one or more of the following: maintain or perform a sequence of physical postures, breathing exercises, and meditation. The word “yoga” is derived from the Sanskrit, “yuj” which means union, or to join. It is well established that regular practice of yoga promotes strength, endurance, and flexibility. It also facilitates characteristics of friendliness, compassion, and greater self-control, while cultivating a sense of calmness and well-being. Though the benefits of yoga has been well demonstrated in adults, its role in children is not known.
It is not clear at what age yoga should be started and whether certain yogas or yogas done improperly can lead to maladaptive plasticity. We report here an unusual case of a 10-year-old boy with tic disorder which was precipitated by yoga.
A 10-year-old boy presented with frequent shrugging of shoulders and involuntary movements of the abdominal wall of one-and-half months duration. A year ago, he complained of blurring of vision while reading. He consulted a local ophthalmologist and later a neurologist, but no abnormalities were found and computed tomography (CT) scan of the brain was normal. His father opted yoga as an alternative therapy. The child was advised to perform a particular form of yoga which involved sitting on floor with legs crossed, closing eyes, and performing frequent rhythmic movements of the chest and abdominal wall, synchronized with respiration. The duration of a yoga session was 15 min and he was instructed to perform 300 movements (~1/s). He mastered the art of this yoga and performed two sessions a day and his visual symptoms also disappeared. After 7–8 months, he complained of dull aching pain in shoulders and neck. He soon learnt that shrugging his shoulders relieved the pain, which he started doing intermittently, but later very frequently often without his knowledge. Though he discontinued yoga, a month later his father noted that the child was performing the rhythmic movements of the chest and abdomen, similar to the yoga, very frequently throughout the day. On questioning, the child did not have any voluntary control over the movements. These movements did not occur during sleep. He did not have any symptoms of obsessive-compulsive behavior and attention deficit hyperactivity disorder.
In our clinic, routine neurological examination including his vision and fundus examination was normal. The abnormal movements were characterized by almost rhythmical movements of lower chest and abdominal wall and frequent shrugging of the shoulders, at an approximate rate of 1–2/s [Video Segment 1]. At times the movements were irregular and jerky. These had characteristics of a tic disorder as the child had an urge to do, could suppress these movements voluntarily for a while followed by a rebound with the movements appearing with greater force and frequency and present even when alone and not being watched. The child was also distressed because of these movements. Distractability was seen but there was no suggestibility. The child was asked to demonstrate the original yoga which he did easily [Video Segment 2]. It was obvious that the tics resembled the original yoga movements. Electroencephalography was normal. Surface electromyography (EMG) showed EMG bursts that were irregular with the EMG burst duration of 100–150 msec. and a frequency of 1–2/s. He was evaluated in detail by the Child psychiatrist and was found to have mild depression on Childhood Depression Inventory. The child was started on behavioral therapy to which there was no significant improvement. He later received tetrabenazine (25 mg in two divided doses for 2 months) with which the abnormal movements disappeared. However, he developed facial tics in the form of facial grimacing [Video Segment 3].
Our patient developed tics after doing yoga for few months. It is difficult to differentiate between organic and psychogenic tics. The age of the patient, premonitory urge, distractability, suppressibility, and rebound of movements with greater force and frequency and response to treatment suggests organic tics in our patient. As observed in [Video Segment 1], the child was able to suppress the movements for approximately 52s. In addition, the shrugging of shoulders to relieve the pain also suggest the organic nature of the tics. There was no antecedent symptoms or associated medical illness to suggest any other etiology for the tics. Functional disturbances with abnormal interaction between the basal ganglia, limbic, and cortical motor and parietal areas may play a role in the genesis of tics. Volumetric analyses in patients with tic disorder have reported reduced volume of dorsolateral prefrontal cortex (DLPFC) which is involved in tic suppression. Studies have shown that there is increased dopamine input to the ventral striatum. The overactive dopamine hypothesis is evidenced by the reduction of tics with the use of D2-receptor antagonists. The dopamine tonic-phasic imbalance leads to higher concentrations of dopamine in the axon terminal with consequent increase of stimulus-dependent dopamine release.
It has been found that at birth a single neuron has approximately 7500 synapses which is followed by a gradual reduction in the number of synaptic connections by apoptosis. Children during their development show adaptive neuroplasticity which is due to long-term potentiation (LTP). This LTP causes changes in the synaptic transmission. Excessive plasticity in the developing brain can lead to maladaptive neuronal circuits which can cause hyperkinetic movement disorders.
Yoga has been found to increase the grey matter volume in cortical, limbic, and cerebellar structures suggesting an increase in plasticity. Yoga therapies reduce markers of inflammation and increase GABA levels in the brain. Perfusion studies have shown increased perfusion in hippocampus and sensory and higher order association regions with decreased perfusion in the DLPFC, anterior cingulate gyrus, striatum, thalamus, pons, and cerebellum. In a positron emission tomography (PET) study, it was shown that there is increased striatal dopamine release during yoga meditation. As the patient’s symptoms improved with antidopaminergic agents and later development of abnormal facial movements during follow-up suggests that the patient had hyperdopaminergic state.
It is possible that the child in this report was genetically predisposed to develop tic disorder which was triggered by yoga. It is not known whether this particular yoga, which was physically strenuous, was done correctly by our patient and whether it resulted in aberrant neuronal circuits resulting from maladaptive plasticity. It is possible that maladaptive process can be common to task-specific dystonia and tics. We hypothesize that a particular form of yoga may lead to tic disorder in a predisposed child. In a systematic review by Kim et al., that included eight studies concluded that vigorous physical activity may exacerbate tics. This lends strength to our hypothesis that physical activity can trigger tics.
This case report has its limitations as the child did not have MRI brain and it was also unclear about the nature of visual problem. Moreover, we could not do the pre-movement potentials (Bereitschaftspotential) in our patient as the movements were more frequent which could have resulted in absent potential. However, clinically the features are more suggestive of organic rather than psychogenic tics.
However, further studies are warranted to confirm the hypothesis.
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