Transcranial Direct Current Stimulation (tdcs) : A novel non-invasive treatment for Tourette Syndrome

A 13-year-old boy studying in class 8th, resident of an urban area and belonging to lower middle-class socio-economic status, was referred by the Neurology Department to the Mental Health and Behavioural Sciences Department of Max Super Speciality Hospital, Dehradun, with complaints of vocal and motor tics for a year, along with hyperactivity and inattention. The tics were present in the form of head jerks, eye blinking, face grimaces, sning, spitting, shoulder jerks, limb jerks, and coprolalia, i.e., the use of abusive and obscene words. The tics were present throughout the day and the patient was symptom-free for 10 seconds maximum when he was purposefully trying to control his head jerks.

The child was diagnosed with Tourette Syndrome (TS). It is a childhood-onset neuropsychiatric disorder, characterised by motor and vocal tics lasting at least a year in duration. Children with TS often experience co-morbid conditions like Obsessive-Compulsive Disorder (OCD) and Attention Deficit Hyperactive Disorder (ADHD).

In his childhood, he was a naughty, stubborn, disobedient kid. As he was growing, he became disorganised and had a dominant nature towards his siblings. In his family environment, his paternal grandfather and father were very ‘chid chida’ and would frequently use Hindi swear/cuss words which the child adopted in his speech, along with the attitude of frequently complaining about everything and defensiveness about his negative qualities. To strangers, he was very shy and timid. In his social life, he found it difficult to make friends.

The first episode of Tourette Syndrome was recorded in school while he was in his Maths class. He was scolded by his Maths teacher, and he shouted back with uncontrolled Hindi swear/cuss words and head jerks. Since then, his vocal and motor tics had progressed.

As Tourette Syndrome progressed, he reported diculties he faced at school in his studies and relationships with peers. He was unable to concentrate on his studies, and his classmates would make fun of him and tease him more, which further aggravated his motor and vocal tics, aecting his socio-emotional functioning and making him isolated and decreasing self-confidence.

When the child was seen in session, the Yale Global Tic Severity Scale (YGTSS) was used to assess his severity of tics and the Connors Parent Rating Scale initially to assess his ADHD severity. According to the scales, he had moderate-to-severe tic severity and impairment due to tics and moderate-to-severe ADHD of Inattention type.

The preferred treatment for Tourette Syndrome in children is Habit Reversal Cognitive Therapy (HRCT). HRCT consists of various components, which include - awareness training with self-monitoring, relaxation training and competing for response training. However, taking care of the child’s background, family environment, clinical presentation, quality of life, and non-adherence to the behaviour-modifying activities at home, we also used Transcranial Direct Current Stimulation (TDCS), for brain stimulation.

Carvalho (2015) conducted a study on patients with TS, using TDCS and reported a 41 % decrease in symptoms of TS after a 15-week follow-up. The cathode was applied at the pre-SMA and the anode at the upper deltoid muscle, 1.4mA, for 30 mins. The doctors used TDCS for brain stimulus on the child based on protocol conducted by this study with a similar modality. The cathode was applied at the pre-supplementary motor area and the anode at the upper right deltoid muscle with a current of 1.5mA for 15 minutes. For the remainder of the 45-minute session, the doctors practised HRCT and attention-enhancing activities. The sessions were held twice a week for two months. The child and parents were given regular homework for attention-enhancing behaviour strategies. YGTSS and Connor’s Parent Rating Scale were conducted at 0, 3-week, 6-week, and 12-week follow-ups.