Tics are brief, sudden, movements (motor tics) or sounds (phonic tics) that are intermittent but may be repetitive and stereotypic (Jankovic et al., 2022). Although tics often spontaneously improve after childhood, they may persist into adulthood and become associated with a variety of comorbid disorders such as attention deficit disorder and obsessive–compulsive disorder. Tourette’s syndrome (TS), considered a genetic and neurodevelopmental disorder, is the most common cause of chronic tics. Motor and phonic tics consist of either simple or complex movements that may be seemingly goal directed. Motor tics may be rapid (clonic) or more prolonged. Many patients exhibit suggestibility and may have a compulsive component, sometimes perceived as an “urge” or a need to perform the movement or sound repetitively until it feels “just right.” Although tics are often considered relatively benign, many patients with TS have severe or disabling tics. “Whiplash” tics can produce disabling compressive myelopathy, and therefore need to be treated early and aggressively. When oral medications fail to provide satisfactory relief of tics, local chemodenervation with botulinum toxin (BoNT) offers the possibility of relaxing the muscles involved in focal tics without causing undesirable systemic side effects.

Tremor is one of the common movement disorders encountered by neurologists in clinical practice. Based on the history and phenomenology, the tremor can be classified commonly as Parkinson’s disease tremor, essential tremor , essential tremor plus, dystonic tremor, task-specific tremor and other tremor syndromes. This chapter describes the role of botulinum neurotoxin (BoNT) in several tremor conditions and provides some practical clinical pearls related to BoNT injection techniques. Specific muscles involved and the dose range of BoNT are tabulated.