As discussed in the previous chapter, a common schema in movement disorders is to classify movement problems broadly as hyperkinetic versus hypokinetic. The majority of movement disorder referrals from primary physicians to child neurologists are for hyperkinetic disorders, and of these, the most common are tics, stereotypies, and tremor.1 Functional neurologic disorders are prevalent and may mimic tics or tremor. This chapter addresses the key points of the clinical approach to evaluation and management of these common presentations and then covers, briefly, less common movements of dystonia and chorea.
Tics are probably the most common pediatric movement disorder.2 They occur at high rates in most community-based, school-age samples. A smaller proportion of patients and parents seek medical care, related to the severity (frequency, intensity, and/or impairment) of the tics, the presence of impairing co-occurring problems such as attention-deficit/hyperactivity disorder (ADHD) or obsessive-compulsive disorder (OCD), or parental anxiety.
Tics are patterned, repetitive, nonrhythmic movements, mostly within the repertoire of normal movements. They should look or, if vocal (phonic), sound pretty much the same each time they are performed. They can be readily performed or imitated. Simple tics are brief and involve a small cluster of muscles. Examples include blinking, eye darting, face scrunching, head jerking, throat clearing, sniffing, grunting, and humming. Complex tics last longer and involve more muscles in ways that sometimes overlap with the compulsions of OCD. Examples include looking to both sides sequentially, hand posturing followed by tapping, hopping, making animal sounds, and saying certain words or phrases. As is the case for many movements, these can be performed automatically throughout the day, with limited insight or awareness. However, particularly for older children or those with more complex tics, they can also be preceded by a premonitory sensation of some sort—an urge to do the movement. The urge is sometimes describable in sensory terms (“an itch”) or as just a feeling (“I have to do it”), but in contrast to compulsions, it should not be related to a recurring, obsessive, intrusive, anxiety-producing thought (“to avoid germs”). The child will often say they feel like the tic is both voluntary (“I’m doing it”) and involuntary (“I have to do it; I can’t stop it”). Children who are aware of their tics should be able to suppress or postpone their tics at least briefly.3 See Table 5–1 for comparative features with stereotypies and functional movements.
Table 5–1.Phenomenology: signs and symptoms of tics, stereotypies, and functional tic/jerks. ||Download (.pdf) Table 5–1. Phenomenology: signs and symptoms of tics, stereotypies, and functional tic/jerks.
| ||Tics ||Stereotypies ||Functional Tic-Like Behaviors |
|Appearance ||Patterned, simple or complex ||Patterned, complex ||Patterned or pseudo-patterned (eg, head jerk direction varies); proximal muscle, large-amplitude jerks; may be predominantly complex (hitting self/others, prolonged and/or ...|