By Leon S. Dure, MD and Jan Rowe, OT
Besides tic disorders, tremor is one of the most commonly encountered movement disorders in a child neurology clinic. However, despite the fact that up to 5% of individuals with essential tremor present in childhood, there are few reports of the condition in childhood, and no studies that address management or treatment. Some of this is likely due to the fact that, when compared to the severity of ET that can be seen in adults, childhood ET tends to be a much milder and less intrusive disorder, seldom requiring treatment with medications. However, there is clearly a lack of information regarding ET in this age group, which is a source of concern to parents, families, and others who come in contact with it. The following is a summary of observations concerning childhood ET that is the product of 20 years of diagnosing and managing ET in children.
As mentioned above, ET can be present in children, with approximately 5% of adults reporting onset before the age of 18 years. It is interesting to note that despite the frequency of occurrence in childhood; relatively few subjects are actually evaluated when young. This may indicate a lack of severity or impact of ET during childhood, limited resources in terms of finding knowledgeable clinicians to diagnose and treat, or both.
Nevertheless, the clinical appearance of ET is similar in children and adults, with the presence of tremor primarily in the hands that occurs with action or while maintaining a posture, but not at rest. By definition, ET is “monosymptomatic”, in that there are no other accompanying neurologic conditions that have a known association with tremor, nor is there a history of taking medications that have tremor as a side effect. There are situations where a child may have another condition, such as autism or developmental delay, which also manifests a tremor that appears identical to ET. Given current terminology, these tremors are classified as “indeterminate”, and among that group of children with action tremor, this type is common. Whether these indeterminate tremors represent ET in the context of another disorder or they are another facet of underlying conditions is an area requiring further study.
In any case, while the clinical presentation of ET in children parallels that of adults, the degree of intrusion or impairment may vary significantly depending on the age of the child. For example, a toddler may be noted to have some degree of hand tremor when engaged in fine motor activities such as playing with toys, but other activities of daily living such as buttoning clothes and tying shoelaces are not yet developmentally appropriate, and cannot be considered part of the clinical reasoning as to whether the tremor is pathologic (caused by disease or medical condition). Indeed, it is sometimes better to observe the very young child over a period of months before making a final determination as to the presence of ET. In these cases, examination of the parents can be quite helpful, as ET in a parent can furnish a compelling case for a pathologic tremor, although even then it must be kept in mind that the presence of tremor in early childhood is often not a stable finding, and may resolve with maturation. On the other hand, tremor in older children and teenagers is much easier to elicit and evaluate. While the clinical examination by an experienced child neurologist or movement disorders neurologist is in itself highly reliable to demonstrate tremor, additional evidence of impairment in daily functioning is also more obvious in the older child. However, it is striking how often children engage in adaptive strategies to minimize the consequences of tremor, thus limiting the impact on function. For example, when asked to write, children with ET will commonly assume a posture of the arm and hand that minimizes interference from tremor, although this may still result in handwriting that is slow and laborious. Families also contribute to adaptations, having learned through experience that offering overfull cups or eating soup with a spoon can be problematic, so it is valuable to assess how often these strategies are being employed.
This brings us to the question of how much impact ET has on children. With respect to physical activities, the spectrum is quite variable and can range from no apparent limitations (albeit with some use of adaptive strategies) to the complete avoidance of certain tasks or actions. In younger children, the necessity for precise motor action is somewhat limited to handwriting, and if there is a complaint, it tends to be in this area. However, in older children and teens, while adaptations have typically been employed to reasonable effect, unwanted peer attention to the tremor can result in significant distress, resulting in isolation and stigmatization. Moreover, since ET and other tremors may become more noticeable when under emotional stress, social pressures alone can engender sufficient anxiety to impair function. It is for these reasons that a thorough functional assessment is necessary before considering management options.
Younger children seldom experience any distress as a consequence of ET, but this is not true for parents and family, who understandably are concerned about their child’s future. It is important that parents recognize the actual magnitude of any impairment in function, and that they be given the tools to cope with any issues that arise with time. A knowledgeable physician can provide this sort of support and anticipatory guidance to families, to the extent that it is rare that any specific management strategy is required through preadolescence. Occasionally, children will be the subjects of unwanted attention by peers. Although commonly equated with teasing or bullying, very often this attention is more a sign of a need for information rather than signifying negative intentions. Appropriate education of family, teachers, friends, and classmates, such as that provided by the International Essential Tremor Foundation, can prove invaluable in these situations. Another situation that may require attention is that of handwriting, which will be discussed.
In contrast to the younger child, adolescents may warrant more aggressive interventions. Despite the typical scenario of a teenager who has manifested tremor for years and engaged in sufficient adaptive strategies to remain functional in school and with activities of daily living, many of these youngsters will express a degree of concern relating to the public expression of their tremor such that they request a medical intervention. The desire not to stand out is appropriate at this age, and even the most resilient patients may reach a point at which they want treatment to minimize their ET. There is a crucial distinction here, in that the clinician is responding to the wishes of the child rather than the parent. However, as with other chronic conditions that affect children and that can persist into adulthood, enlisting the child in the therapeutic relationship is both respectful and sound medical practice.
To address these concerns, occupational therapy (OT) may be warranted for any children who are experiencing limitations with performance in occupations (education, play/leisure, and activities of daily living) and possible social embarrassment. Occupational therapists are present in school settings and can address first-hand the issues a child might encounter in the course of a school day. In addition, the school OT can provide strategies for success in the home and community. If the child is not having limitations in the school environment or does not qualify for services, a medical based OT with expertise in pediatric neurology would be appropriate.
Common OT interventions for consideration are the use of weights, stabilization or adaptation, and technology. The use of weights can include weighted utensils and/or weighting a limb. Feeding utensils, writing tools and cups can be weighted to dampen the tremor. The use of sport cuff weights is unobtrusive, inexpensive and these items are easy to procure. Preteens and young adolescents are more receptive to the idea of weighting a limb whereas older adolescents and young adults are more inclined to adapt or weight a device/activity. Adaptations can be as simple as filling a glass or bowl less than full to increase the chance of success. Using straws for drinking or sports bottles with straws are popular and widely accepted affording the child the opportunity to ‘fit in’ with peers and not bring attention to him/herself due to accidents.
Stabilization is also a useful method with essential tremor. Stabilizing the upper body by leaning into a surface or holding onto something stationary with the uninvolved limb are strategies children and adolescents often come up with on their own. Stabilizing a device/utensil can be accomplished with non-skid mats, suction cups or Velcro. A child or adolescent will likely sift through many options before settling on one or two preferred techniques.
The most common occupation affected by ET is that of writing. In order for the child to be successful and competitive in the academic environment, they will do best with technology. Occupational therapists in the school environment are equipped to obtain devices and train students on an array of technology options for best performance. Technology is readily available to individuals and should be employed sooner rather than later. Waiting until a child or adolescent is frustrated by the labor involved in writing is unnecessary given the plethora of technology resources today. If these strategies are unsuccessful or occupational therapy in the school environment cannot be implemented, a medical based occupational therapist with experience in pediatric neurology would be the next course of action.
When medical intervention is deemed appropriate, it is usually in an older child. In these instances, medical treatment is often the same as in adults. Primidone and propranolol are agents that have been effectively used to treat ET in adults, and there is wide experience with their use in children for other conditions. The only distinction in children may be that propranolol is contraindicated in children with asthma, so it is important to determine the presence or absence of reactive airways disease. Topiramate has been reported to be beneficial in ET as well, and can be considered, but it is important to note that no clinical trials demonstrating efficacy have ever been performed in children with any of these agents, which is a sign of the need for greater understanding in this area. However, response rates seem to be comparable to those of adults, with good tolerance. Interestingly, some teens who have begun medical treatment with an agent will subsequently discontinue the drug. They come to realize that the perceived benefit may not outweigh either the side effects of a drug or the responsibility that comes with taking a daily medication. This underscores the benefit of treating the older child as a partner in the therapeutic relationship.
Leon Dure, MD is a Professor of Pediatrics, Neurology, and Neurobiology at the University of Alabama School of Medicine and The Children’s Hospital in Birmingham, AL, and is a member of the IETF Medical Advisory Board. Jan Rowe, DrOT, OTR L, FAOTA, is an Associate Professor in the Department of Occupational Therapy at the School of Health Professions at the University of Alabama at Birmingham.