Tremor in a Population-Based Cohort of Children in New York City

Abstract

Background There have been virtually no surveys of the prevalence, clinical features or correlates of tremor in children, and none in the United States. Methods 317 children (age 11.0 ± 1.1 years, range = 9.0 – 14.7) underwent an evaluation at one time point. Each drew Archimedes spirals, which were rated by a senior neurologist specializing in movement disorders. Results A spiral score of 1 (mild but consistent tremor) was present in either hand in 105 (33.1%) children; a higher score (1.5, mild to moderate tremor) was present in either hand in 7 (2.2%) children. Higher spiral scores were associated with poorer motor hand function as assessed using the Purdue Pegboard test. Spiral scores were higher in boys than girls, were inversely associated with age, and were higher in the non-dominant than dominant hand. Spiral scores were highest in children who were taking psychiatric medications and in children with psychiatric or neurological disorders. Conclusions Mild tremor is common in children, and covaries significantly with several demographic and clinical factors as well as usage of certain medications. It also lessens with advancing age. Rather than an isolated finding, tremor was associated with other measures of poorer motor hand function.

Prenatal exposure to the organophosphate pesticide chlorpyrifos and childhood tremor

“…In a recent study using a larger sample from the same cohort as the present study, we showed that mild tremor (rating of 1) was present in both arms in approximately 1 in 10 children, indicating that there is some measureable tremor in this age group (Louis et al, 2015). Tremor was associated with poorer motor dexterity (i.e., poorer motor hand function), as assessed by the Purdue Pegboard test.…”

“…We recently reported that tremor was associated with poorer motor hand function as assessed using the Purdue Pegboard test (Tiffin, 1968; Louis et al, 2015), indicating either that the tremor itself resulted in some reduction in dexterity or that both the tremor and the loss of dexterity were a result of an underlying perturbed motor state. The possible links between CPF exposure, tremor, and additional measures of motor function remain to be studied.…”

“…Tremor ratings, published previously (Louis et al, 2011, 2015) for each spiral were: 0 (no tremor), 0.5 (subtle, low amplitude oscillations are present in a few spots but are not consistently present throughout the spiral), 1.0 (low amplitude oscillations are present in multiple places), 1.5 (low amplitude oscillations are present in multiple places and oscillations can at times reach moderate amplitude), 2 (moderate amplitude oscillations present throughout the spiral) (for examples of rated spirals, see Figs. 2–4 in Louis et al, 2015). During spiral rating, the neurologist was careful to distinguish clear, regular, oscillations from sloppiness, spatial errors, and other irregularities or movement dysfluencies that were not strictly oscillatory.…”

“…Less attention has been devoted to the prevalence, clinical features and correlates of tremor among children. A recent report showed that mild tremor is common in children (33.1% of an urban sample with mean age of 11 years), and covaries significantly with several demographic and clinical factors as well as usage of certain medications (Louis et al, 2015). …”

Current behavioral assessments of movement disorders in children

“…Subjective tools commonly used for adults, such as the Clinical Rating Scale for Tremor, are rarely used for children. Instead, pediatric evaluations usually use the 5‐spiral‐drawing method, wherein children are required to draw five spirals. First, an Archimedes spiral is drawn with the dominant hand for practice, followed by two spirals drawn with the dominant hand and two with the non‐dominant hand.…”