A 14-year-old girl is brought to the office for evaluation of hand tremors. A week ago, the patient began experiencing a fluttering sensation, followed by involuntary shaking of her right hand. The shaking resolved spontaneously after an hour but has recurred several times since and also involved the left hand. The tremor occurs at rest or during activities and can be interrupted only by either grasping an object or clenching the hand. Vital signs are within normal limits. On physical examination, the patient has a flat affect. At rest, low-frequency tremors of both hands are present. Cranial nerve examination, motor strength, and deep tendon reflexes are normal. The tremors cease during the examination, but at the end, a bilateral coarse tremor can be observed. Which of the following is the most likely diagnosis?

Question

A 14-year-old girl is brought to the office for evaluation of hand tremors.  A week ago, the patient began experiencing a fluttering sensation, followed by involuntary shaking of her right hand.  The shaking resolved spontaneously after an hour but has recurred several times since and also involved the left hand.  The tremor occurs at rest or during activities and can be interrupted only by either grasping an object or clenching the hand.  Vital signs are within normal limits.  On physical examination, the patient has a flat affect.  At rest, low-frequency tremors of both hands are present.  Cranial nerve examination, motor strength, and deep tendon reflexes are normal.  The tremors cease during the examination, but at the end, a bilateral coarse tremor can be observed.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Explanation: This patient has an inconsistent tremor of the hands with abrupt onset and cessation. It is present at rest and during movement, stops with distraction (ie, during examination), and is not associated with other neurologic findings. This is suspicious for a functional tremor, the most common of the functional movement disorders, which are characterized by involuntary movements that are not consistent with a neurologic cause and that improve with distraction. Features suggestive of functional tremor include: Abrupt onset and static course that results in functional disability out of proportion to tremor magnitude Increased severity with attention and decreased with distraction Complex features or clinical inconsistencies with known tremor syndromes (eg, can write words but not draw spirals); fingers are often spared. Changeable features including shifting tremor frequency (can be provoked by having patient tap an uninvolved extremity, causing the tremulous extremity to shift to that frequency) or the ability to "chase" the tremor (restraint of the affected limb causes the tremor to move locations) Although functional tremor was previously known as psychogenic tremor and can be accompanied by psychiatric comorbidities, many patients do not have known psychopathology. Providers should provide compassionate education to patients regarding the diagnosis, taking their complaints seriously and emphasizing to them that their symptoms are not "in their head" and are involuntary. Physical and occupational therapy, sometimes including intensive inpatient rehabilitation, is another important component of management. (Choice A) Although cerebellar tremors are classically low frequency (<5 Hz) and high amplitude, as seen in this patient, they typically increase as an action approaches a target rather than ceasing with activity. They are also usually accompanied by other cerebellar signs (eg, ataxia, dysmetria, impaired rapidly alternating movements). (Choice B) Although essential tremor is often seen most prominently in the hands and can be worsened by anxiety, it most often presents in older adults as a tremor of the hands that is suppressed at rest, exacerbated by outstretched arms, and more pronounced at the end of goal-directed movements. (Choice D) An orthostatic tremor typically affects the legs and trunk, rather than the hands, and occurs only when standing. (Choice E) A physiologic tremor is not normally visible, although in some patients it can be augmented and become visible by increased sympathetic activity (eg, caffeine, hyperthyroidism, anxiety). In contrast to a functional tremor, it is typically low amplitude and is relatively fast (10-12 Hz). It also typically worsens with movement and improves with rest. Educational objective: Functional (psychogenic) tremors often present abruptly with significant disability. They often decrease with distraction, have changeable or inconsistent features, and are not consistent with known tremor syndromes.

A 14-Year-Old Girl Is Brought to the Office for Evaluation