Holmes tremor

First identified by Gordon Holmes in 1904, Holmes tremor can be described as a wing-beating movement localized in the upper body that is caused by cerebellar damage. Holmes tremor is a combination of rest, action, and postural tremors. Tremor frequency ranges from 2 to 5 Hertz and is aggravated with posture and movement. It may arise from various underlying structural disorders including stroke, tumors, trauma, and other cerebellar lesions. Because Holmes tremor is rare, much of the research is based on individual cases.

The formation of tremors is due to two main factors: the over-excited rhythmic movement of neuronal loops and permanent structural changes from neurodegeneration. Two major neuronal networks, the corticostriatothalamocortical hap and the inferior olivary nucleus (ION) specifically target the development of the tremors. When diagnosing a patient with Holmes tremor, one must look at the neurological signs and symptoms, as well as the possibility that the tremor is caused by medications or other stimulants. In most cases, the patient’s history and a targeted neurological examination is enough to give a diagnosis.

Treatment for Holmes tremor is dependent on the characteristics of the tremor. Because the disease is involved with the dopaminergic system, most treatments involve levodopa. Drugs used to treat other types of tremors are applicable to the treatment of Holmes tremor; however, these drugs have a low success rate.

Holmes tremor is typically characterized by a low frequency tremor (below 4.5 Hz) that has a repeated series of rest and intention tremors. These tremors move slowly and are generally specific to an upper area of the body. They can consist of postural tremors in nearby muscles as well. These tremors involve uncontrollable shaking despite efforts to be still. Holmes tremor is considered a rest-intention posture tremor. These irregular movements occur while muscles are at rest, but worsen during voluntary muscle contractions. Symptoms usually appear delayed one to twenty-four months after the lesion is created.

Risk factors for Holmes tremor include excess exposure to heavy metals, such as mercury and lead, as well as an increased intake of various drugs and toxins. Researchers found that raising the dose of antidepressants or neuroleptics elevate the risk for developing Holmes tremor. Increasing intake of coffee, tea, or other stimulants can also cause for greater risk of development. Tremors depend on dosage and amount of exposure to these factors and will typically decrease dramatically if the intake is reduced. Hyperthyroidism and hyperglycemia also increase the likelihood of developing Holmes tremor.

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