Intention tremor

Intention tremor is a dyskinetic disorder characterized by a broad, coarse, and low-frequency (below 5 Hz) tremor evident during deliberate and visually-guided movement (hence the name intention tremor). An intention tremor is usually perpendicular to the direction of movement. When experiencing an intention tremor, one often overshoots or undershoots one's target, a condition known as dysmetria. Intention tremor is the result of dysfunction of the cerebellum, particularly on the same side as the tremor in the lateral zone, which controls visually guided movements. Depending on the location of cerebellar damage, these tremors can be either unilateral or bilateral. Several causes have been discovered to date, including damage or degradation of the cerebellum due to neurodegenerative diseases, trauma, tumor, stroke, or toxicity. Currently, no pharmacological treatment has been established, but some success has been seen using treatments designed for essential tremors. Patients with intention tremors usually complain of difficulties with activities of daily living, including drinking from a cup, grabbing utensils to eat, and problems with coordination eye to an object or ambulation. Associated cerebellar signs can include nystagmus, dysmetria, dysdiadochokinesia, hypotonia, proprioception deficits, and gait ataxia. Intention tremors are common among individuals with multiple sclerosis (MS). One common symptom of MS is ataxia, a lack of coordinated muscle movement caused by cerebellar lesions characteristic of MS. The disease often destroys physical and cognitive function of individuals. Intention tremors can be a first sign of MS, since loss or deterioration of motor function and sensitivity are often one of the first symptoms of cerebellar lesions. Intention tremors have a variety of other recorded causes, as well, including a variety of neurological disorders, such as stroke, alcoholism, alcohol withdrawal, peripheral neuropathy, Wilson's disease, Creutzfeldt–Jakob disease, Guillain–Barré syndrome, and fragile X syndrome, as well as brain tumors, low blood sugar, hyperthyroidism, hypoparathyroidism, insulinoma, normal aging, and traumatic brain injury.