Causes of Benign Essential Tremor

Benign essential tremor, often called simply essential tremor (ET), is a nerve disorder characterized by uncontrollable tremors, or shaking, in various parts of the body. The area most affected is the hands, but some individuals experience tremors in their arms, head, chin, tongue and larynx. The lower parts of the body are rarely affected by this disorder. Although benign essential tremor is not a life-threatening condition, it can affect a sufferer's ability to attend to daily activities, such as getting dressed, writing, brushing teeth, drinking and eating.

Thalamus Malfunction

Medical research has not been able to determine the exact cause of benign essential tremor, but many scientists believe that the uncontrollable shaking might be caused by abnormal brain activity in the thalamus. The thalamus is located deep within the brain beneath the cerebrum. Its primary function is to process and relay sensory information to selected areas of the cerebral cortex. Some of the information it handles pertains to muscle activity and coordination. Benign essential tremor might be the result of the thalamus sending the wrong information to the cerebral cortex.

Genetics

Medical researchers have determined that about half of all benign essential tremor cases are caused by some sort of genetic mutation that is referred to as a familial tremor. ET is considered an autosomal dominant disorder, meaning that just one parent needs to pass on the defective gene responsible for this medical condition. An individual with one parent who possesses the genetic mutation has up to 50 percent chance of inheriting the gene responsible for tremors, Not all individuals with the genetic mutation actually experience any benign essential tremor symptoms, however.

Other Factors

The severity of benign essential tremors can become worse if a sufferer is experiencing emotional stress or extreme fatigue, consuming too much caffeine or is exposed to extremely hot or cold temperatures. The occurrence and severity of ET might also fluctuate during pregnancy. ET patients should avoid caffeine and other stimulants, get a minimum of seven hours of sleep every night, exercise regularly and use relaxation techniques. Benign essential tremors tend to worsen with age, although it is not a part of the natural aging process.

Diagnosis

There is not a specific medical test for benign essential tremors. Physicians typically diagnose ET according to a patient's report of symptoms and a neurological exam. The exam includes testing muscular reflexes, muscle tone and strength, coordination and posture. Doctors also try to rule out any other possible causes of the uncontrollable shaking, such as excess caffeine consumption, a reaction to medications or thyroid disease.

Treatment

Most patients who suffer from mild benign essential tremor don't undergo any type of treatment. More severe cases might require a prescribed oral medication aimed at reducing the severity of the tremors. Some common medicines prescribed for ET include beta-blockers, anti-seizure medication or tranquilizers. Botulinum toxin, or botox, injections can help individuals who experience uncontrollable tremors in the head or larynx. The most common surgical option is deep brain stimulation (DBS), which involves implanting electrical leads directly into the thalamus. Adults with essential tremors have reported that drinking a small amount of alcohol actually reduces the tremors for an hour or two.

Resources

• Thalamus and Hypothalamus