[Health Tip] Hands Trembling Even When Using Chopsticks... How to Treat Essential Tremor?

Most symptoms improve through medication treatment,
but surgery is considered if there is no effect or due to drug side effects

[Image source=Pixabay]

[Asia Economy Reporter Kim Young-won] Essential tremor is a common movement disorder that occurs in about 4% of the population over 40 years old. It is also a neurodegenerative disease whose incidence increases with age. Although the exact cause of tremors is not yet clearly understood, it is generally known that abnormal hyperactivity in the motor function-related neural circuits connecting the cerebellum, brainstem, thalamus, and cerebral cortex causes the tremors.

In movement disorders such as Parkinson's disease or dystonia, hand tremors may accompany the main symptoms, and when the cause is difficult to identify, it is called "essential tremor." In essential tremor, there is no tremor at rest, but tremors occur when assuming a posture or performing an action. They can occur during everyday activities such as writing or using chopsticks, and symptoms worsen with tension, causing many patients to experience difficulties in social life. Professor Lee Eun-jung of Seoul National University Hospital's Department of Neurosurgery introduced various treatment methods for hand tremors caused by essential tremor.

Essential Tremor: Medication vs. Surgical Treatment

According to Professor Lee, medication is the first line of treatment for hand tremors caused by essential tremor. About two-thirds of patients experience symptom improvement through medication. However, the effect of symptom improvement is sometimes less than expected, or patients experience side effects, leading to lower medication adherence compared to other chronic diseases such as hypertension or diabetes. Additionally, since the appropriate type and dosage of medication vary for each patient, it is important to select the most effective drug for each individual through specialist consultation.

If the effect of medication is insufficient, surgical treatment is considered. Surgery targets the thalamic ventral intermediate nucleus, which is part of the neural circuit related to tremors. Generally, there are four surgical methods: radiofrequency ablation, deep brain stimulation, radiosurgery, and ultrasound surgery. All surgeries are performed under local anesthesia.

Deep brain stimulation suppresses the function of the lesion's nerves through electrical stimulation. Radiofrequency ablation, radiosurgery, and ultrasound surgery each destroy the lesion by concentrating radiofrequency electrical energy, radiation, or ultrasound energy on the target. The method can be chosen based on the patient's condition and the advantages and disadvantages of each surgery.

Advantages and Disadvantages of Each Surgery

Radiofrequency ablation involves drilling a hole in the skull and inserting an electrode to thermally coagulate the target. It is effective but has the disadvantage of difficulty in accurately measuring the target temperature and a relatively large lesion formation, which increases the risk of neurological complications.

Deep brain stimulation involves drilling a hole in the skull and inserting an electrode to apply high-frequency electrical stimulation to functionally suppress the target. After surgery, the electrical stimulation mode can be adjusted to effectively respond to disease progression. However, since a device is implanted, hardware problems may occur, and the current-generating device must be replaced every few years, which is inconvenient.

Radiosurgery is a treatment method that destroys the lesion by irradiating a high dose of radiation and does not require skin incision or drilling, making it an option for elderly patients. However, unlike other surgeries where symptom improvement and side effects can be immediately confirmed during surgery, radiosurgery's therapeutic effect appears only months later. Therefore, the target must be indirectly determined based solely on imaging during surgery, and if the target location is inaccurate, the treatment effect may decrease or neurological sequelae may occur.

Ultrasound surgery has established itself as a new alternative for hand tremor surgery. It treats by focusing multiple ultrasound waves through the skull onto the target, but surgery may be limited depending on the skull's thickness and condition. Professor Lee explained, "Recently, with the ability to accurately measure tissue temperature using MR thermometry, it has become possible to deliver the appropriate energy to the target, increasing the frequency of ultrasound surgery use." She added, "Since its FDA approval in the U.S. in 2016, it has rapidly spread and is actively performed in over 100 medical institutions worldwide."

This surgical method gradually increases ultrasound energy while evaluating whether the tremor improves, whether there are neurological abnormalities, and whether the target location is appropriate. During treatment, magnetic resonance (MR) imaging guidance allows observation of the lesion's location, size, and real-time lesion formation, making it safer and more effective. Additionally, there are no hardware problems after surgery, and even if side effects occur, they are mostly temporary and mild.

This content was produced with the assistance of AI translation services.