Essential Tremor
Disease Details
Family Health Simplified
- Description
- Essential tremor is a neurological disorder characterized by involuntary and rhythmic shaking, typically affecting the hands and forearms.
- Type
- Essential tremor is a neurological disorder. The genetic transmission is primarily autosomal dominant.
- Signs And Symptoms
- In mild cases, ET can manifest as the inability to stop the tongue or hands from shaking, the ability to sing only in vibrato, and difficulty doing small, precise tasks such as threading a needle. Even simple tasks such as cutting in a straight line or using a ruler can range from difficult to impossible, depending on the severity of the condition. In disabling cases, ET can interfere with a person's activities of daily living, including feeding, dressing, and taking care of personal hygiene. Essential tremor generally presents as a rhythmic tremor (4–12 Hz) that occurs only when the affected muscle is exerting effort. Any sort of physical or mental stress tends to make the tremor worse.The tremor may also occur in the head (neck), jaw, and voice, as well as other body regions, with the general pattern being that the tremor begins in the arms and then spreads to these other regions in some people. Women are more likely to develop the head tremor than are men. Other types of tremor may also occur, including postural tremor of the outstretched arms, intention tremor of the arms, and rest tremor in the arms. Some people may have unsteadiness and problems with gait and balance.ET-related tremors do not occur during sleep, but people with ET sometimes complain of an especially coarse tremor upon awakening that becomes noticeably less coarse within the first few minutes of wakefulness. Tremor and disease activity can intensify in response to fatigue, strong emotions, low blood sugar, cold and heat, caffeine, lithium salts, some antidepressants, stress, and other factors.Parkinson's disease and parkinsonism can also occur simultaneously with ET. The degree of tremor, rigidity, and functional disability did not differ from patients with idiopathic Parkinson's disease. Hand tremor predominated (as it did in Parkinson's disease), and occurred in nearly all cases, followed by head tremor, voice tremor, neck, face, leg, tongue, and trunk tremor. Most other tremors occurred in association with hand tremor. More severe tremors, a lower sleep disorder frequency, and a similar prevalence of other non-motor symptoms also can occur.Walking difficulties in essential tremor are common. About half of patients have associated dystonia, including cervical dystonia, writer's cramp, spasmodic dysphonia, and cranial dystonia, and 20% of the patients had associated parkinsonism. Olfactory dysfunction (loss of sense of smell) is common in Parkinson's disease, and has also been reported to occur in patients with essential tremor. A number of patients with essential tremor also exhibit many of the same neuropsychiatric disturbances seen in idiopathic Parkinson's disease.Essential tremor with tremor onset after the age of 65 has been associated with mild cognitive impairment, as well as dementia, although the link between these conditions, if any, is still not understood.Essential tremor has two tremor components, central and peripheral. These two tremor components were identified by measuring the tremor of ET patients once with no weights on their hands and then with 1-pound weights on their hands. The addition of the weights resulted in a tremor spectrum with two peaks, one that maintained the same frequency (the central tremor) and one that decreased in frequency (the peripheral tremor). Only with the addition of the weights was the peripheral tremor distinguishable from the central tremor.The frequency of essential tremor is 4 to 11 Hz, depending on which body segment is affected. Proximal segments are affected at lower frequencies, and distal segments are affected at higher frequencies.
- Prognosis
- Although essential tremor is often mild, people with severe tremor have difficulty performing many of their routine activities of daily living. ET is generally progressive in most cases (sometimes rapidly, sometimes very slowly), and can be disabling in severe cases.
- Onset
- Essential tremor typically has an onset at any age, but it is most common in individuals over the age of 40. The condition is characterized by uncontrolled shaking, usually in the hands, which can be exacerbated by movement.
- Prevalence
- Essential tremor is a common neurological disorder. Its prevalence is estimated to be around 0.4% to 1% in the general population, increasing to about 4% to 5% in people aged 65 and older.
- Epidemiology
- ET is one of the most common neurological diseases, with a prevalence around 4% in persons age 40 and older and considerably higher among persons in their 60s, 70s, and 80s, with an estimated 20% of individuals in their 90s and over. Aside from enhanced physiological tremor, it is the most common type of tremor and one of the most commonly observed movement disorders.
- Intractability
- Essential tremor is generally not considered intractable, as various treatments can help manage the symptoms. While it is a chronic condition with no cure, many patients experience significant symptom relief through medications, lifestyle changes, or surgical interventions such as deep brain stimulation. The effectiveness of these treatments can vary among individuals.
- Disease Severity
- Essential tremor can vary in severity from mild to severe. Mild tremors might not significantly impact daily activities, while severe tremors can interfere with tasks such as eating, writing, or dressing. The progression and severity of essential tremor can differ greatly among individuals.
- Healthcare Professionals
- Disease Ontology ID - DOID:4990
- Pathophysiology
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In terms of pathophysiology, clinical, physiological and imaging studies point to an involvement of the cerebellum and/or cerebellothalamocortical circuits. Changes in the cerebellum could also be mediated by alcoholic beverage consumption. Purkinje cells are especially susceptible to ethanol excitotoxicity. Impairment of Purkinje synapses is a component of cerebellar degradation that could underlie essential tremor. Some cases have Lewy bodies in the locus ceruleus. ET cases that progress to Parkinson's disease are less likely to have had cerebellar problems. Recent neuroimaging studies have suggested that the efficiency of the overall brain functional network in ET is disrupted.
In 2012, the National Toxicology Program concluded that sufficient evidence exists of an association between blood lead exposure at levels >10 μg/dl and essential tremor in adults, and limited evidence at blood lead levels >5 μg/dl. - Carrier Status
- Essential tremor is generally not described in terms of "carrier status" because it is not a single-gene disorder with a straightforward inheritance pattern like some genetic conditions. It tends to run in families, suggesting a genetic component, but multiple genes and environmental factors likely contribute to its development. Therefore, there is no specific "carrier status" for essential tremor.
- Mechanism
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Essential tremor (ET) is a neurological disorder commonly characterized by involuntary, rhythmic shaking, particularly in the hands, but it can also affect other parts of the body.
**Mechanism:**
The exact cause of essential tremor is not completely understood. However, it is generally believed to involve abnormalities in the functioning of certain brain circuits, particularly those involving the cerebellum and its connections to other parts of the brain, including the thalamus and the motor cortex.
**Molecular Mechanisms:**
1. **Genetic Factors:** Essential tremor has a hereditary component, with about 50% of cases having a familial link. Several genes, including ETM1 and ETM2, have been implicated, although no specific gene mutation has been definitively identified as the cause.
2. **Neurotransmitter Abnormalities:** Dysfunction in neurotransmitter systems, particularly gamma-aminobutyric acid (GABA), has been observed. GABA is the primary inhibitory neurotransmitter in the brain, and abnormalities in GABAergic function in the cerebellum and related pathways may contribute to the tremor.
3. **Mitochondrial Dysfunction:** There is some evidence to suggest that mitochondrial abnormalities could be involved, potentially leading to cellular energy deficits that affect normal neuronal function.
4. **Calcium Channel Function:** Mutations in genes encoding calcium channels (e.g., CACNA1A) have also been considered, as these channels play a crucial role in neuronal excitability and neurotransmitter release.
Overall, essential tremor is likely to result from a combination of genetic predisposition and dysfunctions in specific neural pathways and neurotransmitter systems. - Treatment
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Treatment options for essential tremor include:
1. **Medications**:
- **Beta-blockers** (e.g., propranolol)
- **Anti-seizure medications** (e.g., primidone, gabapentin)
- **Tranquilizers** (e.g., benzodiazepines)
- **Botox injections** for certain types of tremor
2. **Therapies**:
- **Occupational therapy**: To improve hand and arm coordination.
- **Physical therapy**: To strengthen muscles and increase coordination.
3. **Surgical Options** (for severe cases):
- **Deep brain stimulation (DBS)**: Involves implanting electrodes in the brain.
- **Focused ultrasound thalamotomy**: This uses sound waves to destroy brain tissue that causes tremor.
4. **Lifestyle and Home Remedies**:
- Avoid caffeine and other stimulants.
- Use alcohol cautiously, as it may reduce tremor in some cases.
- Employ assistive devices as needed (e.g., weighted utensils).
For patients unresponsive to traditional treatments, experimental therapies and ongoing clinical trials may provide additional options. - Compassionate Use Treatment
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For essential tremor, compassionate use treatments and off-label or experimental treatments include:
1. **Focused Ultrasound (FUS)**: This non-invasive procedure targets brain areas responsible for tremors using MRI-guided ultrasound waves. This technique is still being studied and is not yet widely available.
2. **Gamma Knife Radiosurgery**: A form of stereotactic radiosurgery that directs radiation precisely to the affected brain area, aiming to reduce tremors. It's an experimental treatment option for those ineligible for surgical interventions.
3. **Cannabinoids**: Some studies suggest that cannabinoids, such as CBD, may help alleviate tremors. However, more research is needed to confirm their efficacy and safety for essential tremor.
4. **Sodium Oxybate**: Typically used for narcolepsy, sodium oxybate has shown potential in improving tremor symptoms in some patients. Its use for essential tremor is off-label and still under investigation.
5. **Transcranial Magnetic Stimulation (TMS)**: This non-invasive method uses magnetic fields to stimulate specific brain regions. TMS is being researched as a potential treatment for reducing tremor severity.
6. **Levetiracetam**: An anticonvulsant medication, often used to treat epilepsy, is being explored for its off-label use in essential tremor management.
7. **Botulinum Toxin (Botox)**: While mainly used for muscle spasticity disorders, botulinum toxin injections have been studied for treating hand tremors. It may weaken the muscles involved in tremor, reducing its severity.
These treatments are still undergoing various levels of research and may not be widely available or universally accepted as standard care practices. Always consult with healthcare professionals for the most appropriate and personalized treatment options. - Lifestyle Recommendations
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Lifestyle Recommendations for Essential Tremor:
1. **Stress Management**: Practice relaxation techniques such as yoga, meditation, or deep-breathing exercises to help manage stress, which can exacerbate tremors.
2. **Diet and Nutrition**: Limit caffeine and alcohol intake as these can worsen tremors. Maintain a balanced diet to support overall health.
3. **Physical Exercise**: Engage in regular physical activity to improve muscle control and coordination. Focus on activities that enhance flexibility and strength.
4. **Occupational Therapy**: Work with an occupational therapist to find adaptive devices and techniques to assist with daily tasks, such as using heavier utensils or special writing tools.
5. **Sleep Hygiene**: Ensure adequate and quality sleep, as fatigue can increase tremor severity.
6. **Support Systems**: Join support groups or seek counseling to cope with the psychological aspects of living with essential tremor.
7. **Avoid Triggers**: Identify and avoid triggers that exacerbate tremors, such as specific medications or environmental factors. - Medication
- For essential tremor, common medications used to manage symptoms include propranolol, a beta-blocker, and primidone, an anticonvulsant. Other options can include medications like gabapentin, topiramate, and occasionally benzodiazepines such as clonazepam. Each patient's treatment plan may vary and should be tailored by a healthcare provider based on the individual's specific medical needs and response to treatment.
- Repurposable Drugs
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Potential repurposable drugs for essential tremor include:
1. **Propranolol** - A beta-blocker commonly used for hypertension.
2. **Primidone** - An anticonvulsant also used for seizures.
3. **Topiramate** - Primarily used for epilepsy and migraine prevention.
4. **Gabapentin** - An anticonvulsant often prescribed for neuropathic pain.
5. **Clonazepam** - A benzodiazepine used for seizure and anxiety disorders.
6. **Botulinum toxin** - While not a traditional drug, it is used off-label to reduce tremors by injecting into affected muscles.
Always consult with a healthcare provider for appropriate treatment options based on individual medical history and condition specifics. - Metabolites
- Essential tremor has been associated with various biochemical changes in the brain, but its exact metabolic profile is not fully understood. Some studies suggest abnormalities in the gamma-aminobutyric acid (GABA) system and the involvement of other neurotransmitters such as glutamate. Specific metabolites have not been definitively linked to essential tremor, and research is ongoing to better understand the metabolic underpinnings of this condition.
- Nutraceuticals
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Essential tremor is a neurological disorder characterized by involuntary and rhythmic shaking, often affecting the hands. There is limited scientific evidence on the effectiveness of nutraceuticals in treating essential tremor. However, some individuals pursue a range of supplements.
1. **Magnesium**: Some believe it helps with muscle and nerve function.
2. **Vitamin B12**: Low levels may exacerbate tremors.
3. **Herbal Remedies**: Such as valerian root, passionflower, and kava, although their efficacy and safety profiles need more research.
Consultation with a healthcare provider is advised before starting any nutraceutical regimen.
(Note: "nan" is not a standard input or nutrient term in this context.) - Peptides
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Essential tremor is primarily a neurological condition characterized by involuntary and rhythmic shaking, usually affecting the hands but can also involve other parts of the body. Some studies suggest that peptides might play a role in neuroprotection and modulation of neural activity. However, there is no established treatment for essential tremor that specifically targets peptides.
Nanotechnology (nan.) is being explored in medical research for various applications, including drug delivery systems. Nanotechnology could potentially offer innovative treatment options for essential tremor by delivering therapeutics more precisely to affected areas of the brain, although such approaches are still largely experimental.