​Kembara Xtra - Medicine - Essential Tremor Syndrome

​Kembara Xtra - Medicine - Essential Tremor Syndrome  
Introduction 

A slow, rhythmic, flexion-extension tremor affecting mostly the hands, forearms, head, or voice, with a frequency of 4 to 12 Hz, can be either postural (occurring with deliberate maintenance of a position against gravity) or kinetic (occurring during voluntary movement).
Tremors can be inherited, sporadic, or linked to other movement disorders; they are more common in the elderly and have a lower prevalence in the young.

The beginning of symptoms can happen at any age, but the incidence and prevalence rise with age.
Affected systems include the nervous, musculoskeletal, and ENT (voice) systems; the tremor can be intermittent and is made worse by mental or physical stressors, exhaustion, and caffeine.

Epidemiology 

In humans, essential tremor constitutes the vast majority of pathologic tremors.

The incidence rate increases sharply beyond the age of 49 and is potentially elevated at any age.
Prevalence
Essential tremor has a relatively low general prevalence (between 0.4% and 0.9%) but is more common in the elderly (4.6% at age 65 years and up to 22% at age 95 years).

The Cause and Effect Pathophysiology 

Essential tremor is not a uniform disorder; many patients exhibit additional motor manifestations and nonmotor features, such as cognitive and psychiatric symptoms, suggesting that it may originate from an abnormal oscillation within thalamocortical and cerebello-olivary loops.

The genetics of it are clear: autosomal dominant inheritance is shown in many families with weak penetrance, and a positive family history is present in 50-70% of patients. Studies of identical twins have hinted at the role of environmental elements.
● The genetic loci at 2p22-2p25, 3q13, and 6p23 have been linked. Another putative risk factor is a Ser9Gly variation in the dopamine D3 receptor gene, which is located on chromosome 3q13.

Related Disorders 
Parkinson's disease (PD) is characterized by a 3- to 5-Hz resting tremor, along with rigidity, bradykinesia, or postural instability, and no change with alcohol use; 10% of PD patients have this symptom.

Essential tremor patients are four times more likely to acquire Parkinson's disease. Up to 20-30% of people with essential tremor exhibit resting tremor, most often in the arm. Action tremor is characteristic of essential tremor, however it also occurs frequently in people with PD.

Core diagnostic criteria include: a history of at least three years of symptoms; a bilateral, action (postural or kinetic), asymmetric tremor of the hands and forearms; the absence of other neurologic signs, with the exception of cogwheel phenomenon; the presence of tremor in other locations, including the head, voice, or lower limbs; and a positive family history and a positive response to alcohol.


Medical Diagnosis 

Upper-extremity tremor affects roughly 95% of individuals.
A tremor can also manifest itself in the hands (34% less frequently), feet (30%), voice (12%), tongue (7%), face (5%), and trunk (5% less frequently).

The differential diagnosis includes Parkinson's disease, drug-induced or enhanced physiologic tremor (amiodarone, cimetidine, lamotrigine, itraconazole, valproic acid, SSRIs, steroids, lithium, cyclosporine, - adrenergic agonists, ephedrine, theophylline, tricyclic antidepressants), Wilson disease, hyperthyroidism, multiple sclerosis, dys


Results from the Lab 
Initial Lab and Imaging Tests
There is currently no reliable diagnostic test or biological marker.
Thyroid-stimulating hormone to rule out thyroid dysfunction Ceruloplasmin and serum copper to rule out Wilson disease
Electrolyte levels in the blood, blood urea nitrogen (BUN), and creatinine levels
Unless Wilson disease is diagnosed or other test findings suggest a central lesion, a brain MRI is usually neither necessary nor indicated.

Different Types of Diagnosis

Over ninety-five percent of people with PD have tremors in the 4- to 6-Hz range, whereas those with essential tremor have tremors in the 5- to 8-Hz range; surface electromyography is less useful in differentiating between the two.
Analysis of Test Results
Exam reveals trembling due to poor posture

When tremor causes impairment in ADLs or emotional discomfort, pharmacologic therapy is an option to consider.

Opening Line
When given in divided doses or as a long-acting formulation, daily doses of 60 to 320 mg of propranolol reduce limb tremor magnitude by 50%, and almost 70% of patients report improvement on clinical rating scales. Propranolol should not be recommended for treating voice tremor at this time.
Some patients find that a single dose of propranolol, administered before entering a social scenario known to increase tremor, is helpful.
The amplitude of tremors can be reduced by 40–50% with primidone 25 mg before bedtime, titrated up to 150–300 mg before bedtime. Doses more than 250 milligrams per day are usually administered twice daily (BID) or three times daily (TID). Treatment at a low dose (250 mg daily) is equally effective as treatment at a high dose (750 mg daily).
Both propranolol and primidone are recommended at the highest level (level A) for the treatment of limb tremor when taken as an initial treatment.

Thirty to fifty percent of patients will not have a positive response to propranolol or primidone.

Position Two
Tremor Rating Scale (TRS) reduction with topiramate at a mean dose of 292 mg/day was significantly greater compared to placebo (7.70 vs. 0.08; p .005; baseline TRS = 37.0) in a small study combining results from three double-blind, randomized, controlled trials following a common protocol. Dropout rates as high as 40% are attributed to side effects such as loss of appetite, weight, paresthesias, and inability to focus.

TID: 400 mg gabapentin
In comparison to propranolol, the evidence supporting the use of the other -blockers (sotalol, nadolol, and atenolol) is weaker.
● Use of clonazepam and alprazolam should be monitored closely due to their abuse potential.
● Clozapine is effective at doses ranging from 6 to 75 mg/day, but due to a 1% risk of agranulocytosis, it is only indicated for refractory cases of limb tremor. Insufficient evidence exists to support or disprove the efficacy of clozapine for chronic usage, according to the American Academy of Neurology (AAN).

Small but considerable improvement was seen in a pilot study with memantine at doses up to 40 mg/day. Dizziness, sleepiness, and lack of energy were some of the side effects reported at this dosage.

Moderate effectiveness in lowering tremor severity was seen with pramipexole (2.1 mg/day) in a pilot study of 29 patients. Both short- and long-acting forms worked just as well.

According to the American Academy of Neurology, acetazolamide, clonidine, flunarizine, methoxolamide, nimodipine, olanzapine, phenobarbital, pregabalin, quetiapine, sodium oxybate, and zonisamide are among the medications that have been evaluated for treatment of essential tremor, but only have limited data to support their use.

● Although alcohol can temporarily alleviate symptoms, it is not a viable long-term therapy choice due to its short-lived effects, inevitable rebound, and high risk of dependency. For temporary, context-dependent relief of symptoms, alcohol consumption could be a viable choice.
Botulinum toxin Blepharospasm, focal upper extremity dystonia, adductor laryngeal dystonia, and essential tremor of the upper extremities may also be treated with A injections, which are strongly recommended for cervical dystonia.
The evidence for its utility in treating head and voice tremor is weak.


Referral 

A neurologist consultation can assist distinguish between dystonia, neuropathic tremor, Parkinson's disease, and tremor caused by medication.

Methods of Surgery 

To alleviate limb tremor that has not responded to medicine, deep brain stimulation may be utilized; it has less side effects than thalamotomy and a greater degree of benefit.
However, paresthesias and dysarthria are possible side effects of bilateral thalamic ventral intermediate nucleus stimulation, which is beneficial in reducing tremor and functional impairment.

When medical treatment has failed to alleviate limb tremor, a unilateral thalamotomy may be an option.
There is a rising interest in developing external neuromodulator devices, such as exoskeletons, orthoses, and biomechanical loading, for the treatment of essential tremor, and bilateral thalamotomy is not suggested due to undesirable side effects. There is a lack of high-quality evidence regarding these gadgets at the moment, therefore more study is required.

Medication Options 

The usage of weighted utensils and other forms of physical treatment for strengthening may be considered as a means of mitigating tremor.
No adverse consequences have been linked to strength training, but there is also no evidence that it improves functional capacity.

Constant Maintenance

The use of caffeine should be avoided.

Essential tremor can severely hinder daily life, yet it does not shorten a person's expected lifespan.


The prognosis for tremor is that its severity will increase with age.