Introduction
The Essential Tremor Syndrome and Its Etiologies
Possible etiologies which can present with an tremor syndrome | |
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Syndromes attributable to selected genes | Frontotemporal dementias, dystonia, Wilson’s disease, neuroferritinopathy, Lesch-Nyhan syndrome, pantothenate kinase–associated neurodegeneration (PEKAN), X-linked Parkinson-dystonia syndrome, primary familial brain calcification, Roussy-Lévy syndrome, hereditary neuropathies, spinocerebellar ataxia (types 12, 20, 27) |
Syndromes attributable to selected chromosomal aberrations | Fragile X syndrome, Prader-Willi, ataxia telangiectasia, XYY syndrome, XXY (Klinefelter syndrome) XXYY syndrome, Angelman syndrome |
Syndromes attributable to trinucleotide repeat diseases | Spinocerebellar ataxia (types 1, 2, 3, 6, 7, and 17), fragile X syndrome, dentatorubral-pallidoluysian atrophy |
Parkinson syndromes | Parkinson’s disease, multiple system atrophy, corticobasal degeneration |
Lysosomal storage disorders | Gaucher’s disease, Niemann-Pick disease, type C, action myoclonus-renal failure syndrome |
Mitochondrial diseases | Syndrome of mitochondrial spinocerebellar ataxia and epilepsy (POLG-related disorders), Leigh syndrome, recessive monogenetic parkinsonian syndromes (DJ-1, PARKIN, PINK1) |
Infectious and inflammatory diseases | Demyelinating diseases, encephalitis lethargica, subacute sclerosing panencephalitis, HIV, tuberculosis, syphilis, measles, typhoid, neuroborreliosis, bacterial or viral encephalitis, autoimmune encephalitis |
(Autoimmune-) neuropathies and spinal muscular atrophies | Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, Lewis-Sumner syndrome, gammopathy of undetermined significance (MGUS) |
Paraneoplasia | Bronchial, breast, uterine, ovarian carcinoma with and without autoantibodies (Yo, Tr, VGKC, mGLuR1, Ri, Hu) |
Endocrine or metabolic diseases | Liver and renal deficiency, hyperthyroidism, hyperparathyroidism, hypoglycemia |
Brain lesions of different etiologies | brain tumors, craniocerebral trauma, electrical injuries, ischemia, bleeding, malformations |
Drug-induced | Cytostatics (vincristine, cisplatin, paclitaxel, doxorubicin, cytosine-arabinoside, ifosfamide, 5-fluorouracil, methotrexate) Immunomodulators (ciclosporin, tacrolimus, interferons) Anticonvulsant drugs (valproate, carbamazepine, phenytoin, lamotrigine) Dopamine receptor blocker/medications depleting dopamine (neuroleptics, metoclopramide, tetrabenazine) Antidepressants (tricyclic antidepressants and selective serotonin/norepinephrine reuptake inhibitor, lithium) Antiarrhythmics (amiodarone, mexiletine, procainamide) Calcium antagonists (nifedipine, amlodipine) Hormones (thyroxine, calcitonin, progesterone, corticosteroids) Sympathomimetics (bronchodilators, β2-agonists) Phosphodiesterase inhibitors (theophylline, aminophylline caffeine) |
Toxins | Mercury, lead, manganese, arsenic, cyanide, DDT, carbon monoxide, naphthalene, toluene, lindane |
Psychoactive drugs | Caffeine, cocaine, nicotine, amphetamines, lysergic acid diethylamide, psilocybin and 3,4-methylenedioxymethamphetamine, alcohol withdrawal, withdrawal from benzodiazepines and others |
Affective changes and consequences of physical exertion | Anxiety, excitement, stress, fatigue, physical exertion, cooling |
Differential Diagnostic Approaches for Tremor
Type of tremor | Rest | Posture | Action |
---|---|---|---|
Physiological | + + | + | |
ET | − | + + | + |
ET plus | + | + + | + |
PD | + + | + | +/− |
Drug-induced | + | + + | + |
Endocrine/metabolic | + + | + | |
Dystonic | +/− | + + | + |
Orthostatic | + + | ||
Neuropathic | + + | + | |
Holmes | + + | + + | + + |
Cerebellar | +/− | + + | |
Psychogenic | + | + |
Syndromes including tremor symptoms | Possible therapeutic interventions | Allocated example |
---|---|---|
Genetic syndromes involving metal metabolism | Chelators | Wilson’s disease |
Storage disorders | Substrate reduction therapy, increase of lysosomal activity | Niemann-Pick type C |
Syndromes attributable to trinucleotide repeat diseases | Antisense oligonucleotides | Spinocerebellar ataxia |
Infection | Treatment of specific infection | Tick-borne encephalitis |
Inflammation | Treatment of specific inflammation | Multiple sclerosis |
Autoimmune neuropathies | Immunoglobulin therapy, corticosteroids | Chronic inflammatory demyelinating polyneuropathy |
Paraneoplasia | Treatment of the underlying cause | Paraneoplastic anti-Yo cerebellar tremor ataxia syndrome |
Endocrine or metabolic diseases | Treatment of the underlying cause | Hyperthyroidism |
Medications | Change or omit the medication | Cyclosporine |
Toxins | Remove toxin | Heavy-metal exposures |
Psychoactive drugs | Omit substances | Caffeine |
Affective changes and consequences of physical exertion | Relaxing techniques and thoughtful physical exertion/exercise | Progressive muscle relaxation |
Overarching Aspects of the Treatment of Essential Tremor
How to Measure Success of Tremor Treatments
Selection of Studies
Treatment of Essential Tremor
Non-pharmacological and Non-surgical Treatment of Tremor
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Use of electric devices replacing mechanical handles (example: electric toothbrush)
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Use of weighted utensils (example: use heavy cup, weighted pens)
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Change dressing (example: elastic shoelaces)
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Use of electronic devices (example: speech-activated software, hands-free speakerphone features)
Medical Treatment of Essential Tremor
Propranolol
Drug | Dosage |
---|---|
Propranolol | 30–240 mg/day |
Primidone | < 30–500 mg mg/day |
Topiramate | 400–800 mg mg/day |
Primidone
Topiramate
Botulinum toxin
Further Drug Treatments
Invasive Treatments for Essential Tremor
Radiofrequency Lesioning of the Vim
Deep Brain Stimulation for Tremors
Radiosurgery for ET
Focused Ultrasound
Comments on the Pragmatic Treatment of Essential Tremor
Deep brain stimulation | Focused ultrasound thalamotomy | Gamma-knife thalamotomy | Radiofrequency thalamotomy | |
Availability | Many centers worldwide | Few centers to-date but rapidly increasing | Extremely rare | Rare |
Experience | Vast experience | Limited experience | Only few centers offer this treatment | Only few centers offer this treatment |
Bilateral treatment necessary | Established option | Only within clinical studies | Almost no data | Not recommended because of side effects |
Exclusion criteria due to patient’s risk profile | Multimorbidity as for other brain surgeries, frailty | Frailty often tolerated | unknown | Multimorbidity as for other brain surgeries, age (?) |
Patients perception of procedural risks | Open brain surgery | Incision-free but invasive | Incision-free but invasive | Open brain surgery |
Procedure under general anesthesia possible | For rare cases, but carries special risks | Not established | Not established | Not established |
Risk of infections/bleedings | Possible, but rare | Fewer than DBS, limited experience | No reported with limited experience | More frequent than for DBS |
Need to shave the head | partial | Complete | no | partial |
Single-stage treatment | Yes, can be done within one surgery or staggered | Yes | Yes | Yes |
Exclusion because of skull density | no | 20-30% of the patients | no | no |
Experienced center for follow-up needed | needed | Not regularly needed | Not regularly needed | Not regularly needed |