Table 1
Clinical Characteristics of Published Symptomatic Orthostatic Tremor Cases
| Conditions | Frequency (Hz) | Other Systemic or Neurological Features | Evolution |
|---|---|---|---|
| Non-tumoral aqueduct stenosis21 | 6–7 | Bradykinesia, rigidity, and postural tremor of upper limbs | Remission with ventriculoperitoneal shunt |
| Chronic relapsing polyradiculoneuropathy21 | 6–7 | Dysesthesias and mild weakness of the limbs, and postural tremor of upper limbs | Remission with prednisone |
| Head trauma22 | 14–15 | – | No improvement |
| Pontine lesions23 | |||
| Cavernoma | 7–8 | Face and arm paresthesia | Partial recovery |
| Tuberculoma | 14–15 | Fever, headache, left predominate postural tremor of the arms | Complete remission |
| Midbrain lesion24 | 16 | Truncal and cranial muscles involvement | Partial recovery |
| Cerebellar degeneration25 | 14–15 | Scanning speech, intention tremor, ataxic gait | – |
| Cerebellar degeneration26 | Gaze-evoked nystagmus, dysmetria of saccades, scanning speech, intention tremor in 4 limbs, and broad-based ataxic gait | ||
| Patient 1 | 14 | Slightly improvement with clonazepam | |
| Patient 2 | 15 | No improvement | |
| Patient 3 | 14 | No improvement | |
| Cerebellar degeneration27 | |||
| Patient 1 | 13.8–15.9 | Dysmetria, ataxic gait, cognitive impairment, and nystagmus | No improvement |
| Spinocerebellar ataxia type 2 | 13 | Dysarthria, dysmetria, ataxic gait, cognitive impairment, and slowing of horizontal pursuit | Improvement with propranolol |
| Spinal cord lesion,28 | 12–13 | Cognitive impairment, voiding difficulty, and postural instability | Complete remission after spinal schwannoma |
| Small cell lung cancer29 | 3–5 | Head and arms tremor, persistence during walking | Rapid worsening |
| Stiff-person syndrome30 | |||
| Patient 1 | – | Stiffness and spasms | Improvement with |
| Patient 2 | 16 | Stiffness and spasms | clonazepam |
| Multiple sclerosis31 | 4 | Dysmetria, ataxia, pyramidal signs and sensorial deficits | No improvement |
| Graves’ disease32 | 14–16 | – | Complete remission after carbimazole |
| Graves’ disease33 | 8-9 | – | Complete remission after methimazole |
| Graves’ disease34 | 8 | Intolerance of heat, excessive sweating and recent loss of weight with increased appetite, dysphagia and dysphonia | Complete remission after methimazole |
| Biclonal IgG and IgA lambda gammopathy of undetermined significance,35 | 17.5 | – | Improvement with gabapentin |
| Thiamine deficiency36 | – | Diplopia, gait difficulty | Slow improvement |
| Vitamin B12 deficiency1 | 15 | Impaired sensation of pain and heat in a stocking distribution | Complete remission after vitamin B12 and clonazepam |
| Secondary to recreational use of solvents.37 | 15 | – | Improvement with clonazepam |
| Secondary to dopamine blocking drugs38 | |||
| Metoclopramide | 5–6 | Mild rigidity | Improvement |
| Sulpiride and thyethylperazine | 6–7 | Resting tremor | Complete remission |
| Sulpiride | 15 | – | Complete remission |
| Sulpiride | 14 | Vertigo and nystagmus | Complete remission |
Figure 1
Typical high-frequency electromyography discharges in orthostatic tremor. Surface electromyography recordings of a 57-year-old female orthostatic tremor patient from left leg muscles showing discharges at the frequency of 16–18 Hz with the patient standing.
Table 2
Consensus Statement on Tremor by the Movement Disorder Society. Criteria for Orthostatic Tremor
| Orthostatic tremor is a unique tremor syndrome characterized by: |
| 1. A subjective feeling of unsteadiness during stance but only in severe cases during gait; patients rarely fall. None of the patients have problems when sitting and lying. |
| 2. Sparse clinical findings that are mostly limited to a visible and occasionally, only palpable fine amplitude rippling of the leg (quadriceps or gastrocnemius) muscles when standing. |
| 3. The diagnosis that can be confirmed only by electromyography recordings (e.g. from the quadriceps muscle) with a typical 13–18 Hz pattern. All of the leg, trunk, and even arm muscles can show this tremor, which is typically absent during tonic activation while the patient is sitting and lying. |
Figure 2
Symptomatic orthostatic tremor caused by a lesion in the posterior fossa. T1-weighted axial magnetic resonance imaging scan showing a lesion involving the right pontine region, compatible with a cavernoma. Case 1 from Benito-León J, Rodríguez J, Ortí-Pareja M, et al. Symptomatic orthostatic tremor in pontine lesions. Neurology 1997;49:1439–1441. Reprinted with permission from Wolters Kluwer Health.
Figure 3
Resting state functional MRI findings in orthostatic tremor. Resting state brain networks showing significant functional connectivity differences between a series of 13 orthostatic tremor patients vs. 13 matched healthy controls.
Figure 4
T1-weighted sagittal magnetic resonance image showing the region of interest (cerebellar vermis) for the proton magnetic resonance spectroscopy study by Benito-León et al.92 The labeled resonances are those of N-acetylaspartate+N-acetylaspartyl glutamate (NAA), total creatine (CR) and total choline-containing compounds (CHO). The spectra are plotted on the same vertical intensity scale normalized to background noise. ppm, Parts Per Million. Note the reduced NAA resonance in a 61-year-old female orthostatic tremor patient (C) compared to that from a matched healthy subject (B), whereas there is a minor decrease in either CHO or CR.
Table 3
Pharmacological Agents to Treat Orthostatic Tremor
| Medication | Dosage | Clinical Efficacy | Comment |
|---|---|---|---|
| Clonazepam | 0.5–6 mg/day | +++ | Documented effect |
| Gabapentin | 300–2400 mg/day | ++ | Documented effect |
| Levodopa | 300–800 mg/day | ++ | Only short-term benefit |
| Pramipexole | 0.75 mg/day | + | Anecdotal effect |
| Primidone | 125–250 mg/day | + | Anecdotal effect |
| Valproic acid | 500–1000 mg/day | +/– | Anecdotal effect |
| Carbamazepine | 400 mg/day | +/– | Anecdotal effect |
| Phenobarbital | 100 mg/day | +/– | Anecdotal effect |
| Intravenous immunoglobulin1 | 2 g/kg over 3 days | + | Anecdotal effect |
| Propanolol | 120 mg/day | – | Without effect |
| Levetiracetam | 3000 mg/day | – | Without effect |
| Botulinum toxin | 200 mU in the tibialis anterior bilaterally | – | Without effect |
| Alcohol | – | – | Without effect |
1 It was used in a case of slow orthostatic tremor associated with a novel antineuronal antibody.103