Shaky-Leg Syndrome and Vitamin B<sub>12</sub>Deficiency

Benito‐León, Julián; Porta‐Etessam, Jesús

doi:10.1056/nejm200003303421318

Cited by 37 publications

(13 citation statements)

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“…The term “orthostatic tremor” (OT), also known as “shaky legs syndrome,” [1] was first coined in 1984 by Heilman, [2] although there may have been earlier descriptions of this entity. [3] This is an intriguing and rare condition, characterized by tremor and unsteadiness when standing that is relieved when sitting or walking.…”

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confidence: 99%

Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor

et al. 2016

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Very little is known about the pathogenesis of orthostatic tremor (OT). We have observed that OT patients might have deficits in specific aspects of neuropsychological function, particularly those thought to rely on the integrity of the prefrontal cortex, which suggests a possible involvement of frontocerebellar circuits. We examined whether resting-state functional magnetic resonance imaging (fMRI) might provide further insights into the pathogenesis on OT. Resting-state fMRI data in 13 OT patients (11 women and 2 men) and 13 matched healthy controls were analyzed using independent component analysis, in combination with a “dual-regression” technique, to identify group differences in several resting-state networks (RSNs). All participants also underwent neuropsychological testing during the same session. Relative to healthy controls, OT patients showed increased connectivity in RSNs involved in cognitive processes (default mode network [DMN] and frontoparietal networks), and decreased connectivity in the cerebellum and sensorimotor networks. Changes in network integrity were associated not only with duration (DMN and medial visual network), but also with cognitive function. Moreover, in at least 2 networks (DMN and medial visual network), increased connectivity was associated with worse performance on different cognitive domains (attention, executive function, visuospatial ability, visual memory, and language). In this exploratory study, we observed selective impairments of RSNs in OT patients. This and other future resting-state fMRI studies might provide a novel method to understand the pathophysiological mechanisms of motor and nonmotor features of OT.

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Section: Introductionmentioning

confidence: 99%

Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor

et al. 2016

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“…Orthostatic tremor (OT), also known as “shaky legs syndrome”, [1] is an enigmatic condition that was first reported in 1970 by Pazzaglia et al, [2] although Heilman [3] coined the term in 1984. The condition is characterized by tremor in the legs and the trunk, which begins upon standing.…”

Section: Introductionmentioning

confidence: 99%

In vivo neurometabolic profiling in orthostatic tremor

et al. 2016

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The pathogenesis of orthostatic tremor (OT) remains unclear, although some evidence points to dysfunction in the brainstem or cerebellum. We used single voxel proton magnetic resonance spectroscopy (1H-MRS) (3 T) to investigate whether neurochemical changes underlie abnormal cerebellar or cortical function in OT. Fourteen OT patients and 14 healthy controls underwent 1H-MRS studies with voxels placed in midparietal gray matter and cerebellum (vermis and central white matter). Spectral analysis was analyzed using the software package LCModel (version 6.3). The absolute metabolite concentrations and ratios of total N-acetylaspartate + N-acetylaspartyl glutamate (NAA), choline-containing compounds, myoinositol, and glutamate + glutamine to creatine were calculated. In midparietal gray matter spectra, we found a significant decrease in the absolute concentration of NAA in OT patients versus healthy controls (7.76 ± 0.25 vs 8.11 ± 0.45, P = 0.017). A similar decrease in NAA was seen in the cerebellar vermis (7.33 ± 0.61 vs 8.55 ± 1.54, P = 0.014) and cerebellar white matter (8.54 ± 0.79 vs 9.95 ± 1.57, P = 0.010). No differences in the other metabolites or their ratios were observed. Reductions in both cerebral cortical and cerebellar NAA suggest that there is neuronal damage or loss in OT, raising the intriguing question as to whether OT is a neurodegenerative disease. Along with clinical history and electrophysio0logical examination, 1H-MRS could serve as a useful diagnostic aid for OT.

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“…Although the association of tremor in adults with vitamin B12 deficiency is very rare [4,5], the patient's tremor disappeared after vitamin B12 supplements, which supports this association. Hyperactivity in the cerebellar hemispheres have been demonstrated with positron emission tomography in PWT, and it is known that these structures may be affected by vitamin B12 deficiency [6].…”

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confidence: 56%

“…The writing tremor may progress to another task specific tremor of specific action, or rest tremor, but not to postural tremor. Tremor temporary suppression by alcohol is observed in about one-third of the cases, and beneficial responses to propranolol, primidone, anticholinergics, botulinum toxin treatment, and stereotactic surgery has been reported [2].Although the association of tremor in adults with vitamin B12 deficiency is very rare [4,5], the patient's tremor disappeared after vitamin B12 supplements, which supports this association. Hyperactivity in the cerebellar hemispheres have been demonstrated with positron emission tomography in PWT, and it is known that these structures may be affected by vitamin B12 deficiency [6].…”

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confidence: 86%

Writing Tremor as a Manifestation of Vitamin B12 Deficiency

Guijarro-Castro¹,

Estallo-Guijarro²

2017

Arch Med

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Postural and kinetic tremor due to vitamin B12 deficit is rare in adults, but secondary writing tremor due this deficit is more unusual. We report the case of a writing tremor patient that was resolved after cyanocobalamin treatment. An 80-year-old man presented with a three-month history of trembling on his right hand, only becoming apparent when writing. He suffered from hypertension and diabetes, had no familial history recorded, and did not take dopaminergic-block drugs. Neurologic examination showed a fine, rapid tremor of the hands that began immediately after the patient began to write. Results of the rest of the examination were normal. Results of laboratory tests were normal, except for a serum vitamin B12 level of 132 ng per liter (normal range, 222 ng/l to 753 ng/l). A Schilling test demonstrated malabsorption of vitamin B12. A magnetic resonance image of the brain was normal. Surface electromyogram showed a 7 Hz synchronous tremor of the flexor and extensor muscles of the forearm that began when the patient was writing and was absent in other actions. Electrophysiological studies also showed mild sensory axonal polyneuropathy. Clonazepam (1 mg per day) and cyanocobalamin (injections of 1000 µg given daily for two weeks, then weekly for two months, and once a month thereafter) provided complete relief of the tremor. Follow-up after one year showed no abnormalities. Then, treatment with clonazepam was discontinued, without recurrence of the tremor. Task-specific tremor is a form of action tremor that occurs when a person is performing a specific task [1]. The most frequent form of task-specific tremor is writing tremor (WT). The pathophysiology of WT is not clear and could be a variant of essential tremor or a type of focal dystonia or an independent entity [2]. However, the results in cortical inhibition during taskspecific contractions indicate that WT is not a variant of focal task-specific dystonia, but rather an independent entity [3]. WT typically occurs at a frequency of 5 Hz to 7 Hz. The writing tremor may progress to another task specific tremor of specific action, or rest tremor, but not to postural tremor. Tremor temporary suppression by alcohol is observed in about one-third of the cases, and beneficial responses to propranolol, primidone, anticholinergics, botulinum toxin treatment, and stereotactic surgery has been reported [2].Although the association of tremor in adults with vitamin B12 deficiency is very rare [4,5], the patient's tremor disappeared after vitamin B12 supplements, which supports this association. Hyperactivity in the cerebellar hemispheres have been demonstrated with positron emission tomography in PWT, and it is known that these structures may be affected by vitamin B12 deficiency [6]. There is only one case of postural and kinetic tremor due to vitamin B12 deficit reported in the last 13 years [4] and, like in our patient, it was quickly resolved after correction of this deficit. The tremor is a characteristic symptom of vitamin B12 deficiency in children, but not know...

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Shaky-Leg Syndrome and Vitamin B₁₂Deficiency

Cited by 37 publications

References 4 publications

Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor

Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor

In vivo neurometabolic profiling in orthostatic tremor

Writing Tremor as a Manifestation of Vitamin B12 Deficiency

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Shaky-Leg Syndrome and Vitamin B12Deficiency

Cited by 37 publications

References 4 publications

Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor

Resting state functional MRI reveals abnormal network connectivity in orthostatic tremor

In vivo neurometabolic profiling in orthostatic tremor

Writing Tremor as a Manifestation of Vitamin B12 Deficiency

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Shaky-Leg Syndrome and Vitamin B₁₂Deficiency