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Wring Tremor as a Manifestaon of Vitamin B12 Deciency
Guijarro-Castro C* and Estallo-Guijarro L
Hospital Virgen de la Luz (Cuenca), Caracas and San Bernardo Medical Center (Madrid), Spain
*Corresponding author: Guijarro-Castro C, Hospital Virgen de la Luz (Cuenca), Caracas and San Bernardo Medical Center (Madrid), Spain, Tel:
34969179900; E-mail: crisna.guijarro@sen.es
Received date: January 12, 2017; Accepted date: January 24, 2017; Published date: January 31, 2017
Citaon: Guijarro-Castro C and Estallo-Guijarro L. Wring Tremor as a Manifestaon of Vitamin B12 Deciency. Arch Med. 2017, 9:1
Copyright: © 2017 Guijarro-Castro C, et al. This is an open-access arcle distributed under the terms of the Creave Commons Aribuon License,
which permits unrestricted use, distribuon, and reproducon in any medium, provided the original author and source are credited.
Leer to Editor
Postural and kinec tremor due to vitamin B12 decit is rare
in adults, but secondary wring tremor due this decit is more
unusual. We report the case of a wring tremor paent that was
resolved aer cyanocobalamin treatment. An 80-year-old man
presented with a three-month history of trembling on his right
hand, only becoming apparent when wring. He suered from
hypertension and diabetes, had no familial history recorded, and
did not take dopaminergic-block drugs. Neurologic examinaon
showed a ne, rapid tremor of the hands that began
immediately aer the paent began to write. Results of the rest
of the examinaon 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 malabsorpon of vitamin B12. A magnec
resonance image of the brain was normal. Surface
electromyogram showed a 7 Hz synchronous tremor of the
exor and extensor muscles of the forearm that began when the
paent was wring and was absent in other acons.
Electrophysiological studies also showed mild sensory axonal
polyneuropathy. Clonazepam (1 mg per day) and
cyanocobalamin (injecons of 1000 µg given daily for two
weeks, then weekly for two months, and once a month
thereaer) provided complete relief of the tremor. Follow-up
aer one year showed no abnormalies. Then, treatment with
clonazepam was disconnued, without recurrence of the
tremor. Task-specic tremor is a form of acon tremor that
occurs when a person is performing a specic task [1]. The most
frequent form of task-specic tremor is wring tremor (WT). The
pathophysiology of WT is not clear and could be a variant of
essenal tremor or a type of focal dystonia or an independent
enty [2]. However, the results in corcal inhibion during task-
specic contracons indicate that WT is not a variant of focal
task-specic dystonia, but rather an independent enty [3]. WT
typically occurs at a frequency of 5 Hz to 7 Hz. The wring
tremor may progress to another task specic tremor of specic
acon, or rest tremor, but not to postural tremor. Tremor
temporary suppression by alcohol is observed in about one-third
of the cases, and benecial responses to propranolol,
primidone, ancholinergics, botulinum toxin treatment, and
stereotacc surgery has been reported [2].
Although the associaon of tremor in adults with vitamin B12
deciency is very rare [4,5], the paent’s tremor disappeared
aer vitamin B12 supplements, which supports this associaon.
Hyperacvity in the cerebellar hemispheres have been
demonstrated with positron emission tomography in PWT, and it
is known that these structures may be aected by vitamin B12
deciency [6]. There is only one case of postural and kinec
tremor due to vitamin B12 decit reported in the last 13 years
[4] and, like in our paent, it was quickly resolved aer
correcon of this decit. The tremor is a characterisc symptom
of vitamin B12 deciency in children, but not known in adults
[7,8]. The vitamin B12 deciency should be added to the list of
diseases that can cause wring tremor. The deciency correcon
completely solves the tremor.
References
1. Bain PG, Findley LJ, Brion TC, Rothwell JC, Gresty MA, et al.
(1995) Primary wring tremor. Brain 118: 1461-72.
2. Pita Lobo P, Quarocchi G, Jutras MF, Sangla S, Apars E, et al.
(2013) Primary wring tremor and writer's cramp: two faces of a
same coin? Mov Disord 28: 1306-1307.
3. Ljubisavljevic M, Kacar A, Milanovic S, Svetel M, Kosc VS (2006)
Changes in corcal inhibion during task-specic contracons in
primary wring tremor paents. Mov Disord 21: 855-859.
4. Koussa S, Taher A, Sayegh R (2003) Postural and kinec tremor
associated with vitamin B12 deciency. Rev Neurol 159:
1173-1174.
5. Benito-León J, Porta-Etessam J (2000) Shaky-leg syndrome and
vitamin B12 deciency. N Engl J Med 342: 981.
6. Katsaros VK, Glocker FX, Hemmer B, Schumacher M (1998) MRI of
spinal cord and brain lesions in subacute combined degeneraon.
Neuroradiology 40: 716-719.
7. Demir N, Koc A, Üstyol L, Peker E, Abuhandan M (2013) Clinical
and neurological ndings of severe vitamin B12 deciency in
infancy and importance of early diagnosis and treatment. J
Paediatr Child Health 49: 820-824.
8. Uddin MK, Rodnitzky RL (2003) Tremor in children. Semin Pediatr
Neurol 10: 26-34.
Letter to Editor
iMedPub Journals
http://www.imedpub.com/
DOI: 10.21767/1989-5216.1000188
ARCHIVES OF MEDICINE
ISSN 1989-5216 Vol.9 No.1:5
2017
© Under License of Creative Commons Attribution 3.0 License | This article is available from: http://www.archivesofmedicine.com/ 1