Primary writing tremor.
Primary writing tremor (PWT) is considered to be a type of task-specific tremor in which tremor predominantly occurs and interferes with handwriting. We describe the clinical and neurophysiological features of 21 patients (20 male and one female) with PWT. Mean age at tremor onset was 50.1 years. A...
| Published in: | Brain: A Journal of Neurology Vol. 118; no. 6; pp. 1461 - 1473 |
|---|---|
| Main Authors: | , , , , , , , , , , , , , |
| Format: | research tables/charts tracings Journal Article |
| Published: |
Oxford University Press / USA
Nov1995
|
| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=107394525&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 107394525 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00068950 2RY jtl: Brain: A Journal of Neurology issn: 00068950 maglogo: N pubinfo: dt: Nov1995 vid: 118 iid: 6 pid: 622 pub: Oxford University Press / USA artinfo: ui: 107394525 107394525 NLM8595477 1996038799 NLM8595477 107394525 ppf: 1461 ppct: 12 formats: tig: atl: Primary writing tremor. aug: au: Bain PG Findley LJ Britton TC Rothwell JC Gresty MA Thompson PD Marsden CD Bain, P G Findley, L J Britton, T C Rothwell, J C Gresty, M A Thompson, P D Marsden, C D affil: MRC Human Movement and Balance Unit, Institute of Neurology, London, UK sug: subj: Tremor Physiopathology Handwriting Funding Source Tremor Familial and Genetic Reflex Biophysical Instruments Median Nerve Physiopathology Myography Tremor Drug Therapy Propranolol Therapeutic Use Nervous System Physiology Electromyography Control Group Descriptive Statistics T-Tests Statistical Significance Adult Middle Age Aged Aged, 80 and Over Male Female Human Adult: 19-44 years Middle Aged: 45-64 years Aged: 65+ years Aged, 80 & over Male Female ab: Primary writing tremor (PWT) is considered to be a type of task-specific tremor in which tremor predominantly occurs and interferes with handwriting. We describe the clinical and neurophysiological features of 21 patients (20 male and one female) with PWT. Mean age at tremor onset was 50.1 years. A family history of PWT was obtained from seven patients. Ten patients obtained benefit from drug treatment (mainly propranalol or primidone) and seven responded to alcohol. The writing speeds of the patients (mean +/- SEM: 73.1 +/- 6.6 letters per minute) when using their preferred hand were significantly reduced (Student's t test: P < 0.001) compared with those of healthy control subjects (mean +/- SEM: 127.7 +/- 6.4). Surface polymyography performed during writing showed 4.1-7.3 Hz rhythmic activity predominantly in the intrinsic hand and forearm muscles. Alternating, extensor activation alone, skipping from alternating to extensor activation, and co-contracting EMG patterns were recorded from the flexor and extensor muscles of the forearm. There was no evidence for excessive 'overflow' of this rhythmic EMG activity, as similar activity was detected in comparable muscle groups of healthy control subjects. Accelerometry confirmed that the frequency of PWT ranged from 4.1-7.3 Hz (median 5.5 Hz) and that normal subjects wrote with a 4.0-7.7 Hz oscillation (median 4.6 Hz). Forearm reciprocal inhibition was normal in PWT (n = 13), and thus patients with PWT can be distinguished from those with writer's cramp in whom decreased presynaptic inhibition has been found. Patients were sub-classified as having either type A (n = 11) or B (n = 10) PWT depending on whether tremor appeared during writing (type A: task induced tremor) or whilst writing and adopting the hand position used in writing (type B: positionally sensitive tremor). However, the only differences between these two groups were that a co-contracting EMG pattern and tremor induced by tendon taps to the volar aspect of the wrist were present in type B but not type A cases. pubtype: Academic Journal doctype: research tables/charts tracings Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
|---|