Tremor

INDEX

ORIGIN

(vv)CurrentMedicalSurgicalTreatmentDystonia2.m4v(tt)Lecture: Current Medical and Surgical Treatments for Dystonia: Professor E Moro

Broadly speaking, dystonia is related to disorganized sensorimotor integration, and abnormal modulation of cortical plasticity. Dystonic tremor (DT) arises in certain types of dystonia, and may be the most obvious manifestation of underlying dystonia

Although not universally true, the following is a nice schema of the development of dystonia:

CLASSIFICATION

Tremor in dystonia may be related to carrying out a specific task, or be more generalized. Note that patients with segmental or multifocal dystonia are more likely to be tremulous than patients with focal dystonia.

When the trembling body part is not affected by dystonia, but dystonic posturing occurs in other body parts, this is referred to as “tremor associated with dystonia”.  See below (Tremor Characteristics).

Dystonia related task specific tremors include:

CLINICAL FEATURES

Presentation of Dystonia with tremor:

Tremor may be a clinical feature of dystonia and patients with dystonia may present with tremor. Some patients display isolated or focal tremor in the absence of any signs of dystonia, which may not become apparent until many years later. Virtually every dystonic syndrome may present with tremor, with typical examples including head tremor in torticollis, hand tremor in writer’s cramp, and jaw tremor in orofacial dystonias.

Tremor characteristics

The tremor in dystonia is irregular in amplitude and periodicity with a broad range of tremor frequency. The tremor is characteristically asymmetrical and jerky (due to variability in axis and amplitude). There may be brief bursts or flurries of tremor, typically enhanced by a task such as rolling the arm back and forth.

(vv)DystonicT.mp4(tt)

Patient with long-standing retrocollis, who developed severe postural tremor.

(vv)Albanese.mp4(tt)

This patient has unilateral right hand resting and postural tremor. During movement with the right fingers, a slight tremor occurs in the left hand (overflow). Reduced right arm swing during gait is associated with right hand tremor, abnormal posturing, and extension of the right wrist4.

  

(vv)six.mp4(tt)

69-year-old man with mild right torticollis. On posture, he has mild bilateral arm tremor that becomes slightly more severe during pronation and supination movements. He has writer’s cramp and severe action tremor in the right arm interfering with both writing and drawing. There is also action tremor in the left arm that is less pronounced compared with the right but still incapacitating.

 

WRITING AND DRAWING

When drawing a spiral, patients with dystonic tremor are likely to generate multiple axes, whereas patients with ET are likely to have a single predominant axis).  In dystonia, the direction of the oscillations varies because dystonic tremor involves co-contraction of agonist and antagonist muscles affecting proximal (shoulder/elbow) as well as distal (wrist/digits) parts. The commonly observed exacerbation of dystonic tremor with certain postures and an overflow of muscle activity with voluntary actions are other contributing factors.

 

 

 

 

 

 

 

 

 

    Spiral drawing of a patient with dystonic tremor; tremor is present but no single predominant axis stands out 5.

 

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    (A) Dystonia and spiral drawing: oscillations occur in all sections of the spirals, denoting a multidirectional axis. The amplitude and frequency also vary, giving a jerky appearance6.

 

 

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    (B) There is evidence of forceful pen pressure consistent with dystonic posturing in the spiral drawings and handwriting samples. Many patients with dystonia have a tendency to draw more than three turns of the spiral. The left-handed spiral demonstrates a multidirectional tremor axis. Straight lines drawn at a steady rate, particularly the vertical one, show that the frequency is variable. On horizontal line and spiral drawings, the tremor amplitude is asymmetric, being larger on the right6.

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    (C) The spiral and line drawings demonstrate a multidirectional tremor axis with a jerky pattern caused by variable amplitude and frequency—all features consistent with dystonic tremor. In this case, the handwriting is normal with very little tremor intrusion6.

 

 

 

 

 

    Characteristics of tremor in writing and drawing tasks.

From: Alty J, Cosgrove J, Thorpe D, Kempster P. How to use pen and paper tasks to aid tremor diagnosis in the clinic.

Pract Neurol. 2017;17(6):456-463. doi:10.1136/practneurol-2017-001719

 

 

 

 

 

 

AGE OF ONSET

Dystonic tremor syndromes have a bimodal age of onset, with 90% of dystonia-associated tremor manifesting by 60 years of age and 90% by 70 years:

Distributions of ages of tremor onset for 95 patients with dystonic tremor syndromes (DTS).

DT: dystonic tremor; TAD: tremor associated with dystonia; DT & TAD: patients with both DT and TAD. From Bain7.

 

 

DISTRIBUTION

Like ET, dystonic tremor, and tremor associated with dystonia usually affects the head, voice or upper limbs.  Most studies report a higher incidence of head tremor than upper-limb tremor, and there is an even lower incidence of voice and leg tremor. Although less common, either isolated voice tremor or a presentation where voice tremor is more severe than hand tremor, is suggestive of dystonic tremor.

Distinguishing ET from Cervical Dystonia associated with tremor.

Although the table below contrasts ET and dystonia, note that head tremor may rarely also be described in PD (both no-no, and yes-yes types). 

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Dystonic head tremor. The patient has right torticollis with horizontal tremulous and jerky head movements.

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Dystonic head tremor. The patient has retrocollis with yes-yes type of dystonic tremor

DIAGNOSIS

Diagnosis is usually made by the presence of typical dystonic features, which may be obvious, but may also need to be carefully looked for.

It is consequently important to examine for features of dystonia by:

  1. Careful inspection of the arms during posture holding and batwing positions. Dystonic features may be brought out by asking the patient to hold the arms extended in front of their body for 30–60 seconds. In this setting, dystonic thumb flexion and other dystonic postures may be seen.
  2. The patient should slowly rotate the outstretched arms from pronation to supination, since this may show a position-specific tremor, indicating an underlying dystonic tremor8.
  3. Ask the patient to perform repetitive hand tasks with each hand sequentially such as finger tapping, rapid opening and closing of the hand, and hand pronation–supination.

Features of dystonia should be actively sought, including the following:

Mirror dystonia represents the expression of motor overflow in dystonia. Mirroring is defined as a unilateral posture or movement that is the same or similar in character to a dystonic feature that can be elicited, usually in the more severely affected side, when contralateral movements or actions are performed. In the case of focal hand dystonia, an example would that a specific task such as writing with the normal hand brings about a dystonic movement or posture in the affected, dystonic side. Mirror movements are also detected in normal individuals, without dystonia or dystonic tremor.

Mirror dystonia (A) Patient starts writing with the non-affected (left) hand and (B) within a few seconds develops mirror dystonia, manifested by extension of the 2nd and 3rd digits in the right hand 11.

 (vv)MirrorWritingTremorDystonicClues.mp4(tt)

Mirror tremor in a dystonic patient.  A 34‐year‐old right‐handed male  presented with a 3‐year history of a gradually progressive shaking in his right hand that only became evident when writing.  Irregular, low‐amplitude, high‐frequency, jerky tremor became apparent in the right hand upon writing. In addition, this tremor was also evident when he was assuming a writing or similar position (see Video 1, Segment 1) during performance of other tasks, but stopped immediately upon slight positional changes of the wrist (see Video 1, Segment 3). During writing with the right hand, slight dystonic posturing of the wrist became apparent. In addition, when writing with the left hand, the same arrhythmic, jerky tremor started in the right hand, representing a task‐specific mirror tremor (see Video 1, Segment 2) 12 

 

DIFFERENTIAL DIAGNOSIS

Potentially broad, and includes:

  1. Parkingon's Disease
  2. Essential Tremor

1. Parkinson's Disease:

In patients with arm tremor, including a resting tremor, and reduced arm swing on the affected side, it can be difficult to differentiate between PD and dystonia at an early stage. 

Signs that may be noted in patients with dystonic tremor and  which might suggest PD include:

Clinical features suggesting dystonic, rather than parkinsonian, tremor include:

The diagnosis may also be made in patients believed to have tremor typical of PD, but whose PET or SPECT imaging rules out a nigrostriatal deficit, that is patients with a ‘‘Scan Without Evidence of Dopaminergic Deficit’’. 

However, it should be noted that patients with dystonic tremor may have:

reduced arm swing, asymmetric jerky rest and postural tremor, hypomimia, increased limb tone, and slow repetitive finger movements which may be mistaken for bradykinesia13.

(vv)TORIASWEDD.mp4(tt)

Patient with normal I 123 -FP-CIT SPECT, and shown to test positive for the DYT-1 mutation. She shows rest and postural tremor in her arms (more so on the right) and had mild dystonic posturing of the right distal arm. There was no decrement in repetitive movements, and she had no facial hypomimia. While walking, there was a reduced bilateral arm swing, and she had a dystonic posturing of both legs

2. Essential Tremor:

Dystonic tremor is frequently misdiagnosed as ET, since patients with dystonia may have classic essential tremor phenomenology. It is not uncommon that patients with isolated upper limb postural/kinetic tremor are misclassified as having classic essential tremor if upper limb tremor is the presenting sign and the patients are observed before they develop any other signs of dystonia15.

Isolated focal, position-specific, and task-specific tremors are not likely to be ET and are often associated with subtle dystonia. Isolated neck tremor is suggestive of dystonia, not ET.

Isolated voice tremor is most suggestive of laryngeal dystonia.

DIAGNOSTIC TESTS

Consider F-dopa PET to distinguish PD from dystonic tremor.

TREATMENT

See reference: Pandey S, Sarma N. Tremor in dystonia. Parkinsonism Relat Disord 16.

Effects of thalamic (VIM) DBS were modest and transient17.

REFERENCES

  1. Madhusudanan M. Dystonia : emerging concepts in pathophysiology. Neurol India. 1999;47(4):263-267. http://www.ncbi.nlm.nih.gov/pubmed/10625895.
  2. Edwards M, Wood N, Bhatia K. Unusual phenotypes in DYT1 dystonia: A report of five cases and a review of the literature. Mov Disord. 2003;18(6):706-711. doi:10.1002/mds.10411
  3. Bajaj NPS, Gontu V, Birchall J, Patterson J, Grosset DG, Lees AJ. Accuracy of clinical diagnosis in tremulous parkinsonian patients: A blinded video study. J Neurol Neurosurg Psychiatry. 2010;81(11):1223-1228. doi:10.1136/jnnp.2009.193391
  4. Albanese A, Lalli S. Is this dystonia? Mov Disord. 2009;24(12):1725-1731. doi:10.1002/mds.22597
  5. Michalec M, Hernandez N, Clark LN, Louis ED. The spiral axis as a clinical tool to distinguish essential tremor from dystonia cases. Park Relat Disord. 2014;20(5):541-544. doi:10.1016/j.parkreldis.2014.01.021
  6. Alty J, Cosgrove J, Thorpe D, Kempster P. How to use pen and paper tasks to aid tremor diagnosis in the clinic. Pract Neurol. 2017;17(6):456-463. doi:10.1136/practneurol-2017-001719
  7. Bain PG. Essential tremor and senile varieties of action tremor an evolving ART. Mov Disord. 2015;30(10):1301-1303. doi:10.1002/mds.26342
  8. Zach H, Dirkx M, Bloem BR, Helmich RC. The clinical evaluation of Parkinson’s tremor. J Parkinsons Dis. 2015;5(3):471-474. doi:10.3233/JPD-150650
  9. Buijink  a WG, Contarino MF, Koelman JHTM, Speelman JD, van Rootselaar  a F. How to tackle tremor - systematic review of the literature and diagnostic work-up. Front Neurol. 2012;3(October):146. doi:10.3389/fneur.2012.00146
  10. LeDoux MS. 3.1.2 Dystonia: Phenomenology. Parkinsonism Relat Disord. 2011;18:S161. doi:10.1016/s1353-8020(11)70696-4
  11. Sitburana O, Chen Wu LJ, Sheffield JK, Davidson A, Jankovic J. Motor overflow and mirror dystonia. Park Relat Disord. 2009;15(10):758-761. doi:10.1016/j.parkreldis.2009.05.003
  12. Schreglmann SR, Baumann CR, Waldvogel D. Mirror Writing Tremor: Dystonic Clues…. Mov Disord Clin Pract. 2015;2(3):316-317. doi:10.1002/mdc3.12182
  13. Bain PG. Dystonic tremor presenting as parkinsonism: long-term follow-up of SWEDDs. Neurology. 2009;72(16):1443-1445. doi:10.1212/WNL.0b013e3181a18809
  14. Cáceres-Redondo MT, Carrillo F, Palomar FJ, Mir P. DYT-1 gene dystonic tremor presenting as a “scan without evidence of dopaminergic deficit” . Mov Disord. 2012;27(11):1469-1469. doi:10.1002/mds.25171
  15. Albanese A, Di Giovanni M, Lalli S. Dystonia: diagnosis and management. Eur J Neurol. 2019;26(1):5-17. doi:10.1111/ene.13762
  16. Pandey S, Sarma N. Tremor in dystonia. Parkinsonism Relat Disord. 2016;29(13):3-9. doi:10.1016/j.parkreldis.2016.03.024
  17. Cury RG, Fraix V, Castrioto A, et al. Thalamic deep brain stimulation for tremor in Parkinson disease, essential tremor, and dystonia. Neurology. 2017;89(13):1416-1423.