Joint Hypermobility Syndrome: a RiskFactor for Fixed Dystonia?

Joint hypermobility syndrome (JHS) is a heritable disor-der of connective tissue, predominantly prevalent infemales,1 that comprises symptomatic hypermobility predis-posing to arthralgia, soft tissue injury, and joint instability.JHS has recently been linked with psychiatric disorders and‘‘medically unexplained’’ symptoms, including panic disor-der, anxiety, irritable bowel syndrome, chronic fatigue syn-drome, and fibromyalgia.2 From recent clinical experience,we formed a clinical impression that JHS occurred morecommonly than would be expected by chance in our patientswith fixed dystonia. We therefore administered a validatedself-completed questionnaire to detect JHS3 to a consecu-tively ascertained cohort of patients with fixed dystonia whohad received botulinum toxin injections between January 1,2009 and June 30, 2010 and in whom we were retrospec-tively assessing long-term benefits of injection.Forty-four patients were identified. Twenty-eight patients

(mean age, 44 years; range, 13–90; 1 male) returned thecompleted questionnaires (64% response rate). Nine patients(32%) satisfied criteria for JHS based on their responses.From these 9 patients, 3 had previously been diagnosed withJHS. Three additional patients indicated a previous diagnosisof JHS, but their questionnaire responses did not satisfy cri-teria for a diagnosis of JHS. The neuropsychological profileof the patients was not available.The prevalence of JHS in the general population is between

10% and 15%,1 but JHS was at least twice as frequent in ourgroup of fixed dystonia patients, suggesting a possible associa-tion of the two conditions. Potential confounding of thefemale gender predominance in our group cannot explain theassociation, because the prevalence of JHS in Caucasianfemales is well below that observed in our group.4

How can a condition of hypermobility with excessive rangeof movement increase the risk for a phenotypically contrastingcondition such as fixed dystonia? There are a number ofpotentially interacting mechanisms. Increased laxity ofligaments and abnormal range of movement, especially inadolescence, commonly result in chronic pain, which canresult in movement avoidance, termed kinesiophobia, reflect-ing a possible mechanism for the adoption of fixed postures.Immobilization of a limb in an abnormal posture (e.g.,through plaster casts) is known to contribute to commonly

precede the development of a permanently ‘‘fixed’’ dystonicposture.5 Peripheral injury is a common event preceding fixeddystonia, and joint instability predisposes patients with JHS toperipheral trauma. The nature of peripherally induced move-ment disorders are hotly debated, with some suggesting thatperipheral trauma can cause (organic) dystonia throughabnormal sensorimotor organization.6 Interestingly, physicalprecipitating events are commonly reported before the onsetof functional neurological disorders, such as functional weak-ness.7 Although opinions differ on whether fixed dystonia isbest considered as a functional (i.e., psychogenic) disorder,5

the association between fixed dystonia and a disorder such asJHS, where physical events (e.g., injury or pain), psychiatricdisorder, and ‘‘medically unexplained’’ symptoms arecommon is clearly of potential pathophysiological significanceto the development of a functional movement disorder.

The limited number of participants does not allow anydefinite conclusions based on these preliminary results, butfurther work may reveal common aspects of the pathophysi-ology of both conditions.

Panagiotis Kassavetis, MD1, Amit Batla, MD1,Isabel Pare�es, MD1, Tabish A. Saifee, MD1,Anette Schrag, PhD2, Carla Cordivari, MD3,

Kailash P. Bhatia, MD1, Mark J. Edwards, PhD1*

1Sobell Department of Motor Neuroscience andMovement Disorders, UCL Institute of

Neurology, London, UK2Department of Clinical Neurosciences, RoyalFree Hospital, University College London,

London, UK3Department of Clinical Neurophysiology,

National Hospital for Neurology andNeurosurgery, Queen Square, London, UK

References1. Martin-Santos R, Bulbena A, Porta M, Gago J, Molina L, Duro JC.

Association between joint hypermobility syndrome and panic disor-der. Am J Psychiatry 1998;155:1578–1583.

2. Bulbena A, Gago J, Pailhez G, Sperry L, Fullana MA, Vilarroya O.Joint hypermobility syndrome is a risk factor trait for anxiety disor-ders: a 15-year follow-up cohort study. Gen Hosp Psychiatry 2011;33:363–370.

3. Hakim AJ, Grahame R. A simple questionnaire to detect hypermo-bility: an adjunct to the assessment of patients with diffuse musculo-skeletal pain. Int J Clin Pract 2003;57:163–166.

4. Remvig L, Jensen DV, Ward RC. Epidemiology of general jointhypermobility and basis for proposed criteria for benign jointhypermobility syndrome: review of the literature. J Rheumatol2007;34:804–809.

5. Schrag A, Trimble M, Quinn N, Bhatia K. The syndrome of fixeddystonia: an evaluation of 103 patients. Brain 2004;127:2360–2372.

6. van Rooijen DE, Geraedts EJ, Marinus J, Jankovic J, van Hilten JJ.Peripheral trauma and movement disorders: a systematic review ofreported cases. J Neurol Neurosurg Psychiatry 2011;82:892–898.

7. Stone J, Warlow C, Sharpe M. Functional weakness: clues to mech-anism from the nature of onset. J Neurol Neurosurg Psychiatry2012;83:67–69.

------------------------------------------------------------*Correspondence to: Mark J. Edwards, Sobell Department of MotorNeuroscience and Movement Disorders, UCL Institute of Neurology,London, UK; m.edwards@ion.ucl.ac.ukRelevant conflicts of interest/financial disclosures: Nothing to report.

Full financial disclosures and author roles may be found in the onlineversion of this article.

Published online 00 Month 2012 in Wiley Online Library(wileyonlinelibrary.com). DOI: 10.1002/mds.25004

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