ISSN 2398-2969      

Paroxysmal dyskinesia


Mark Lowrie

Laurent Garosi

Synonym(s): Paroxysmal movement disorder, Dystonia, Chorea, Athetosis, ballism, choreoathetosis


  • Definition: the term ‘dyskinesia’ is a Greek word literally meaning ‘bad movement’ with paroxysmal depicting the intermittent nature of the problem. Therefore paroxysmal movement disorders are a group of conditions characterized by episodes of abnormal movement in dogs and cats that are self-limiting with long periods of normality in between episodes.
  • Cause: PD may be primary (ie they are of idiopathic or familial etiology) or secondary (ie resulting from drug-administration or a structural CNS lesion).
  • Signs: episodic involuntary movements including:
    • Ballismus - abrupt contraction of limb muscles causing a flailing movement of the limb, this is often unilateral, as in hemiballismus).
    • Dystonia - sustained involuntary contraction of a group of muscles producing abnormal postures).
    • Chorea - abrupt, non-sustained contraction of different groups of muscles in the same patient).
    • Athetosis - prolonged contraction of trunk muscles causing a bending or writhing motion, this often accompanies chorea, thus described as choreathetosis).
  • Diagnosis: is by inspection (ie observing a typical episode recorded by the owner) with clinical history and episode phenomenology being fundamental to this diagnosis.
  • Treatment: medications used in the management of PD have variable and often limited efficacy. Some forms of PD have responded to diet (eg canine epileptoid cramping syndrome).
  • Prognosis: although often refractory to medication, PD is non-progressive, benign and may be self-limiting.
Print off the owner factsheet on Paroxysmal dyskinesia (movement disorder) to give to your client.



  • Etiological classification is one method proposed to segregate PDs into their different types.
  • Most PDs in people are classified as primary (ie they are of idiopathic or familial etiology, and are not part of a degenerative process).
  • The term ‘primary’ is designated to PDs that are not associated with neurological signs between episodes and that have no evidence of pathological abnormalities.
  • Other causes in people exist, eg secondary or symptomatic dyskinesias, ie those resulting from structural CNS lesions such as multiple sclerosis, head trauma, cerebral palsy, cerebrovascular accidents or encephalitis.
  • Secondary PDs tend to be accompanied by additional neurological signs that are persistent between attacks.
  • Not well defined with 2 main theories:
    1. A manifestation of transient dysfunction of the basal nuclei.
    2. PD is an epileptic disorder.

Predisposing factors


  • PKDs are triggered by sudden movement in people.
  • PNKDs usually occur in people spontaneously but can be precipitated by stress, tiredness or consumption of caffeine or alcohol.
  • PEDs are characterized by attacks of involuntary movement that are induced by prolonged sustained exercise.
  • Similar triggers are suspected in dogs but not proven.


  • Although not fully understood, some of the specific breed related dyskinesias are slowly being defined.
  • Canine epileptoid cramping syndrome is believed to be a manifestation of a gluten sensitivity with multi-system manifestations possible (eg signs indicative of dermatological or gastrointestinal disease).
  • Episodic falling of the Cavalier King Charles Spaniel results from a microdeletion affecting the brevican gene (BCAN) which encodes the brain-specific extracellular matrix proteoglycan brevican:
    • Brevican belongs to the lectican family of aggregating extracellular matrix (ECM) proteoglycans, which comprises aggrecan, brevican, neurocan and versican.
    • The ECM complex at node of Ranvier is thought to play a pivotal role in maintaining a local microenvironment, acting as a diffusion barrier for K+ and Na+ around the perinodal extracellular space.
    • The disruption of ECM complexes governing synapse stability and nerve conduction velocity is likely to underlie the episodic falling phenotype.
  • Soft coated Wheaten terriers suffer from a PD with a mutation in the PIGN gene:
    • The PIGN gene encodes glycosylphosphatidylinositol anchors that attach many different proteins to cell surfaces.
    • In people, this same mutation causes a distinct phenotype known as multiple congenital anomalies-hypotonia-seizures syndrome 1 (MCASH1).
    • To date, this mutation has not been associated with PD in people and the reason it causes PD in dogs is not understood.
  • However, the pathophysiology of the large majority of PDs is not understood.


  • Dogs may present as young as 3 months old up to 13 years of age.
  • Episode frequency and duration is highly variable.


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Further Reading


Refereed Papers

  • Recent references from PubMed and VetMedResource.​
  • Lowrie M, Garosi L (2016) Natural history of canine paroxysmal movement disorders in Labrador retrievers and Jack Russell terriers. Veterinary Journal 213, 33-7 PubMed.
  • Lowrie M, Hadjivassiliou M, Sanders D S, Garden O A  (2016) A presumptive case of gluten sensitivity in a border terrier: a multisystem disorder? Veterinary Record 179 (22), 573 PubMed.
  • Royaux E, Bhatti S, Harvey R, Garosi L, Shelton G D, Van Ham L (2016) Acetazolamide-responsive paroxysmal dyskinesia in a 12-week-old female golden retriever dog. The Veterinary Quarterly 36, 45-49 PubMed.
  • Lowrie M, Garden O A, Hadjivassiliou M, Harvey R J, Sanders D S, Powell R, Garosi L (2015) The clinical and serological effect of a gluten-free diet in Border terriers with epileptoid cramping syndrome. Journal of Veterinary Internal Medicine 29, 1564-1568 PubMed.
  • O’Brien D P, Kolicheski A, Packer R, Thomovsky S, Taylor J, Schnabel R, Berg J, Vasquez L, Johnson G (2015) Paroxysmal non-kinesogenic dyskinesia in soft coated wheaten terriers is associated with a missense mutation in PIGN and responds to acetazolamide therapy. Journal of Veterinary Internal Medicine 29, 1267.
  • Urkasemsin G, Olby N (2015) Clinical characteristics of Scottie cramp in 31 cases. Journal of Small Animal Practice 56, 276-280 PubMed.
  • Black V, Garosi L, Lowrie M, Harvey R J, Gale J (2014) Phenotypic characterisation of canine epileptoid cramping syndrome in the Border terrier. Journal of Small Animal Practice 55, 102-107 PubMed.
  • Forman O P, Penderis J, Hartley C, Hayward L J, Ricketts S , Mellersh C S (2012) Parallel mapping and simultaneous sequencing reveals deletions in BCAN and FAM83H associated with discrete inherited disorders in a domestic dog breed. PLoS Genetics 8(1), e1002462 PubMed.
  • Gill J L, Tsai K L, Krey C, Noorai R E, Vanbellinghen J F, Garosi L S, Shelton G D, Clark L A, Harvey R J (2012) A canine BCAN microdeletion associated with episodic falling syndrome. Neurobiology of disease 45, 130-136 PubMed.
  • Packer R A, Patterson E E, Taylor J F, Coates J R, Schnabel R D, O'Brien D P (2010) Characterization and mode of inheritance of a paroxysmal dyskinesia in Chinook dogs. Journal of Veterinary Internal Medicine 24, 1305-1313 PubMed.
  • Harcourt-Brown T (2008) Anticonvulsant responsive, episodic movement disorder in a German shorthaired pointer. Journal of Small Animal Practice 49 (8), 405-407 PubMed.
  • Kube S A, Vernau K M, LeCouteur R A (2006) Dyskinesia associated with oral phenobarbital administration in a dog. Journal of Veterinary Internal Medicine 20, 1238-1240 PubMed.
  • Garosi L S, Platt S R, Shelton G D (2002) Hypertonicity in Cavalier King Charles spaniels. Journal of Veterinary Internal Medicine 16, 330 ResearchGate.
  • Jankovic J, Demirkiran M (2002) Classification of paroxysmal dyskinesias and ataxias. Advances in Neurology 89, 387-400 PubMed.
  • Penderis J, Franklin R J (2001) Dyskinesia in an adult bichon frise. Journal of Small Animal Practice 42, 24-25 PubMed.
  • Ramsey I K, Chandler K E, Franklin R J (1999) A movement disorder in boxer pups. Veterinary Record 144, 179-180 PubMed.
  • Demirkiran M, Jankovic J (1995) Paroxysmal dyskinesias: clinical features and classification. Annals of Neurology 38 (4), 571-579 PubMed.
  • Herrtage M E, Palmer A C (1983) Episodic falling in the cavalier King Charles spaniel. Veterinary Record 112 (19), 458-459 PubMed.
  • Woods C B (1977) Hyperkinetic episodes in two Dalmatian dogs. JAAHA 13 (2), 255-257 VetMedResource.

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