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| | {{Short description|A neurological disorder characterized by sudden involuntary movements}} |
| {{Infobox medical condition (new) | | {{Infobox medical condition (new) |
| | name = {{PAGENAME}} | | | name = Paroxysmal kinesigenic choreoathetosis |
| | synonyms = Familial PKD | | | synonyms = Familial PKD, Paroxysmal kinesigenic dyskinesia |
| | image = Autosomal dominant - en.svg | | | image = Autosomal dominant - en.svg |
| | alt = | | | alt = |
| | caption = Paroxysmal kinesigenic choreoathetosis is inherited in an autosomal dominant manner | | | caption = Paroxysmal kinesigenic choreoathetosis is inherited in an [[autosomal dominant]] manner |
| | pronounce = | | | pronounce = |
| | field = | | | field = [[Neurology]], [[Genetics]] |
| | symptoms = | | | symptoms = Sudden, brief episodes of [[chorea]], [[athetosis]], or [[dystonia]] triggered by voluntary movement |
| | complications = | | | complications = Impaired mobility during attacks, anxiety related to attacks |
| | onset = | | | onset = Childhood or adolescence |
| | duration = | | | duration = Chronic, lifelong condition |
| | types = | | | types = Primary (familial) or secondary to other disorders |
| | causes = | | | causes = Mutations in the [[PRRT2]] gene (most commonly) |
| | risks = | | | risks = Family history of similar movement disorders |
| | diagnosis = | | | diagnosis = Clinical evaluation, family history, genetic testing |
| | differential = | | | differential = Epilepsy, other paroxysmal dyskinesias, tic disorders |
| | prevention = | | | prevention = Avoiding movement triggers may reduce episodes |
| | treatment = | | | treatment = [[Anticonvulsants]] such as [[carbamazepine]] or [[oxcarbazepine]] |
| | medication = | | | medication = Carbamazepine, oxcarbazepine, phenytoin |
| | prognosis = | | | prognosis = Good with appropriate medication; episodes often decrease with age |
| | frequency = | | | frequency = Rare |
| | deaths = | | | deaths = Not typically life-threatening |
| }} | | }} |
| '''Paroxysmal kinesigenic choreoathetosis''' ('''PKC''') also called '''paroxysmal kinesigenic dyskinesia''' ('''PKD''') is a [[Hyperkinesia|hyperkinetic]] [[movement disorder]] characterized by attacks of involuntary movements, which are triggered by sudden voluntary movements. The number of attacks can increase during puberty and decrease in a person's 20s to 30s. Involuntary movements can take many forms such as ballism, [[Choreia|chorea]] or [[dystonia]] and usually only affect one side of the body or one limb in particular. This rare disorder only affects about 1 in 150,000 people,<ref name= khan>{{Cite journal | last1 = Khan | first1 = W. U. | last2 = Staios | first2 = G. | last3 = Rana | first3 = A. Q. | title = Paroxysmal kinesigenic dyskinesia in a mother and daughter | journal = Acta Neurologica Belgica | volume = 110 | issue = 2 | pages = 201–202 | year = 2010 | pmid = 20873453}}</ref> with PKD accounting for 86.8% of all the types of [[paroxysmal dyskinesia]]s,<ref name= analyzing>{{Cite journal | last1 = Zhou | first1 = J. Q. | last2 = Zhou | first2 = L. M. | last3 = Fang | first3 = Z. Y. | last4 = Wang | first4 = Q. | last5 = Chen | first5 = Z. Y. | last6 = Yang | first6 = L. B. | last7 = Chen | first7 = S. D. | last8 = Cai | first8 = X. D. | title = Analyzing clinical and electrophysiological characteristics of Paroxysmal Dyskinesia | journal = Journal of Research in Medical Sciences | volume = 16 | issue = 1 | pages = 110–114 | year = 2011 | pmid = 21448393 | pmc = 3063430}}</ref> and occurs more often in males than females. There are two types of PKD, primary and secondary. Primary PKD can be further broken down into familial and sporadic. Familial PKD, which means the individual has a family history of the disorder, is more common, but sporadic cases are also seen.<ref name= bruno>{{Cite journal | doi = 10.1212/01.WNL.0000147298.05983.50 | last1 = Bruno | first1 = M. K. | last2 = Hallett | first2 = M. | last3 = Gwinn-Hardy | first3 = K. | last4 = Sorensen | first4 = B. | last5 = Considine | first5 = E. | last6 = Tucker | first6 = S. | last7 = Lynch | first7 = D. R. | last8 = Mathews | first8 = K. D. | last9 = Swoboda | first9 = K. J. | last10 = Harris | first10 = J. | last11 = Soong | first11 = B. W. | last12 = Ashizawa | first12 = T. | last13 = Jankovic | first13 = J. | last14 = Renner | first14 = D. | last15 = Fu | first15 = Y. H. | last16 = Ptacek | first16 = L. J. | title = Clinical evaluation of idiopathic paroxysmal kinesigenic dyskinesia: New diagnostic criteria | journal = Neurology | volume = 63 | issue = 12 | pages = 2280–2287 | year = 2004 | pmid = 15623687}}</ref> Secondary PKD can be caused by many other medical conditions such as [[Multiple sclerosis|multiple sclerosis (MS)]], [[stroke]], [[pseudohypoparathyroidism]],<ref>{{Cite journal | last1 = Thomas | first1 = K. P. | last2 = Muthugovindan | first2 = D. | last3 = Singer | first3 = H. S. | doi = 10.1016/j.pediatrneurol.2010.03.012 | title = Paroxysmal Kinesigenic Dyskinesias and Pseudohypo-parathyroidism Type Ib | journal = Pediatric Neurology | volume = 43 | issue = 1 | pages = 61–64 | year = 2010 | pmid = 20682207| pmc = }}</ref> [[Hypocalcaemia|hypocalcemia]], [[hypoglycemia]], [[hyperglycemia]],<ref name= bruno /> [[central nervous system]] trauma, or [[peripheral nervous system]] trauma.<ref name= mehta/> PKD has also been linked with [[infantile convulsions and choreoathetosis]] (ICCA) syndrome, in which patients have [[Normal human body temperature|afebrile]] seizures during infancy ([[benign familial infantile epilepsy]]) and then develop paroxysmal choreoathetosis later in life.<ref name= weber>{{Cite journal | last1 = Weber | first1 = Y. G. | last2 = Lerche | first2 = H. | doi = 10.1007/s11910-009-0031-8 | title = Genetics of paroxysmal dyskinesias | journal = Current Neurology and Neuroscience Reports | volume = 9 | issue = 3 | pages = 206–211 | year = 2009 | pmid = 19348709| pmc = }}</ref> This phenomenon is actually quite common, with about 42% of individuals with PKD reporting a history of afebrile seizures as a child.<ref name= weber/> | | '''Paroxysmal kinesigenic choreoathetosis''' (PKC), also known as '''paroxysmal kinesigenic dyskinesia''' (PKD), is a rare [[neurological disorder]] characterized by sudden, involuntary movements triggered by voluntary movement. These episodes are typically brief, lasting seconds to minutes, and can include [[chorea]], [[athetosis]], or [[dystonia]]. |
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| ==Genetics == | | ==Presentation== |
| Paroxysmal kinesigenic dyskinesias are often inherited in an [[autosomal dominant]] fashion and several genes have now been identified where mutations can cause this disease. The genes typically code for proteins known to be involved in synaptic transmission, ion channels or ion transporters.<ref name="Papandreou">{{cite journal | vauthors = Papandreou A, Danti FR, Spaull R, Leuzzi V, Mctague A, Kurian MA | title = The expanding spectrum of movement disorders in genetic epilepsies | journal = Developmental Medicine and Child Neurology | volume = 62 | issue = 2 | pages = 178–191 | date = February 2020 | pmid = 31784983 | doi = 10.1111/dmcn.14407 }}</ref> The first gene to be identified was the ''[[PRRT2]]'' gene on chromosome 16, found in 2011 to be the cause of the disease in some patients.<ref name=gene>{{Cite journal | last1 = Chen | first1 = W. J. | last2 = Lin | first2 = Y. | last3 = Xiong | first3 = Z. Q. | last4 = Wei | first4 = W. | last5 = Ni | first5 = W. | last6 = Tan | first6 = G. H. | last7 = Guo | first7 = S. L. | last8 = He | first8 = J. | last9 = Chen | first9 = Y. F. | last10 = Zhang | doi = 10.1038/ng.1008 | first10 = Q. J. | last11 = Li | first11 = H. F. | last12 = Lin | first12 = Y. | last13 = Murong | first13 = S. X. | last14 = Xu | first14 = J. | last15 = Wang | first15 = N. | last16 = Wu | first16 = Z. Y. | title = Exome sequencing identifies truncating mutations in PRRT2 that cause paroxysmal kinesigenic dyskinesia | journal = Nature Genetics | volume = 43 | issue = 12 | pages = 1252–1255 | year = 2011 | pmid = 22101681 | pmc = }}</ref> The mutations in this gene included a [[nonsense mutation]] identified in the [[genome]] of one family and an [[Insertion (genetics)|insertion mutation]] identified in the genome of another family.<ref name=wang>{{Cite journal | last1 = Wang | first1 = J. -L. | last2 = Cao | first2 = L. | last3 = Li | first3 = X. -H. | last4 = Hu | first4 = Z. -M. | last5 = Li | first5 = J. -D. | last6 = Zhang | first6 = J. -G. | last7 = Liang | first7 = Y. | last8 = San-a | last9 = Li | first9 = N. | last10 = Chen | doi = 10.1093/brain/awr289 | first10 = S. -Q. | last11 = Guo | first11 = J. -F. | last12 = Jiang | first12 = H. | last13 = Shen | first13 = L. | last14 = Zheng | first14 = L. | last15 = Mao | first15 = X. | last16 = Yan | first16 = W. -Q. | last17 = Zhou | first17 = Y. | last18 = Shi | first18 = Y. -T. | last19 = Ai | first19 = S. -X. | last20 = Dai | first20 = M. -Z. | last21 = Zhang | first21 = P. | last22 = Xia | first22 = K. | last23 = Chen | first23 = S. -D. | last24 = Tang | first24 = B. -S. | title = Identification of PRRT2 as the causative gene of paroxysmal kinesigenic dyskinesias | journal = Brain | volume = 134 | issue = 12 | pages = 3493–3501 | year = 2011 | pmid = 22120146 | pmc =3235563 }}</ref> Researchers found ''PRRT2'' mutations in 10 of 29 sporadic cases affected with PKD, thus suggests ''PRRT2'' is the gene mutated in a subset of PKD and PKD is genetically heterogeneous.<ref>Li J, Zhu X, Wang X et al. J Med Genet. 2012 Feb;49(2):76-8. Epub 2011 Nov 30. Targeted genomic sequencing identifies PRRT2 mutations as a cause of paroxysmal kinesigenic choreoathetosis.</ref> Later reports have identified the genes ''[[SCN8A]]'', ''[[CHRNA4]]'', and ''[[SLC16A2]]'' as further causes of PKD.<ref name="Papandreou" />
| | PKC is marked by episodes of abnormal movements that are often precipitated by sudden voluntary movements, such as standing up or beginning to walk. The episodes can vary in frequency and severity, and they typically last less than a minute. Patients may experience multiple episodes per day. The movements can include: |
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| | * '''Chorea''': Rapid, irregular, and unpredictable movements. |
| | * '''Athetosis''': Slow, writhing movements, particularly of the hands and feet. |
| | * '''Dystonia''': Sustained muscle contractions causing twisting and repetitive movements or abnormal postures. |
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| ==Pathophysiology== | | ==Pathophysiology== |
| The [[pathophysiology]] of PKD is not fully explained. A few mechanisms have been suggested thus far: | | The exact cause of PKC is not fully understood, but it is believed to involve dysfunction in the [[basal ganglia]], a group of nuclei in the brain associated with movement control. Genetic factors play a significant role, with several cases linked to mutations in the [[PRRT2]] gene. This gene is involved in synaptic function and neuronal communication. |
| #[[gamma-Aminobutyric acid|GABA]] dysregulation
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| #Abnormal breakdown of [[dopamine]] in the [[basal ganglia]]
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| #Dysfunction of the [[substantia nigra]]<ref name = joo>{{Cite journal | last1 = Joo | first1 = E. Y. | last2 = Hong | first2 = S. B. | last3 = Tae | first3 = W. S. | last4 = Kim | first4 = J. H. | last5 = Han | first5 = S. J. | last6 = Seo | first6 = D. W. | last7 = Lee | first7 = K. H. | last8 = Kim | first8 = M. H. | last9 = Kim | first9 = S. | last10 = Lee | doi = 10.1007/s00259-005-1814-z | first10 = M. H. | last11 = Kim | first11 = B. T. | title = Perfusion abnormality of the caudate nucleus in patients with paroxysmal kinesigenic choreoathetosis | journal = European Journal of Nuclear Medicine and Molecular Imaging | volume = 32 | issue = 10 | pages = 1205–1209 | year = 2005 | pmid = 15948007| pmc = }}</ref>
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| #A form of epilepsy<ref name=analyzing />
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| Multiple methods are being used to study the potential brain abnormalities of individuals with PKD compared with “normal” individuals. These methods include [[Single-photon emission computed tomography|SPECT]] studies, [[Functional magnetic resonance imaging|fMRI]] studies, and [[diffusion tensor imaging]]. The main problem with many of the studies concerned with the pathophysiology of the disorder is the small sample size. Because the studies normally only include about 7-10 patients with PKD, the results cannot be generalized to the entire population of patients. However, the studies do bring up possibilities for further study.
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| ===SPECT studies===
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| In a study by Joo et al., the researchers performed interictal studies, meaning they scanned the patient's brain between attacks to find an underlying abnormality, rather than ictal scans, which look at the abnormalities that present themselves during an attack.<ref name= joo /> The researchers found interictally decreased cerebral blood flow in the [[Anatomical terms of location#Anterior and posterior|posterior]] parts of the [[Caudate nucleus|bilateral caudate nucleus]].<ref name= joo/> However, the literature does state that although this could be a cause of PKD, it could also be a result of PKD.<ref name= joo /> Another SPECT study showed an increase in the cerebral blood flow in the [[Thalamus|left posterior thalamus]] in a PKD patient during an attack.<ref name= shirane>{{Cite journal | last1 = Shirane | first1 = S. | title = Increased ictal perfusion of the thalamus in paroxysmal kinesigenic dyskinesia | doi = 10.1136/jnnp.71.3.408 | journal = Journal of Neurology, Neurosurgery & Psychiatry | volume = 71 | issue = 3 | pages = 408–410 | year = 2001 | pmid = 11511723| pmc =1737540 | last2 = Sasaki | first2 = M | last3 = Kogure | first3 = D | last4 = Matsuda | first4 = H | last5 = Hashimoto | first5 = T }}</ref> The researchers also subtracted the ictal from the postictal scans, and saw increased blood flow in the thalamus. They ultimately suggested that hyperactive blood flow in this area could be causing the pathophysiology of PKD. This study, however, was only performed on one patient, and would need to be replicated many more times in order to be generalized to the population of PKD patients. Other SPECT studies have been cited showing hyperactivity in the basal ganglia.<ref name= zhou1>{{Cite journal | last1 = Zhou | first1 = B. | last2 = Chen | first2 = Q. | last3 = Gong | first3 = Q. | last4 = Tang | first4 = H. | last5 = Zhou | first5 = D. | title = The thalamic ultrastructural abnormalities in paroxysmal kinesigenic choreoathetosis: A diffusion tensor imaging study | doi = 10.1007/s00415-009-5334-9 | journal = Journal of Neurology | volume = 257 | issue = 3 | pages = 405–409 | year = 2009 | pmid = 20012544| pmc = }}</ref>
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| ===fMRI studies===
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| In a study by Zhou et al.,<ref name=hyper>{{Cite journal | last1 = Zhou | first1 = B. | last2 = Chen | first2 = Q. | last3 = Zhang | first3 = Q. | last4 = Chen | first4 = L. | last5 = Gong | first5 = Q. | last6 = Shang | first6 = H. | last7 = Tang | first7 = H. | last8 = Zhou | first8 = D. | doi = 10.1002/mds.22967 | title = Hyperactive putamen in patients with paroxysmal kinesigenic choreoathetosis: A resting-state functional magnetic resonance imaging study | journal = Movement Disorders | volume = 25 | issue = 9 | pages = 1226–1231 | year = 2010 | pmid = 20629125| pmc = }}</ref> the researchers performed fMRI studies on PKD patients, and analyzed the differences between the [[Amplitude of low frequency fluctuations|amplitude low frequency fluctuations (ALFF)]] of the patients. They found that the [[Postcentral gyrus|left postcentral gyrus]] and the [[Putamen|bilateral putamen]] had increased ALFF in PKD patients.<ref name= hyper/> The researchers concluded that the hyperactivity in these regions suggested that there is a dysfunction in the basal ganglia-thalamo-cortical circuit in PKD. This circuit is part of the motor control circuit in the brain, making it a reasonable place for abnormality in a movement disorder, but again, researchers are still unsure of the role these differences they found play in the disease pathology.
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| ===Diffusion tensor imaging===
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| [[Diffusion tensor imaging]] (DTI) displays physical alterations in the brain that may not be seen on regular [[Magnetic resonance imaging|MRI]].<ref name= zhou1 /> In one study researchers found that some of the patients had abnormalities in their thalamus. However, this does not prove that all patients have abnormalities in their thalamus. Other cases are cited, including a patient who developed a similar paroxysmal dyskinesia after a thalamic [[infarction]],<ref name=zhou1 /> implicating that an abnormality in the thalamus of individuals could contribute to PKD. It is not fully known, however, what role a thalamic abnormality plays in the disease pathophysiology.
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| ==Diagnosis== | | ==Diagnosis== |
| Paroxysmal kinesigenic dyskinesia is diagnosed using a strict set of guidelines. These criteria were studied and confirmed by Bruno et al. in a study of 121 individuals with PKD.<ref name= bruno /> The age at onset is between 1 and 20 years old. The attacks of involuntary movements last less than one minute and have a known trigger, usually a sudden voluntary movement. For example, if a PKD patient stands up or begins walking after being sedentary for a period of time, or a person goes from a walk to a run, it can trigger an attack. Persons with PKD do not lose consciousness during attacks and have a full memory of the entire attack. Lastly, people with the disorder have a good response to medication and are usually prescribed [[anticonvulsant]]s. The study also found that patients with familial PKD exhibit symptoms that follow the diagnostic criteria closely, while sporadic PKD individuals may deviate slightly.<ref name= mehta/> Prior to criteria for diagnosis being set out, many patients with PKD were often diagnosed with some form of [[epilepsy]]. Many patients also experience an [[Aura (symptom)|aura]], similar to those experienced with epilepsy, preceding their attacks. Some patients describe it as a [[Paresthesia|tingling sensation]] in the affected limb or “butterflies in their stomach.” Some individuals also have precipitants, such as stress and anxiety, that make it more likely for attacks to occur.
| | Diagnosis of PKC is primarily clinical, based on the characteristic presentation of the disorder. A detailed patient history and neurological examination are essential. [[Magnetic resonance imaging]] (MRI) and other neuroimaging techniques are typically normal but may be used to rule out other conditions. Genetic testing can confirm mutations in the PRRT2 gene, supporting the diagnosis. |
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| The above diagnostic criteria also set PKD apart from the other paroxysmal dyskinesias, which include [[paroxysmal nonkinesigenic dyskinesia]] (PNKD) and [[Paroxysmal exercise-induced dystonia|paroxysmal exercise-induced dyskinesia]] (PED). While PKD attacks last less than one minute, PNKD attacks last a few minutes to a few hours, and as the name suggests, the attacks do not occur because of a sudden voluntary movement like PKD.<ref name= mehta>{{Cite journal | last1 = Mehta | first1 = S. H. | last2 = Morgan | first2 = J. C. | last3 = Sethi | first3 = K. D. | doi = 10.1007/s11940-009-0020-x | title = Paroxysmal dyskinesias | journal = Current Treatment Options in Neurology | volume = 11 | issue = 3 | pages = 170–178 | year = 2009 | pmid = 19364451| pmc = }}</ref> Additionally, PKD can almost always be managed with drug therapy, while PNKD is not as responsive to anticonvulsants. PED, on the other hand, separates itself from PKD in that it is caused by prolonged exercise. Attacks from PED will cease soon after exercise is stopped.<ref name= mehta />
| | ==Management== |
| ==Treatment==
| | Management of PKC involves both pharmacological and non-pharmacological approaches. The primary treatment is the use of [[anticonvulsants]], such as [[carbamazepine]] or [[phenytoin]], which can significantly reduce the frequency and severity of episodes. Lifestyle modifications, including avoiding known triggers, can also be beneficial. |
| Almost all patients respond positively to antiepileptic (anticonvulsant) drugs. One of the drugs most often mentioned in the literature is carbamazepine, and is the most widely used drug for treating PKD. Other anticonvulsants like valproic acid, phenytoin and clonazepam are common alternatives. Other categories of drugs have also been used, such as [[dopamine]] affecting drugs like [[L-DOPA|Levodopa]] or [[Tetrabenazine]].<ref name= mehta /> Individuals with the disorder can also modify their behavior to lessen their attacks without the influence of drug therapy. For example, decreasing stress to avoid precipitants can help patients decrease the number of attacks. In addition, avoiding any sudden movements can also prevent an attack. In order to prevent an attack, some individuals use their auras as a warning, while others purposefully perform slow gestures or movements prior to a triggering movement.<ref name= analyzing /> Many, if not most, individuals end up growing out of the attacks with age, even without medicinal therapy, but some patients will go back to having attacks after a period of remission.<ref name= bruno /> In regards to secondary PKD, treatment of the primary condition can lessen the PKD attacks in those individuals.<ref name= mehta />
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| ==History ==
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| A movement order similar to PKD first mentioned in research literature in 1940 by Mount and Reback. They described a disorder consisting of attacks of involuntary movements but unlike PKD, the attacks lasted minutes to hours and were found to be caused by alcohol or caffeine intake.<ref name= bhatia/> They named it paroxysmal dystonic choreoathetosis. Kertesz later described another new movement disorder in 1967. He described a disorder that was induced by sudden movements, and responded to [[anticonvulsant]]s, naming it paroxysmal kinesigenic choreoathetosis. Finally in a review in 1995 Demirkiran and [[Joseph Jankovic|Jankovic]] stated the disease should be called paroxysmal kinesigenic dyskinesia instead, pointing out that the attacks could manifest as any form of dyskinesia, not just choreoathetosis.<ref name=bhatia>{{Cite journal | last1 = Bhatia | first1 = K. P. | title = Paroxysmal dyskinesias | doi = 10.1002/mds.23765 | journal = Movement Disorders | volume = 26 | issue = 6 | pages = 1157–1165 | year = 2011 | pmid = 21626559| pmc = }}</ref>
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| ==See also== | | ==Prognosis== |
| * [[Paroxysmal dyskinesia]]
| | The prognosis for individuals with PKC is generally favorable, especially with appropriate treatment. Many patients experience a significant reduction in symptoms with medication. The disorder does not typically progress, and life expectancy is normal. |
| * [[Paroxysmal nonkinesogenic dyskinesia]]
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| * [[Paroxysmal exercise-induced dystonia]]
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| ==References== | | ==Related pages== |
| {{Reflist}}
| | * [[Chorea]] |
| | | * [[Athetosis]] |
| == External links ==
| | * [[Dystonia]] |
| {{Medical resources
| | * [[Basal ganglia]] |
| | ICD10 = G24.8
| | * [[PRRT2]] |
| | ICD9 = <!--{{ICD9|xxx}}-->
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| | ICDO =
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| | OMIM = 128200
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| | DiseasesDB =
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| | MedlinePlus =
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| | eMedicineSubj =
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| | eMedicineTopic =
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| | MeSH =
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| | GeneReviewsNBK =
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| | GeneReviewsName =
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| | Orphanet = 98809
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| }}
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| *[https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=pknd GeneReviews/NIH/NCBI/UW entry on Familial Paroxysmal Kinesigenic Dyskinesia] | |
| * [https://www.ncbi.nlm.nih.gov/omim/128200,611031 OMIM entries on Familial Paroxysmal Kinesigenic Dyskinesia] | |
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| {{DEFAULTSORT:Paroxysmal Kinesogenic Choreoathetosis}}
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| [[Category:Neurological disorders]] | | [[Category:Neurological disorders]] |
| {{dictionary-stub1}}
| | [[Category:Movement disorders]] |
A neurological disorder characterized by sudden involuntary movements
| Paroxysmal kinesigenic choreoathetosis
|
|
| Synonyms
|
Familial PKD, Paroxysmal kinesigenic dyskinesia
|
| Pronounce
|
|
| Field
|
Neurology, Genetics
|
| Symptoms
|
Sudden, brief episodes of chorea, athetosis, or dystonia triggered by voluntary movement
|
| Complications
|
Impaired mobility during attacks, anxiety related to attacks
|
| Onset
|
Childhood or adolescence
|
| Duration
|
Chronic, lifelong condition
|
| Types
|
Primary (familial) or secondary to other disorders
|
| Causes
|
Mutations in the PRRT2 gene (most commonly)
|
| Risks
|
Family history of similar movement disorders
|
| Diagnosis
|
Clinical evaluation, family history, genetic testing
|
| Differential diagnosis
|
Epilepsy, other paroxysmal dyskinesias, tic disorders
|
| Prevention
|
Avoiding movement triggers may reduce episodes
|
| Treatment
|
Anticonvulsants such as carbamazepine or oxcarbazepine
|
| Medication
|
Carbamazepine, oxcarbazepine, phenytoin
|
| Prognosis
|
Good with appropriate medication; episodes often decrease with age
|
| Frequency
|
Rare
|
| Deaths
|
Not typically life-threatening
|
Paroxysmal kinesigenic choreoathetosis (PKC), also known as paroxysmal kinesigenic dyskinesia (PKD), is a rare neurological disorder characterized by sudden, involuntary movements triggered by voluntary movement. These episodes are typically brief, lasting seconds to minutes, and can include chorea, athetosis, or dystonia.
Presentation[edit]
PKC is marked by episodes of abnormal movements that are often precipitated by sudden voluntary movements, such as standing up or beginning to walk. The episodes can vary in frequency and severity, and they typically last less than a minute. Patients may experience multiple episodes per day. The movements can include:
- Chorea: Rapid, irregular, and unpredictable movements.
- Athetosis: Slow, writhing movements, particularly of the hands and feet.
- Dystonia: Sustained muscle contractions causing twisting and repetitive movements or abnormal postures.
Pathophysiology[edit]
The exact cause of PKC is not fully understood, but it is believed to involve dysfunction in the basal ganglia, a group of nuclei in the brain associated with movement control. Genetic factors play a significant role, with several cases linked to mutations in the PRRT2 gene. This gene is involved in synaptic function and neuronal communication.
Diagnosis[edit]
Diagnosis of PKC is primarily clinical, based on the characteristic presentation of the disorder. A detailed patient history and neurological examination are essential. Magnetic resonance imaging (MRI) and other neuroimaging techniques are typically normal but may be used to rule out other conditions. Genetic testing can confirm mutations in the PRRT2 gene, supporting the diagnosis.
Management[edit]
Management of PKC involves both pharmacological and non-pharmacological approaches. The primary treatment is the use of anticonvulsants, such as carbamazepine or phenytoin, which can significantly reduce the frequency and severity of episodes. Lifestyle modifications, including avoiding known triggers, can also be beneficial.
Prognosis[edit]
The prognosis for individuals with PKC is generally favorable, especially with appropriate treatment. Many patients experience a significant reduction in symptoms with medication. The disorder does not typically progress, and life expectancy is normal.
Related pages[edit]
