Childhood paroxysmal kinesigenic dyskinesia: report of seven cases with onset at an early age

We report on seven children who developed abnormal involuntary movements as early as 1.5 years after unremarkable term births. The paroxysmal episodes of abnormal movements were typically precipitated by sudden, voluntary movements, or a startle. The clinical features in each case were consistent with the diagnosis of paroxysmal kinesigenic dyskinesia (PKD). The episodes of abnormal movements are described. EEG was obtained in all cases, and video/electroencephalography (VEEG) monitoring was performed to exclude the possibility of epilepsy in six patients. VEEG studies revealed multiple events consistent with PKD; no ictal epileptiform discharges were recorded. The apparent benign nature of the disorder, as well as treatment options with antiepileptic drugs, was discussed with the parents, and most chose no pharmacologic treatment. We discuss clinical characteristics of PKD, treatment with anticonvulsant therapy, and recent insights into its possible pathophysiology.     

The Pathogenesis of Paroxysmal Kinesigenic Dyskinesia: Current Concepts

Paroxysmal kinesigenic dyskinesia (PKD) is a movement disorder characterized by recurrent and transient episodes of involuntary movements, including dystonia, chorea, ballism, or a combination of these, which are typically triggered by sudden voluntary movement. Disturbance of the basal ganglia-thalamo-cortical circuit has long been considered the cause of involuntary movements. Impairment of the gating function of the basal ganglia can cause an aberrant output toward the thalamus, which in turn leads to excessive activation of the cerebral cortex. Structural and functional abnormalities in the basal ganglia, thalamus, and cortex and abnormal connections between these brain regions have been found in patients with PKD. Recent studies have highlighted the role of the cerebellum in PKD. Insufficient suppression from the cerebellar cortex to the deep cerebellar nuclei could lead to overexcitation of the thalamocortical pathway. Therefore, this literature review aims to provide a comprehensive overview of the current research progress to explore the neural circuits and pathogenesis of PKD and promote further understanding and outlook on the pathophysiological mechanism of movement disorders. © 2023 International Parkinson and Movement Disorder Society.     

Paroxysmal kinesigenic dyskinesia: cortical or non-cortical origin

Paroxysmal kinesigenic dyskinesia (PKD) is characterized by involuntary dystonia and/or chorea triggered by a sudden movement. Cases are usually familial with an autosomal dominant inheritance. Hypotheses regarding the pathogenesis of PKD focus on the controversy whether PKD has a cortical or non-cortical origin. A combined familial trait of PKD and benign familial infantile seizures has been reported as the infantile convulsions and paroxysmal choreoathetosis (ICCA) syndrome. Here, we report a family diagnosed with ICCA syndrome with an Arg217STOP mutation. The index patient showed interictal EEG focal changes compatible with paroxysmal dystonic movements of his contralateral leg. This might support cortical involvement in PKD.     

A locus for paroxysmal kinesigenic dyskinesia maps to human chromosome 16

OBJECTIVE: To use genetic linkage analysis to localize a gene for paroxysmal kinesigenic dyskinesia (PKD) in a three generation African-American kindred. BACKGROUND: PKD is a rare autosomal dominant disorder characterized by episodic choreiform or dystonic movements that are brought on or exacerbated by voluntary movement. There are individuals with the clinical features of PKD but with no family history of the disease, but whether these sporadic cases represent spontaneous mutations of PKD or have a distinct condition is unknown. METHODS: A genome-wide linkage scan of polymorphic microsatellites at 25 cM resolution was performed to localize a gene for PKD in one African-American kindred. Pairwise multipoint linkage analyses were performed at different penetrance estimates. RESULTS: Evidence for linkage of the kinesigenic form of paroxysmal dyskinesia to chromosome 16 was obtained. A maximum lod score of 4.40 at theta = 0 was obtained with D16S419. Critical recombinants place the PKD gene between D16S3100 and D16S771. CONCLUSIONS: A paroxysmal kinesigenic dyskinesia (PKD) locus lies within an 18 cM interval on 16p11.2-q11.2, between D16S3100 and D16S771. A gene for infantile convulsions with paroxysmal choreoathetosis has also been mapped to this region. These two regions overlap by approximately 6 cM. These two diseases could be caused by different mutations in the same gene or two distinct genes may lie within this region.     

Association of Parry-Romberg syndrome and paroxymal kinesigenic dyskinesia

Introduction

Parry-Romberg syndrome is a rare entity of unknown etiology, characterized by hemifacial or hemibody atrophy affecting subcutaneous tissues. Its main clinical manifestations are neurological, ocular and dermatological. Paroxysmal kinesigenic dyskinesia (PKD) is characterized by brief episodes of choreic/dystonic movements triggered by sudden movements and improved by antiepileptic drugs particularly carbamazepine. It can be sporadic or familial with an autosomal dominant inheritance. Little is known about the pathophysiology of PKD, although a channelopathy is thought likely. The association of these two diseases is rare.

Case report

Over three years, a 42-year-old patient progressively developed left hemiatrophy. Since age 14, he presented paroxysmal dystonic disorders of the limbs triggered by sudden movements and controlled by carbamazepine. The diagnosis of PKD associated with Parry-Romberg syndrome was established. Investigations revealed immunologic and diffuse electrophysiological abnormalities (EEG and EMG).

Conclusion

PKD associated with Parry-Romberg syndrome is very rare but does not appear to be fortuitous. It suggests a common mechanism via an underlying channelopathy or dysimmune disorder.     

发作性肌张力障碍38例临床分析

目的提高对发作性肌张力障碍临床特征的认识,以引起临床重视,减少误诊。方法对发作性肌张力障碍的类型、临床特征、电生理表现、治疗转归以及发病机制等进行总结、分析。结果发作性肌张力障碍临床可分三型,不同类型有不同的诱因;患者多为青少年男性,发作表现为舞蹈样手足徐动、躯体扭转及扮鬼脸等肌张力障碍,形式多样,发作时无意识丧失;发作期及发作间期脑电图均无特异性异常,其余多项辅助检查也无异常。结论发作性肌张力障碍是一种不同于癫癎的独立的疾病。     

Paroxysmal kinesigenic dyskinesia and generalized seizures: clinical and genetic analysis in a Spanish pedigree

Familial paroxysmal kinesigenic dyskinesia (PKD) is a rare disorder featuring brief, dystonic or choreoathetotic attacks, typically triggered by sudden movements. Symptoms usually start in mid-childhood, although in several pedigrees infantile convulsions have been reported as the presenting sign. Previous linkage studies have identified two PKD loci on 16 p12.1-q21. We report here the clinical features of a Spanish kindred with autosomal dominant PKD, in which haplotype data are compatible with linkage to the pericentromeric region of chromosome 16 and exclude linkage to the locus for Paroxysmal Non Kinesigenic Dyskinesia (PNKD) on chromosome 2 q35. In this family, the conservative candidate region for the disease lies between markers D16S3145 and GATA140E03 on 16 p12.1-q21 and partially overlaps with both the Paroxysmal Kinesigenic Dyskinesia - Infantile Convulsions (PKD-IC) critical interval and the Episodic Kinesigenic Dyskinesia 2 (EKD2) locus. Unusual findings in our pedigree were early infantile onset of the dyskinesias in one patient and generalized seizures as adults in two, adding to previous observations of phenotypic overlap between epileptic and non-epileptic paroxysmal disorders. Further clinical and genetic studies are needed to elucidate whether PKD and PKD-IC are allelic disorders with age-dependent phenotypic expression.     

中国发作性运动诱发性运动障碍患者社会心理学调查研究

研究背景发作性运动诱发性运动障碍是一组由突然动作诱发的非随意性运动障碍性疾病,表现为反复发作的短暂性肌张力障碍或舞蹈样动作。本研究旨在调查中国发作性运动诱发性运动障碍患者社会心理学特点,并探讨发作性运动诱发性运动障碍及其相关影响因素之间的关系。方法采用自行设计的发作性运动诱发性运动障碍调查问卷对188例发作性运动诱发性运动障碍患者进行调查,包括症状自测量表(SCL-90)和世界卫生组织生活质量量表(WHOQoL-100)两部分,分别评价精神心理症状和生活质量,Pearson相关分析和偏相关分析以及多重回归分析评价发作性运动诱发性运动障碍生活质量及其相关影响因素之间的关系。结果 188例患者最终回收有效问卷120份,与中国人群常模数据相比,发作性运动诱发性运动障碍患者SCL-90量表中文版之躯体化(P=0.000)、强迫症状(P=0.000)、人际关系敏感(P=0.000)、抑郁症状(P=0.000)、焦虑症状(P=0.000)、敌对(P=0.000)、恐怖(P=0.000)、偏执(P=0.000)和精神病性症状(P=0.000)以及总症状指数均增加,WHOQoL-100量表中文版之总体生活质量(P=0.000)和生理(P=0.000)、心理(P=0.000)、独立性(P=0.000)、社会关系(P=0.000)评分均降低。Pearson相关分析和偏相关分析显示,发作类型之复杂型发作性运动诱发性运动障碍和自愈倾向与发作性运动诱发性运动障碍生活质量呈正相关(P=0.016,0.000),躯体化、强迫症状、人际关系敏感、抑郁症状、焦虑症状、敌对、恐怖、偏执、精神病性症状等精神心理症状与发作性运动诱发性运动障碍生活质量呈负相关(均P=0.000)。多重回归分析显示,自愈倾向(P=0.024)和抑郁症状(P=0.000)与发作性运动诱发性运动障碍生活质量显著相关,其影响程度依次为自愈倾向(R~2=0.423)和抑郁症状(R~2=0.398)。结论发作性运动诱发性运动障碍患者普遍存在精神心理负担,且在生理、心理、独立性和社会关系方面生活质量较差。临床医师应对发作性运动诱发性运动障碍患者可能存在的精神心理症状进行及时评价和必要心理干预,尤其应注意抑郁症状评分较高且无自愈倾向的患者。     

Secondary paroxysmal dyskinesias.

Paroxysmal dyskinesias (PxDs) are involuntary, episodic movements that include paroxysmal kinesigenic (PKD), paroxysmal nonkinesigenic (PNKD), and paroxysmal hypnogenic (PHD) varieties. Although most PxDs are primary (idiopathic or genetic), we found 17 of our 76 patients with PxD (22%) to have an identifiable cause for their PxD (10 men; mean age, 41.4 years). Causes included peripheral trauma (in three patients), vascular lesions (in four), central trauma (in four), kernicterus (in two), multiple sclerosis (in one), cytomegalovirus encephalitis (in one), meningovascular syphilis (in one), and migraine (in one). The latency from insult to symptom onset ranged from days (trauma) to 18 years (kernicterus), with a mean of 3 years. Nine patients had PNKD, two had PKD, five had mixed PKD/PNKD, and one had PHD. Hemidystonia was the most common expression of the paroxysmal movement disorder, present in 11 patients. Both of the patients with PKD had symptom durations of <5 minutes. Symptom duration ranged from 10 seconds to 15 days for PNKD and from 5 minutes to 45 minutes for mixed PKD/PNKD. There were no uniformly effective therapies, but anticonvulsant drugs, clonazepam, and botulinum toxin injections were the most beneficial. Awareness of the variable phenomenology and the spectrum of causes associated with secondary PxD will allow for more timely diagnosis and early intervention.     

Moyamoya-induced paroxysmal dyskinesia.

Moyamoya disease (MMD) is an uncommon intracranial vasculopathy that typically presents with ischemic or hemorrhagic stroke. Persistent choreoathetosis has been identified as a rare early manifestation of MMD. We present 2 patients with paroxysmal dyskinesia as the initial symptom of MMD, one resembling paroxysmal kinesigenic dyskinesia (PKD) and the other paroxysmal non-kinesigenic dyskinesia (PNKD). We also review the cases of moyamoya-induced chorea reported previously, none of which resembled PKD or PNKD. We hypothesize that both hormonal and ischemic factors may be implicated in the pathogenesis of these abnormal involuntary movements. These cases suggest that MMD should be included in the differential diagnosis of PKD and PNKD.     

12例发作性运动诱发性肌张力障碍的临床、脑电图特点及文献复习

目的观察发作性运动诱发性肌张力障碍(PKD)的临床表现、脑电图特征,提高对本病的认识及选择有效的治疗药物。方法回顾性分析12例PKD患者的临床资料、脑电及影像学改变,并结合文献进行总结分析。结果临床症状表现为发作性运动诱发性手足扭转、肢体僵直、舞蹈手足徐动征等,有明确的运动诱发因素,同步脑电记录无异常,正确选择抗癫痫药物可有效控制其发作。结论 PKD是一种少见的运动障碍疾病,应与癫痫、假性发作、TIA、部分性发作等相鉴别。对抗癫痫药物敏感,早期诊断早期治疗预后较好。     

Genetic and phenotypic heterogeneity in sporadic and familial forms of paroxysmal dyskinesia

Paroxysmal dyskinesia (PxD) is a group of movement disorders characterized by recurrent episodes of involuntary movements. Familial paroxysmal kinesigenic dyskinesia (PKD) is caused by PRRT2 mutations, but a distinct etiology has been suggested for sporadic PKD. Here we describe a cohort of patients collected from our movement disorders outpatient clinic in the period 1996–2011. Fifteen patients with sporadic PxD and 23 subjects from three pedigrees with familial PKD were screened for mutations in candidate genes. PRRT2 mutations co-segregated with PKD in two families and occurred in two sporadic cases of PKD. No mutations were detected in patients with non-kinesigenic or exertion-induced dyskinesia, and none in other candidate genes including PNKD1 (MR-1) and SLC2A1 (GLUT1). Thus, PRRT2 mutations also cause sporadic PKD as might be expected given the variable expressivity and reduced penetrance observed in familial PKD. Further genetic heterogeneity is suggested by the absence of candidate gene mutations in both sporadic and familial PKD suggesting a contribution of other genes or non-coding regions.     

Paroxysmal kinesigenic dyskinesias

The paroxysmal dyskinesias (PxDs) are involuntary, intermittent movement disorders manifested by dystonia, chorea, athetosis, ballismus or any combination of these hyperkinetic disorders. Paroxysmal kinesigenic dyskinesia (PKD), one of the four main types of PxD, involves sudden attacks of dyskinesias induced by voluntary movements. PKD most commonly occurs sporadically or as an autosomal-dominant familial trait with variable penetrance. Many causes of secondary PKD are being recognized. The exact pathophysiology of the PxDs awaits further elucidation, although basal ganglia dysfunction appears to play a major role. Although the precise gene remains unknown, genetic linkage studies have isolated loci on chromosome 16, which colocalizes with the locus for familial infantile convulsions and paroxysmal choreoathetosis in some studies. The episodic nature of PKD and its relationship with other episodic diseases, such as epilepsy, migraine, and episodic ataxia, suggests channelopathy as a possible underlying etiology. PKD may remit spontaneously, but it also responds well to anticonvulsants as well as some other agents.     

Paroxysmal kinesigenic dyskinesia: a channelopathy? Study of 19 cases

INTRODUCTION: Paroxysmal kinesigenic dyskinesia (PKD) is characterized by brief episodes of dystonia and choreoathetosis triggered by sudden voluntary movements. Disease onset is seen in the first or second decade. The attacks typically last less than one minute. Three autosomal dominant PKD loci are identified: EKD1, EKD2 and EKD3. EKD1 has an overlap with the locus of the "Infantile Convulsion and Choreoathetosis (ICCA) syndrome". The favorable natural history, the episodic nature of the symptoms and their sensitivity to anticonvulsant therapy suggest channelopathy as a mechanism of PKD. PATIENTS AND METHODS: We reviewed the clinical features, the family history, the treatment response, the evolution and the technical investigations in 19 affected individuals. RESULTS: All cases were idiopathic. Ten patients had a positive familial history. Three patients suffered from ICCA syndrome. Some atypical features were seen, such as the association of kinesigenic and nonkinesigenic attacks and the presence of migraine, ataxia, seizures and myoclonus. Acetazolamide responsiveness was seen in two patients. CONCLUSION: The coexistence of PKD and nonkinesigenic dyskinesia in several patients confirms the earlier described presence of intermediary forms, nonrepresented in the current classification of paroxysmal dyskinesias. Our study results suggest channel dysfunction and basal ganglia involvement in the pathophysiology of PKD.     

Clinical features of paroxysmal kinesigenic dyskinesia: Report of 24 cases

Paroxysmal kinesigenic dyskinesia (PKD) is the most common type of paroxysmal dyskinesia and is characterized by involuntary, intermittent movements induced by sudden movements. Here, we describe 24 patients with PKD, whose clinical data were analyzed. The attacks of involuntary movements were all short lasting, and could involve extremities, trunk, neck, or face without alteration of consciousness. The motor function was normal between attacks, and in some cases, attacks could be evoked during examination. Most patients had normal electroencephalogram (EEG) and neuroimaging results, but 2 cases had abnormal EEGs, and another 2 cases had bilateral calcification of basal ganglion on brain computed tomography (CT) scans. Previous history of misdiagnosis was a predominant feature, while treatments based on misdiagnosis sometimes did lead to improvement. Here, we discuss the clinical characteristics, especially the abnormalities of investigations and misdiagnosis, and recent insights into the pathophysiology of PKD.     

家族性发作性运动诱发性运动障碍三个家系的临床及遗传学特点

目的探讨家族性发作性运动诱发性运动障碍（paroxysmal kinesigenic dyskinesia，PKD）的临床及遗传学特点，提高临床医师对该病的认识。方法总结分析3个汉族家族性PKD家系患者的临床资料，并进行详细的家系调查。结果3个家系共有患者25例，其中男性16例，女性9例。起病年龄1～10岁，发作由运动诱发，发作时意识清楚，发作持续时间在30s以内。查体未见异常，无明显智能障碍。发作次数10～50次／d，随年龄增长发作次数减少，卡马西平可完全缓解症状。家系遗传方式均符合常染色体显性遗传模式。家系中男性患者的临床表现比女性严重，未经治疗时，女性患者症状自然缓解的年龄比男性患者早。结论家族性PKD的主要遗传方式为常染色体显性遗传，在临床及遗传上可能存在异质性。男性患者临床表现比女性严重，可能与不同种族的遗传异质性有关。女性患者比男性症状轻，自然缓解年龄早，可能导致多数女性患者不完全外显，使得女性发病相对较少。     

Mutation analysis of the sodium/hydrogen exchanger gene (NHE5) in familial paroxysmal kinesigenic dyskinesia

Summary. Familial Paroxysmal Kinesigenic Dyskinesia (PKD) is an autosomal dominant condition characterized by attacks of dystonia or chorea triggered by sudden movements. Recently two separate loci for PKD, Episodic Kinesigenic Dyskinesia 1 (EKD1) and Episodic Kinesigenic Dyskinesia 2 (EKD2), have been mapped to chromosome 16 but the causative genes have not been identified. The Na⁺/H⁺ exchanger gene (NHE5) involved in regulating intracellular pH lies in the EKD2 region. The coding region of the NHE5 gene in familial PKD was sequenced. We did not identify any mutations in the exons, intron/exon boundaries or the 5′ and 3′UTR. This excludes mutations in the coding region of the NHE5 gene as a cause for familial PKD, but does not rule out a possible role of sequence variants in introns or regulatory regions. Received March 16, 2002; accepted March 22, 2002 Published online June 28, 2002     

Extended surround inhibition in idiopathic paroxysmal kinesigenic dyskinesia

ObjectiveParoxysmal kinesigenic dyskinesia (PKD) is characterized by recurrent attacks of dyskinesia, in which movement of one body part produces involuntary movements of other body parts. Surround inhibition (SI), a mechanism for suppression of unwanted movements, could be deficient in these patients. To test this idea, we performed a transcranial magnetic stimulation (TMS) study in drug-naive patients with PKD.MethodsTMS was set to be triggered by self-initiated flexion of the index finger at different intervals. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest. Normalized MEP amplitudes of the patients’ self-triggered TMS sessions at different intervals were compared to those of the controls.ResultsDuring index finger flexion, MEP amplitudes from the little finger muscle were unchanged in both the patients and normal subjects, however, post-movement MEP enhancement observed in the normal subjects was absent in patients with PKD. These results suggest that the functional operation of SI is itself preserved, but that post-movement excitation of surrounding muscles is deficient in PKD.ConclusionsThis finding may represent that the operation of SI is extended to the post-movement period, perhaps as a compensatory mechanism for preventing unwanted movement in surrounding muscles.SignificanceWhile many types of impaired inhibition have been described previously in PKD, this is the first possible example of increased inhibition.