Response to levodopa treatment in dopa-responsive dystonia

BACKGROUND: Dopa-responsive dystonia (DRD) is similar to Parkinson disease in that both disorders have impaired dopamine synthesis and respond to levodopa treatment. Dopa-responsive dystonia differs in that dopamine storage is intact in contrast to Parkinson disease in which it is markedly reduced. OBJECTIVE: To examine the short- and long-duration responses to levodopa dosing in subjects with DRD. METHODS: The response to brief infusions of levodopa was examined in 4 subjects with DRD and the effects of withdrawal of levodopa for 3 to 7 days studied in the 3 subjects receiving long-term levodopa therapy. Motor function was measured with tapping speed, Unified Parkinson's Disease Rating Scale motor score, and global dystonia score. RESULTS: The short-duration response to levodopa dosing seems to develop more slowly and persists longer in subjects with DRD than in subjects with Parkinson disease. Withdrawal of levodopa leads to a gradual decline in tapping speed and reemergence of dystonia over several days, similar to the rate of decay of motor function in Parkinson disease. The short- and long-duration responses were not clearly differentiated in DRD. CONCLUSIONS: This pilot study suggests that retained dopamine storage in DRD may prolong the short-duration response and blur the distinction of the short- and long-duration responses. The decline in motor function in DRD on withdrawal of long-term levodopa therapy resembles that in Parkinson disease, suggesting that a long-duration response, if it exists in DRD, is unrelated to dopamine storage.     

成年人的多巴反应性肌张力失常

目的 加强对多巴反应性肌张力失常的认识和重视。方法 回顾近2年我们诊治的3例成年人DRD患者之临床表现、辅助检查与治疗。结果 3例均为女性,无家族史。发病年龄14～29岁,平均20±7.94岁,平均误诊时间29.33±15.95年。表现为缓慢起病,四肢发僵,活动困难或伴有肢体震颤,足趾屈曲、内翻畸形;症状呈晨轻暮重。查体发现四肢肌张力强直性或齿轮样增高,双下肢腱反射活跃至亢进,1例病理征可疑阳性和脊柱前屈。辅助检查:血清学检查、CSF、头颅CT或MRI和神经电生理检查均正常。用小剂量复方左旋多巴有显著改善,平均剂量为98.21±49.17mg/d,使用最长者已达14年,无需增加剂量。结论 本病为少见的运动障碍疾病,在诊断中应与帕金森病鉴別。小剂量复方左旋多巴有显著、持久的疗效,早期应用安坦、金刚烷胺也有效。     

The metabolic pathology of dopa-responsive dystonia

We used [(18)F]-fluorodeoxyglucose and positron emission tomography to determine a discrete cerebral pattern of abnormal glucose utilization in dopa-responsive dystonia. Network analysis demonstrated that dopa-responsive dystonia is associated with a specific pattern of regional metabolic covariation, characterized by increases in the dorsal midbrain, cerebellum, and supplementary motor area, as well as reductions in motor and lateral premotor cortex and in the basal ganglia. This pattern was not expressed in mutation carriers for primary torsion dystonia. Dopa-responsive dystonia has a unique metabolic architecture that differs from other inherited forms of dystonia.     

Familial dopa-responsive cervical dystonia

The authors present four cases from two unrelated families with young-onset predominant cervical dystonia with a dramatic sustained response to levodopa. Onset age was 12 years (range 9 to 15). Additional symptoms included postural hand tremor and laryngeal dystonia. Genetic testing for GTP cyclohydrolase I, tyrosine hydroxylase, and sepiapterin reductase was negative. These cases may represent new forms of dopa-responsive dystonia. Levodopa is advisable in all patients with young-onset cervical dystonia.     

Misdiagnoses in children with dopa-responsive dystonia

Dystonia is a state of continuous contraction of groups of agonist and antagonist muscles resulting in a sustained abnormal posture. Dopa-responsive dystonia was first described in 1976 by Segawa. Patients typically have diurnal variation of their symptoms with worsening at the end of the day and a dramatic response to low-dose L-dopa. This report presents five consecutive children with dopa-responsive dystonia who were misdiagnosed initially as spastic diplegic cerebral palsy, intractable epilepsy, hereditary spastic paraplegia, or a neurodegenerative disorder. There were two males and three females aged 3-13 years (mean 8.6 years). They were monitored for up to 2 years (mean 14.8 months). One had focal, one axial, one segmental, and two generalized dystonia. The dystonia was paroxysmal in two (tiptoe walking and opisthotonus), and all had a progressive course. All children responded dramatically to L-dopa (mean 200 mg/day), including three who were wheelchair-bound for several years. The difficulties in early diagnosis, variability of clinical presentation, and dramatic response to L-dopa will be illustrated. To conclude, dopa-responsive dystonia should be considered in any child who presents with paroxysmal or progressive hypertonia of unknown etiology, because it responds so dramatically to L-dopa.     

多巴反应性肌张力障碍的临床特点

目的探讨多巴反应性肌张力障碍（DRD）的病因、临床特点及治疗方法，加强对该病的认识。方法对13例确诊的DRD患者的临床资料进行回顾性分析。结果本组发病年龄为（14．69±4．01）岁（10～27岁），病程6月～16年。最常见的临床表现为步态、姿势异常及震颤，症状日间波动明显，容易误诊为脑瘫、帕金森病、神经症等。服用小剂量多巴制剂有显著而持久的疗效。结论DRD患者具有症状多样及日间波动的特点。对儿童及青壮年本病患者可首选小剂量左旋多巴试验性治疗。     

多巴反应性肌张力障碍临床分析

目的回顾性分析多巴反应性肌张力障碍患者的临床特点和治疗原则。方法选择2005年3月-2010年7月门诊或住院治疗且诊断明确的多巴反应性肌张力障碍患者,面对面采集临床资料并门诊或电话随访,对其性别、年龄、发病年龄、家族史、首发症状、就诊症状、诊断延误时间及治疗过程进行分析。结果共21例患者入组,男4例、女17例,平均发病年龄(7.19±3.40)岁,平均诊断延误时间(13.76±11.38)年。均以肢体肌张力障碍为首发症状,20例(95.24%)呈现晨轻暮重现象,6例(28.57%)伴帕金森样症状,2例(9.52%)伴痉挛性截瘫;经小剂量左旋多巴/多巴丝肼治疗后症状显著缓解。随访l 8例患者,仅1例治疗后仍遗留肢体残疾;3例失访。随访期间左旋多巴/多巴丝肼平均维持剂量(175.35±113.51)mg/d,3例患者辅助应用盐酸苯海索(4～6 mg/d)治疗。结论多巴反应性肌张力障碍患者多于儿童期以肢体肌张力障碍发病,小剂量左旋多巴/多巴丝肼治疗效果显著。因此,对于儿童肌张力障碍或青年帕金森样症状患者应行小剂量左旋多巴/多巴丝肼诊断性治疗,以降低多巴反应性肌张力障碍的误诊率。     

多巴反应性肌张力障碍的临床特点

目的研究多巴反应性肌张力障碍患者的临床特点。方法对16例家族性患者和10例散发性多巴反应性肌张力障碍患者进行病史采集、神经系统体格检查和CT或MRI检查,所得数据应用SPSS13.0软件进行统计分析。结果26例患者,男10例,女16例;发病年龄为4～48岁,平均(17.46±12.95)岁。(1)首发症状:儿童期(12例)和青春期(6例)发病患者多以肌张力障碍为首发症状,成年期(8例)发病者则以帕金森综合征或肌张力障碍发病。(2)症状波动性:儿童期组和青春期组患者症状均呈现日间波动性,成年期组仅4例症状具有日间波动性,3组相比差异具有显著性意义(χ2=10.227,P=0.006);而且症状波动性与年龄呈负相关(r=#0.715,P<0.01)。(3)姿势性震颤:3组患者姿势性震颤的发生率差异具有显著性意义(χ2=8.073,P=0.018),其中以儿童期发病者发生率最低(5/12),成年期发生率最高(8/8);姿势性震颤的发生与患者年龄呈正相关(r=0.483,P=0.012)。(4)腱反射:3组间腱反射亢进发生率差异无显著性意义(χ2=5.303,P=0.071),腱反射亢进发生率与年龄呈负相关(r=#0.356,P=0.044)。(5)药物反应:26例患者均对左旋多巴治疗有明显而持续的反应。结论多巴反应性肌张力障碍临床表现呈多样化,临床表现与年龄密切相关。左旋多巴对多巴反应性肌张力障碍患者可产生明显而持续的疗效。     

多巴反应性肌张力障碍的临床特点

目的分析对多巴反应性肌张力障碍(DRD)的临床特点。方法回顾性分析15例确诊的DRD患者的临床特点及误诊原因。结果本组男4例,女11例,病程2—29年,平均12．1年。女性患者多在妊娠、分娩后症状明显加重,最常见的临床表现为步态、姿势异常及震颤,可伴假性锥体束征,症状日间波动明显,容易误诊为脑瘫、扭转痉挛、原发性震颤、帕金森病、神经症等。本组患者服用小剂量关多巴后2周内均明显好转,随访2～4年基本恢复正常。结论DRD患者具有症状多样及日问波动的特点。对儿童及青壮年本病患者可首选小剂量左旋多巴试验性治疗。     

D2 receptor binding in dopa-responsive dystonia

We have studied dopamine D₂ receptor binding by [¹¹C]raclopride positron emission tomography in 14 patients with dopa-responsive dystonia (DRD). Data were compared with 16 levodopa-treated patients with Parkinson's disease (PD) and 26 healthy controls. The results revealed an elevated [¹¹C]raclopride binding index in the putamen and caudate nucleus of DRD patients compared with controls as well as significant elevation in the caudate nucleus compared with PD patients. The increase of [¹¹C]raclopride binding may be interpreted either as reduced tracer displacement by endogenous dopamine, or as an alteration of the receptor features due to chronic dopamine deficiency. The difference in [¹¹C]raclopride binding in DRD and PD patients in the caudate nucleus suggests that this structure may be of pathophysiological relevance in the presentation of the clinical features of both diseases.     

Cerebral atrophy and long-term response to levodopa in Parkinson's disease

Summary In 92 parkinsonian patients (42 men, 50 women) aged from 37–79 years (mean 62.8) the impact of cerebral atrophy as assessed by computed tomography on the course of the clinical symptomatology under levodopa during a period of 1 to 5 years was investigated. It could be shown that patients suffering from medium to severe degrees of atrophy—independent of its special location—have a less favorable response than those with normal CT findings. The data do not allow a definite decision whether cortical artrophy or ventricular enlargement are of major importance. At any rate, the width of the third ventricle seems to have no influence on the course of the clinical symptoms. After 3 years of levodopa treatment a dissociation between cerebral atrophy and therapeutic effectiveness can be observed.

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Zusammenfassung An 92 Parkinsonkranken (42 Männer, 50 Frauen) im Alter von 37–79 Jahren (mittleres Alter 62,8 J.) wurde der Einfluß computertomographisch erfaßter hirnatrophischer Veränderungen auf den Verlauf der klinisch-neurologischen Symptomatik unter L-Dopa während einer Beobachtungszeit von 1–5 Jahren untersucht. Die Ergebnisse zeigen, daß Kranke mit einer Hirnatrophie mittleren bis schweren Grades — unabhängig von der jeweiligen Lokalisation — einen geringeren Besserungsgrad aufweisen als solche mit einem normalen CT-Befund. Die Daten erlauben keine eindeutige Entscheidung darüber, ob die kortikale Atrophie oder die Ventrikelerweiterung von größerer Wichtigkeit sind. Keinen Einfluß auf den Verlauf scheint die Weite des 3. Ventrikels zu haben. Nach dem 3. Behandlungsjahr kommt es zu einer Dissoziation der Beziehungen zwischen Hirnatrophie und Behandlungseffekt.

     

Phenotypic heterogeneity of dopa-responsive dystonia in monozygotic twins

The clinical expression of dopa-responsive dystonia (DRD) was found to be different in a pair of affected monozygotic twins. An earlier onset was associated with a more disabling course of disease. Whereas monozygosity was genetically proven, the search for pathogenic mutations in the GTP-cyclohydrolase-1 gene was negative. The contribution of environmental factors appeared minimal. Intrafamilial variability of DRD phenotype may be related to yet unknown non-Mendelian epigenetic or proteomic factors.     

多巴反应性肌张力障碍10例分析

目的认识多巴反应性肌张力障碍的临床特征,以期早期诊治,并加深对该病的认识。方法对10例DRD患者进行临床分析。结果10例患者,男3例,女7例,发病年龄4~28岁,平均12岁,首发症状均为肌张力障碍,下肢起病者8例,上肢起病2例,全部病人均有晨轻暮重的现象,给予美多巴62.5~125mg/d治疗有显著疗效。结论DRD是一种较为罕见的遗传性运动障碍疾病,小剂量多巴制剂有显著、持续疗效,早期治疗效果好,需与其他肌张力障碍相鉴别。     

Broadening the phenotype of childhood-onset dopa-responsive dystonia

BACKGROUND: Dopa-responsive dystonia (DRD) may cause early-onset dystonia, with extrapyramidal or pyramidal tract dysfunction. OBJECTIVE: To broaden the phenotype of DRD. SETTING: Tertiary referral university hospital. PATIENTS: We describe 4 female siblings with genetically confirmed DRD, 3 of whom presented with "unsteadiness" and 1 with scoliosis. All had dystonia and pyramidal tract signs, 3 had additional extrapyramidal features (resting tremor, bradykinesia, or rigidity), and at least 2 had definite signs of cerebellar dysfunction. MAIN OUTCOME MEASURES: The subjective response to treatment with 62.5 mg of a combination product of levodopa and carbidopa 3 times daily was assessed at both 6- and 12-month follow-up visits with the 7-item Patient's Global Impression of Change Scale as very much improved, much improved, a little improved, no different, a little worse, much worse, or very much worse. RESULTS: All patients showed a good response to levodopa therapy 41 to 49 years after symptom onset. CONCLUSION: Cerebellar signs may be observed in patients with DRD and may improve in response to levodopa.     

Brain biopterin and tyrosine hydroxylase in asymptomatic dopa-responsive dystonia

It is assumed that brain biopterin and dopamine loss should not be as severe in asymptomatic dopa-responsive dystonia caused by GCH1 mutations as it is in symptomatic dopa-responsive dystonia. However, the actual status of dopaminergic systems in asymptomatic cases is unknown. In the autopsied putamen of an asymptomatic GCH1 mutation carrier, we found that brain biopterin loss (-82%) paralleled that reported in dopa-responsive dystonia patients (-84%). However, tyrosine hydroxylase protein and dopamine levels (-52 and -44%, respectively) were not as severely affected as in symptomatic patients (exceeding -97 and -88%, respectively). Our data suggest that the extent of striatal tyrosine hydroxylase protein loss may be critical in determining dopa-responsive dystonia symptomatology.     

多巴反应性肌张力障碍36例临床分析

目的探讨多巴反应性肌张力障碍的病因、临床特点和治疗。方法回顾性分析36例多巴反应肌张力障碍患者的临床资料。结果 36例中男8例,女28例,其中包含2个家系。发病年龄平均9.5岁。均为缓慢起病,首发症状为始自下肢的肌张力障碍者32例,4例以帕金森病样表现起病。症状均呈晨轻暮重。头颅CT、MRI、神经电生理等检查均正常。小剂量多巴制剂治疗有明显疗效。结论本病临床特征显著,只要认识到位,诊断不难,小剂量多巴制剂治疗效果好。