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Objective: To determine whether neuroanatomically heterogeneous strokes causing hemichorea-hemiballismus localize to a common functional network., Methods: We identified 29 cases of lesion-induced hemichorea-hemiballismus from the literature and mapped each lesion volume onto a reference brain. Using a recently validated technique termed lesion network mapping, we tested whether these lesions belonged to the same functional network. To accomplish this, the network of brain regions functionally connected to each lesion was identified using a connectome dataset from healthy participants. Network maps were overlapped to identify any region functionally connected to our set of lesions. Specificity was evaluated using a case-control design; control cohorts included a group of similar lesions randomized to different brain locations and a second group of lesions causing a separate movement disorder, asterixis. Reproducibility was evaluated using an independent cohort of 10 additional hemichorea-hemiballismus cases., Results: Lesions showed heterogeneity in anatomical location, consistent with prior reports. However, at least 90% of these lesions showed network overlap in the posterolateral putamen. This result was specific to lesions causing hemichorea-hemiballismus and reproducible in an independent cohort. The putaminal overlap site was itself connected to a broader motor network that predicted the distribution of lesions causing hemichorea-hemiballismus., Conclusions: Strokes causing hemichorea-hemiballismus, while anatomically heterogeneous, localize to a common functional network. Specifically, lesions occur in regions functionally connected to the posterolateral putamen, a region previously implicated in hyperkinetic movement disorders. Lesion network mapping may be useful in identifying the neuroanatomical substrates of heterogeneous lesion-based disorders., (© 2016 American Academy of Neurology.)

Objective: We aimed to investigate the clinical and genetic features of paroxysmal kinesigenic dyskinesia (PKD) in a large population and to analyze the genotype-phenotype correlation of PKD., Methods: We analyzed clinical manifestations and conducted PRRT2 screening in 110 patients with PKD. Clinical data were compared between 91 probands with and without PRRT2 mutations., Results: Among the enrolled participants (45 from 26 families, 65 sporadic cases), 8 PRRT2 mutations were detected in 20 PKD families (76.9%) and 14 sporadic cases (21.5%), accounting for 37.4% (34/91) of the study population. Five mutations (c.649dupC, c.649delC, c.487C>T, c.573dupT, c.796C>T) were already reported, while 3 mutations (c.787C>T, c.797G>A, c.931C>T) were undocumented. A patient harboring a homozygous c.931C>T mutation was shown to have inherited the mutation via uniparental disomy. Compared with non-PRRT2 mutation carriers, the PRRT2 mutation carriers were younger at onset, experienced longer attacks, and tended to present with complicated PKD, combined phenotypes of dystonia and chorea, and a positive family history. A good response was shown in 98.4% of the patients prescribed with carbamazepine., Conclusions: PRRT2 mutations are common in patients with PKD and are significantly associated with an earlier age at onset, longer duration of attacks, a complicated form of PKD, combined phenotypes of dystonia and chorea, and a tendency for a family history of PKD. A patient with uniparental disomy resulting in a homozygous c.931C>T mutation is identified in the present study. Carbamazepine is the first-choice drug for patients with PKD, but an individualized treatment regimen should be developed., (© 2015 American Academy of Neurology.)

Objective: To characterize movement-related neural oscillatory activity and to clarify its neurophysiologic role in paroxysmal kinesigenic dyskinesia (PKD)., Methods: We recorded neuromagnetic event-related desynchronization (ERD) and event-related synchronization (ERS) activities in response to a self-paced finger-lifting task in 16 patients with PKD and 17 healthy controls., Results: The amplitude of α-ERD was comparable between the healthy controls and patients with PKD, whereas either the contralateral or ipsilateral β-ERS was decreased. The peak latency of contralateral β-ERS was delayed in patients with PKD. Patients with less frequent dyskinetic attacks demonstrated a larger ipsilateral β-ERS. Moreover, some patients with PKD revealed a lesser degree of contralateral preponderance of β-ERS generation., Conclusions: The present data imply a decreased postmovement inhibition of motor cortex in patients with PKD, and the inhibitory function in the contralateral hemisphere is more affected than that in the ipsilateral hemisphere.

Objective: To describe a more limited and less malignant form of Rasmussen encephalitis (RE)., Methods: Three subjects (all women; 37, 31, and 32 years of age) developed childhood or late onset chronic focal encephalitis, with a relatively nonprogressive form of the disorder., Results: In our patients, clinical features were dominated by partial seizures without marked focal motor deficit and in two with choreo-dystonic movements. The diagnosis of RE was supported by histologic examination and anatomic and functional MRI., Conclusions: These cases extend the phenotypic presentations of Rasmussen encephalitis and confirm Theodore Rasmussen's suggestion that there may be mild and nonprogressive forms of the disease.

Background: Paroxysmal nonkinesigenic dyskinesia (PNKD) is a rare disorder characterized by episodic hyperkinetic movement attacks. We have recently identified mutations in the MR-1 gene causing familial PNKD., Methods: We reviewed the clinical features of 14 kindreds with familial dyskinesia that was not clearly induced by movement or during sleep. Of these 14 kindreds, 8 had MR-1 mutations and 6 did not., Results: Patients with PNKD with MR-1 mutations had their attack onset in youth (infancy and early childhood). Typical attacks consisted of a mixture of chorea and dystonia in the limbs, face, and trunk, and typical attack duration lasted from 10 minutes to 1 hour. Caffeine, alcohol, and emotional stress were prominent precipitants. Attacks had a favorable response to benzodiazepines, such as clonazepam and diazepam. Attacks in families without MR-1 mutations were more variable in their age at onset, precipitants, clinical features, and response to medications. Several were induced by persistent exercise., Conclusions: Paroxysmal nonkinesigenic dyskinesia (PNKD) should be strictly defined based on age at onset and ability to precipitate attacks with caffeine and alcohol. Patients with this clinical presentation (which is similar to the phenotype initially reported by Mount and Reback) are likely to harbor myofibrillogenesis regulator 1 (MR-1) gene mutations. Other "PNKD-like" families exist, but atypical features suggests that these subjects are clinically distinct from PNKD and do not have MR-1 mutations. Some may represent paroxysmal exertional dyskinesia.

A 59-year-old man presented with orthostatic headaches, memory complaints, pronounced choreiform movements, and related hyperkinetic dysarthria and titubations. Head MRI findings were suggestive of CSF leak. CSF pressure was low. CT myelography documented CSF leak at the cervicothoracic junction. Targeted epidural blood patch led to resolution of symptoms, including complete disappearance of choreiform movements.

The authors describe a family with six patients with muscular dystrophy with a variable course. One is a compound heterozygote for CAPN3 mutations (calpainopathy) and the others have a single CAPN3 mutation. Linkage analysis and sequencing revealed a XK gene mutation (McLeod syndrome). This illustrates the variable phenotype of XK mutations and suggests the possibility that CAPN3 heterozygotes may have their condition caused by nonallelic mutations in other unrelated genes.

Presented is a pedigree with infancy-onset benign hereditary chorea (BHC) caused by a novel nonsense mutation in exon 3 (523G-->T, E175X) of the TITF-1 (Nkx2.1) gene. Four confirmed mutation carriers showed the typical movement disorder of BHC and congenital hypothyroidism. Surprisingly, treatment with levodopa improved gait dramatically and reduced chorea in two patients. Dopaminergic drugs should be considered a useful therapeutic option in BHC.

The authors investigated obsessive-compulsive behavior, obsessive-compulsive disorder (OCD), and attention deficit and hyperactivity disorder (ADHD) in 50 healthy subjects, 50 patients with rheumatic fever without chorea, and 56 patients with Sydenham chorea. Obsessive-compulsive behavior, OCD, and ADHD were more frequent in the Sydenham chorea group (19%, 23.2%, 30.4%) than in the healthy subjects (11%, 4%, 8%) and in the rheumatic fever without chorea group (14%, 6%, 8%). ADHD was more common in persistent Sydenham chorea.

Objective: To describe a second family with benign hereditary chorea (BCH, OMIM 118700) and suggestive linkage to chromosome 14q. BCH is an autosomal dominant disorder of early onset that differs from Huntington disease in being nondementing and nonprogressive without other neurologic signs. There has been controversy regarding the existence of BCH as a discrete disorder., Background: A single kindred was recently reported with linkage of BCH to a 20.6-KcM region on chromosome 14q., Methods: In a four-generation family with BCH, linkage was evaluated to markers in a 23-KcM region between D14S49 and D14S66 that contains the putative BCH locus., Results: A multipoint nonparametric lod score of 3.01 is consistent with linkage of disease in this family to the 14q BCH locus. A recombination event in one affected individual enabled the critical region to be narrowed to 6.93 KcM flanked by D14S1068 and D14S1064. This region contains two candidate genes: glial maturation factor beta and guanosine triphosphate cyclohydrolase 1 (GCH1). Survival motor neuron (SMN) interacting protein-1 is eliminated as a candidate gene because it lies outside the critical region. No sequence alteration was identified in the coding region of GCH1 in an affected individual., Conclusion: These data provide further evidence that BCH is a distinct entity, narrow the location of BCH to a 6.93-KcM region on chromosome 14q, and exclude SMN interacting protein-1 as a candidate gene.

The authors report the effect of chronic stimulation of the ventrointermediate (Vim) thalamus for treatment of dystonic paroxysmal nonkinesigenic dyskinesias (PNKD). A 37-year-old patient had a 4-year history of severe and painful PNKD of the right arm. Chronic stimulation through a stereotactically implanted monopolar electrode in the left Vim resulted in a decrease of the frequency, duration, and intensity of the dystonic paroxysmal movement disorder. The benefit of stimulation has been maintained over 4 years of follow-up.

We describe clinical features of a large Polish-American kindred in which autosomal-dominant, paroxysmal dystonic choreoathetosis (PDC) was linked to a locus on chromosome 2q. Episodes of generalized dystonia and choreoathetosis involving the face and all extremities began in early childhood, lasted for 30 minutes to several hours, and occurred up to several times each week. There was no interruption of consciousness and EEGs were normal during the episodes. Paroxysmal dyskinesia occurred at rest both spontaneously and following caffeine or alcohol consumption. Neurologic examinations were normal between attacks. The cause of PDC is unknown. We deduced a model of PDC pathophysiology from analyzing neurophysiologic effects of alcohol and caffeine (which provoke attacks of PDC), the variably beneficial effects of levodopa-carbidopa, and the occurrence of dystonia and paroxysmal dyskinesia in biopterin synthesis disorders. We propose that nigrostriatal neurons in PDC patients have either marginally deficient dopamine synthesis or excessive alcohol- and caffeine-induced dopamine release; and that following alcohol- and caffeine-induced dopamine release, PDC patients experience a period of dopamine deficiency.

We describe seven patients with cocaine-induced movements, including choreoathetosis, akathisia, and parkinsonism with tremor. All were seen in 2 years at a municipal hospital, during which 701 visits were attributed to complications of cocaine. Dopaminergic changes are hypothesized to cause euphoria, addiction, and abnormal movements.

We report 6 patients with hemichorea/hemiballism of vascular origin who were treated with divalproex sodium (Depakote). Four of 6 responded initially. Marked improvement was seen in 2 patients only and in 1 of these hemiballism recurred despite continuing therapy. Divalproex sodium is not uniformly effective in the treatment of hemichorea/hemiballism.

Twenty-five patients convalescing from Sydenham's chorea were contrasted by clinical examination, electroencephalograms, and psychometric and psychologic tests to 15 siblings and 20 matched rheumatic fever controls. A group of 10 postchoreic patients who had two or more signs could be identified. Patients in this group had all the signs classified as moderate or severe, performed less well than other choreic subjects on the Bender gestalt test, and had a higher percentage of abnormal electroencephalograms but not a higher incidence of behavioral disorders. This subgroup could not be predicted from a review of neurologic history or from analysis of the acute episode of chorea. Our data would suggest that uncomplicated Sydenham's chorea is not necessarily a benign self-limited affliction of the central nervous system and that some patients are left with definite, albeit minimal, neurologic residua.