Idiopathic Movement Disorders Research Articles

Episodic mandibular tremor in dogs: an idiopathic movement disorder or a manifestation of pain.

Episodic mandibular tremor (EMT), manifested as teeth chattering, is not well described in dogs. The aim of this study was to describe clinical signs, MRI findings, and outcome of dogs with EMT. 11 dogs retrospectively and 31 dogs in an online survey. A retrospective multicenter study of dogs with EMT between 2018 and 2023 and prospective online questionnaire open to owners of pets with teeth chattering. All dogs had rapid and short-lasting (< 1 minute) episodes of EMT in the absence of other neurological signs. Lip smacking occasionally accompanied the tremor in 5 of 11 (45.5%) hospital dog cases. Excitement was a common trigger in 14 of 31 (45.2%) dogs from the survey. Cavalier King Charles Spaniel was the most common breed in both clinical and survey populations. Median age at presentation was 3 years for both hospital cases and the survey dogs. A concurrent medical condition was present in 8 of 11 (72.7%) hospital cases and 20 of 31 (64.5%) survey dogs. In 3 hospital dogs that underwent further investigations, no brain disease was present. EMT and its clinical features are presented for the first time, shedding light on a clinical sign that might resemble an idiopathic movement disorder or a manifestation of pain in dogs.

The Spectrum of Early Movement Disorders in Congenital Defects of Biogenic Amine Metabolism

This article analyzes the pattern of movement disorders in children with primary defects of biogenic amine metabolism emerging during the first 3 year of life. A PubMed search was performed using the keywords “monoamine neurotransmitter disorders,” “congenital defects of biogenic amine metabolism,” “early onset movement disorders,” “autosomal dominant guanosine-triphosphate-cyclohydrolase deficiency,” “autosomal recessive guanosine-tryphosphate-cyclohydrolase deficiency,” “6-pyruvoyl-tethrahydropterin synthase deficiency,” “sepiapterin reductase deficiency,” “dihydropteridine reductase deficiency,” “tyrosine hydroxilase deficiency,” “aromatic l-amino acid decarboxylase deficiency,” “dopamine transporter deficiency,” and “vesicular monoamine transporter 2.” A personal series of 27 patients affected by these disorders was presented and discussed. Primary defects of biogenic amine metabolism result in a spectrum of movement disorders associated with derangement of postural reaction and global development delay. Movement disorders virtually represent the presentation symptoms in most of these diseases. The prominent early clinical patterns of movement disorders are akinesia (with rigidity or hypotonia) and hyperkinesia (dystonia, myoclonic jerks, and tremor). While some diseases present with a rather stereotyped clinical pattern (i.e., Aromatic l -amino acid decarboxylase, sepiapterin reductase, and Dopamine transporter deficiencies), others (i.e., Guanosine-triphosphate-cyclohydrolase, 6-pyruvoyl tetrahydropterin synthase, dihydropteridine reductase, and tyrosine hydroxylase deficiencies) may present with more pleomorphic features. As a general rule, earlier the onset of the disease is, more severe and generalized is the derangement of motor functions. Inherited disorders of monoamine neurotransmitter metabolism include the few idiopathic movement disorders with the possibility of etiological treatments. For these reasons, they should always be considered in the diagnostic work-up of children with early onset movement disorders.

The Pathogenic Role of Low Range Repeats in SCA17.

IntroductionSCA17 is an autosomal dominant cerebellar ataxia with expansion of the CAG/CAA trinucleotide repeats in the TATA-binding protein (TBP) gene. SCA17 can have various clinical presentations including parkinsonism, ataxia, chorea and dystonia. SCA17 is diagnosed by detecting the expanded CAG repeats in the TBP gene; however, in the literature, pathologic repeat numbers as low as 41 overlap with normal repeat numbers.MethodsThe subjects in this study included patients with involuntary movement disorders such as cerebellar ataxia, parkinsonism, chorea and dystonia who visited Seoul National University Hospital between Jan. 2006 and Apr. 2014 and were screened for SCA17. Those who were diagnosed with other genetic diseases or nondegenerative diseases were excluded. DNA from healthy subjects who did not have a family history of parkinsonism, ataxia, psychiatric symptoms, chorea or dystonia served as the control. In total, 5242 chromosomes from 2099 patients and 522 normal controls were analyzed.ResultsThe total number of patients included in the analysis was 2099 (parkinsonism, 1706; ataxia, 345; chorea, 37; and dystonia, 11). In the normal control, up to 44 repeats were found. In the 44 repeat group, there were 7 (0.3%) patients and 1 (0.2%) normal control. In 43 repeat group, there were 8 (0.4%) patients and 2 (0.4%) normal controls. In the 42 repeat group, there were 16 (0.8%) patients and 3 (0.6%) normal controls. In 41 repeat group, there were 48 (2.3%) patients and 8 (1.5%) normal controls. Considering the overlaps and non-significant differences in allelic frequencies between the patients and the normal controls with low-expansions, we could not determine a definitive cutoff value for the pathologic CAG repeat number of SCA17.ConclusionBecause the statistical analysis between the normal controls and patients with low range expansions failed to show any differences so far, we must consider that clinical cases with low range expansions could be idiopathic movement disorders showing coincidental CAG/CAA expansions. Thus, we need to reconsider the pathologic role of low range expansions (41–42). Long term follow up and comprehensive investigations using autopsy and imaging studies in patients and controls with low range expansions are necessary to determine the cutoff value for the pathologic CAG repeat number of SCA17.

Editorial: Psychomotor Symptomatology in Psychiatric Illnesses.

In this research topic, we have gathered articles focusing on the psychomotor component of psychiatric disorders. Indeed, motor symptoms remain as an important dimension of psychopathology that can be assessed by objective means. Particularly, in major depressive disorder and schizophrenia, motor signs have been acknowledged from the very early descriptions (1–3). But, psychomotor abnormalities have also been demonstrated in other psychiatric disorders. This research topic included nine original articles, four reviews, three opinion papers, and one mini-review. Catatonia has been subjected to two reviews (4, 5) and one investigation of its prevalence among acutely hospitalized patients (6). Neurological soft signs have been shown to occur in autism spectrum disorders (7), in Alzheimer’s disease (8) and have been reviewed for their predictive validity in the course of schizophrenia (9). Fine motor tasks demonstrated that motor learning was preserved in schizophrenia despite cognitive and motor impairments (10, 11). In addition, psychomotor retardation was found in depressed elderly more than in elderly without depression (12). A neuroimaging study explored the cingulate motor area in motor retardation in major depression (13). The functional neuroanatomy of motor retardation in depression was also subjected to a mini-review (14). The topography of the cerebellum has been suggested as interesting focus of study to disentangle motor and cognitive functions in schizophrenia spectrum disorders (15). Two studies using actigraphy reported on gross motor activity in the course of schizophrenia (16, 17). Finally, Gawrilow and colleagues summarized the importance of motor activity in ADHD (18). Currently, ambiguous terminology and definitions hamper research on psychomotor phenomena. In addition, some studies focus exclusively on single signs probably missing the complete picture. Therefore, we have tried to put forward a systematic approach to study psychomotor phenomena in psychotic disorders (19). In addition, van Harten and colleagues have proposed to consider movement disorders as non-mental signs of psychotic disorders just as psychiatric symptoms are classified as non-motor signs in idiopathic movement disorders (20). One example of ongoing debate is the current discussion on the catatonia syndrome. Depending on the criteria applied, prevalence rates differ substantially (6, 21, 22), challenging the specificity of assessment methods. Despite the fact that the syndrome is quite remarkable, there is not much of a common ground in the literature as to what catatonia should be defined as. Clearly, this ambiguity of definitions has contributed to the scarcity of descriptive and interventional studies in the catatonia syndrome. Another important field of research is the outcome of interventions in motor symptoms. Further research needs to clarify whether the motor dimension in psychiatric disorders is properly ameliorated by treating the underlying disorder or whether specific therapeutic options are required. The former would call for generalized therapies in depression, schizophrenia, or autism. The latter would instead require searching for new therapeutic targets, such as in movement disorders known in neurology. Clearly defined psychomotor disturbances may benefit from deep brain stimulation of the subthalamic nucleus (23), pedunculopontine nucleus (24), or other targets such as the reward system (25). Likewise, non-invasive brain stimulation may become a treatment option in those psychomotor disturbances related to dysfunctions in cortical motor areas. Taken together, clarified terminology, increased awareness, and improved assessment methods will help psychomotor symptoms to become an important objective dimension of psychopathology that is informative on underlying neuropathology and longitudinal course. These transitions in psychiatric assessment will also allow for more specialized interventions for psychomotor symptoms.

P-809 - Obsessive-compulsive symptoms in primary focal dystonia: a shared frontal cortical-basal dysfunction?

Primary focal dystonia (PFD) is an idiopathic movement disorder that manifests as involuntary, sustained muscle contractions, leading to abnormal postures. Its pathophysiology probably involves a functional disorder of the basal ganglia and their frontal cortical connections. The hypothetical association with obsessive-compulsive disorder (OCD) has raised particular interest, as both disorders seem to involve frontal cortical-basal dysfunction. Anyway, evidence supporting this association is scarce and contradictory. To address the next two questions: (1) Do primary dystonia patients have high obsessive-compulsive symptom scores? (2) Are these symptoms more severe in dystonia than in controls with equivalent peripheral neurological disorders? We’ve conducted a cross-sectional, descriptive, controlled study comprising 45 consecutive patients with PFD (i.e., blepharospasm, spasmodic torticollis, or writer's cramp), 46 consecutive patients with hemifacial spasm, cervical spondylarthropathy, or carpal tunnel syndrome, and 30 healthy volunteers. Assessment included the DSM-IV based psychiatric interview, Symptom Check- list 90R, Yale-Brown Obsessive-Compulsive Scale and Checklist, and the Unified Dystonia Rating Scale. Dystonia patients had higher Yale-Brown scores than both control groups. Major depression and generalized anxiety disorder were the most frequent psychiatric diagnoses in PFD. Obsessive-compulsive disorder frequency was 6.7%. PFD patients have higher obsessive-compulsive symptom scores than individuals with similar functional disabilities resulting from other neurological disorders, suggesting that obsessive-compulsive symptoms in dystonia are not reactive to chronic disability. Dystonic muscle contractions and obsessive-compulsive symptoms may share a common neurobiological basis related to cortical-basal dysfunction. Psychopathology, especially obsessive-compulsive symptoms, should be actively explored and treated in primary focal dystonia.

Bilateral pallidal deep brain stimulation in primary Meige syndrome

Primary Meige syndrome is an idiopathic movement disorder that manifests as craniofacial and often cervical dystonias. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has emerged as a powerful surgical option in the treatment of primary generalized or segmental dystonia. However, the experience with GPi-DBS in Meige syndrome is limited. We followed 5 patients with disabling Meige syndrome treated by bilateral GPi-DBS for 49 ± 43.7 (mean ± SD) months. All patients were assessed before surgery and at the last follow-up after surgery using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) which includes both the movement and disability scales. Bilateral GPi-DBS produced a sustained and long-lasting improvement in dystonia symptoms associated with Meige syndrome. At the last follow-up, the mean scores of BFMDRS movement and disability scales improved significantly by 84 ± 6.8% (range, 75–94%) and 89 ± 8.1% (range, 80–100%), respectively. Bilateral pallidal stimulation is a beneficial therapeutic option for long-term relief of the disabling dystonia symptoms in Meige syndrome.

Anti-basal Ganglia Antibodies: A Possible Diagnostic Utility in Idiopathic Movement Disorders?

Anti-basal Ganglia Antibodies: A Possible Diagnostic Utility in Idiopathic Movement Disorders?

Anti-basal ganglia antibodies: a possible diagnostic utility in idiopathic movement disorders?

Background: The spectrum of post-streptococcal brain disorders includes chorea, tics, and dystonia. The proposed mediators of disease are anti-basal ganglia (neuronal) antibodies (ABGA). Aim: To evaluate ABGA as a potential...

Neurodegenerative Diseases of Childhood

To evaluate the diagnostic utility of MR and CT in neurodegenerative diseases of childhood, we examined 63 children (MR in 44, CT in 53) carrying diagnoses of Leigh disease (14 patients), various metabolic diseases (13 patients), leukodystrophies (13 patients), other specific degenerative diseases (10 patients), and unclassified neurodegenerative disorders (13 children). Magnetic resonance yielded positive findings in 86% and CT in 81%. Lesion extent and conspicuity were consistently greater with MR. The high frequency of abnormalities detected on MR, and to a lesser extent on CT, helps distinguish children with neurodegenerative diseases from those with nonprogressive idiopathic movement disorders. The most common abnormalities included signal alterations (MR) or decreased attenuation (CT) of the basal ganglia and cerebral white matter, as well as local or generalized brain atrophy. Although considerable overlap was present, the findings showed four general patterns that may assist in tentative classification of patients with nonspecific clinical and laboratory findings.

Movement disorders in alcoholism

A wide variety of movement disorders are associated with alcohol abuse. Some idiopathic movement disorders are markedly improved by small amounts of alcohol and this response occasionally may lead to alcoholism. Alcohol abuse alone or combined with hepatic encephalopathy can cause various types of tremor, asterixis, and cerebellar dysfunction. Alcohol withdrawal is occasionally complicated by transient basal ganglia dysfunction manifested by parkinsonism or chorea. These syndromes are distinct from the movement disorders complicating acquired hepatolenticular degeneration occurring in some chronic alcoholics. This review discusses the clinical and pathophysiologic aspects of the movement disorder syndromes that complicate alcohol abuse.

The genetics of primary torsion dystonia

Primary torsion dystonia is an idiopathic movement disorder presumably caused by abnormal function of the basal ganglia. The disorder may be inherited either as an autosomal dominant, autosomal recessive, or X-linked recessive trait. At least six forms of autosomal dominant torsion dystonia can be distinguished clinically. Linkage analysis in one form of autosomal dominant torsion dystonia permits the assignment of a "torsion dystonia locus" to the long arm of chromosome 9.

Wallerian degeneration: evaluation with MR imaging.

Twenty-three patients who underwent routine magnetic resonance (MR) imaging of the brain were found to have signal or structural abnormalities corresponding to white matter tracts. Images were evaluated for anatomic and MR signal characteristics of the involved tract, associated primary lesions, and, when possible, changes in MR signal and anatomic structures with time. Images from 20 patients demonstrated a thin band of abnormal signal contiguous with the primary lesion and conforming to the known anatomic pathway of a white matter tract. Cerebral infarction was the most common associated primary disorder (n = 17). Neoplasms (n = 2), demyelinating (n = 1) and posthemorrhagic (n = 2) conditions, and an idiopathic movement disorder (n = 1) were associated with white matter tract signal abnormalities that were indistinguishable from those seen with infarction. Signal abnormality corresponding to the corticospinal tract was the type most commonly seen. No change in signal characteristics was seen with time (six cases) or following contrast material administration (two cases). The authors conclude that MR imaging provides a sensitive method of evaluating wallerian degeneration in the living human brain.