Environmental circumstances influencing tic expression in children

AIM

To assess the clinical features and severity of tics and environmental factors influencing tic expression in a cohort of children with tic disorders.

METHODS

We performed a cross-sectional study in a cohort of children and adolescents (N = 92) with tic disorders referred to the outpatient clinic of a tertiary-level paediatric centre in Barcelona. The severity of tics was evaluated using the Yale Global Tic Severity Scale (YGTSS). A questionnaire including a list of environmental factors and common daily activities that might influence tic occurrence was completed for patients greater than 5 years old.

RESULTS

Children were classified as having Tourette syndrome (TS) (52 patients), chronic motor or phonic tics (22 patients) and tics of less than 12 months' duration (18 patients). Tics worsened with stressful situations, activities related to school, playing video games and watching TV. A significant proportion of children reported a reduction in tics while they were concentrating on artistic or creative activities or when playing sports and participating in outdoor activities. The YGTSS scores were higher for TS patients (P < .001) and correlated positively with the time of evolution of tics (r = .273, P = .026). Poor school performance was associated with TS (p = .043) and higher scores on the YGTSS (P = .018), as well as attention deficit/hyperactivity disorder (P = .007).

CONCLUSIONS

Several activities of daily living were identified as modifying tic severity in children and may be important clues for tic management. In a subgroup of children with TS, tics were associated with significant morbidity and poor academic performance. Our results emphasise the importance of developing specific school programmes and tailored recommendations in patients with TS.

[Deep brain recording and length of surgery in stereotactic and functional neurosurgery for movement disorders]

OBJECTIVE

Our objectives were to study the length of multi-unit recordings (MURs) of brain activity in 20 years of movement disorder neurosurgeries and to determine the number of times in which it was necessary for the teams using single-unit recording (SUR) to explore all the electrode tracks in the simultaneously recorded sites (SRS).

MATERIAL AND METHOD

This was a retrospective descriptive statistical analysis of MUR length on 4,296 tracks in 952 surgeries. The exclusion criteria were: tracks with fewer than 5 recorded signals, tracks that had a signal length different from the habitual 2s, or there being unusual situations not related to the MUR, as well as the first 20 surgeries of each surgical target. This yielded a total of 3,448 tracks in 805 surgeries. We also determined the number of the total 952 surgeries in which all the tracks in the SURs of the SRS were explored.

RESULTS

The mean and its confidence interval (P=.05) of time per MUR track were 5.49±0.16min in subthalamic nucleus surgery, 8.82±0.24min in the medial or internal globus pallidus) and 18.51±1.31min in the ventral intermediate nucleus of the thalamus. For the total sum of tracks per surgery, in 75% of cases the total time was less than 39min in subthalamic nucleus, almost 42min in the medial or internal globus pallidus and less than 1h and 17min in ventral intermediate nucleus of the thalamus. All the tracks in the SUR SRS were explored in only 4.2% of the surgeries.

CONCLUSIONS

The impact of MUR on surgical time is acceptable for this guide in objective localization for surgical targets, without having to use several simultaneous electrodes (not all indispensable in most of the cases). Consequently, there is less risk for the patient.

Profile of extrapyramidal manifestations in 85 patients with spinocerebellar ataxia type 1, 2 and 3

This study aimed to determine the prevalence and type of extrapyramidal signs (EPS) in spinocerebellar ataxia (SCA) type 1, 2 and 3. Eighty-five patients with genetically confirmed SCA (SCA1=40, SCA2=28, SCA3=17) were evaluated for the prevalence and types of EPS. Forty-one SCA patients (48.2%) had one or more types of EPS. The prevalence of EPS was 60.7% in SCA2, 52.9% in SCA3, and 37.5% in SCA1. Among SCA2 patients, bradykinesia was the most frequent (35.3%), followed by reduced facial expression, postural tremor and dystonia (29.4% each), rest tremor, titubation and rigidity (23.5% each), and lip/jaw tremor and chorea (11.8% each). In SCA3 the common EPS were bradykinesia (44.4%), staring look, postural tremor and dystonia (33.3% each), and reduced facial expression and rigidity (22.2% each). In SCA1, staring look was the most common (53.3%), followed by dystonia and bradykinesia (33.3% each), and postural tremor (26.7%). In all three groups, there was no significant difference in the mean length of repeat of the abnormal allele between those with and without EPS. To conclude bradykinesia, staring look, dystonia and postural tremor were the most frequent EPS observed in SCA. In SCA1, these signs were seen more often in younger patients with early onset of symptoms.

C19orf12 mutation leads to a pallido-pyramidal syndrome

Pallido-pyramidal syndromes combine dystonia with or without parkinsonism and spasticity as part of a mixed neurodegenerative disorder. Several causative genes have been shown to lead to pallido-pyramidal syndromes, including FBXO7, ATP13A2, PLA2G6, PRKN and SPG11. Among these, ATP13A2 and PLA2G6 are inconsistently associated with brain iron deposition. Using homozygosity mapping and direct sequencing in a multiplex consanguineous Saudi Arabian family with a pallido-pyramidal syndrome, iron deposition and cerebellar atrophy, we identified a homozygous p.G53R mutation in C19orf12. Our findings add to the phenotypic spectrum associated with C19orf12 mutations.

Autoimmune-induced glutamatergic receptor dysfunctions: conceptual and psychiatric practice implications

Glutamatergic neurotransmission is mediated via complex receptorial systems including N-methyl-d-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolpropionic acid (AMPA) and metabotropic receptor subtypes and plays a critical role in the modulation of synaptic plasticity, mood, cognitive processes and motor behavior. Glutamatergic function deficits are hypothesized to contribute to the pathogenesis of neuropsychiatric disorders, including schizophrenia, mood and movement disorders. Accumulating data are rapidly leading to the characterization of specific types of autoimmune encephalitis in which the receptors and proteins critically involved in glutamatergic neurotransmission, e.g., NMDA, AMPA receptors, are antigen targets. Characteristic of these syndromes, antibodies alter the structure and/or function of the corresponding neuronal antigen resulting in clinical pictures that resemble pharmacological disease models. Presently the best characterized autoimmune glutamatergic disorder is anti-NMDA receptor encephalitis. This disorder manifests with intertwined psychiatric and neurological features, defines a new syndrome, reclassifies poorly defined clinical states and extends previous hypotheses, such as hypo-NMDA receptor function in schizophrenia. The characterization of autoimmune-induced glutamatergic receptor dysfunctions (AGRD) is likely to have a substantial conceptual impact upon our understanding of neuropsychiatric disorders including schizophrenia, affective and movement dysfunctions. Further definition of AGRD will provide additional guidelines for psychiatric diagnoses, identification of homogeneous patient subtypes within broad phenomenological classifications and will contribute to the development of personalized treatments. The body of knowledge already accumulated on anti-NMDA receptor encephalitis highlights the need for wide dissemination of these concepts among psychiatrists, and in suspected cases, for early recognition, prompt clinical and laboratory investigation and efficient interface between mental health and medical teams.

GLUT1 deficiency syndrome: an update

INTRODUCTION

Glucose transporter type 1 deficiency syndrome is caused by heterozygous, mostly de novo, mutations in the SLC2A1 gene encoding the glucose transporter GLUT1. Mutations in this gene limit brain glucose availability and lead to cerebral energy deficiency.

STATE OF THE ART

The phenotype is characterized by the variable association of mental retardation, acquired microcephaly, complex motor disorders, and paroxysmal manifestations including seizures and non-epileptic paroxysmal episodes. Clinical severity varies from mild motor dysfunction to severe neurological disability. In patients with mild phenotypes, paroxysmal manifestations may be the sole manifestations of the disease. In particular, the diagnosis should be considered in patients with paroxysmal exercise-induced dyskinesia or with early-onset generalized epilepsy. Low CSF level of glucose, relative to blood level, is the best biochemical clue to the diagnosis although not constantly found. Molecular analysis of the SLC2A1 gene confirms the diagnosis. Ketogenic diet is the cornerstone of the treatment and implicates a close monitoring by a multidisciplinary team including trained dieticians. Non-specific drugs may be used as add-on symptomatic treatments but their effects are often disappointing.

CONCLUSION

Glucose transporter type 1 deficiency syndrome is likely under diagnosed due to its complex and pleiotropic phenotype. Proper identification of the affected patients is important for clinical practice since the disease is treatable.

Is action tremor in Parkinson's disease related to resting tremor?

OBJECTIVE

Action tremor (AT) and resting tremor (RT) have been widely cited in many studies with Parkinson's disease (PD) patients, but studies looking at the association between the two tremor types are few and show inconsistent results. This study will look at the prevalence and association of AT and RT in a large sample of idiopathic PD patients, and will put the results into context with the literature.

METHODS

A retrospective chart review analysis of 332 patients with idiopathic PD was performed. Prevalence rates of particular tremor types were noted. The presence of AT was analyzed relative to the presence and severity of RT.

RESULTS

Nearly all individuals with AT also had RT. The concurrence of the two tremor types was found to be highly significant by statistical analysis (P < 0.0001). The severity of RT, measured by its laterality, may also be of importance, albeit to a much smaller extent if at all. Neither presence of tremor nor type of tremor present was influenced by patient gender, age, or Hoehn and Yahr stage of PD.

CONCLUSIONS

The results indicate that AT has extensive presence in PD. This and its seemingly close relationship to RT suggest that AT may be considered a variant of RT, particularly in PD patients. The degree of association between RT and AT needs to be further analyzed in PD, as well as in essential tremor (ET) and ET-PD.

Three-dimensional rodent motion analysis and neurodegenerative disorders

BACKGROUND

Three-dimensional (3D) motion analysis is established in investigating, human pathological motion. In the field of gait, its use results in the objective identification of primary, and secondary causes of deviations, many current interventions are the result of pre- and post-testing, and it was shown recently that it can result in decreased number of surgeries and overall cost of care. Consequently, recent attempts have implemented 3D motion analysis using rat models to study, parkinsonism. However, to-date, a 3D user friendly analytical approach using rodent models to, identify etiologies of age-related motor impairment and accompanying pathologies has not been, implemented.

NEW METHOD

We have developed and presented all aspects of a 3D, three body-segment rodent model, to analyze motions of the lower, upper and head segments between rodents of parkinsonism-type and, normal aging during free walking. Our model does not require transformation matrices to describe the, position of each body-segment. Because body-segment positions are not considered to consist of three, rotations about the laboratory axes, the rotations are not sequence dependent.

RESULTS

Each body-segment demonstrated distinct 3D movement patterns. The parkinsonism-type, genotype walked slower with less range of motion, similarly to patients with parkinsonism.

COMPARISON WITH EXISTING METHODS

This is the first model considering the rodent's body as three, distinct segments. To the best of our knowledge, it is the first model to ever consider and report the 3D, head motion patterns.

CONCLUSIONS

This novel approach will allow unbiased analysis of spontaneous locomotion in mouse, models of parkinsonism or normal aging.

Samuel Alexander Kinnier Wilson. Wilson's disease, Queen Square and neurology

This historical article describes the life and work of the British physician Samuel Alexander Kinnier Wilson (1878-1937), who was one of the world's greatest neurologists of the first half of the 20th century. Early in his career, Wilson spent one year in Paris in 1903 where he learned from Pierre-Marie at Bicêtre Hospital. He subsequently retained uninterrupted links with French neurology. He also visited in Leipzig the German anatomist Paul Flechsig. In 1904, Wilson returned to London, where he worked for the rest of his life at the National Hospital for the Paralysed and Epileptic (later the National Hospital for Nervous Diseases, and today the National Hospital for Neurology and Neurosurgery) in Queen Square, and also at Kings' College Hospital. He wrote on 'the old motor system and the new', on disorders of motility and muscle tone, on the epilepsies, on aphasia, apraxia, tics, and pathologic laughing and crying, and most importantly on Wilson's disease. The other objective of our paper is to commemorate the centenary of Wilson's most important work published in 1912 in Brain, and also in Revue Neurologique, on an illness newly recognized and characterized by him entitled "Progressive lenticular degeneration, a familial nervous disease associated with liver cirrhosis". He analyzed 12 clinical cases, four of whom he followed himself, but also four cases previously published by others and a further two that he considered in retrospect had the same disease as he was describing. The pathological profile combined necrotic damage in the lenticular nuclei of the brain and hepatic cirrhosis. This major original work is summarized and discussed in the present paper. Wilson not only delineated what was later called hepato-lenticular degeneration and Wilson's disease, but also introduced for the first time the terms extrapyramidal syndrome and extrapyramidal system, stressing the role of the basal ganglia in motility. The present historical work emphasizes the special contributions made by Wilson to the study of movement disorders, including akinesia and bradykinesia in Parkinson's disease, and their relation to basal ganglia pathology.

Clinical neurophysiology of psychogenic movement disorders: how to diagnose psychogenic tremor and myoclonus

Tremor and myoclonus are very common manifestations of psychogenic movement disorders (PMD). In this context, recording of movement disorders aims to provide objective criteria for a positive diagnosis of PMD, independently of the psychological situation. Neurophysiological observations are therefore considered to have a huge impact both on diagnosis and on therapeutic approaches. A specific recording strategy should be employed whenever the medical history or clinical clues raise the eventuality of a PMD. Polymyography coupled to accelerometry is used to demonstrate the major electrophysiological criteria of psychogenic tremor, namely spontaneous variability of tremor frequency and frequency entrainment induced by contralateral rhythmic tasks. Other features, such as paradoxical increase of tremor amplitude with mass loading, co-activation preceding tremor onset and alteration of voluntary contralateral motor performances when tremor is present, are also of interest. The clinical presentation of psychogenic myoclonus is extremely rich and polymorphous and can mimic virtually all forms of cortical, subcortical or spinal myoclonus. Focal, multifocal, axial or generalized jerks can occur. Psychogenic jerks can be sporadic or repetitive, rhythmic or arrhythmic, spontaneous or stimulus-induced. All of these parameters are crucial to determine an individualized neurophysiological strategy. Polymyography is critical to identify a ballistic pattern or a discordant or non-reproducible temporo-spatial organisation of the jerks, but has usually to be completed by other potentially decisive approaches. Reflex psychogenic myoclonus for example displays stimulus-response delays that are too long and variable. Spontaneous psychogenic jerks may be also preceded by a pre-movement potential, detectable by jerk-locked-back-averaging methods.

The neuropsychiatry of hyperkinetic movement disorders: insights from neuroimaging into the neural circuit bases of dysfunction

BACKGROUND

Movement disorders, particularly those associated with basal ganglia disease, have a high rate of comorbid neuropsychiatric illness.

METHODS

We consider the pathophysiological basis of the comorbidity between movement disorders and neuropsychiatric illness by 1) reviewing the epidemiology of neuropsychiatric illness in a range of hyperkinetic movement disorders, and 2) correlating findings to evidence from studies that have utilized modern neuroimaging techniques to investigate these disorders. In addition to diseases classically associated with basal ganglia pathology, such as Huntington disease, Wilson disease, the neuroacanthocytoses, and diseases of brain iron accumulation, we include diseases associated with pathology of subcortical white matter tracts, brain stem nuclei, and the cerebellum, such as metachromatic leukodystrophy, dentatorubropallidoluysian atrophy, and the spinocerebellar ataxias.

CONCLUSIONS

Neuropsychiatric symptoms are integral to a thorough phenomenological account of hyperkinetic movement disorders. Drawing on modern theories of cortico-subcortical circuits, we argue that these disorders can be conceptualized as disorders of complex subcortical networks with distinct functional architectures. Damage to any component of these complex information-processing networks can have variable and often profound consequences for the function of more remote neural structures, creating a diverse but nonetheless rational pattern of clinical symptomatology.

Phosphodiesterases: Regulators of cyclic nucleotide signals and novel molecular target for movement disorders

Movement disorders rank among the most common neurological disorders. During the last two decades substantial progress has been made in understanding of the pathological basis of these disorders. Although, several mechanisms have been proposed, downregulation of cyclic nucleotide mediated signaling cascade has consistently been shown to contribute to the striatal dysfunctioning as seen in movement disorders. Thus, counteracting dysregulated cyclic nucleotide signaling has been considered to be beneficial in movement disorders. Cyclic nucleotide phosphodiesterases (PDEs) are the enzymes responsible for the breakdown of cyclic nucleotides and upregulation in PDE activity has been reported in various movement disorders. Thus, PDE inhibition is considered to be a novel strategy to restore cerebral cyclic nucleotide levels and their downstream signalling cascade. Indeed, various PDE inhibitors have been tested pre-clinically and were reported to be neuroprotective in various neurodegenerative disorders associated with movement disabilities. In this review, we have discussed a putative role of PDE inhibitors in movement disorders and associated abnormalities.

The differential diagnosis of Huntington's disease-like syndromes: 'red flags' for the clinician

A growing number of progressive heredodegenerative conditions mimic the presentation of Huntington's disease (HD). Differentiating among these HD-like syndromes is necessary when a patient with a combination of movement disorders, cognitive decline, behavioural abnormalities and progressive disease course proves negative to the genetic testing for HD causative mutations, that is, IT15 gene trinucleotide-repeat expansion. The differential diagnosis of HD-like syndromes is complex and may lead to unnecessary and costly investigations. We propose here a guide to this differential diagnosis focusing on a limited number of clinical features ('red flags') that can be identified through accurate clinical examination, collection of historical data and a few routine ancillary investigations. These features include the ethnic background of the patient, the involvement of the facio-bucco-lingual and cervical district by the movement disorder, the co-occurrence of cerebellar features and seizures, the presence of peculiar gait patterns and eye movement abnormalities, and an atypical progression of illness. Additional help may derive from the cognitive-behavioural presentation of the patient, as well as by a restricted number of ancillary investigations, mainly MRI and routine blood tests. These red flags should be constantly updated as the phenotypic characterisation and identification of more reliable diagnostic markers for HD-like syndromes progress over the following years.

[Elaboration of the SPM template for the standardization of SPECT images with 123I-Ioflupane]

PURPOSE

Statistical parametric mapping (SPM) is a widely used produced for normalization of functional images. This study has aimed to develop a normalization template of (123)I-Ioflupane SPECT-imaging DaTSCAN(®), GE Healthcare), not available in SPM5, and to validate it compared to other quantification methods.

MATERIAL AND METHODS

In order to write the template we retrospectively selected 26 subjects who had no evidence of nigrostriatal degeneration and whose age distribution was similar to that of the patients in the usual practice of our Department: 2 subjects (7.6%) were < 35 years, 9 between 35-65 years (34.6%) and 15 > 65 years (57.7%). All the studies were normalized with the T1-template available in SPM5 and an average image of the value was obtained for each voxel. For validation we analyzed 60 patients: 30 with idiopathic Parkinson's disease patients (iPD) with right involvement (66.83±12.20 years) and 30 with essential tremor patients (ET) (67.27±8.33 years). Specific uptake rates (SUR) of different striatal regions were compared after image normalization with our template and the application of a semiautomated VOIs-map created with Analyze v9.0 ((©)BIR, Mayo Clinic), against two quantification methods: a) manual adjustment of a ROIs-map drawn in Analyze, and b) semi-automated method (HERMES-BRASS) with normalization and implementation of VOIs-map.

RESULTS

No statistically significant differences in the iPD/ET discriminatory capacity between the three methods analyzed were observed (p<0,001). The correlation of SUR after normalization with our «template» was higher than that obtained by method b) (R>0,871, p<0,001). This difference was greater in patients with PD.

CONCLUSIONS

Our study demonstrates the efficacy of our SPM «template» for (123)I-Ioflupane SPECT-imaging, obtained from normalization with «T1-template».

Secondary paroxysmal dyskinesia associated with 2009 H1N1 infection

Neurological complications associated with 2009 H1N1 infection in children have been reported and recognized worldwide. The most commonly reported neurological complications are seizures and encephalopathy. Secondary movement disorders are also associated with the infection, but such cases are rarely reported. Here, we describe the case of a 14-year-old boy with paroxysmal kinesigenic dyskinesia secondary to 2009 H1N1 infection, who presented with dystonia and choreic movement triggered by sudden voluntary movement.

Movement disorders after stroke in adults: a review

Background

Movement disorders occur in association with stroke and may have important clinical implications.

Methods

We reviewed the medical literature regarding the clinical phenomenology, prevalence, localization and etiologic implications, and treatments for movement disorders occurring after stroke in adult patients.

Results

Movement disorders occur uncommonly after stroke and include both hyperkinetic and parkinsonian conditions. They can occur at the time of stroke or appear as a later manifestation. Stroke lesions are typically due to small vessel cerebrovascular disease in the middle or posterior cerebral artery territory, vessels supplying the basal ganglia. Hemorrhagic lesions are more likely to induce hyperkinetic movements. Movement disorders in the setting of stroke tend to resolve spontaneously over time. Medical and surgical therapies are available to treat the movement problems.

Discussion

Movement disorders after stroke can be helpful in localizing lesions after stroke, determining the etiology of stroke, may need to be a target for therapy and may importantly influence long term outcome.

Stereotactic radiosurgery for movement disorders

Initially designed for the treatment of functional brain targets, stereotactic radiosurgery (SRS) has achieved an important role in the management of a wide range of neurosurgical pathologies. The interest in the application of the technique for the treatment of pain, and psychiatric and movement disorders has returned in the beginning of the 1990s, stimulated by the advances in neuroimaging, computerized dosimetry, treatment planning software systems, and the outstanding results of radiosurgery in other brain diseases. Since SRS is a neuroimaging-guided procedure, without the possibility of neurophysiological confirmation of the target, deep brain stimulation (DBS) and radiofrequency procedures are considered the best treatment options for movement-related disorders. Therefore, SRS is an option for patients who are not suitable for an open neurosurgical procedure. SRS thalamotomy provided results in tremor control, comparable to radiofrequency and DBS. The occurrence of unpredictable larger lesions than expected with permanent neurological deficits is a limitation of the procedure. Improvements in SRS technique with dose reduction, use of a single isocenter, and smaller collimators were made to reduce the incidence of this serious complication. Pallidotomies performed with radiosurgery did not achieve the same good results. Even though the development of DBS has supplanted lesioning as the first alternative in movement disorder surgery; SRS might still be the only treatment option for selected patients.

Electrophysiological evidences of organization of cortical motor information in the Basal Ganglia

During the last two decades, the many developments in the treatment of movement disorders such as Parkinson disease and dystonia have enhanced our understanding on organization of the basal ganglia, and this knowledge has led to other advances in the field. According to many electrophysiological and anatomical findings, it is considered that motor information from different cortical areas is processed through several cortico-basal ganglia loops principally in a parallel fashion and somatotopy from each cortical area is also well preserved in each loop. Moreover, recent studies suggest that not only the parallel processing but also some convergence of information occur through the basal ganglia. Information from cortical areas whose functions are close to each other tends to converge in the basal ganglia. The cortico-basal ganglia loops should be comprehended more as a network rather than as separated subdivisions. However, the functions of this convergence still remain unknown. It is important even for clinical doctors to be well informed about this kind of current knowledge because some symptoms of movement disorders may be explained by disorganization of the information network in the basal ganglia.

Movement dysfunction in patients with Parkinson's disease: A literature review

Experimental evidence has shown that people with Parkinson's disease have deficits in the initiation and execution of movements. The delay in response initiation may be due to impairment in the organisation or translation of motor programs into muscle actions. The slowness in the execution of simple movements may result from inappropriate scaling of muscle activity, defective predictive function or defective memory for the computed forces. Extra slowness in the execution of complicated concurrent movements appears to be a result of deficits in switching from one program to another within a motor plan in sequential movements, or in superimposition of motor programs to form a motor plan in simultaneous movements.