-
Brain : a Journal of Neurology Aug 2023In the field of rare diseases, progress in molecular diagnostics led to the recognition that variants linked to autosomal-dominant neurodegenerative diseases of later...
In the field of rare diseases, progress in molecular diagnostics led to the recognition that variants linked to autosomal-dominant neurodegenerative diseases of later onset can, in the context of biallelic inheritance, cause devastating neurodevelopmental disorders and infantile or childhood-onset neurodegeneration. TOR1A-associated arthrogryposis multiplex congenita 5 (AMC5) is a rare neurodevelopmental disorder arising from biallelic variants in TOR1A, a gene that in the heterozygous state is associated with torsion dystonia-1 (DYT1 or DYT-TOR1A), an early-onset dystonia with reduced penetrance. While 15 individuals with AMC5-TOR1A have been reported (less than 10 in detail), a systematic investigation of the full disease-associated spectrum has not been conducted. Here, we assess the clinical, radiological and molecular characteristics of 57 individuals from 40 families with biallelic variants in TOR1A. Median age at last follow-up was 3 years (0-24 years). Most individuals presented with severe congenital flexion contractures (95%) and variable developmental delay (79%). Motor symptoms were reported in 79% and included lower limb spasticity and pyramidal signs, as well as gait disturbances. Facial dysmorphism was an integral part of the phenotype, with key features being a broad/full nasal tip, narrowing of the forehead and full cheeks. Analysis of disease-associated manifestations delineated a phenotypic spectrum ranging from normal cognition and mild gait disturbance to congenital arthrogryposis, global developmental delay, intellectual disability, absent speech and inability to walk. In a subset, the presentation was consistent with foetal akinesia deformation sequence with severe intrauterine abnormalities. Survival was 71%, with higher mortality in males. Death occurred at a median age of 1.2 months (1 week-9 years), due to respiratory failure, cardiac arrest or sepsis. Analysis of brain MRI studies identified non-specific neuroimaging features, including a hypoplastic corpus callosum (72%), foci of signal abnormality in the subcortical and periventricular white matter (55%), diffuse white matter volume loss (45%), mega cisterna magna (36%) and arachnoid cysts (27%). The molecular spectrum included 22 distinct variants, defining a mutational hotspot in the C-terminal domain of the Torsin-1A protein. Genotype-phenotype analysis revealed an association of missense variants in the 3-helix bundle domain to an attenuated phenotype, while missense variants near the Walker A/B motif as well as biallelic truncating variants were linked to early death. In summary, this systematic cross-sectional analysis of a large cohort of individuals with biallelic TOR1A variants across a wide age-range delineates the clinical and genetic spectrum of TOR1A-related autosomal-recessive disease and highlights potential predictors for disease severity and survival.
Topics: Male; Humans; Cross-Sectional Studies; Mutation; Phenotype; Dystonia; Dystonic Disorders; Nervous System Malformations; Molecular Chaperones
PubMed: 36757831
DOI: 10.1093/brain/awad039 -
BMJ Clinical Evidence Jun 2011Dystonia is usually a lifelong condition with persistent pain and disability. Focal dystonia affects a single part of the body; generalised dystonia can affect most or... (Review)
Review
INTRODUCTION
Dystonia is usually a lifelong condition with persistent pain and disability. Focal dystonia affects a single part of the body; generalised dystonia can affect most or all of the body. It is more common in women, and some types of dystonia are more common in people of European Ashkenazi Jewish descent.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments, surgical treatments, and physical treatments for focal, and for generalised dystonia? We searched: Medline, Embase, The Cochrane Library, and other important databases up to February 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 15 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review, we present information relating to the effectiveness and safety of the following interventions: acetylcholine release inhibitors (botulinum toxin), acupuncture, anticholinergic/antihistaminic drugs, anticonvulsants, atypical antipsychotic drugs, benzodiazepines, biofeedback, chiropractic manipulation, deep brain stimulation of thalamus and globus pallidus, dopaminergic agonists and antagonists, gamma-aminobutyric acid (GABA) analogues, microvascular decompression, muscle relaxants, myectomy, occupational therapy, osteopathy, pallidotomy, physiotherapy, selective peripheral denervation, serotonergic agonists and antagonists, speech therapy, and thalamotomy.
Topics: Botulinum Toxins; Dystonia; Dystonia Musculorum Deformans; Dystonic Disorders; GABA Antagonists; Globus Pallidus; Humans
PubMed: 21663705
DOI: No ID Found -
Current Opinion in Neurology Aug 2019Our understanding of X-Linked Dystonia-Parkinsonism (XDP) has advanced considerably in recent years because of a wealth of new data describing its genetic basis,... (Review)
Review
PURPOSE OF REVIEW
Our understanding of X-Linked Dystonia-Parkinsonism (XDP) has advanced considerably in recent years because of a wealth of new data describing its genetic basis, cellular phenotypes, neuroimaging features, and response to deep brain stimulation (DBS). This review provides a concise summary of these studies.
RECENT FINDINGS
XDP is associated with a SINE-VNTR-Alu (SVA)-type retrotransposon insertion within the TAF1 gene. This element includes a hexameric DNA repeat expansion, (CCCTCT)n, the length of which varies among patients and is inversely correlated to age of disease onset. In cell models, the SVA alters TAF1 splicing and reduces levels of full-length transcript. Neuroimaging data have confirmed previous neuropathology studies that XDP involves a progressive striatal atrophy, while further detecting functional alterations in additional brain regions. In patients exhibiting features of both dystonia and parkinsonism, pallidal DBS has resulted in rapid improvement of hyperkinetic movements, but effects on hypokinetic features have been inconsistent.
SUMMARY
The discovery that XDP is linked to a polymorphic hexameric sequence suggests that it could share mechanisms with other DNA repeat disorders, whereas the transcriptional defect in cell models raises the possibility that strategies to correct TAF1 splicing could provide therapeutic benefit.
Topics: Brain; DNA Repeat Expansion; Deep Brain Stimulation; Dystonic Disorders; Genetic Diseases, X-Linked; Humans
PubMed: 31116117
DOI: 10.1097/WCO.0000000000000708 -
Science Translational Medicine May 2023Dystonia, a neurological disorder defined by abnormal postures and disorganized movements, is considered to be a neural circuit disorder with dysfunction arising within...
Dystonia, a neurological disorder defined by abnormal postures and disorganized movements, is considered to be a neural circuit disorder with dysfunction arising within and between multiple brain regions. Given that spinal neural circuits constitute the final pathway for motor control, we sought to determine their contribution to this movement disorder. Focusing on the most common inherited form of dystonia in humans, DYT1-, we generated a conditional knockout of the torsin family 1 member A () gene in the mouse spinal cord and dorsal root ganglia (DRG). We found that these mice recapitulated the phenotype of the human condition, developing early-onset generalized torsional dystonia. Motor signs emerged early in the mouse hindlimbs before spreading caudo-rostrally to affect the pelvis, trunk, and forelimbs throughout postnatal maturation. Physiologically, these mice bore the hallmark features of dystonia, including spontaneous contractions at rest and excessive and disorganized contractions, including cocontractions of antagonist muscle groups, during voluntary movements. Spontaneous activity, disorganized motor output, and impaired monosynaptic reflexes, all signs of human dystonia, were recorded from isolated mouse spinal cords from these conditional knockout mice. All components of the monosynaptic reflex arc were affected, including motor neurons. Given that confining the conditional knockout to DRG did not lead to early-onset dystonia, we conclude that the pathophysiological substrate of this mouse model of dystonia lies in spinal neural circuits. Together, these data provide new insights into our current understanding of dystonia pathophysiology.
Topics: Humans; Mice; Animals; Dystonia; Dystonia Musculorum Deformans; Mice, Knockout; Brain; Molecular Chaperones
PubMed: 37134150
DOI: 10.1126/scitranslmed.adg3904 -
BMJ Clinical Evidence Sep 2008Dystonia is usually a lifelong condition with persistent pain and disability. Focal dystonia affects a single part of the body; generalised dystonia can affect most or... (Review)
Review
INTRODUCTION
Dystonia is usually a lifelong condition with persistent pain and disability. Focal dystonia affects a single part of the body; generalised dystonia can affect most or all of the body. It is more common in women, and some types of dystonia are more common in people of European Ashkenazi Jewish descent.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments, surgical treatments, and physical treatments for focal, and for generalised dystonia? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 13 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: acetylcholine receptor inhibitors, acupuncture, anticholinergic drugs, anticonvulsants, atypical antipsychotic drugs, benzodiazepines, biofeedback, botulinum toxin, chiropractic manipulation, deep brain stimulation of thalamus and globus pallidus, dopaminergic agonists and antagonists, gamma-aminobutyric acid (GABA) inhibitors, microvascular decompression, myectomy, occupational therapy, osteopathy, pallidotomy, physiotherapy, selective peripheral denervation, serotonergic agonists and antagonists, speech therapy, and thalamotomy.
Topics: Botulinum Toxins; Deep Brain Stimulation; Dystonia; Dystonia Musculorum Deformans; Dystonic Disorders; Follow-Up Studies; GABA Antagonists; Globus Pallidus; Humans
PubMed: 19445800
DOI: No ID Found -
JAMA Neurology Jun 2015Dystonia is a heterogeneous neurologic disorder characterized by abnormal muscle contractions for which standard medical therapy is often inadequate. For such patients,... (Review)
Review
IMPORTANCE
Dystonia is a heterogeneous neurologic disorder characterized by abnormal muscle contractions for which standard medical therapy is often inadequate. For such patients, therapeutic brain stimulation is becoming increasingly used.
OBJECTIVES
To review the evidence and effect sizes for treating different types of dystonia with different types of brain stimulation and to discuss recent advances relevant to patient selection, surgical approach, programming, and mechanism of action.
EVIDENCE REVIEW
PubMed was searched for publications on the clinical effect of brain stimulation in dystonia up through December 31, 2014. Recent meta-analyses, consensus statements, and evidence-based guidelines were incorporated. Emphasis was placed on deep brain stimulation (DBS) and randomized clinical trials; however, other stimulation modalities and trial designs were included. For each intervention the mean change in dystonia severity, number of patients studied, and evidence of efficacy based on American Academy of Neurology criteria were determined.
FINDINGS
Strong (level B) evidence supports the use of DBS for the treatment of primary generalized or segmental dystonia, especially when due to mutation in the DYT1 gene, as well as for patients with cervical dystonia. Large effect sizes have also been reported for DBS treatment of tardive dystonia, writer's cramp, cranial dystonia, myoclonus dystonia, and off-state dystonia associated with Parkinson disease. Lesser benefit is generally seen in dystonia secondary to structural brain damage. Other brain stimulation techniques, including epidural cortical stimulation and noninvasive brain stimulation, have been investigated, but generally report smaller effect sizes in fewer patients.
CONCLUSIONS AND RELEVANCE
Patients with dystonia that is not adequately controlled with standard medical therapy should be referred for consideration of DBS, especially patients with generalized, segmental, or cervical dystonia. Other less-invasive stimulation modalities require further research before being considered a therapeutic alternative.
Topics: Deep Brain Stimulation; Dystonia Musculorum Deformans; Humans
PubMed: 25894231
DOI: 10.1001/jamaneurol.2015.51 -
Neurobiology of Disease May 2011Primary torsion dystonia (PTD) is defined as a syndrome in which dystonia is the only clinical sign (except for tremor), and there is no evidence of neuronal... (Review)
Review
Primary torsion dystonia (PTD) is defined as a syndrome in which dystonia is the only clinical sign (except for tremor), and there is no evidence of neuronal degeneration or an acquired cause by history or routine laboratory assessment. Seven different loci have been recognized for PTD but only two of the genes have been identified. In this review we will describe the phenotypes associated with these loci and discuss the responsible gene. This article is part of a Special Issue entitled "Advances in dystonia".
Topics: Age of Onset; Dystonia Musculorum Deformans; Humans; Phenotype
PubMed: 21168499
DOI: 10.1016/j.nbd.2010.12.012