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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stereotypies are patterned, repetitive, purposeless movements that are performed the same way each time. They are commonly seen in individuals with autism, schizophrenia, or mental retardation, and also occur as a feature of tardive dyskinesia and as movements in those with akathisia. We studied 10 children who had stereotypies but were not autistic or mentally retarded. Although most had an uneventful delivery, seven had mild to moderately delayed developmental milestones. Five had hyperactive behavior or attention-deficit problems. All appeared to be of normal intelligence. The median age of onset of stereotypies was 12 months. The stereotypies including arm flapping, arm and hand posturing, finger wiggling, body rocking, leg shaking, facial grimacing, involuntary noises, neck extension, and eye blinking. Of the 10 children, only two stopped having stereotypies eventually without medications.
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PMID:The characterization and outcome of stereotypical movements in nonautistic children. 899 53

Motor and phonic tics are most frequently due to Tourette syndrome, but there are many other causes of tics. We analyzed data on 155 patients with tics and co-existent disorders (101M/54F; mean age 40.5 +/- 20.2 years). Fourteen (9.0%) patients had tics associated with an insult to the basal ganglia, such as head trauma (N = 4, 2.5%), stroke (N = 2, 1.2%), encephalitis (N = 3, 1.9%) and other causes. In addition, certain drugs, toxins, and post-infectious causes were associated with tics. Rarely, peripheral injury can cause movement disorders, including tics (N = 1, 0.6%). Pervasive developmental disorders, including Asperger's syndrome (N = 13, 8.3%), mental retardation (N = 4, 2.5%), autism (N = 3, 1.9%), and Savant's syndrome (N = 1, 0.6%), also may be associated with tics, as noted in 21 of the 155 patients (13.5%). Genetic and chromosomal disorders, such as Down's syndrome 5 (3.2%), neuroacanthocytosis (N = 2, 1.2%), and Huntington's disease (N = 1, 0.6%), were associated with tics in 16 patients (10.3%). We have also examined the co-existence of tics and other movement disorders such as dystonia (N = 31, 20.0%) and essential tremor (N = 17, 10.9%). Sixteen (10.3%) patients presented psychogenic tics, and one (0.6%) psychogenic tics and dystonia; conversely, Tourette syndrome preceded the onset of psychogenic dystonia (N = 1, 0.6%), and psychogenic tremor (N = 1, 0.6%) in two patients. Finally, 12 (7.7%) patients had tics in association with non-movement related neurological disorders, such as static encephalopathy (N = 2, 1.2%) and seizures (N = 3, 1.9%). To understand the physiopathology of tics and Tourette syndrome, it is important to recognize that these may be caused or associated with other disorders.
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PMID:Secondary tics and tourettism. 1596 46

The fragile X mental retardation 1 gene (FMR1) mutation causes two disorders: fragile X syndrome (FXS) in those with the full mutation and the fragile X-associated tremor/ataxia syndrome (FXTAS) in some older individuals with the premutation. FXS is caused by a deficiency of the FMR1 protein (FMRP) leading to dysregulation of many genes that create a phenotype with ADHD, anxiety, and autism. FXTAS is caused by the elevation of FMR1-mRNA to levels 2 to 8 times normal in the premutation. This causes an RNA gain of function toxicity leading to brain atrophy, white matter disease, neuronal and astrocytic inclusion formation, and subsequent ataxia, intention tremor, peripheral neuropathy, and cognitive decline. The neurobiology and pathophysiology of FXS and FXTAS are described in detail.
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PMID:Lessons from fragile X regarding neurobiology, autism, and neurodegeneration. 1651 73

Recent advances in our understanding of the clinical and molecular features of the fragile-X mental-retardation 1 gene, FMR1, highlight the importance of single-gene disorders. 15 years after its discovery, FMR1 continues to reveal new and unexpected clinical presentations and molecular mechanisms. Loss of function of FMR1 is a model for neurodevelopmental and behavioural disorders, including mental retardation, autism, anxiety, and mood instability. In addition, overexpression and CNS toxicity of FMR1 mRNA causes a late-onset neurodegenerative disorder, the fragile-X-associated tremor/ataxia syndrome (FXTAS). A similar mechanism is probably involved in premature ovarian failure, which affects up to 20% of female carriers of an altered FMR1 gene.
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PMID:Fragile-X syndrome and fragile X-associated tremor/ataxia syndrome: two faces of FMR1. 1716 1

Premutation alleles (55-200 CGG repeats) of the fragile X mental retardation 1 (FMR1) gene are associated with autism spectrum disorder in childhood, premature ovarian failure, and the neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome (FXTAS). FXTAS, and perhaps the other clinical presentations among carriers, are thought to be due to toxic gain-of-function of elevated levels of the expanded-repeat FMR1 mRNA. Previous structural MRI studies have implicated the amygdala as a potential site of dysfunction underlying social deficits and/or risk for FXTAS. As a preliminary investigation of this possible association, adult males with the premutation, and male controls matched for IQ, age and education, completed three protocols that probe amygdala and sympathetic function: (i) a functional MRI paradigm that measures brain response to fearful faces; (ii) a fear-potentiated startle paradigm that differentiates responses to fearful faces and fearful non-social images and (iii) measurement of skin conductance level during a brief social encounter. Compared with controls, men with the FMR1 premutation demonstrated diminished brain activation in the amygdala and several brain areas that mediate social cognition while viewing fearful faces. The reduced amygdala activation in the premutation group was significantly associated with self-report of psychological symptoms on the Symptom Checklist-90--Revised. These men also displayed a lack of startle potentiation while viewing fearful faces and showed reduced skin conductance response when greeting an unfamiliar experimenter in comparison with the control group. The current findings may be related to social cognition deficits reported previously in children and adults with the premutation. The aetiology for this dysfunction may be elevated FMR1 mRNA or reduced FMR1 protein that occurs in carriers with higher premutation CGG repeat alleles.
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PMID:Amygdala dysfunction in men with the fragile X premutation. 1716 60

This work represents a first step towards the development of a sensorised environment for behavioral phenotyping of animal models. In particular, this paper focuses on tremor analysis in reeler mice, an emerging potential animal model for anatomical and behavioral traits observed in autism. Ground Reaction Force (GRF) sensing is indeed the most direct means of measuring tremor. Although force platforms have extensively been used for large size animals, only few attempts have been made to measure GRF at a single paw for animals as small as mice or rats. Under the hypothesis that in-plane GRF components are directly connected to tremor, a small size, low-cost, 2-axis force sensor for measuring the in-plane components of GRF was designed and developed. Special care was paid to allow self-aligned assembly for repeatability and modularity for combining multiple platforms for a sensorised floor. Preliminarily testing was performed with both reeler and wildtype mice. Fourier analysis was deployed to extract information due to tremor, validating the hypothesis of a direct connection between tremor and in-plane GRFs.
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PMID:Design and development of a miniaturized 2-axis force sensor for tremor analysis during locomotion in small-sized animal models. 1728 82

Premutation carriers of repeat expansions in the fragile X mental retardation (FMR1) gene develop kinetic tremor and ataxia or the 'fragile X associated tremor/ataxia syndrome' (FXTAS). Affected FMR1 premutation carriers also have parkinsonism, but have not been reported to meet criteria for Parkinson disease. This case series illustrates that some patients who are FMR1 premutation carriers may appear by history and examination to have idiopathic Parkinson disease. Based on previous studies, it is likely that the genetic mutation and parkinsonism are associated. Although screening all PD patients is likely to be low yield, genetic testing of FMR1 in individuals with PD and a family history of fragile X syndrome, autism or developmental delay, or other related FMR1 phenotypes is warranted.
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PMID:Parkinsonism in FMR1 premutation carriers may be indistinguishable from Parkinson disease. 1856 83

Bipedal locomotion and fine motility of hand and larynx of humans introduced musculoskeletal adaptations, new pyramidal, corticostriatal, corticobulbar, nigrostriatal, and cerebellar pathways and expansions of prefrontal, cingular, parieto-temporal and occipital cortices with derived new brain capabilities. All selectively degenerate in aged homo sapiens following 16 syndromic presentations: (1) Parkinsonism: nigrostriatal control for fast automatic movements of hand, larynx, bipedal posture and gait ("simian gait and hand"). (2) Frontal (highest level) gait disorders (lower body parkinsonism, gait apraxia, retropulsion): prefrontostriatal executive control of bipedal locomotion. (3) ataxia: new synergistic coordination of bipedal gait and fine motility. (4) Dyskinesias (chorea, dystonia, tremor...): intrusions of simian basal ganglia motor subroutines. (5) motoneuron diseases: new proximo-distal and bulbar motoneurones, preserving older ones (oculomotor, abdominal...). (6) Archaic reflexes: prefrontal disinhibition of old mother/tree-climbing-oriented reflexes (sucking, grasping, Babinski/triple retraction, gegenhalten), group alarms (laughter, crying, yawning, grunting...) or grooming (tremor=scratching). (7) Dysautonomia: contextual regulation (orthostatism...). (8) REM sleep disorders of new cortical functions. (9) Corticobasal syndrome: melokinetic control of hand prehension-manipulation and language (retrocession to simian patterns). (10) Frontal/temporal lobe degeneration: medial-orbitofrontal behavioural variant: self monitoring of internal needs and social context: apathy, loss of personal hygiene, stereotypia, disinhibition, loss of concern for consequences of acts, social rules, danger and empathy; dorsolateral executive variant: inadequacy to the context of action (goal, environmental changes...); progressive non-fluent aphasia: executive and praxic processing of speech; temporal variant: abstract concepts for speech, gestures and vision (semantic dementia, progressive nonfluent aphasia) (11) Temporomesial-limbic-paralimbic-associative cortical dementias (Alzheimer's disease, Lewy body, progressive amnesia): processing of explicit cognition: amnesic syndrome, processing of hand, larynx and eye: disorientation, ideomotor apraxia, agnosia, visuospatial processing, transcortical aphasia. (12) Focal posterior atrophy (Benson, progressive apraxia): visuomotor processing of what and where. (13) Macular degeneration: retinal "spot" for explicit symbols. (14) "Psychiatric syndromes": metacognition, self monitoring and regulation of hierarchical processing of metacognition: hallucinations, delusions, magic and mystic logic, delusions, confabulations; drive: impulsivity, obsessive-compulsive disorders, mental automatisms; social interactions: theory of mind, autism, Asperger. (15) Mood disorders: control on emotions: anxio-depressive and bipolar disorders, moria, emotional lability. (16) Musculoskeletal: inclusion body myositis: muscles for bipedal gait and fine motility. Paget's disease: bones for bipedal gait and cranium. Understanding of the genetic mechanisms underlying the evolution of these recent human brain regions and paleoneurology my be the key to the focal, asymmetrical or systemic character of neurodegeneration, the pathologic heterogeneity/overlap of syndromic presentations associating gait, hand, language, cognition, mood and behaviour disorders.
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PMID:Paleoneurology: neurodegenerative diseases are age-related diseases of specific brain regions recently developed by Homo sapiens. 1870 90

The FMR1 mutations can cause a variety of disabilities, including cognitive deficits, attention-deficit/hyperactivity disorder, autism, and other socioemotional problems, in individuals with the full mutation form (fragile X syndrome) and distinct difficulties, including primary ovarian insufficiency, neuropathy and the fragile X-associated tremor/ataxia syndrome, in some older premutation carriers. Therefore, multigenerational family involvement is commonly encountered when a proband is identified with a FMR1 mutation. Studies of metabotropic glutamate receptor 5 pathway antagonists in animal models of fragile X syndrome have demonstrated benefits in reducing seizures, improving behavior, and enhancing cognition. Trials of metabotropic glutamate receptor 5 antagonists are beginning with individuals with fragile X syndrome. Targeted treatments, medical and behavioral interventions, genetic counseling, and family supports are reviewed here.
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PMID:Advances in the treatment of fragile X syndrome. 1911 5

CGG repeat expansions in the 5' noncoding region of the fragile X mental retardation 1 gene (FMR1) give rise to both neurodevelopmental and neurodegenerative human diseases depending on the length of the expansion. Expansions beyond 200 repeats (full mutation) generally result in gene silencing and fragile X syndrome (FXS), the leading heritable form of cognitive impairment and autism. Smaller expansions (55-200 CGG repeats; "premutation") give rise to the neurodegenerative disorder fragile X-associated tremor/ataxia syndrome (FXTAS) through an entirely distinct, toxic mRNA gain-of-function mechanism. A rapid means for both high-risk and newborn screening for allele size would provide a greater opportunity for early intervention and family counseling as well as furnish critical data on repeat size distribution and expanded allele frequencies. In the current work, we propose a novel mass spectrometry (MS) based method for the rapid identification of expanded CGG repeats to complement a recently described polymerase chain reaction (PCR) method for large population screening. In this combined approach, the optimized PCR method is used to amplify the relevant region of FMR1, followed by extensive nonspecific nuclease digestion. The resulting oligonucleotides are analyzed by MS in a manner that provides the relative proportion of triplet repeat oligonucleotides in seconds per sample. This assay enables swift and reproducible detection of expanded CGG alleles using a single blood spot and in principle is suitable for large scale studies and newborn screening. Moreover, this analytical scheme establishes a unique new intersection of MS with molecular biology, with potential for significant interdisciplinary impact.
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PMID:Polymerase chain reaction, nuclease digestion, and mass spectrometry based assay for the trinucleotide repeat status of the fragile X mental retardation 1 gene. 1951 25


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