Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heavily T2-weighted high-field MR images provide a unique opportunity for the evaluation of the extrapyramidal motor system. The images are affected by the presence of small amounts of naturally occurring paramagnetic substances--principally iron--that delineate the neostriatum (caudate and putamen), globus pallidus, red nucleus, substantia nigra, and dentate nucleus, primarily by a decrease in signal secondary to the T2* effect. Movement disorders are associated with either increased or decreased signal or both in these structures, depending on the pathologic process. In the initial evaluation of 113 patients with a variety of movement disorders, good correlation of imaging abnormalities can be made with a simplified schema of the extrapyramidal pathways and a system of classification of abnormal movements, parkinsonism/tremor, dystonia, chorea, myoclonus, and hemiballismus. Parkinsonisms are characterized by abnormalities of the cortico-ponto-cerebello-dentato-rubro-thalamo-cortico-spinal tract or the nigrostriatal tract. Dystonias are characterized by abnormalities of the neostriatum predominantly affecting the putamen. Choreas are also characterized by abnormalities of the neostriatum but predominantly affecting the caudate nucleus. Hemiballismus is characterized by lesions affecting the subthalamic nucleus or associated pathway.
 ...
PMID:Study of movement disorders and brain iron by MR. 244 Feb 91

Tardive dyskinesia (TD) is a consequence of chronic neuroleptic therapy. It is an irregular stereotyped movement disorder that is usually choreic in appearance, and is subject to temporary volitional control. Dystonia, akathisia, and tics are uncommon variants of the classic tardive syndrome. Characteristic clinical features including amelioration by action, augementation by distraction, partial volitional suppressibility, and lack of subjective distress help differentiate TD from other movement disorders such as resting tremor, Huntington's disease, spontaneous dyskinesias, and abnormal movements accompanying psychiatric illnesses.
 ...
PMID:Recognition and differential diagnosis of tardive dyskinesia. 257 70

Movement disorders are well-known presenting signs of metabolic disorders. Focal motor abnormalities may be the chief initial presentation of diabetes mellitus in the nonketotic hyperglycemic state in 6% of patients. Nonketotic hyperglycemia (NKH), in particular, may manifest any of a wide variety of movement disorders. These have been described as focal seizures, epilepsia partialis continua, myoclonus, and opsoclonia. There are descriptions of movement disorders in hyperglycemia that are similar to the coarse flapping tremor of asterixis, the posturing of paroxysmal kinetogenic choreoathetosis, and of "fencing (stance) seizures." Disorders of facial motor function including aphasia, facial muscle twitching and jerking, and disorders of muscular tone have been described. These may include hemiparesis and hemiplegias as well as increased tone, in some cases mimicking the nuchal rigidity of meningitis. The movement disorders in NKH may mimic cerebral vascular accidents, meningitis, or psychiatric disorders, as well as various types of seizures. Clinicians may be able to avoid expensive and time-consuming diagnostic evaluations to rule out NKH in patients with movement disorders. We present two patients with focal motor abnormalities associated with nonketonic hyperglycemia and review the pertinent literature.
 ...
PMID:Movement disorders as a manifestation of nonketotic hyperglycemia. 260 Mar 93

Two patients with legs tremor present on standing, but none on walking or sitting, are reported. Tremor was not exclusive or orthostatism and was also evoked by strong tonic contraction of leg muscles. Synchronous EMG bursts were recorded in antagonistic muscle groups at 8-10 Hz in the first patient and at 16 Hz in the second. EMG activity was synchronous in corresponding muscles of both legs. The occurrence of EMG activity was not influenced by stimulation of nerve afferent fibers. We suggest that this movement disorder may be an exaggeration of physiological tremor due to synchronization of motor units by spontaneous oscillations in central structures.
 ...
PMID:Orthostatic tremor: report of two cases and an electrophysiological study. 271 18

Movement disorders other than cerebellar tremor are rare clinical manifestations of multiple sclerosis (MS). Two cases of parkinsonism and a case of chorea associated with MS are reported, and the literature is reviewed.
 ...
PMID:Movement disorders in multiple sclerosis. 306 39

The anatomical location of the thalamic target (ventrolateral nucleus) during stereotactic thalamotomy for a movement disorder was determined using magnetic resonance imaging (MRI) to define the anterior and posterior commissures and the intercommissural plane. Precise targeting was confirmed by intraoperative stereotactic computed tomography (CT), electrophysiological stimulation, and a gratifying postoperative response (disappearance of contralateral tremor and rigidity). The use of a MRI- and CT-compatible stereotactic coordinate frame allowed multiplanar imaging with excellent spatial and contrast resolution, visualization of the source of the tremor (prior embolic stroke affecting the dentatorubrothalamic pathway), and correction for the more medial location of the internal capsule in this patient. Location did not vary among target sites seen with MRI and CT imaging techniques. In this patient MRI during stereotactic thalamotomy supplemented CT and the electrophysiological technique that we conventionally use to define the ventrolateral nucleus. Although the importance of possible magnetic susceptibility imaging artifacts remains to be elucidated, stereotactic MRI may prove sufficiently accurate in the future to replace other imaging techniques used during functional neurosurgery.
 ...
PMID:Magnetic resonance imaging stereotactic thalamotomy: report of a case with comparison to computed tomography. 306 14

The genetically dystonic rat (dt) displays a complex movement disorder in the absence of morphological defects in the nervous system. This mutant is also insensitive to the tremorogenic effects of harmaline. Because harmaline is known to act on the cells of the inferior olive to induce activity at the tremor frequency in the olivocerebellobulbar pathway, this pathway has been investigated as a possible site of a defect in the dt rat. Biochemical studies suggested the presence of abnormalities at the level of the Purkinje cell or its afferent input. Thus, the present study investigated the harmaline response of Purkinje cells in dt rats and unaffected littermate controls with extracellular single-unit recording techniques. The spontaneous, simple spike and complex spike firing rates of dt rats were significantly lower than those of normal littermate controls. In normal rats, 2 responses to systemic harmaline injection were seen. Simple spikes were either completely suppressed for periods of 30-180 min, or were intermittently suppressed, pausing repeatedly for periods of 1-18 sec. Cells that showed complete suppression of simple spike activity also showed increased frequency and rhythmicity of complex spikes. In dt rats, intermittent simple spike responses were seen in a proportion (41%) similar to that in normal rats (53%). However, the proportion of cells showing high-frequency, rhythmic, complex spikes and complete suppression of simple spikes was low in the dt rats in comparison with littermate controls (18 versus 47%). In addition, 41% of the cells from dt rats displayed no change, or an anomalous change, in firing patterns in response to harmaline. Since the rhythmic activation of olivary neurons that results in the rhythmic, complex spike discharge of Purkinje cells is assumed to be responsible for the appearance of harmaline tremor, the failure of the dt rat to display tremor is most likely due to a failure at the olivocerebellar level, rather than at a site efferent to the cerebellum.
 ...
PMID:Spontaneous and harmaline-stimulated Purkinje cell activity in rats with a genetic movement disorder. 317 80

Movement disorders are usually of central origin, but sometimes involuntary movements occur after peripheral trauma. Twenty eight patients, 13 women and 15 men, mean age 37 years (range 15-78), were studied with dystonia or tremor in whom the onset of abnormal movements was related, in time and in distribution, to injury of a body part. Among 23 patients with latency of less than one year after injury, focal dystonia of the involved body part was found in 18, nine of whom had associated reflex sympathetic dystrophy (RSD). One of five patients with peripherally induced tremor had RSD. Abnormal electromyography or nerve conduction velocities were found in the affected limb in four patients, but other electrophysiologic techniques provided evidence for disturbed central function. In 15 patients (65%) possible predisposing factors may have contributed to the pathogenesis of the trauma induced abnormal involuntary movements.
 ...
PMID:Dystonia and tremor induced by peripheral trauma: predisposing factors. 322 Dec 19

Two hundred consecutive patients affected by essential tremor (ET), referred to the Movement Disorders Center of the University of Bologna between January 1977 and December 1981, were studied to identify the different clinical features of this disorder, and its associated neurological signs. In this series, 169 patients suffered from typical essential tremor (TET); in the other 31 cases uncommon clinical features were detected: 25 presented postural, action and rest tremor (continuous tremor: CT); 5 had orthostatic tremor (OT) and 1 was affected by writing tremor (WT). Buccolinguofacial dyskinesias (BLFD) were associated with ET in 19 cases; 2 presented dystonia, and in 6 mild extrapyramidal signs were detected. Uncommon types of tremor: ET plus BLFD and ET associated with extrapyramidal signs had an higher incidence in older people. No patient developed Parkinson's disease (PD) during the follow-up period (2-5 years).
 ...
PMID:Different clinical features of essential tremor: a 200-patient study. 357 75

We studied seven patients with AIDS or AIDS-related complex (ARC) and movement disorders. Three had hemichorea-ballismus, two had segmental myoclonus, one had postural tremor with dystonia, and one had paroxysmal dystonia. Besides the hyperkinesias, two patients had parkinsonism, and one had cerebral Whipple's disease. In two, the movement disorder preceded other evidence of AIDS; in three others, the diagnosis of AIDS was not considered until there was a movement disorder. The movement disorders were attributed to toxoplasmosis in four patients (one confirmed at autopsy), viral encephalitis, vacuolar myelopathy, and CNS Whipple's disease.
 ...
PMID:Movement disorders and AIDS. 379 36


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>