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

Physiological and pharmacological studies of more than 150 patients with movement disorders are reported. Particular attention is paid to the differentiation of various types of tremor on the basis of rate, rhythm, and pattern of EMG activity in antagonistic muscles. The typical 'tremor-at-rest' of Parkinson's disease--3-7 Hz activity which alternates between antagonistic muscles--is suppressed, at least briefly, during voluntary activity, at which time typical 8--12 Hz 'physiological tremor' may be seen. Essential tremor and its familial or senile variants also have a characteristic EMG pattern during voluntary activity--5-8 Hz bursts of activity which are synchronous in antagonistic muscles. This type of tremor may also be present in patients with Parkinson's disease and in certain kinships with a Charcot-Marie-Tooth polyneuropathy. Other tremors in association with polyneuropathy ('neuropathic tremor') have different physiological characteristics. Myoclonus is of essentially two types ('positive' with EMG bursts and 'negative' with brief pauses in ongoing activity, as with asterixis) and may, at times, mimic tremor. Certain specific tremors respond predictably to specific pharmacological therapy.
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PMID:Physiological and pharmacological aids in the differential diagnosis of tremor. 0 92

We present a study of 7 cases of Charcot-Marie-Tooth disease, associated with a dyskinesia clinically identical with essential tremor, in which motor conduction velocity in the upper limbs was normal or slightly diminished. An analysis of age of onset, sex distribution and clinical signs from cases in the literature is compared with the present series. A family with Charcot-Marie-Tooth disease in which affected members have widely different motor conduction velocity values is reported. Stress is laid upon the fact that categorization of this disease on electrophysiological studies in the upper limbs may present considerable difficulties.
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PMID:Charcot-Marie-Tooth disease associated with 'essential tremor' and normal and/or slightly diminished motor conduction velocity. Report of 7 cases. 43 63

1. A clinical, genetic, electrophysiological and nerve biopsy study of 49 index cases with peroneal muscular atrophy is reported. 2. In dominantly inherited cases, motor conduction velocities of the upper limbs within kinships indicated segregation into five groups which we have termed: a) hypertrophic neuropathy (less than 25 m/sec); b) intermediate group (25-45 m/sec); c) neuronal sensorimotor neuropathy (greater than 45 m/sec); d) neuronal motor neuropathy (greater than 45 m/sec); e) neuronal motor neuropathy with upper motor neurone involvement (greater than 45 m/sec). 3. The intermediate group is distinguished from the hypertrophic neuropathy group by the absence of clinically observed nerve hypertrophy and by the presence of a number of clinical features, including a more rapidly progressive disease. It is concluded to be genetically separate. This group is similarly quite distinct from the neuronal groups. Nerve biopsy studies support this view (Madrid et al., 1977; Bradley et al., 1977). 4. There was a relationship between severity of the disease and the conduction velocity which was most evident in the intermediate group. 5. There appeared to be an increase in motor conduction velocity with age in the hypertrophic neuropathy group, while the velocity fell in older patients in the intermediate group. 6. Sensory conduction velocity generally paralleled motor velocity but showed relatively less reduction. 7. Upper motor neurone features were not uncommon, appearing particularly in the intermediate group. Their presence may not therefore be a reliable basis for the classification of cases of peroneal muscular atrophy. 8. Tremor was observed in the hypertrophic, intermediate and neuronal motor neuropathy groups of patients, and does not provide a useful criterion for the classification of peroneal muscular atrophy. 9. There was occasional evidence to suggest poor or abnormal expression of the gene in dominantly inherited cases. Until more specific markers are available sporadic cases should be classified on the basis of the dominant forms, though they show a greater variability.
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PMID:The peroneal muscular atrophy syndrome: clinical, genetic, electrophysiological and nerve biopsy studies. I. Clinical, genetic and electrophysiological findings and classification. 75 65

Biopsy of the sural nerves distinguished two groups of patients with peroneal muscular atrophy (Charcot-Marie-Tooth): a hypertrophic type and a neuronal type. In patients with the hypertrophic type (10 nerves), 30-100 per cent of teased fibres of the sural nerve had demyelinated segments, numerous onion-bulb formations and often an increase in endoneurial space. Large and small fibres, with a diameter of more than 7 micron and less than 5 micron were diminished in number. Regeneration was scarce. There were more fibres with 60-120 myelin lamellae than in normal nerve, suggesting an atrophy of the axon. Biopsy of 19 sural nerves of patients with the neuronal type of PMA showed loss of large fibres (more than 7 micron in diameter). The number of small fibres was normal, presumably due to regeneration, since there were many "clusters" of small myelinated fibres. Fibres with demyelinated segments and onion-bulb formations were absent or rare and the endoneurial space was normal or slightly increased. Neither in the hypertrophic nor in the neuronal type did fibre loss occur selectively among the very largest fibres. Nine nerves from patients with hereditary spastic paraplegia and from a family with tremor and spasticity in addition to PMA showed changes similar in type but often milder in degree than nerves of the neuronal type of PMA. The number of unmyelinated fibres was normal in 12 of 21 nerves from patients with PMA; it was increased in 5 and diminished in 3 nerves.
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PMID:Peroneal muscular atrophy (PMA) and related disorders. II. Histological findings in sural nerves. 86 16

A study of 7 cases of Charcot-Marie-Tooth disease associated with a dyskinesia resembling benign essential tremor is presented. In 4 patients, the family history strongly suggested an autosomal mode of transmission, 2 cases were sporadic without an established genetic pattern and 1 was probably recessive. The distal parts of the upper and lower limbs showed imparied muscle strength with slight or no atrophy in 4 patients and conspicuous weakness and wasting in another 2. One patient was a chairbound. Although essential tremor and the tremor seen in these patients are clinically (phenotypically) similar it seems possible that they result from two different genotypes. Further, it seems that cases with Charcot-Marie-Tooth disease and "essential tremor" are not the result of the association of two separate dominant characteristics which are generally inherited as mendelian dominant traits. In spite of the diversity of the clinical manifestations of the peripheral neuropathy, the semiologically different types of essential tremor and the electrophysiological data, it is concluded that patients who develop a peripheral neuropathy on a familial basis and who exhibit clinical features of similar character, suffer from a common type of pathological disorder. Stress is laid upon the fact that Friedreich's ataxia and Charcot-Marie-Tooth disease share many clinical features. It is suggested that when Friedreich's ataxia and Charcot-Marie-Tooth disease seem to be present in the same individual and/or alternate in different members of the same family, the process is likely to be one of Charcot-Marie-Tooth disease. The value of the type of inheritance, natural history, clinical examination and electrophysiological data in differentiating Charcot-Marie-Tooth disease (with or without essential tremor) from other degenerative disorders is analyzed.
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PMID:Charcot-Marie-Tooth disease associated with "essential tremor": Report of 7 cases and a review of the literature. 93 72

Much confusion and disagreement exists regarding the classification and characteristics of inherited disorders manifesting neurogenic muscular atrophy. Many authors consider Charcot-Marie-Tooth syndrome (CMTS) and Roussy Levy syndrome (RLS) forme fruste or variants of Friedreich's ataxia (FA). Familial kyphoscoliosis has often been described in FA and RLS but not with CMTS. The purpose of this paper is to present detailed clinical and laboratory findings in a family with three cases of Scheuermann's kyphoscoliosis and CMTS in three generations. In all cases Scheuermann's kyphoscoliosis was associated with pes cavus, markedly diminished vibratory and position sensation in the lower extremities, absent deep tendon reflexes and muscular atrophy, predominantly of the distal muscles. Fine rhythmic tremor of outstretched hands and positive Romberg sign were present in one case only. Serum creating phosphokinase was elevated in two cases. Motor nerve conduction studies revealed impaired function in the median, ulnar, tibial and peroneal nerves. Sensory nerve conduction wal also impaired in median and ulnar nerves. There was evidence of left ventricular hypertrophy in one case only. The nosology and relationship between CMTS, RLS and FA are discussed.
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PMID:Scheuermann's kyphoscoliosis associated with Charcot-Marie-Tooth syndrome. 94 37

In the cases of Charcot-Marie-Tooth disease associated with essential tremor so far reported, motor conduction velocity studies strongly suggested that demyelination was a prominent feature of the neuropathy. For the first time two sibs are reported in whom the electrophysiological changes favour axonal degeneration as the main trait of their peripheral neuropathy.
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PMID:Unusual motor conduction velocity values in Charcot-Marie-Tooth disease associated with essential tremor: report of a kinship. 114 57

The autosomal dominant trembler mutation (Tr), maps to mouse chromosome 11 (ref. 2) and manifests as a Schwann-cell defect characterized by severe hypomyelination and continuing Schwann-cell proliferation throughout life. Affected animals move clumsily and develop tremor and transient seizures at a young age. We have recently described a potentially growth-regulating myelin protein, peripheral myelin protein-22 (PMP-22; refs 7, 8), which is expressed by Schwann cells and found in peripheral myelin. We now report the assignment of the gene for PMP-22 to mouse chromosome 11. Cloning and sequencing of PMP-22 complementary DNAs from inbred Tr mice reveals a point mutation that substitutes an aspartic acid residue for a glycine in a putative membrane-associated domain of the PMP-22 protein. Our results identify the PMP-22 gene as a likely candidate for the mouse trembler locus and will encourage the search for mutations in the corresponding human gene in pedigrees with hypertrophic neuropathies such as Charcot-Marie-Tooth and Dejerine-Sottas diseases (hereditary motor and sensory neuropathies I and III).
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PMID:Trembler mouse carries a point mutation in a myelin gene. 155 43

An autopsy case of hereditary peroneal muscular atrophy (PMA) with rigidity and static tremor is presented. The patient developed slowly progressive distal muscular atrophy of the legs at the age of 15 years. By the age of 52 years, PMA became marked associated with pes cavus, and tremor and rigidity of the extremities were noted. Motor and sensory conduction velocities gradually depressed and lost near the end of his life. At autopsy, the major neuropathological abnormalities involved the peripheral nervous systems, and were characterized by axonal atrophy and loss of myelinated fibers. These changes involved both the proximal and distal nerves, being more severely affected in the distal. The pathological changes in other regions of the nervous systems were mainly confined to the spinal cord, dorsal ganglia and spinal nerve roots, and pigmented neurons in the brain stem. Morphometrically, the total fascicular area was much smaller than in control, but the total number of myelinated fibers greatly outnumbered that of control 75,200 to 48,200 at the proximal sciatic nerve and then gradually decreased towards the periphery; however, even in the distal sural nerve, the total number of myelinated fibers exceeded that of control (6820 to 5469). Thus, the density of myelinated fibers were much higher, being 1.5 to 2 times greater, than in control. Its abrupt decline at the distal nerve might account for neurogenic atrophy of the distal musculature. Unmyelinated fibers were slightly increased in density and not atrophic. This case is unique in its clinicopathology and does not belong to any subtypes of PMA including "neuronal plus".
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PMID:An autopsy case of peroneal muscular atrophy with rigidity and tremor. Ultrastructural and systematic morphometrical studies on peripheral nerves. 227 41

A clinical study of 42 patients with essential tremor is presented. In the case of 12 patients the family history strongly suggested an autosomal dominant mode of transmission, in four the mode of inheritance was indeterminate, and the remaining 26 patients were sporadic cases without an established genetic basis. The tremor involved the upper extremities in 41 patients, the head in 25, lower limbs in 15, and trunk in two. Seven patients showed involvement of speech. Variations were found in the speed and regularity of the tremor. Leg involvement took a variety of forms: (1) direct involvement by tremor; (2) a painful limp associated with forearm tremor; (3) associated dyskinetic movements; (4) ataxia; (5) foot clubbing; and (6) evidence of peroneal muscular atrophy. Several minor symptoms-hyperhidrosis, cramps, dyskinetic movements, and ataxia-were associated with essential tremor. Other features were linked phenotypically to the ataxias and system degenerations. Apart from minor alterations in tone, expression, and arm swing, features of Parkinsonism were notably absent.
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PMID:Clinical manifestations of essential tremor. 503 10


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