Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016719 (Friedreich's ataxia)
 2,098 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The value of evoked potentials in studying conduction in the somatosensory pathway was assessed in patients with various neurological disorders. In patients with multiple sclerosis (MS) abnormalities of the cervical response (N14) were found particularly in longstanding cases but also in the early stages of the disease, even in patients without sensory symptoms or signs, and were reversible in some patients. The cortical response was also abnormal in some cases but the two were not always affected together. In Friedreich's ataxia both the cervical and cortical responses were usually abnormal. Subclinical abnormalities of the cervical responses were found in some patients with hereditary spastic paraparesis or mixed forms of spinocerebellar ataxia. The cervical responses were also abnormal in patients with peripheral neuropathy and cervical radiculopathy, and in some patients with brain-stem or thalamic lesions. Cervical and cortical responses were normal in the lateral medullary syndrome, whereas the cortical response was markedly abnormal in patients with high brain-stem or cerebral hemisphere vascular lesions. Cortical and subcortical responses were abnormal in some patients with stereotactic thalamic lesions. Enhanced cortical responses were found in patients with lesions at different levels in the CNS. The most marked enhancement was observed in patients with familial myoclonic epilepsy. Lesser degrees were found in some patients with MS, progressive supranuclear palsy, thalamic lesions, brain-stem encephalitis and syringomyelia. Enhanced responses were usually found in patients with minimal or no clinical sensory involvement. It is postulated that this type of abnormality results from an interference to the inhibitory mechanisms which normally operate at various levels in the somatosensory pathway. It is concluded that evoked potential studies are a valuable adjunct to the clinical evaluation of sensation, and that they may provide useful information on the pathophysiology of conduction in the somatosensory pathway.
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PMID:The contribution of evoked potentials in the functional assessment of the somatosensory pathway. 22 50

Electromography, motor, sensory and mixed nerve conduction velocity, and H reflex were studied in four patients with ataxia-telangiectasia. The earliest and most striking electrophysiologial finding was the reduced amplitude of evoked nerve potentials. In the oldest patient, findings suggestive of spinal atrophy and mild reduction of the motor and sensory nerve conduction velocities were found. Reduced amplitude in the evoked nerve potentials can be observed without clinical evidence of peripheral neuropathy. Electrophysiological abnormalities are more severe in older than in young patients. Sural nerve biopsy in one patient showed mild changes: loss of the largest myelinated fibres and demyelination of some fibres. The ratio between maximum conduction velocity of the sural nerve and the diameter of the largest fibres was in the lower limits of the normal range. The resemblance between electrophysiological abnormalities in Friedreich's ataxia and ataxia-telangiectasia is discussed.
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PMID:Abnormalities in sensory and mixed evoked potentials in ataxia-telangiectasia. 84 6

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

Friedreich's ataxia (FA) was investigated in Western Norway, an area comprising several isolated communities and with a population of 725,000 as at 1 January 1968. The prevalence of FA was estimated to be 1/100,000 in this population. An autosomal recessive mode of transmission appeared likely in all instances. The gene frequency was only 7-9.10 minus 5, but the consanguinity rate was high in the families observed. The mutation rate was relatively high at 1-6.10 minus 5. The clinical features displayed by the 10 examined patients agreed well with those observed by other investigators. Spinal and cerebellar ataxia dominated the clinical picture. In most cases signs of peripheral neuropathy were also observed. Epilepsy was seen in some cases, and also dementia. Unspecific neuropathy, defined according to a scoring system may represent disease manifestation in FA heterozygotes.
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PMID:Friedreich's ataxia in Western Norway. 112 51

An electrophysiological study, comprehensive of peripheral sensory and motor conduction velocity (SCV, MCV), motor cortical stimulation (CS), median nerve somatosensory evoked potentials (SSEPs), brainstem evoked potentials (BAEPs) and sural nerve biopsy, was performed on 100 hereditary ataxia patients: 48 with Friedreich's ataxia (FA), 18 with Early Onset Cerebellar Ataxia (EOCA) and 34 with Autosomal Dominant Cerebellar Ataxia (ADCA). An early "peripheral" and "central" sensory impairment was observed in FA probably due to axonal loss and not related to disease severity or duration. On the contrary, BAEP and CS findings suggested a progressive involvement of the auditory and motor pathways. The presence of a non progressive sensory neuropathy allowed a distinction of EOCA patients in two groups: with and without peripheral neuropathy. The clinical and genetic heterogeneity was confirmed by the variability of evoked potential results. The ADCA patients showed the mildest degree of electrophysiologic abnormalities with an involvement of the peripheral pathways, both sensory and motor, more frequent than the central ones.
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PMID:[Clinical and electrophysiological findings in various hereditary sensory neuropathies]. 129 78

An electrophysiologic and histologic study was performed on 18 patients affected by early onset cerebellar ataxia with retained tendon reflexes (EOCA). Sensory and motor conduction velocity (SCV, MCV) was measured along peripheral nerves in all patients, somatosensory (SSEP) and brainstem auditory evoked potentials (BAEP) were recorded in 13; cortical stimulation (CS) in 12, and sural nerve biopsy in 4 patients were also performed. The results as a whole allow a division of EOCA patients into 2 groups: with (7 patients) and without (11 patients) peripheral neuropathy. Among EOCA patients with neuropathy a differential diagnosis with Friedreich's disease patients was not possible according to BAEPs and CS, while SSEPs could differentiate 2 out 5 patients in whom they were performed.
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PMID:Is early onset cerebellar ataxia with retained tendon reflexes identifiable by electrophysiologic and histologic profile? A comparison with Friedreich's ataxia. 146 54

To investigate subclinical sensory impairment in spinocerebellar degenerations, median nerve somatosensory evoked potentials (SEPs) were examined in 16 patients with chronic cerebellar ataxia who were originally diagnosed by clinical neurologists as having olivopontocerebellar atrophy (OPCA). Two types of abnormal SEP patterns were found in six patients. Two patients had the SEP pattern of peripheral neuropathy, which was also detected by peripheral sensory nerve conduction studies. Four patients had abnormal SEPs seen in patients with the lesions in the central nervous system (dorsal column, medial lemniscus). Magnetic resonance imaging (MRI) showed multiple sclerosis (MS). It is possible that clinically diagnosed OPCA sometimes includes a similar form of Friedreich's ataxia with subclinical sensory fiber neuropathy detected by SEPs and peripheral sensory conduction studies. In cases of lesions in the central nervous system demonstrated by both SEPs and MRI, there must be a follow-up in order to make a final diagnosis. In those cases, an alternative diagnosis of MS must be considered when the temporal profile of symptoms and signs characteristic of MS is observed.
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PMID:Two types of abnormal somatosensory evoked potentials in chronic cerebellar ataxias. 200 66

Electromyographic responses to stretches of hand muscles (first dorsal interosseus) and leg muscles (triceps surae, tibialis anterior) were investigated in patients with cerebellar disorders of different locations. Stimuli consisted of short dorsiflexions of the index finger during background force and in tilting (toe up) of a movable platform on which the subject stood. The most important findings were increased long latency responses in upper and lower extremities. For hand muscles it was the late part of the long latency complex, which was increased. For leg muscles it was the long latency response in the anterior tibialis muscle, the antagonist of the stretched triceps surae. The medium latency response in the triceps surae was unaffected. Latencies of the early segmental reflexes and the long latency responses were normal except for cases with peripheral neuropathy (moderate increase in latency of all EMG responses) and diseases affecting both the peripheral nerves and the dorsal columns (for example Friedreich's ataxia). The latter leads to a pronounced delay of the short latency response and a massive delay of the long latency complex in the first dorsal interosseus and of the long latency response in the anterior tibialis muscle.
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PMID:Long latency EMG responses in hand and leg muscles: cerebellar disorders. 381 58

A family is described in which a hereditary peripheral neuropathy occurs, inherited as an autosomal dominant character. The syndrome is present at birth and does not show any significant progression thereafter. Three of the cases have suffered from arthrogryposis multiplex congenita. A secondary myopathy is also present. The condition appears to be intermediary between peroneal muscular atrophy and Friedreich's ataxia. Appearance at birth, presence of arthrogryposis multiplex congenita, and the non-progressive nature separate it sharply from the other heredofamilial ataxias and peripheral neuropathies.
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PMID:Congenital non-progressive peripheral neuropathy with arthrogryposis multiplex. 436 74

Familial vitamin E deficiency (AVED) causes ataxia and peripheral neuropathy that resembles Friedreich's ataxia. AVED is thought to be caused by a defect in the transport of vitamin E in liver cells, which is the probable function of alpha-tocopherol transfer protein (alphaTTP). We have cloned the cDNA and several genomic phage clones covering the entire human alphaTTP gene and determined the junctions between the five exons and four introns that composed the gene for human alphaTTP. Three mutations in three unrelated North American families with AVED were identified. Two mutations, 485delT and 513insTT, cause a frame shift and a premature stop codon and the third mutation 574G-->A would substitute Arg192 to His in alphaTTP. The 2 patients with a severe form of AVED were homozygous with 485delT and 513insTT, respectively, while the patient with a mild form of the disease was compound heterozygous with 513insTT and 574G-->A. These findings have identified the underlying genetic defect in AVED and have confirmed the role of alphaTTP in AVED.
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PMID:Human alpha-tocopherol transfer protein: gene structure and mutations in familial vitamin E deficiency. 860 47


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