RESUMO
OBJECTIVE: A characteristic feature of spinocerebellar ataxia type 2 (SCA2) is saccadic slowing at early disease stages. We sought to determine whether this sign is detectable before clinical manifestation and quantifies the disease progression throughout life in linear fashion. METHODS: In a specialized ataxia clinic, 54 presymptomatic carriers of SCA2 polyglutamine expansions and 56 relatives without mutation were documented with regard to their maximal saccade velocity (MSV). RESULTS: Among the control individuals, a significant effect of aging on MSV was observed. After elimination of this age influence through a matched-pair approach, a presymptomatic decrease of MSV could be shown. The MSV reduction was stronger in carriers of large expansions. In the years before calculated disease manifestation, the MSV impairment advanced insidiously. CONCLUSION: Saccade velocity is a sensitive SCA2 endophenotype that reflects early pontine degeneration and may be a useful diagnostic parameter before the onset of ataxia. SIGNIFICANCE: Future neuroprotective therapies of polyglutamine neurodegeneration may be assessed by MSV from earliest to prefinal disease stages.
Assuntos
Transtornos da Motilidade Ocular/etiologia , Transtornos da Motilidade Ocular/fisiopatologia , Músculos Oculomotores/fisiopatologia , Movimentos Sacádicos/fisiologia , Ataxias Espinocerebelares/complicações , Ataxias Espinocerebelares/fisiopatologia , Adolescente , Adulto , Idoso , Ataxinas , Cerebelo/fisiopatologia , Progressão da Doença , Diagnóstico Precoce , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/genética , Vias Neurais/fisiopatologia , Transtornos da Motilidade Ocular/diagnóstico , Músculos Oculomotores/inervação , Valor Preditivo dos Testes , Prognóstico , Ataxias Espinocerebelares/diagnóstico , Adulto JovemRESUMO
A characteristic feature of spinocerebellar ataxia type 2 (SCA2) is saccadic slowing at early disease stages. We sought to determine whether this sign is detectable before clinical manifestation and quantifies the disease progression throughout life in linear fashion. In a specialized ataxia clinic, 54 presymptomatic carriers of SCA2 polyglutamine expansions and 56 relatives without mutation were documented with regard to their maximal saccade velocit Spinocerebellar ataxia type 2 Among the control individuals, a significant effect of aging on MSV was observed. After elimination of this age influence through a matched-pair approach, a presymptomatic decrease of MSV could be shown. The MSV reduction was stronger in carriers of large expansions. In the years before calculated disease manifestation, the MSV impairment advanced insidiously.Saccade velocity is a sensitive SCA2 endophenotype that reflects early pontine degenerationPolyglutamine expansion and may be a useful diagnostic parameter before the onset of ataxia. Significance: Future neuroprotective therapies of polyglutamine neurodegeneration may be assessed by MSV from earliest to prefinal disease stages...(AU)
Assuntos
HumanosRESUMO
Spinocerebellar ataxia type 2 (SCA2, OMI health, reproductive, financial matters, and183090) belongs to a group of hereditary family planning. Therefore, we undertook a sur-neurodegenerative diseases caused by the expan- vey of the age of onset in a cohort of SCA2sion of a CAG repeat tract in coding regions of patinovel genes. This group includes Huntingtonsdisease (HD), spinal and bulbar muscularatrophy (SBMA), dentatorubral-pallidoluysianatrophy, and the spinocerebellar ataxias type 1,3, 6, 7, and 17 (1). These mutations show a veryhigh penetrance, and they follow an autosomaldominant inheritance pattern with the onlyexception of SBMA (X-linked); each descendantof an affected patient has an a priori risk of 50%.However, it has been proven that the empiric riskof having inherited the mutation causing HD orSCA3 (MachadoJoseph disease) lessens withadvancing age (2, 3). This fact has significantimplications in the genetic counseling of at-riskindividuals. The accuracy and precision that areachieved in the estimate of the risk of developinga certain hereditary illness will have a very...(AU)
Assuntos
Humanos , Ataxias Espinocerebelares , Degenerações Espinocerebelares , Ataxias Espinocerebelares/diagnósticoRESUMO
Spinocerebellar ataxia type 2 (SCA2) is an autosomal-dominant disorder mani-festing with gait, limb, and speech incoordination, and with distinctive symptomssuch as early slowing of horizontal eye movements and early neuropathy.13 Neuro-pathological analysis has demonstrated severe olivopontocerebellar atrophy (OPCA)early in the course of disease, progressing to involve the anterior horn, substantia ni-gra, thalamus, and somatosensory pathways.4,5 Clinical onset is usually in midlife,but has been observed to range from 1 to 65 years of age, depending on the size ofthe underlying mutation, a CAG (cytosine-adenine-guanine)-trinucleotide repeat ex-pansion in exon 1 of the SCA2 gene...(AU)
Assuntos
Humanos , Ataxias Espinocerebelares , Atrofias OlivopontocerebelaresRESUMO
The spinocerebellar ataxia type 2 has a prevalence of 43 per 100,000 inhabitants in Holguín province,which is the highest one reported worldwide. It is due to an intergenerational CAG repeat expansion contained in the first exonof diseasecausinggene, and it is characterized by a high variability in its clinical and electrophysiological presentation, evenintrafamiliarly. Objective. Factors identification, which explains this variability, could lead to the findings of therapeuticalways that may retard the disease onset. Patients and methods. We have done this research in order to contribute to thisphenotypic variability knowledge of the different structures and functions of the nervous system. Results. By means of molecularand electrophysiological studies we have found two groups well differentiated in a 52patientsample. The first one wascharacterized by CAG repeat expansions above 41 units and by the total blockade of the afferent conduction that is, basicelectrophysiological alteration with axonal damage predominance. The second one was characterized by CAG repeat expansionslower or equal to 41 units and showed a high variability in its electrophysiological behavior with myelinic damage predominance.We realized of the existence of statistical significance correlations between the electrophysiological, clinical and molecularvariables considered. Conclusions. These findings suggest that for by CAG repeat expansions lower or equal to 41 unitsshould be affecting other genetics and/or environmental factors that explain the variability found in this group which arenot significant for clinical and electrophysiological presentation in individuals with CAG repeat expansions...(AU)
Assuntos
Humanos , Ataxias Espinocerebelares/diagnóstico , Eletrofisiologia , DisartriaRESUMO
INTRODUCTION: Dysautonomic features are the clinical signs and symptoms derived from anomalous functioning of the sympathetic or parasympathetic nervous systems in either the peripheral or central parts. OBJECTIVE: To identify the clinical features related to dysautonomia in a patient with spinocerebellar ataxia with severe functional disability. PATIENTS AND METHODS: We studied a series of cases, including 21 patients with severe disability (confirmed to their bed or wheelchair, unable to walk and totally or partly dependent on other people for essential everyday activities). The patients and their families were closely questioned, and full clinical examination included a test for orthostasia. RESULTS: All patients had some signs of peripheral dysautonomia: all had vasomotor disorders (orthostasia, distal pallor and coldness, Raynaud s phenomenon, etc.), 95.2% (constipation, urinary and rectal incontinence, polachuria, palpitations, tachycardia at rest, etc.), exocrine gland disorders in 71.4% (increased lachrymation, reduced sweating, increased or reduced salivation), 87.5% peripheral tissue nutrition disorders. Similarly, in all patients studied there was evidence of central dysautonomic disorder, with a syndrome of cachexia with bulimia, sleep disorders together with dysregulation of thirst and body temperature. CONCLUSIONS: In patients with type 2 hereditary spinocerebellar ataxia with severe disability there was involvement of the peripheral and central nervous system regulating autonomic function.
Assuntos
Sistema Nervoso Periférico/fisiopatologia , Síndrome de Shy-Drager/diagnóstico , Síndrome de Shy-Drager/fisiopatologia , Ataxias Espinocerebelares/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atrofias Olivopontocerebelares/patologia , Índice de Gravidade de DoençaRESUMO
INTRODUCTION: A patient with type 2 spino cerebellar ataxia has difficulty in carrying out alternate movements such as pronation and supination. OBJECTIVES. To evaluate the function of an automatized system for measuring disorders of alternate movements. PATIENTS AND METHODS: We studied the measurement of diadochokinesia in two groups of healthy patients, a first group (64 persons) to determine the normal intervals and a second group to validate the test (52 persons). We also studied 100 patients for validation of the system. A further 53 patients were evaluated before and after rehabilitation. RESULTS: Analysis of the basic measurements for diagnosis of duodochokinesia showed that the higher the cut off point, the greater the sensitivity of the test, whereas the opposite occurred with the specificity. Thus, regarding a higher cut off, there is a five times greater probability of a positive results in the patients than in healthy persons. However, the probability of a normal result is six times higher in healthy than in affected persons. The results of variant analysis done on patients before and after rehabilitation suggest that the presence of quantitative changes in the second study was due to the positive effect of neuro rehabilitation. CONCLUSION: The technique used is effective for differentiation of affected from healthy persons and its use is justified in the evaluation of co ordination ability after rehabilitation
Assuntos
Braço/fisiopatologia , Movimento/fisiologia , Ataxias Espinocerebelares/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A patient with type 2 spinocerebellar ataxia has difficulty in carrying out alternate movements such aspronation and supination. Objectives. To evaluate the function of an automatized system for measuring disorders of alternatemovements. Patients and methods. We studied the measurement of diadochokinesia in two groups of healthy patients, a first group (64persons) to determine the normal intervals and a second group to validate the test (52 persons). We also studied 100 patients forvalidation of the system. A further 53 patients were evaluated before and after rehabilitation. Results. Analysis of the basic measurementsfor diagnosis of diadochokinesia showed that the higher the cutoff point, the greater the sensitivity of the test, whereas the oppositeoccurred with the specificity. Thus, regarding a higher cutoff, there is a five times greater probability of a positive results in the patientsthan in healthy persons. However, the probability of a normal result is six times higher in healthy than in affected persons. The resultsof variant analysis done on patients before and after rehabilitation suggest that the presence of quantitative changes in the second studywas due to the positive effect of neurorehabilitation...(AU)
Assuntos
Humanos , Ataxias Espinocerebelares , Extremidade Superior , Transtornos dos MovimentosRESUMO
INTRODUCTION: The spinocerebellar ataxia type 2 has a prevalence of 43 per 100,000 inhabitants in Holguín province, which is the highest one reported worldwide. It is due to an intergenerational CAG repeat expansion contained in the first exon of disease causing gene, and it is characterized by a high variability in its clinical and electrophysiological presentation, even intrafamiliarly. OBJECTIVE: Factors identification, which explains this variability, could lead to the findings of therapeutical ways that may retard the disease onset. PATIENTS AND METHODS: We have done this research in order to contribute to this phenotypic variability knowledge of the different structures and functions of the nervous system. RESULTS: By means of molecular and electrophysiological studies we have found two groups well differentiated in a 52-patient sample. The first one was characterized by CAG repeat expansions above 41 units and by the total blockade of the afferent conduction that is, basic electrophysiological alteration with axonal damage predominance. The second one was characterized by CAG repeat expansions lower or equal to 41 units and showed a high variability in it s electrophysiological behavior with myelinic damage predominance. We realized of the existence of statistical significance correlations between the electrophysiological, clinical and molecular variables considered. CONCLUSIONS: These findings suggest that for by CAG repeat expansions lower or equal to 41 units should be affecting other genetics and/or environmental factors that explain the variability found in this group which are not significant for clinical and electrophysiological presentation in individuals with CAG repeat expansions above 41 units.
Assuntos
Ataxias Espinocerebelares/fisiopatologia , Expansão das Repetições de Trinucleotídeos/genética , Adolescente , Adulto , Idoso , Criança , Cuba , Estimulação Elétrica , Eletrofisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Filogenia , Índice de Gravidade de Doença , Ataxias Espinocerebelares/classificação , Ataxias Espinocerebelares/genética , Estatística como AssuntoRESUMO
Se realizó un estudio de 18 familias de pacientes con diagnóstico de sordera hereditaria no sindrómica, residentes en la Provincia de Holguín, Cuba con el objetivo de realizar su caracterización genotípica. Se realizaron estudios audiométricos a los padres de los casos propósitos y, en los casos que fueron positivos, se les hizo además a otros miembros de la familia por vía parenteral afectada. Se concluyó, que el patrón de herencia autosómico dominante fue el más frecuente y se comprobó que existía expresividad variable y penetrancia reducida del gen lo que podía llevar a confusión sobre el tipo de herencia
Assuntos
Humanos , Potenciais Evocados Auditivos/genética , Audiometria , Surdez/congênito , Surdez/genética , Surdez/diagnósticoRESUMO
Se realizó un estudio de 18 familias de pacientes con diagnóstico de sordera hereditaria no sindrómica, residentes en la provincia de Holguín, Cuba, con el objetivo de realizar su caracterización genotípica. Se realizaron estudios audiométricos a los padres de los casos propósitos y, en los casos que fueron positivos, se les hizo además a otros miembros de la familia por la vía parental afectada. Se concluyó, que el patrón de herencia autosómico dominante fue el más frecuente y se comprobó que existía expresividad variable y penetrancia reducida del gen lo que podía llevar a confusión sobre el tipo de herencia (AU)