RESUMO
The occurrences of factor V Leiden mutation (Arg506Gln) and antiphospholipid antibodies (APA) in migraine patients have been reported, but the findings are controversial. We investigated the presence of factor V Leiden and the serum level of anticardiolipin antibodies (aCL) in a consecutive series of 70 migraine patients (47 women; mean age, 34.1 years). Of these, 40 patients had migraine with aura. A matched sample of 70 healthy people was considered as the control group. Heterozygous genotype for factor V Leiden mutation was detected in 4 (5.7%) migraine patients (of which 2 had migraine with aura) and in 2 (2.8%) subjects of the control group. Although proportionally more migraine patients harbored the factor V Leiden mutation, this difference was not statistically significant, perhaps due to the small number of patients involved. We found normal serum levels of aCL in all migraine patients. Further studies and a long-term follow-up are warranted to determine the significance of this genetic abnormality in migraine.
Assuntos
Anticorpos Anticardiolipina/sangue , Fator V/genética , Transtornos de Enxaqueca/sangue , Transtornos de Enxaqueca/genética , Mutação Puntual , Adulto , Substituição de Aminoácidos/genética , Arginina/genética , Distribuição de Qui-Quadrado , Intervalos de Confiança , Feminino , Genótipo , Glutamina/genética , Humanos , Itália/epidemiologia , Masculino , Transtornos de Enxaqueca/epidemiologia , Razão de ChancesRESUMO
Recently Ugawa and co-workers reported that motor cortex excitability after magnetic stimulation in man can be reduced by coupling an electrical transcranial stimulus over the base of the skull. They hypothesised that the motor cortex inhibition observed was determined by activation of cerebellar structures. Nevertheless, the paradigm employed did not allow to exclude interference from extracerebellar structures due to spread of the electrical stimulus. In order to ascertain the role of the cerebellum in determining the modulation of the motor cortex excitability we examined, in 10 normal subjects and in 2 patients with unilateral cerebellar lesions, the effects of electrical stimuli over the base of the skull on the motor responses evoked by cortical magnetic stimulation. In both patients no inhibition of motor responses was present in the muscles ipsilateral to the lesion, whereas an inhibition, similar to that observed in controls, was evident on the opposite side. The present findings suggest the cerebellar origin of the motor effects seen after electrical stimulation of the base of the skull and further clarify the physiological cerebro-cerebellar interactions in man.
Assuntos
Doenças Cerebelares/fisiopatologia , Cerebelo/fisiopatologia , Córtex Motor/fisiopatologia , Potenciais de Ação/fisiologia , Idoso , Análise de Variância , Cerebelo/patologia , Estimulação Elétrica , Humanos , Imageamento por Ressonância Magnética , Magnetismo , Masculino , Pessoa de Meia-Idade , Córtex Motor/patologia , Músculos/fisiopatologia , Tempo de Reação/fisiologiaRESUMO
The excitability of the motor cortex to magnetic stimulation was evaluated in seven patients with cerebellar lesions (six patients with a unilateral lesion) and in 20 control subjects. Magnetic motor threshold was defined at rest. In all but one of the patients with a hemicerebellar lesion the threshold was higher in the motor cortex contralateral to the impaired hemicerebellum and the right/left threshold asymmetry was clearly greater than normal. In the patient with a lesion involving both cerebellar hemispheres the magnetic threshold was above the normal limit on both sides. The latencies of motor responses were normal in all patients. This increase in the magnetic threshold of the motor cortex functionally related to the impaired hemicerebellum suggests the existence of a facilitating tonic action of the cerebellum on central motor circuits that might act at the cortical, or spinal level, or both.
Assuntos
Doenças Cerebelares/diagnóstico , Cerebelo/fisiopatologia , Magnetismo , Córtex Motor/fisiologia , Adulto , Idoso , Doenças Cerebelares/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiologiaRESUMO
Four patients with subacute combined degeneration were studied through upper and lower limb SEPs recorded with a non-cephalic reference montage and through cortical and spinal magnetic stimulation. Clinical signs were confined to the lower limbs in 3 patients; the remaining patient presented only paraesthesiae in 4 limbs. Median nerve SEPs showed a normal cervical N13 response with a significant increase of central conduction time concerning exclusively the P9-P14 interpeak interval. Central motor conduction to upper and lower limb muscles was abnormal. Nerve conduction studies provided no evidence of peripheral nerve involvement. These electrophysiological findings suggest that in vitamin B12 deficiency the higher segments of the cervical cord are usually affected first and that central sensory and motor conduction studies are sensitive methods for detecting such damage.
