Assuntos
GTP Fosfo-Hidrolases/genética , Mutação de Sentido Incorreto , Mutação Puntual , Paraplegia Espástica Hereditária/genética , Adolescente , Adulto , Idade de Início , Substituição de Aminoácidos , Criança , Pré-Escolar , Éxons/genética , Feminino , Proteínas de Ligação ao GTP , Transtornos Neurológicos da Marcha/genética , Humanos , Lactente , Escore Lod , Masculino , Proteínas de Membrana , Linhagem , Paraplegia Espástica Hereditária/diagnóstico , Paraplegia Espástica Hereditária/epidemiologiaRESUMO
Neuronal voltage-dependent P/Q Ca2+ channels are genetically abnormal in many cases of familial hemiplegic migraine and possibly associated with the more common forms of migraine with and without aura. Besides the brain, these channels are found in motor nerve endings where they control stimulation-induced acetylcholine release. Using single fiber EMG recordings we were able to demonstrate subclinical abnormalities of neuromuscular transmission in a subgroup of patients suffering from migraine with aura. This could be related to genetic abnormalities of P/Q Ca2+ channels in certain patients suffering from migraine with aura, which needs to be explored by proper genetic analyses.
Assuntos
Enxaqueca com Aura/fisiopatologia , Junção Neuromuscular/fisiopatologia , Transmissão Sináptica , Adulto , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Método Simples-CegoRESUMO
PURPOSE: To evaluate ankle areflexia in Holmes-Adie syndrome (HAS). PATIENTS AND METHODS: Hoffmann (H) and Tendon (T) soleus reflexes, tonic vibration reflex (TVR), and polysynaptic extension reflex of soleus muscle (PERS) were evaluated in eight patients with idiopathic HAS. Motor (MNCV) and sensory (SNCV) nerve conduction velocities, compound motor-action potential (CMAP), and sensory action potential (SAP) were also determined in upper and lower limbs. RESULTS: Soleus T reflex was obtained in one out of eight patients, and H-reflex was found in none of the patients. TVR was recorded in four out of eight patients, and PERS in all of the patients. MNCV, SNCV, CMAP and SAP showed normal values in all patients. In six out of the eight patients a late response following the tibial nerve stimulation showed constant latency, amplitude and morphology, with no recovery cycle or vibration inhibition. CONCLUSION: In this study, the neurophysiological spinal reflex circuitry evaluations support the view that HAS ankles areflexia is due to a selective impairement of monosynaptic connections of Ia afferents. A normal nuclear excitability is suggested by polysynaptic activation of the soleus motor nucleus.