Electromyography in Congenital Zika Syndrome.

INTRODUCTION: Congenital Zika virus syndrome is a distinct pattern of birth defects in fetuses infected by the Zika virus. It presents a broad clinical spectrum that includes occurrences of microcephaly, hypertonia, dysphagia, hyperexcitability, seizures, and arthrogryposis. Imaging findings show neuronal migration disorders. METHODOLOGY: Case reports have suggested that arthrogryposis has a neurogenic cause. We analyzed needle electromyography and nerve conduction examinations on 77 patients aged 2-24 months presenting highly probable congenital Zika virus syndrome, with or without arthrogryposis. RESULTS: All those with arthrogryposis presented with chronic muscle denervation in the electromyography examination. Similarly, children with single or reversible joint abnormalities at birth showed the same findings. Denervation in the paravertebral musculature was found in all of the children with diaphragmatic paralysis or thoracic deformities. CONCLUSIONS: We propose that congenital contractures associated with congenital Zika virus syndrome are caused by the malformation of upper and lower motor neurons during embryogenesis.

Resilience in migraine brains: decrease of coherence after photic stimulation.

BACKGROUND: During migraine attacks, patients generally have photophobia and phonophobia and seek for environments with less sensorial stimulation. Present work aimed to quantify cortical partial directed coherence (PDC) of electroencephalographic (EEG) recordings from migraine patients and controls in occipital, parietal, and frontal areas with or without photic stimulation. Our hypothesis is that migraine patients with visual aura might have neuronal networks with higher coherence than controls even in interictal periods due to a predisposition in sensory cortical processing. METHODS: Eleven adult women with migraine with visual aura (at least 48 h without previous attacks) and seven healthy adult woman were submitted to EEG recording in basal state and during photic stimulation. RESULTS: When compared to healthy volunteers, migraine patients show different coherence profiles. Migraine patients had greater coherence than controls during the basal period (without photic stimulation), showing predisposition for sensory processing in many frequency ranges. After photic stimulation, patients showed a decrease in cortical coherence while controls had an increase. CONCLUSIONS: When compared to healty subjects, migraineurs show increased cortical coherence before photic stimulation, but a decrease when stimulation starts. This may be the expression of a resilience mechanism that allows migraineurs the interictal period. The PDC analysis permits to address a patient coherence profile, or "coherence map," that can be utilized for management of the headache disorder or following up treatments.

[Auditory steady-state response in the auditory evaluation: clinical application]. / A resposta auditiva de estado estável na avaliação auditiva: aplicação clínica.

BACKGROUND: the auditory steady state response (ASSR) is an electrophysiological procedure that evaluates, at the same time, the hearing thresholds of both ears at various frequencies. This procedure reduces the time of testing and enables the stimulation of levels close to 125dB HL, characterizing residual hearing. AIM: to verify the applicability of the ASSR to determine the hearing thresholds in different levels of sensorineural hearing loss. METHOD: 48 individuals aged 7-30 years, with different levels of hearing loss were assessed. The Pure tone Audiometry (PTA) and the ASSR were carried out in following carrier frequencies 0.5; 1; 2 and 4k Hz. The carrier frequencies in the ASSR were modulated in amplitude and frequency, with multiple dicotic stimulation for mild and moderate hearing loss. Simple stimulation was used to test the other hearing deficit levels. RESULTS: there was a significant association (p<0.01) between the thresholds obtained in the PTA and in the ASSR for all of the tested frequencies, especially for the severe levels. However, for some patients, the hearing loss level was overestimated in the ASSR. CONCLUSION: the ASSR can be used to estimate the PTA threshold; nevertheless, it should not be analyzed in an isolated way, but seen as a complementary procedure to the behavioral auditory assessment.

A resposta auditiva de estado estável na avaliação auditiva: aplicação clínica / Auditory steady-state response in the auditory evaluation: clinical application

TEMA: a resposta auditiva de estado estável (RAEE) é um procedimento eletrofisiológico que permite avaliar ao mesmo tempo os limiares auditivos de várias freqüências em ambas às orelhas, reduzindo assim o tempo de teste, e permite estimular até níveis próximos a 125dB HL, caracterizando assim a audição residual. OBJETIVO: verificar a aplicabilidade da RAEE para determinar os limiares auditivos nos diferentes graus de perda auditiva neurossensorial coclear. MÉTODO: foram avaliados 48 indivíduos com idade entre sete e trinta anos e diferentes graus de perdas auditivas. A Audiometria Tonal Liminar (ATL) e a RAEE foram avaliadas nas seguintes freqüências portadoras, 0,5; 1; 2 e 4k Hz. As freqüências portadoras na RAEE foram moduladas em amplitude e freqüência, com estimulação múltipla e dicótica nas perdas auditivas de grau leve e moderado. Estimulação simples foi utilizada nos outros graus de perdas auditivas. RESULTADOS: houve associação significante (p < 0,01) entre os limiares obtidos na ATL e RAEE para todas as freqüências testadas, principalmente para perdas auditivas de grau profundo. Contudo em alguns pacientes o grau da perda auditiva pode ser super-estimado. CONCLUSÃO: a RAEE pode ser utilizada para predizer os limiares auditivos da ATL, porém não deve ser analisada de forma isolada, mas de forma complementar a avaliação audiológica comportamental.

BACKGROUND: the auditory steady state response (ASSR) is an electrophysiological procedure that evaluates, at the same time, the hearing thresholds of both ears at various frequencies. This procedure reduces the time of testing and enables the stimulation of levels close to 125dB HL, characterizing residual hearing. AIM: to verify the applicability of the ASSR to determine the hearing thresholds in different levels of sensorineural hearing loss. METHOD: 48 individuals aged 7-30 years, with different levels of hearing loss were assessed. The Pure tone Audiometry (PTA) and the ASSR were carried out in following carrier frequencies 0.5; 1; 2 and 4k Hz. The carrier frequencies in the ASSR were modulated in amplitude and frequency, with multiple dicotic stimulation for mild and moderate hearing loss. Simple stimulation was used to test the other hearing deficit levels. RESULTS: there was a significant association (p<0.01) between the thresholds obtained in the PTA and in the ASSR for all of the tested frequencies, especially for the severe levels. However, for some patients, the hearing loss level was overestimated in the ASSR. CONCLUSION: the ASSR can be used to estimate the PTA threshold; nevertheless, it should not be analyzed in an isolated way, but seen as a complementary procedure to the behavioral auditory assessment.