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Background: Coma after acute brain structural injury (ABI) are associated with high mortality and disability. Somatosensory evoked potentials (SSEP) N20 and N70 are used to predict prognosis. Purpose: We assessed the utility of SSEP (N20-N70) as an early indicator of long-term functional prognosis in these patients. Methods: We conducted a retrospective cohort study of patients admitted to the intensive care unit (ICU) with a diagnosis of coma after ABI (n=60). An SSEP study including N20 and N70 was performed 24-72 hours after coma onset. Functional recovery was evaluated 6 to 12 months later using the Modified Glasgow Scale (mGS). The study was approved by our local research ethics committee. Results: The absence of N20 (41% specificity=100%) or N70 (78%) was a strong indicator of a poor outcome. In contrast, the presence of N70 was an indicator of a good outcome (specificity=64.2% sensitivity=91.3%). Conclusion: SSEP N20 and N70 are useful early prognostic markers with high specificity (N20) and sensitivity (N70). N70 has potential additional value for improving the prediction of good functional outcomes in the long term.
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Aim: The functional prognosis of patients after coma following either cardiac arrest (CA) or acute structural brain injury (ABI) is often uncertain. These patients are associated with high mortality and disability. N20 and N70 somatosensory evoked potentials (SSEP) are used to predict prognosis. We evaluated the utility of SSEP (N20-N70) as an early indicator of long-term prognosis in these patients. Methods: This was a retrospective cohort study of patients (n = 120) admitted to the intensive care unit (ICU) with a diagnosis of coma after CA (n = 60) or ABI (n = 60). An SSEP study was performed, including N20 and N70 at 24-72 h, after coma onset. Functional recovery was assessed 6-12 months later using the modified Glasgow scale (mGS). The study was approved by our local research ethics committee. Results: In the CA and ABI groups, the absence of N20 (36% of CA patients and 41% of ABI patients; specificity = 100%) or N70 (68% of CA patients and 78% of ABI patients) was a strong indicator of poor outcome. Conversely, the presence of N70 was an indicator of a good outcome (AC: specificity = 84.2%, sensitivity = 92.7%; ABI: specificity = 64.2% sensitivity = 91.3%). Conclusion: Somatosensory evoked potentials are useful early prognostic markers with high specificity (N20) and sensitivity (N70). Moreover, N70 has additional potential value for improving the prediction of good long-term functional outcomes. Clinical Trial Registration: [https://clinicaltrials.gov/], identifier [2018/01/001].
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Introducción. El parpadeo es un movimiento habitualmente espontáneo, consecuencia de la actividad alternante y antagónica de los músculos orbicularis oculi y levator palpebrae superioris. Para conseguir un movimiento eficiente se regulan por inhibición recíproca de tal modo que el movimiento agonista provoca la inhibición simultánea del antagonista, y viceversa. La cocontracción es la disfunción de este mecanismo, y constituye un fenómeno relevante en trastornos distónicos, en especial en movimientos simples no sujetos a variabilidad como el parpadeo. El blefaroespasmo es la distonía más frecuente del adulto y su diagnóstico es sencillo. En procesos incipientes puede presentar dificultades e incluso confundirse con otros procesos. Evaluamos la posibilidad de diagnóstico precoz de blefaroespasmo en pacientes con hiperfunción palpebral de poco tiempo de evolución. Pacientes y métodos. Hemos evaluado prospectivamente a 23 pacientes con sospecha de blefaroespasmo. Se les realizó un estudio electromiográfico simultáneo de los músculos orbicularis oculi y levator palpebrae. Resultados. La presencia de cocontracción en alguno de los parpadeos registrados se relacionó con el desarrollo o no de blefaroespasmo en los años siguientes. Ningún paciente sin parpadeos distónicos presentó blefaroespasmo en los años del seguimiento; por el contrario, todos los que presentaron alguno lo desarrollaron. Conclusiones. Hemos obtenido parpadeos distónicos en todos los pacientes que desarrollaron blefaroespasmo, y los parpadeos fueron fisiológicos en aquellos que no lo presentaron. La evaluación electromiográfica simultánea de la musculatura palpebral es una exploración sencilla, sensible, bien tolerada y especialmente específica para determinar si se desarrollará blefaroespasmo en un momento evolutivo temprano (AU)
Introduction. Blinking is usually a spontaneous movement that takes place as a consequence of the alternating and antagonistic activity of the orbicularis oculi and levator palpebrae superioris muscles. In order to achieve an efficient movement, they are regulated by a reciprocal inhibition in such a way that the agonistic movement triggers the simultaneous inhibition of the antagonist, and vice-versa. Co-contraction is the dysfunction of this mechanism and is a significant phenomenon in dystonic disorders, especially in simple movements that are not subject to variability, as is the case of blinking. Blepharospasm is the most frequent dystonia affecting adults and it is easy to diagnose. In incipient processes it may offer some difficulties and can even be mistaken for other processes. We evaluate the possibility of an early diagnosis of blepharospasm in patients with palpebral hyperfunction with a short time to progression. Patients and methods. A prospective evaluation of 23 patients with suspected blepharospasm was conducted. Each of them was submitted to a simultaneous electromyographic study of the orbicularis oculi and levator palpebrae muscles. Results. The presence of co-contraction in any of the blinking movements recorded was related with the chances of developing blepharospasm in the following years. None of the patients who did not have dystonic blinking presented blepharospasm in the years of the follow-up; in contrast, it was developed by all of those who presented it on some occasion. Conclusions. Dystonic blinking was observed in all the patients with blepharospasm, and blinking was physiological in those who did not present it. Simultaneous electromyographic evaluation of the muscles of the eyelids is a simple, sensitive, well-tolerated and particularly specific examination that can be used to determine whether a patient will show blepharospasm in an early stage of development (AU)
Assuntos
Humanos , Eletromiografia/métodos , Blefarospasmo/fisiopatologia , Músculos Faciais/fisiopatologia , Estudos Prospectivos , Distonia/fisiopatologia , Piscadela/fisiologia , Transtornos dos Movimentos/fisiopatologia , Fatores de RiscoRESUMO
INTRODUCTION: Blinking is usually a spontaneous movement that takes place as a consequence of the alternating and antagonistic activity of the orbicularis oculi and levator palpebrae superioris muscles. In order to achieve an efficient movement, they are regulated by a reciprocal inhibition in such a way that the agonistic movement triggers the simultaneous inhibition of the antagonist, and vice-versa. Co-contraction is the dysfunction of this mechanism and is a significant phenomenon in dystonic disorders, especially in simple movements that are not subject to variability, as is the case of blinking. Blepharospasm is the most frequent dystonia affecting adults and it is easy to diagnose. In incipient processes it may offer some difficulties and can even be mistaken for other processes. We evaluate the possibility of an early diagnosis of blepharospasm in patients with palpebral hyperfunction with a short time to progression. PATIENTS AND METHODS: A prospective evaluation of 23 patients with suspected blepharospasm was conducted. Each of them was submitted to a simultaneous electromyographic study of the orbicularis oculi and levator palpebrae muscles. RESULTS: The presence of co-contraction in any of the blinking movements recorded was related with the chances of developing blepharospasm in the following years. None of the patients who did not have dystonic blinking presented blepharospasm in the years of the follow-up; in contrast, it was developed by all of those who presented it on some occasion. CONCLUSIONS: Dystonic blinking was observed in all the patients with blepharospasm, and blinking was physiological in those who did not present it. Simultaneous electromyographic evaluation of the muscles of the eyelids is a simple, sensitive, well-tolerated and particularly specific examination that can be used to determine whether a patient will show blepharospasm in an early stage of development.
