Singh G, Khurana D, Avasthi G, Mahajan R, Soni R K
Department of Medicine, Dayanand Medical College, Ludhiana - 141 001, India.
Neurol India. 1998 Jan-Mar;46(1):28-35.
Electrodiagnostic findings in 55 patients with acute organophosphorus intoxication have been correlated with clinical severity. Patients were assigned 3 grades of intoxication, depending upon the clinical severity of poisoning, muscarinic and nicotinic manifestations, ventilatory failure and altered sensorium. Repetitive responses upon single supramaximal stimulation of the median motor nerve were noted in all three grades of intoxication. In mild intoxication (grade I), low frequency repetitive nerve stimulation (< 3 Hz) produced no change in the amplitudes of the successive compound muscle action potentials. High frequency repetitive nerve stimulation (30 Hz and 50 Hz) resulted in either incremental responses (18 out of 29 cases), decremental responses (5 out of 29 cases) or decremental - incremental responses (6 out of 29 cases). Thirty five electrodiagnostic evaluations were performed in patients with overt neuromuscular weakness but not requiring mechanical ventilation (grade 2). Decremental responses were noted in only 3 instances at low frequency (< 3 Hz) repetitive nerve stimulation and in 34 out of 35 cases with high rates of stimulation. Patients who required mechanical ventilation had decremental responses at high (30 and 50 Hz) (12 out of 12 cases) as well as low rates (3 and 5 Hz) (7 out of 12 cases) of repetitive nerve stimulation. Serial electrodiagnostic evaluations, which were done in 12 patients, revealed that neuromuscular transmission abnormalities were either mild or absent within 24 hours in 9 patients. A deterioration in the neuromuscular transmission studies was noted during subsequent examinations performed, 1- 4 days later in these 9 patients. Electrodiagnostic testing is highly sensitive for establishing a diagnosisof organophosphorus poisoning and correlates well with clinical findings and the severity of poisoning. It may, however be normal in the early stages of intoxication.
55例急性有机磷中毒患者的电诊断结果与临床严重程度相关。根据中毒的临床严重程度、毒蕈碱和烟碱样表现、呼吸衰竭及意识改变，将患者分为3级中毒。在所有3级中毒患者中均观察到正中运动神经单次超强刺激后的重复反应。在轻度中毒（I级）时，低频重复神经刺激（<3Hz）未引起连续复合肌肉动作电位幅度的改变。高频重复神经刺激（30Hz和50Hz）导致递增反应（29例中的18例）、递减反应（29例中的5例）或递减 - 递增反应（29例中的6例）。对有明显神经肌肉无力但无需机械通气的患者（2级）进行了35次电诊断评估。在低频（<3Hz）重复神经刺激时仅3例出现递减反应，而在35例高频率刺激时34例出现递减反应。需要机械通气的患者在高频率（30和50Hz）（12例中的12例）以及低频率（3和5Hz）（12例中的7例）重复神经刺激时均出现递减反应。对12例患者进行了系列电诊断评估，结果显示9例患者在24小时内神经肌肉传递异常轻微或无异常。在随后1 - 4天进行的检查中，这9例患者的神经肌肉传递研究出现恶化。电诊断测试对有机磷中毒的诊断高度敏感，与临床发现及中毒严重程度密切相关。然而，在中毒早期可能正常。
