A clinical and neurophysiological study of scorpion envenomation in Assiut, Upper Egypt.

Scorpion envenomation (SE) represents an agonizing problem in many countries, especially in rural areas. This clinical and neurophysiological study aimed to determine the relative frequency of scorpion envenomation in the Assiut area, in Upper Egypt. Full clinical evaluation was carried out for all children < or =18 y of age included in the study. Electroencephalography (EEG), electromyography (EMG) and motor conduction velocity measurements were carried out for a variable number of children. SE was recorded in 302 cases per year in this area. Of these, 78.5% were < or =18 y of age. SE occurred most commonly during the summer months. Clinical evaluation revealed that SE results in marked autonomic manifestations, principally sinus tachycardia (78.1%), vomiting (70.5%) and hyperthermia (53.2%). It also results in many neuropsychiatric manifestations, such as agitation and restlessness (17.7%) and disturbance of consciousness (8.0%). Electroencephalographic study of 184 cases of SE in paediatric patients aged < or =18 y revealed abnormalities in 77.7%. Study of mean distal latency and motor conduction velocity revealed that patients had a significantly shorter distal latency and a more rapid motor conduction velocity compared with the control group. This was true for both the inflicted limb and the contralateral limb. Most of the complications of SE are due to irritability of the central and peripheral nervous systems.