Opisthotonus posture is caused by wof
STRYCHNOS NUX VOMICA Strychnine ( kuchila) is a powerful alkaloid obtained from the seeds of strychnos nux vomica. The seeds contain two principal alkaloids; strychnine and brucine. Mech of Action: It competitively blocks ventral horn motor neurone postganglionic receptor sites in the spinal cord and brainstem and prevents the effects of glycine (the presumed inhibitory transmitter). Widespread inhibition in the spinal cord results in &;release&; excitation. The action is paicularly noted in the anterior horn cells. It stimulates the cerebralcoex. GABA, the neurotransmitter for presynaptic inhibitory neurons is not affected. Signs and Symptoms: When crushed seeds are taken, the symptoms are delayed for an hour or more. If the alkaloid is swallowed, the symptoms occur very rapidly, usually within five to fifteen minutes. Bitter taste in the mouth, sense of uneasiness and restlessness, feeling of suffocation and fear, and difficulty in swallowing occur. The convulsions are preceded by such prodromal symptoms as increased acuity of perception, increased rigidity of muscles, and muscular twitchings. Convulsions are produced due to direct action on the reflex centres of spinal cord, and affect all the muscles at a time. These are at first clonic, but eventually become tonic. During the convulsions, the face is cyanosed and has anxious look, eyes are staring, eyeballs prominent and pupils are dilated. Risus sardonicus results from contraction of the jaws and facial muscles in which the corners of the mouth are drawn back. The mouth is covered with froth, frequently bloodstained. The convulsions are most marked in anti-gravity muscles, so that the body typically arches in hyperextension (opisthotonos). In supine position, the body is suppoed by the heels and head. The legs are adducted and extended, the arms are flexed over the chest or rigidly extended, and the hands are tightly clenched. The head is bent backwards, and the whole of the body becomes rigid, often assuming a bow-like form. Sometimes, the spasm of the abdominal muscles may bend the body forward (emprosthotonos), or to the side (pleorosthotonos). Consciousness is not lost and the mind remains clear till death. Ref:- k s narayan reddy; pg num:-612,613, image plate14
Ricinus communis
Papaver somniferum
Coccaine
Strychnous nux vomica
Poisoning