Adrenaline increases the "alertness" of the nervous system, meaning it's ready to trigger muscle contraction. It also increases the amount of blood flow and changes the tension of the muscles, which, ...

Infectious agents can cause muscle twitching and spasms, too. The most commonly known is probably tetanus, which causes a phenomenon called lockjaw, where the neck and jaw muscles contract to the ...

The patient's symptomatology started 22 years ago with tightness and cramps in his lower extremities. Subsequently, he developed fasciculations and weakness in proximal as well as distal muscles in ...