All parts of the jimsonweed plant are poisonous to horses and humans; toxicity is caused by tropane alkaloids. Symptoms of poisoning in horses include a weak, rapid pulse, dilated pupils, dry mouth, incoordination, diarrhea, convulsions, coma, and sometimes death.
Meningioma Causes. The causes of meningioma are not yet fully understood. In fact, several research studies suggest that many meningiomas develop spontaneously, or without a known cause. Sometimes, these tumors can disappear spontaneously as well. Meningiomas, like other solid tumors, develop when healthy cells undergo genetic mutations that cause them to replicate uncontrollably.
Causes of Meningioma. The causes of meningioma are not clear, though one possible culprit is hormonal fluctuations that may cause the tumors to grow (however, more research is needed on this hypothesis). It is also unclear whether whatever prompts these meninges cells to multiply out of control is inherited, related to a personâs environment or both.