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.
Neurology and Neurosurgery. Meningioma Center. Meningiomas are tumors that originate in the meninges, which are the outer three layers of tissue between the skull and the brain that cover and protect the brain just under the skull. The middle layer of the meninges, called the arachnoid, is where meningiomas form.