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.
Because meningiomas tend to grow inward, they commonly cause pressure on the brain or spinal cord. They can also grow outward causing the skull to thicken (hyperostosis). Figure 1. A meningioma is a tumor that grows from the dura covering of the brain and spinal cord. Meningiomas are named according to their location. Meningiomas are classified by their cell type and grade by viewing the cells taken during a biopsy under a microscope. Treatment varies depending on the grade of the meningioma.