The corpora quadrigemina (quadruplet bodies) are four solid lobes on the dorsal side of the cerebral aqueduct, where the superior posterior pair are called the superior colliculi and the inferior posterior pair are called the inferior colliculi. The four solid lobes help to decussate several fibres of the optic nerve.
Although many patients lead full and rewarding lives, MS can cause impaired mobility and disability in more severe cases. Multiple sclerosis affects neurons, the cells of the brain and spinal cord that carry information, create thought and perception, and allow the brain to control the body. Surrounding and protecting some of these neurons is a fatty layer known as the myelin sheath, which helps neurons carry electrical signals.
Cold can also be a problem. Some people with MS notice that symptoms, particularly spasticity, become worse in cold weather. It is generally recommended that people with MS who are sensitive to temperature try to avoid extremes of either hot or cold.