Complex sentence: According to recent research not a single theory is able to explain the cause fully, however current plausible theories include infection with "Toxoplasma gondii", Herpes simplex virus, Rubella, neurogenic causes, and autoimmune pathology.
Split into simpler sentences: According to recent research not a single theory is able to explain the cause fully. However current plausible theories include infection with "Toxoplasma gondii", Herpes simplex virus, Rubella, neurogenic causes, and autoimmune pathology.