The nervous system can be affected by a wide range of diseases and medical conditions and there are hundreds of medicines available to treat them. Symptoms of Parkinson's disease are often managed with medicines such as co-beneldopa, co-careldopa or ropinirole. The progression of Alzheimer's disease may be slowed by medicines such as donepezil or memantine. Epilepsy covers a range of conditions where over-activity of the brain leads to seizures. Seizures can be controlled with anti-convulsant medicines such as carbamazepine, lamotrigine, levetiracetam or sodium valproate.