Multiple sclerosis (MS) is in all probability an autoimmune disease causing severe neurological disability due to inflammation and degeneration in the central nervous system (CNS). MS affects over 1 million people worldwide. Central neuropathic pain is associated with approximately 30% of all patients with MS. MS-accompanying pain has a major impact on the patients' quality of life as usual conventional analgesics are little effective. The aim of this clinical study is to determine whether Dronabinol is effective and safe in relieving central neuropathic pain in multiple sclerosis patients.