I have a friend found out she was misdiagnosed with MS today. Neuro at hospital said that she has something worse than ms. What other diseases??

MS? There are some other neurological diseases worse than MS, but it would be pointless to speculate here. She should consider getting a second opinion. Best wishes to you and your friend.
Take a deep breath! If your friend told you someone told her she had something worse than multiple sclerosis but did not say what it is, then I wonder if she misunderstood. When people hear what doctor's say when they are sick & scared, they may only hear part & not all the explanation, or misunderstand what they were told. Some docs, give a range of causes of symptoms, from good to bad but only the bad's "heard."
Many? There are unfortunately many diseases that one might consider worse than MS. You will need to ask your friend what she was diagnosed with. Best wishes.
It depends... Neurological conditions of the brain, besides, MS, include SLE, Parkinson's and fibromyalgia and others. While the Neurologist may have a diagnosis for your friend, her prognosis would ultimately depend upon not only her current symptoms, level of disability, but also family history, her will power and consistency in medical and treatment follow ups.