Stephen King, liar.

Recently, I watched Pet Sematary for the first time. I know, a rather large gap to have left in my horror movie education, but what's done is done, and what isn't isn't. My suspicious were aroused at the point in the movie where Tasha Yar's sister has been turned into a hideous skeletal zombie creature and locked in a room upstairs for years because of spinal meningitis. This struck me as a mite queer remembering how a friend of a friend had succumbed to the "same" illness in the course of an evening. As I remembered it, in the case I had heard about, the kid just went to sleep complaining of a stiff neck and never woke up. Didn't begin to resemble a corpse until after he died.
Through the magic of basic research, I have discovered that there are different forms of Meningitis, viral, bacterial, or fungal, but all of them affect the meninges: the system of membranes that envelop the central nervous system. Bacterial Meningitis is particularly serious form will kill within 24 hours without prompt medical treatment (in the form of strong antibiotics, or steroids).

Here is a list of symptoms associated with Meningitis from Wikipedia:

Symptoms of meningitis are: Sudden high fever, drowsiness or confusion, severe, unrelenting headache, stiff neck, intolerance to bright light and sounds, twitching, convulsions, delirium particularly in children, and/or a rash of small, irregular purple or red spots all over the body may indicate meningococcal meningitis. Chills, nausea, or vomiting, may also occur. Seizures may occur in about 20 to 40% of patients. Other signs include Kernig's sign and Brudzinski's sign. Although commonly tested, the sensitivity and specificity of Kernig's and Brudzinski's tests are uncertain.

Spinal Meningitis, though serious, is not a chronic illness. I think Zelda was misdiagnosed:

Either that or Stephen King just opened up his "Big Book of Medical Ailments" and picked something that sounded good. Don't trust everything you see in pulp horror.

See also:
Understanding Meningitis
Mayo Clinic: Meningitis
Wikipedia:Meninges