Well, actually cerebral palsy is a non-progressive disorder, that is, the lesions that cause cerebral palsy do not progress with time. If there is a worsening of symptoms, it is due to other associated lesions. So, ask your doctor if you need a MRI.
The reasons could be stress, functionally small bladder, diabetes mellitus, diabetes insipidus, urinary bladder wall instability, UTI, stones and neurological problems.
Limit fluids in the evening. Set up an alarm your self and try and wake up 3-4 hours after sleep and use the washroom. Ask your doctors to look into these causes. Diabetes can also affect nerves and cause muscle related problems. Hope this helps. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.