The mumbness of the limbs and/or head COULD be a sign of Vitamin B-12 deficiency, this is a side effect from long term use of meds in some cases.
It can be detected through a simple blood test.
I've had Epilepsy for 31 years and I was experiencing the same signs (among others) and my Neurologist ordered a blood test and said this is quite often the cause (although everybodys body chemistry is different)
Diagnosed with Epilepsy & Ulcerative Colitis.
Current Medications: Diantin 275mg, Pheonobarb 150mg, Asocol 3,000 mg.