is this patient an unknown diabetic? If we have discussed a neurological explanations perhaps vascular possibilities should be considered...I agree with gcoe the age of this client makes this situation a little concerning, and a space occupying lesion at the dorsal column could be responsible...either way an Wikipedia reference-linkMRI is good idea...

I would consider ruling out diabetes also...this is another condition wherein all central neuro tests will be ok when tested...

She needs to be fully examined, blood work and all...to be honest