Where, as above, C is annuity payment, PV is principal, n is number of payments, starting at end of first period, and i is interest rate per period. Equivalently C is the periodic loan repayment for a loan of PV extending over n periods at interest rate, i.
Refractory epilepsy is a seizure disorder that resists drug treatment. There is some debate among clinicians and researchers about how to define refractory epilepsy. As a result, this term is used in a variety of ways, and when a patient's epilepsy is described as refractory, resistant, or nonresponsive, it can be advisable to ask for more detail about what the diagnosis means.
Definition and terminology of chronic refractory cough. Cough is a reflex activity with elements of voluntary control. It forms part of the somatosensory system that involves visceral sensation, a reflex motor response, and associated behavioral responses.