In 1973, my grandmother (approx. 65 years old and afflicted with Parkinsons) had knee replacement surgery in Boston. Prior to the surgery her mental capacities were 100%. Following the operation, she lost her short term memory. I don't mean to be too depressing, but from that point on her abilities and capacities decreased. As this occured, however, we would NEVER EVER do anything that made her feel that we thought she had any problems with this. We are also convinced that the medications for Parkinsons, which changed periodically, may also have been causal wrt her diminishing memory et al. The doctors, when confronted, emphatically denied that the general an. or subsequent post-op medications/pain killers and Parkinsons medications or combinations thereof could have impacted her mental capacities. They also stated, from what I remember, that she must have been in this condition prior to the operation. I lost a great deal of respect for M.D.'s during that period. -Matt McKenna