My mother is 80 years old. She has had Myasthenia Gravis for over 55 years and has been in a wheelchair most of that time. A few years ago she was diagnosed with Parkinson’s. This past year she began feeling pain in her neck and shoulder and was told it was spinal stenosis. She has successfully used Prostigmine for years to help with her muscle weakness, however it become unavailable this past summer so she switched to Mestinon for 6 months. She did not do very well on the Mestinon. Her muscles were weak and she was not as mentally sharp as she normally is – I kept thinking her sodium was low. During the 6 months she was on the Mestinon she fell out of her wheel chair and hit her head on the bathroom sink giving her mild subdural hematoma. An MRI was done and everything looked ok. After all this her neck dropped forward. Over about a 3 month period her head dropped and is causing her pain and discomfort and making eating and swallowing difficult due to the forward position of her neck. Her facial muscles are not weak. Her neurologist performed an EMG and there was evidence of mild exacerbation of MG symptoms. Meanwhile we found some Prostigmine and switched her from Mestinon back to Prostigmin. Her mind clarity improved immediately and her muscle strength improved enough so that she is again able to transfer herself from chair to wheelchair, but her head is still dropped. She tried IVIG treatment but that did not help. She’s considering plasma apheresis which helped her about 30 years ago during a difficult MG period. She’s miserable because of her neck but I’m not sure the plasma apheresis will help her neck. Any ideas or suggestions to help her?

Summarized question: What is the cause of the dropped head due to myasthenia gravis?