My comments will be in Red! Hope this helps  I've attached the Wikipedia.com information for your records (and reference cites) as well.
From Wikipedia, the free encyclopedia
HM (also known as "H.M." and "Henry M.," born 1926 in Connecticut) is an anonymous memory impaired patient who has been widely studied since the late 1950s and has been very important in the development of theories that explain the link between brain function and memory, and in the development of cognitive neuropsychology, a branch of psychology that studies brain injury to infer normal psychological function. He is still alive today and resides in a care institute located in Hartford, Connecticut, where he remains in ongoing investigation. Audio-recordings from the 1990s of him talking to scientists were released in early 2007.
HM suffered from intractable epilepsy that has been often?though inconclusively?attributed to a bicycle accident at the age of seven. He suffered from partial seizures for many years, and then several tonic clonic seizures (seizures with a loss of consciousness and convulsions) following his sixteenth birthday. In 1953, HM was referred to William Scoville, a surgeon at Hartford Hospital, for treatment.
Scoville localized HM's epilepsy to his medial temporal lobe (MTLs) and suggested surgical resection ...
Henry M. and Alzheimer's Disease