According to a new paper, one of neurosciences most famous case-studies came about as a result of a serious medical blunder.
Henry Molaison (1926 2008), better known as HM, was an American man who developed a dramatic form of amnesia after receiving surgery that removed part of the temporal lobes of his brain. The 1953 operation was intended to treat HMs epilepsy, but it had the side effect of leaving him unable to form new memories.
The consequences of HMs surgery are well known his amnesia was the subject of dozens of scientific papers. But whats been less discussed is why HM was given such a drastic operation.
According to Francois Mauguire and Suzanne Corkin, the authors of the new paper, the whole thing was a mistake. They argue that HM had a form of epilepsy that cant be treated by any kind of surgery and his doctors should have known this, even back in 1953. (Corkin worked with HM for many years and recently published a book about his life, Permanent Present Tense.)
Regarding HMs diagnosis, Mauguire and Corkin argue that HM almost certainly suffered from idiopathic generalized epilepsy (IGE). A defining feature of IGE is that the seizures do not start from any particular place in the brain. In other forms of epilepsy, there is a focus. The focus is often (although not always) found in the temporal lobe. Surgical removal of such a focus can be an effective treatment. But in IGE, there is no focus.
If Mauguire and Corkin are right, the tissue that was removed from HMs temporal lobes was perfectly healthy. A sobering thought. Whats more, the authors say that HMs doctors at the time knew that he probably had no epileptic focus. So why did they cut up his brain?
It appears that the answer lies in a dubious theory that William B. Scoville, the neurosurgeon who proposed the operation, held. Scoville believed that cutting certain brain pathways could raise the seizure threshold in the brain, and hence treat any kind of epilepsy, whether or not there was a focus.
Indeed, shortly after operating on HM, Scoville published a brief paper in which he suggested that in the future, surgery might render anti-epileptic drugs obsolete:
Who knows if neurosurgeons may even carry out selective rhinencephalic ablations in order to raise the threshold for all convulsions, and thus dispense with pharmaceutical anticonvulsants?
Its not clear where Scoville got this idea from, although Mauguire and Corkin suggest that it ultimately derives from the world of psychosurgery the neurosurgical treatment of mental illness. Psychosurgery was based around the idea that particular surgical lesions could re-balance the whole brain (and mind). Scoville was himself an active psychosurgeon.
See the original post:
Was Neuroscience's Most Famous Amnesiac, "HM", A Victim of Medical Error?