Well I’m back! I’m not going to pretend like you missed me but I hope your glad to see another post out of me. I did a bit of writing during my time off to build up a bit of a backlog so hopefully I can keep posting regularly for a while. Anyway, without any further ado…
Jumping Frenchmen of Maine Syndrome
Best. Disease. Name. Ever.
This disease was first observed in 1878 by the neurologist Dr. George Miller Beard, a guy I will definitely talk about again, in French-Canadians, lumberjacks and presumably some French-Canadian lumberjacks living in northern Maine. So that explains the “Frenchman” and “Maine” parts but lets look at what makes this a “Jumping Syndrome”.
|This is the famous jumping Frenchman Patrick de Gayardon. He has nothing to do with this story. Left Right.|
This syndrome is due to an exaggerated startle reflex resulting in uncontrolled jumps commonly but can also manifest as spasms throughout the body. The startle reflex is very important and forms part of the ‘fight or flight response’ normally.
Essentially a startle (which by definition has an auditory component) has three major neurological routes in the brain that have a number of effects. First, the auditory nerve fibres stimulate the cochlear root neurons (CRN) that form the first part of the central nervous systems auditory processing. Following this stimulation the CRN’s stimulate the nucleus reticularis pontis caudalis cells (PnC) located in the Pons (part of the brainstem). Finally the input into the Pons results in stimulation of motor neurons, particularly to the head and neck and the spinal cord. This results in the jerking response aimed at orientating you to the source of the startle while also priming your body for a response.
|Left shows brain side on with exposed brain stem and pons are highlighted while right shows the dorsal view of the brain stem (dorsal means back, think about the location of the dorsal fin on a dolphin) with the CRN highlighted.|
One thing that I think is important to point out is how fast this all is. The time taken from the detection of the stimulus to the first muscles to react (in your jaw) is roughly 14 milliseconds! The last muscles to react (unsurprisingly in your feet and legs) receive stimulation after only 400 milliseconds!
Jumping seemed to not be the only unusual response in the Jumping Frenchman. Some exhibited echolalia (one of my favourite words and albums) or echopraxia. Others yelled, spasmed or hit out and another observation was made that confused matters further. Some jumpers would inexplicably follow commands given alongside their stimulus including one man who was startled whilst being given an order to throw causing him to launch the knife in his hand across the room. This was observed to be repeatable and the sufferer was ordered to throw a bunch of objects including a pipe he had just finished packing.
Researchers have looked for something in this community to explain this unusual stimulus response. This isolated community exhibits all the hallmarks of a population that might result in mutations that could develop and persist. Lending credence to this possibility were Beard’s original observations that the jumpers were confined to family groups but so far no genetic analysis has show a causal link to the condition.
These studies have suggested a different cause. In particular the work of the Saint-Hilaire’s which involved videotape evidence of a number of sufferers seems to suggest the response is psychological, not neurological, and may have been brought on by positive re-enforcement of this unusual behaviour in the small community.
Whatever the cause the disease still has a funny name. Almost feels like it should have been a Monty Python sketch if you ask me.
Saint-Hilaire MH, Saint-Hilaire JM, & Granger L (1986). Jumping Frenchmen of Maine. Neurology, 36 (9), 1269-71 PMID: 3528919
Saint-Hilaire, M., & Saint-Hilaire, J. (2001). Jumping Frenchmen of Maine Movement Disorders, 16 (3), 530-530 DOI: 10.1002/mds.1080
Howard R, & Ford R (1992). From the jumping Frenchmen of Maine to post-traumatic stress disorder: the startle response in neuropsychiatry. Psychological medicine, 22 (3), 695-707 PMID: 1410093