To walk, the arms and legs are ultimately mere secondary tools, totally useless without a functioning brain. This was indicated on Monday by Yves Agid, professor of neurology, in the program Well done for you on Europe 1. A veritable control tower of the human body, the brain directs the movements of individuals.
But in the event of neurodegenerative disorders, linked to lesions in certain parts of the brain, the gait of said individuals may be affected. “As soon as we have diseases that affect the nervous system, the legs, the spinal cord, the cerebellum or really the main part of the brain, that is to say all this mass of almost three pounds that we have under the skull, each time there are defects that lead to very specific symptoms of walking,” he explains.
Listen to a patient’s gait
However, gait dysfunctions linked to neurological diseases should not be confused with those which have a purely orthopedic origin, for example, “if you have osteoarthritis or a sequelae of a broken leg”, illustrates Yves Agid.
To differentiate between these two scenarios, the neurologist uses a very specific technique. “I use what I call the horse dealer’s sign. Horse dealers listen to the sprained legs of horses when they trot. Me, when I see people entering the consulting room, I hear. And when I ‘hear a little limp, something like that, I say to myself ‘that’s not neurological'”.
Structural damage
Otherwise, different distinctive signs do not deceive. “An individual with Parkinson’s disease is recognized because he walks in one piece slightly leaning forward. The arms no longer swing, the feet rub the ground”, writes Yves Agid.
A behavior which is explained by “a defect of structures located in the middle of the brain”. “There are structures in the brain that manage the automation of all our motor behaviors that we don’t think about.” Swinging the arms, for example, is totally part of it. In the case of Parkinson’s disease, the patient has “lost automatic movements” and must therefore “compensate with willpower”.