What is Hemiparesis vs Hemiplegia?
The central nervous system is an intricate web of nerves that is responsible for perceiving stimuli, processing them, and sending signals in response to them. For this to work, these pathways and processing centers need to function properly.
The problem arises when there is an alteration in one of these points.In spite of what many people believe, and of being very similar words, they mean opposite but much related things.
Hemiplegia, on the one hand, has to do with total motor loss, where half of the body does not respond and is paralyzed. However, in hemiparesis, which is a neurological condition, the body does respond to signals from the brain and is able to move, but weakly.
Nerves are long structures that form cords that travel through our marrow. In hemiplegia, these cords can be completely severed (broken or separated) preventing signals from being properly transmitted. However, in hemiparesis there may be certain injured nerves within these cords, but not all of them, so movement and a certain degree of response are possible.
Hemiparesis – Responding to Movement
As we have emphasized, in this case there is only a decrease in motor force or some kind of partial paralysis that will affect, of course, half of the body. It is much more evident when it affects the extremities, arms and legs, than when it affects the face, given that movements are less relevant to the development of our daily lives.
As for the causes, it can be due to many disorders. It can range from damage to the spinal cord (where all the cords with nerves that transmit information are found), to brain injuries (the processing center of this information). Therefore, it can exist in diseases such as multiple sclerosis, spinal cord tumors, stroke, neurodegenerative diseases, etc.
Read More: Multiple Sclerosis
As in many neurological disorders, depending on where the injury is that we will have symptoms. If it is due to a stroke in the left hemisphere, for example, it is most likely that the hemiparesis is reflected in the right hemibody. However, if the lesion is in the lower part of the spinal cord, it is most likely that symptoms will manifest on the same affected side.
Hemiplegia – Movement’s Abolition
In this case, no signal reaches the hemibody, so it is impossible that there is any type of movement, no matter how small. This disorder is one of the most frequent when we talk about brain injuries, and occurs especially in older people.
Unfortunately, we almost never find only the paralysis of half of the body, but it is common to see it associated with other diseases such as memory loss, decreased ability to control sphincters, speech problems, and consciousness disorders.
Many factors can be the cause of this condition; however, the most common are two: strokes and head injuries.
In stroke, oxygen does not reach a sector of the brain for a certain period of time, causing the “origin” of signals that go to the rest of the body by ischemia to be lost.
In the case of trauma, the damage is more direct and we simply cut the transmission route or the origin, depending on the location.