Definition and Symptoms
Micrographia is a symptom of motor disorders in humans characterized by
writing that starts normal sized and then becomes increasingly smaller.
Micrographia represents part of the constellation of symptoms presented by
Parkinson's disease. The reason Parkinson's disease commonly results in
micrographia is because Parkinson's disease inflicts one of the most important
centers for motor control in the brain: the basal
ganglia. The basal ganglia is comprised of several parts, all of which are
responsible, among other things, for the fine motor control necessary to perform
such tasks.
Here is how micrographia might demonstrate itself in a patient with
Parkinson's disease, without the help of visual guidelines:
Hello, I
have Parkinson's disease
Solution
Thankfully, when it comes to motor control, the human brain is highly
redundant. The precentral gyrus (primary motor cortex - M1),
cerebellum, and various other places along the cortex serve as centers
and relay stations for motor activity. Therefore, many other parts of the brain
are capable of performing the functions necessary to overcome micrographia.
Nevertheless, the patient will not be able to write fluidly in the proper
horizontal gauge without visual guidelines, or cues. By simply offering two
lines in which to write, much like the lined writing paper found in grade
schools, the patient can overcome the micrographia:
__________________________________________
Hello, I have Parkinson's disease.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
This sort of compensation for motor difficulties using visual guidelines is
typical of other physical training for people with Parkinson's disease. While
walking becomes a difficult, fettered activity for those inflicted, a
checkered floor can assist the patient in walking by presenting a visual cues
for calculating the length of their gait. This checkered floor training appears
in the movie The Awakening, if that strikes a chord.
Physicians often use the severity of micrographia to determine
for the level of progression of Parkinson's disease. If a patient's micrographia
is more severe than last session's results, Parkinson's disease has overtaken
more of the basal ganglia and is therefore in a more advanced state.
Refernces:
http://www.pdf.org/ ~ Parkinson's Disease
Foundation
http://www.healthandage.org/Home/gm=2!gid2=2562