Movement Disorders (Week 5)

The human movement is the basic framwork of the prefrontal and premotor cortex. Different routes in our brain are responsible for diverse actions that create control of thought and cognition. Movement is controlled by our spatial reference frame that involves knowledge about the location of the body in space and of course about the object you are paying attention for, such as grasping for a pen, your eyes focus on the object, your hand reaches out and makes the correct hand movement to grasp for it, this process is also called as sensory-motor transformation. Our premotor areas, are mainly dealing with internal and external events from our day to day life, also involved in specific goal targets, also called achievement, these are lying to the back of the prefrontal cortex. The prefrontal cortex is occupied with tasks like planning and decision-making, paying attention and deals more with general actions than object specific. The occipital lobes is involved with our visual system, where projections from the retrina are received where different types of neurons provide certain information for colour, orientation and motion. Two important pathways are responsible for our conscious information, the dorsal stream transmits to the to the parietal lobes and identifies where objects are located and the ventral stream provides information to the temporal lobes and categorizes what objects are. If damage to the ventral stream has occurred, visual agnosia can develop and also impairment in identifying objects, colour etc is highly likely. Another form of damage are movement disorders, that occur due to damage in the left hemisphere in the brain and cause physical impairment of movement, like gestures and grasping. If there has been damage to the Basal Ganglia, impairments in movement are expected. Different disorders are Parkinson’s, Huntington's and apraxia. Research has found that most patients with practical and dissociative impairment deal with more than one symptom, and it can also be said that that when a patient deals with more indications of the illness it might be quit mysterious how these come together, such as walking problems, twitches and uncontrollable arm movement called tremor. 

This model of movement disorders I'll find enormously helpful, to identify, of what brain area the disorder comes from  and also the yellow and red markings help to understand which ones are "positive" and "negative. Whereas positive and negative are the wrong terms to use, as its too extreme, all disorders are negative, however some have further damage than others.  

For the movement disorder, Parkinsons Disease what mainly affects elderly people, I have found a really good and interesting article by BBC, which made me smile today. I felt that even within all these sad disorder theories, a surgery of an elderly man with parkinsons disease was successful and he has 95% of his life back:

                       http://news.bbc.co.uk/1/hi/england/south_yorkshire/7243974.stm

I also have found an interesting page towards functional movement disorders, that support people with the disorder and help to adapt to the real world, as psychological seen some patients believe that the disorder develops as they would have done something wrong in their life, which is not true. 


    http://www.neurosymptoms.org/#/movement-disorders/4533053142


I have read the paper about, "Abnormalities in the awareness of action" by Blakemore,Wolpert and Frith (2002). A particular model was designed to establish motor learning and control in individuals to identify which parts of our motor control are responsible for the human awareness. It has been found that individuals not always have conscious motor control of things. Such as picking up a pen, you are targeted towards the pen, and already make the correct hand movement, grasping for it. So you are consciously aware for that but unconsciously there goes far more work into one movement, like strengthen and loosing your muscle tone. Abnormalities in movement are described as a dismissed control of action. One of the abnormalities is called "optic Ataxia", I´ll find that one a slightly confusing as i thought the patient would not be able to see the object properly, but actually the subject has problems grasping the item, so the individual can see quit good, just cannot focus completely on the object. However that does not mean if you character wise a bit clumsy that you have a disorder. Another abnormality, I´ll find quit fascinating is the "utilization behavior" which means that patients use some objects at the wrong time, like it is raining outside and the patient wants to wear its swimming costume, which obviously is not really wrong but in that moment, it would be used inappropriately. However there are some other abnormalities that are being discussed in the paper and i have also read some more about them, I do feel that the model itself and topics addressed by the researcher are sometimes controversial, as not enough evidence has been found to what circumstances does our awareness becomes more central for the model, to conclude the paper, I feel that some more research has to be done and belief that neurological and psychiatric factors have to be more systematically evaluated to complete the model to understand the main principles of motor control and awareness.