Currently, has a persistent disorder of consciousness for

Currently,
general knowledge states that a patient who has a persistent disorder of
consciousness for more than twelve months is unlikely to recover. This creates
a very hard decision for family members of patient’s in a vegetative state who
must decide how take care of these patients who are alive yet unresponsive. In
the article by Neuroscience News
called “After 15 Years
in a Vegetative State, Nerve Stimulation Restores Consciousness” new hope is
created for possible treatments for patients who have been in a persistently
vegetative state.

            The study examined in
this article is a case study of a 35 year old man who had been in a vegetative
state for 15 years following a car accident. He had shown no evidence of
improvement and therefore was chosen for the stimulation study because any
improvement could be more easily linked to the treatment. The patient had a
vagus nerve stimulator implanted in his chest and the stimulator was run for a
month. After a month, neuropsychological tests, an EEG and PET scan were run.

The neuropsychological tests showed an improvement in orientation as the
patient was now able to follow an object with his eyes, turn his head upon
request and stay awake when his therapist was reading to him. The EEG showed an
increase in overall brain activity, and the PET scan for metabolic activity
showed an increase in functional connectivity throughout both cortical and
subcortical regions. These changes indicated that the patient had entered a
minimally conscious state after 15 years in a vegetative state.

            This research is very
important as it upturns the idea that a patient will not recover from a
vegetative state after more than a year of persistent disturbances in
consciousness. It also introduces new treatment possibilities or at least new
areas of research for treatment. In addition, the return of consciousness
suggests that the brain may be more plastic and have a larger capacity for
repair than previously believed, and suggests that certain interventions can
assist in speeding this healing even after long term damage. Finally, this
study gives more evidence for how consciousness occurs. By seeing that
consciousness can be recovered after such a long disturbance and with electrical
stimulation may suggest that consciousness is tightly linked to the electrical
activity in the brain and that the level of electrical activity may be what
creates consciousness. This seems like a reasonable explanation as EEG studies
are currently used to understand different levels of consciousness.

            The main limitation of
this study is the fact that it is a case study and thus is not generalizable.

Although it does provide interesting information that can be used to develop
further research studies, it only provides anecdotal evidence of the
effectiveness of the treatment. In addition, since the disturbance is implied
to be due to a traumatic injury the treatment may not be effective for loss of
consciousness in disturbances caused by infections or neurodegenerative
disorders. Limitations of the media article include the lack of detail on where
the brain damage occurred or where exactly improvement on the PET scan was
seen. This is a problem, as the results may not be generalizable to brain
damage in other regions. Also, it is important to understand which areas of the
brain showed improvement on the PET scan in order to hypothesize which parts of
the brain may be the most linked to consciousness. The article did not detail
why stimulation to the vagus nerve instead of another area was decided on. This
would be important information for understanding how why vagus nerve
stimulation resulted in the re-development of consciousness. Finally, the
article does not mention the reaction of other medical professionals and if they
approved of the studies protocols and conclusions. This is an issue because of
the lack of even informal peer review.  A
strength of the article is that it was very objective and stuck to the facts
without providing further conclusions or interpretation.

            The main relation this
article had to class concepts was in the neuroimaging chapter. The study shows why
PET scans can be more advantageous than fMRIs in some cases. In class, we discussed
how PET scans had low temporal resolution and how activated areas seen on the
scan may not be essential to the task. For these reasons, we said that fMRI was
usually favored over PET but that PET could be very useful in the medical
field. This use in the medical field was shown through this study in how the
interest was more in gross connectivity rather than task specific activity. The
PET scan was favored here because exact functioning was not desired so low
temporal resolution with PET was not considered a disadvantage and the cheaper
nature of PET made PET the better choice. In addition, this study shows when
invasive electrode stimulation is appropriate in humans. Although, as discussed
in class, electrode stimulation is primarily used in animals, this shows how it
can be used in humans in extreme cases. Although the location of brain damage
was not explicitly stated in this article, the research shows the importance of
the brain stem in consciousness. In class, the brain stem was discussed as a
place where if brain damage occurred life was majorly in danger. This study
shows this in the lack of consciousness.