Hi kate2004,
The term "deep coma" is not a precise medical term. Even amongst
medical professionals, there is a lack of agreement on the terminology
to be used for various kinds of comatose state. The Neurosurgery
InfoNet site of the University of Southern California discusses the
common (informal) meaning of the term "deep coma" by comparision with
a "light coma":
Neuropathophysiology - consciousness - coma
http://uscneurosurgery.com/classroom/science/pathophysiology/topics/coma.htm
There are many causes of coma, and for any given cause there can be
multiple progressions of recovery, so it's hard to generalize about
survival rates. The factors affecting survival rates and recovery
timescales after coma that was caused by traumatic brain injury are
discussed here:
Traumatic Brain Injury - Prognosis - Neurology Channel
http://www.neurologychannel.com/tbi/prognosis.shtml
A report by D.E. Levy et al (Ann Intern Med. 1981 Mar;94(3):293-301)
has a very readable abstract that summarises their findings regarding
nontraumatic coma:
Entrez-PubMed: Prognosis in nontraumatic coma (Levy DE, Bates D...)
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7224376&dopt=Abstract
"We conducted serial neurologic examinations on 500 patients in
nontraumatic coma to identify factors predicting recovery. Overall, 81
patients (16%) led an independent life at some point within the first
year; the remainder either died without recovery from coma (61%),
never improved beyond the vegetative state (12%), or regained
consciousness but remained dependent on others for daily activities
(11%). Functional recovery did not depend on age but was to some
degree related to the cause of coma (subarachnoid hemorrhage and other
cerebrovascular disease having the worst recovery; hypoxia-ischemia,
intermediate; and hepatic and miscellaneous causes, best) and
especially to early clinical signs of brain dysfunction. Even within
hours of the onset of coma, only one of 120 patients lacking two of
corneal, pupillary, and oculovestibular responses ever regained
independent function. The study identifies clinical features of
comatose patients that appear within the first week and that are
important for predicting recovery and designing future therapeutic
trials."
If you follow the above link, then click on "Related Articles", you
will see a listing of many more research papers whose abstracts
include the words "coma" and "prognosis". You can click on the yellow
"page" symbol next to each listing to view its abstract (summary).
Additional links:
"International Working Party Report on the Vegetative State"
produced by The Royal Hospital for Neuro-disability, London, U.K.
http://www.comarecovery.org/pvs.shtm
A fairly comprehensive overview, which includes a few statistics on
recovery timescales.
Coma Recovery Association
http://www.comarecovery.org/
A non-profit support organization.
Google search strategy:
"deep coma"
://www.google.com/search?q=%22deep+coma%22
coma prognosis
://www.google.com/search?q=coma+prognosis
Regards,
eiffel-ga |
