Can Brain Scans Predict Coma Recovery?

A coma, which comes from Greek meaning deep sleep,  is a frightening, suspended state of being, involving an extended period of unconsciousness that is usually temporary, lasting from a few days to a few weeks. Medical diagnostics are not easily foreseen and vary from a full recovery; an awakening with varying degrees of physical and and cognitive impairment; a vegetative state with little or no awareness; or death. Educated predictions of coma recovery are difficult because every once in a while, someone who has been comotose for years can suddenly regain consciousness. Up until now, doctors have lacked the necessary tools to determine which coma sufferers might awaken.

What is an fMRI?

Functional Magnetic Resonance Imaging is a technique concerning two diverse aspects. 'Functional' indicates that brain function during a specific experimental period of time is involved. It differs from other MRIs, which are fixed in position and often utilized to diagnose brain pathology. 'Magnetic Resonance Imaging' refers to the magnetic field that MRI scanners use to align the hydrogen atoms in brain tissue before radio waves cause them to spin and computers to measure that spin.



A new and important study

A new study conducted at INSERM U825, one of France's national research institutes in Toulouse and published in the online issue of the journal, Neurology, involved the brain scans of 27 people in  a coma and 14 healthy patients. The researchers used a technique called fMRI and focused their energies on a poorly studied region of the brain called the posterior cingulate cortex (PCC), which is associated with consciousness. They discovered that when head trauma or cardiac arrest occurs in this area of the brain, the patient is not likely to ever recover from a comatose state.


 fMRI DiagramfMRI Diagram


The study further indicated  that all of the comatose patients suffered from malfunctions in the connections to and within the PCC. Despite this, four of the coma patients did recover consciousness and still had brain activity between the PCC and the medial prefrontal cortex, whose function is associated with decision-making and the retrieval of remote, long-term memory.

The study also pointed to the fact that between healthy patients and those who regained consciousness the neural activity between the two areas of the brain was identical. This  suggests that fMRI brain scans of the PCC can serve as diagnostic tools for doctors by providing them with information about likely outcomes and possibly better treatment options.


Patient Undergoing fMRIPatient Undergoing fMRI


Dr. Stein Silva, lead author of the study, believes the results are very promising but confirmation of results will require more statistical power and studies involving  a larger number of participants. Not enough studies have been made on the posterior cingulate cortex because difficulties in imaging the area make it less accessible to brain scans.

In the words of James Bernat, a coma expert and professor of neurology and medicine at the Dartmouth-Hitchcock Medical Center in New Hampshire: "The new study adds one piece of a very large puzzle of how the brain regulates conscious awareness."

Do you thnk that other little known areas of the brain will one day be explored?

Closing thoughts on comas:

...I  had a profound sense of being at a crossroads, a turning point, somewhere between death  and life. ~ Hal Zina Bennett