Recent reports of evaluating former Israeli Prime Minister Ariel Sharon’s brain activity with functional magnetic resonance imaging (fMRI) do not indicate that he is on the verge of awakening from a coma after his severe stroke seven years ago.
For 20 years, fMRI has been a useful and often fascinating tool for neuroscientists to investigate brain function, for neurologists to diagnose ailments and assess the response to treatments, and for neurosurgeons to plan and conduct complex surgery on the brain. This technique measures changes in cerebral blood flow related to something that patients do (such as tapping their fingers or reading a word list) or the response to a stimulus like patterns of light, pictures or touching the feet. Nevertheless, fMRI is unproven to monitor patients after any severe brain injury or as a way to assess prognosis.
It is not clear why Mr. Sharon underwent these tests. Regardless of the results, the most important way to predict recovery is a traditional clinical neurological exam, wherein a physician assesses motor and sensory skills, balance and coordination, nerve function, reflexes and the patient's level of awareness and interaction with the environment.
Unless Mr. Sharon exhibited otherwise unreported improvements during a clinical neurological exam, the fMRI means little or nothing with regard to his recovering any meaningful brain activity.
This post was written by Michael Schulder, MD, vice-chairman of neurosurgery at North Shore University Hospital, who is also the director of the Brain Tumor Institute and a professor of neurosurgery at the Hofstra North Shore-LIJ School of Medicine.
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