Gupta is a member of the staff and faculty of the Department of Neurosurgery at Emory University School of Medicine in Atlanta, Georgia.

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"Alfredo is an outstanding surgeon, and takes very humane and very skilled care of patients with brain tumors, " says Dr. Henry Brem, chairman of the department of neurosurgery at Johns Hopkins Medicine.

CNN: From migrant worker to neurosurgeon

The skull of a child is thinner, allowing radiation to penetrate deeper compared with that of an adult, according to Dr. Keith Black, chairman of Cedars-Sinai Hospital's Department of Neurosurgery in Los Angeles.

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Such results suggest there may be some higher processing of information going on, and that areas of the brain important for processing complex stimuli are still functioning, said Dr. Keith L. Black, chairman and professor in the department of neurosurgery at Cedars-Sinai Medical Center, who is not involved in Sharon's care.

CNN: Sharon brain results not proof he'll wake up

Doctors at the neurology department at Lariboisiere Hospital in Paris, writing in the Journal of Neurology, Neurosurgery and Psychiatry, said it was a unique case.

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