As the awakening of Rep. Gabrielle Giffords has demonstrated these last… (Susan Walsh / Associated…)
The spectral images, reproduced in neurosurgery journals and textbooks, could be captioned "Beauty and the Beast."
Captured by X-ray and CT scan, the human brain is pierced by a bullet, nail, pool cue or chunk of razor-sharp debris. The intruding object has ripped a jagged vortex of destruction through the brain's gelatinous lobes and forged an even wider path of quivering shock. If the projectile came in hard and fast, shards of broken skull will be scattered through the delicate tissue. The bullet might have ricocheted off bone and tumbled wildly in the cavity, bursting blood vessels and carving uneven holes where, only moments before, healthy brain cells had hummed.
FOR THE RECORD:
Gunshot wounds: A Jan. 24 Health Section article on the prognosis for patients with gunshot wounds to the brain said that Dr. Ian Armstrong was a neurosurgeon based in Century City. His office is in Culver City. —
Such havoc, you would think, would put an abrupt end to the brain's rhythmic buzz of activity and extinguish the life defined by its complex inner work-ings. But — as the awakening of Rep. Gabrielle Giffords has demonstrated these last weeks — the human brain can be resilient, capable of withstanding brutish damage and then masterminding its reconstruction.
"I have seen every foreign body in the world pass through the brain, and I never cease to be amazed that some seem to survive and do amazingly well," said Dr. Ian Armstrong, a Century City neurosurgeon, shortly after Giffords was shot.
Make no mistake: Bullets usually kill when they enter the brain. The U.S. Centers for Disease Control and Prevention estimates that in 90% of brain injuries that stem from firearms, the patient dies. Of the lucky 1 in 10, virtually all are thought to live with persistent disabilities.
In the last 15 years, however, better treatments have greatly improved the odds of survival. "In Iraq, we were fooled many times," said Duke University neurosurgeon Gerald Grant, who was an Air Force physician at Joint Base Balad in that country. Patients whose scans showed that shrapnel had crossed between the brain's hemispheres or cut a wide swath of destruction — injuries long thought to be a swift sentence of death — would often live.
But the result, as Giffords may yet show, is almost always a person profoundly changed by the injury.
As many as half of those who have had penetrating brain injury will suffer epileptic seizures and will have a higher risk of them for the rest of their lives, experts say.
Because these injuries often leave a victim fully conscious during and immediately after, many will retain vivid memories of the horror and suffer flashbacks, nightmares, anxiety and withdrawal, the hallmarks of post-traumatic stress disorder.
Vietnam veterans with a penetrating brain injury have shown steeper cognitive decline than that of their uninjured peers — apparently an accelerated version of normal age-related decline.
Beyond those broad strokes, the exact consequences of a penetrating brain injury depend heavily on where and at what speed the foreign body penetrated the skull.
"There are some parts of the brain that have high real estate value," says Dr. Jam Ghajar, president of the Brain Trauma Foundation and clinical professor of neurological surgery at Weill Cornell Medical College in New York City. "If you go into the brainstem, or a millimeter to the right or left, you can have massive disruption and almost certain death. You go into the frontal lobe and you have a lot more room for error."
The brain is a marvel of redundancy, parallel networks and interlocking message centers that might, with time, rewire around obstacles. But many clusters have precise functions — governing word access or face recognition, or processing vision, hearing and smell. Damage to those can cause specific, maybe permanent, impairments.
Damage to deep brain structures such as the amygdala or the hypothalamus will likely disturb a victim's ability to fully form, retain and retrieve memories that are freighted with emotion. Such impairments can wreak havoc on relationships and day-to-day functioning.
Some damage is subtler still. When a penetrating object has stretched or torn some tissue, including the connective "white matter" that forms bridges among brain regions, problems of attention, memory and social processing make it tough to navigate the demands of work, high-level thinking or new social situations.
Damage to the frontal lobes — common in traumatic brain injury because they lie right behind the forehead — can disturb a person's ability to formulate plans, read or respond to social cues, and suppress the impulse to do or say things that might be socially inappropriate.