脳深部電気刺激で脳損傷患者が意識回復

 重度の脳損傷後遺症で、6年間も注入栄養で発語不能だった38才の患者が、深部脳刺激DBSにより意識状態が改善し、食事摂取や発語が可能になった。
 この患者は、覚醒システムに問題があり、脳皮質にかなりの障害はあるが基本的な領域は保たれているために、この治療の対象として選ばれた。電気刺激の部位である視床は視覚など知覚情報を脳皮質へ伝える経路であり、意識に関与しており、運動制御にも関与している。

深部脳刺激療法Deep Brain Stimulation:DBS)とは:難治性のパーキンソン病やジストニアなどの不随意運動症に対する脳外科治療として、従来より脳の特定の部分を破壊する治療が行われていたが、これに代わり、脳の深部に留置した電極からの電気刺激により、脳深部の破壊術と同様な効果を得るという治療法。


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Last Updated: Wednesday, 1 August 2007, 17:02 GMT 18:02 UK
Electrical pulses 'rouse' patient
http://news.bbc.co.uk/2/hi/health/6926158.stm

画像X-ray of electrodes placed in brain
The electrodes were placed at specific points in the brain

Deep brain stimulation with electrical pulses may offer hope for patients trapped in a minimally conscious state.

Treatment of a 38-year-old man with a severe brain injury enabled him to use words and gestures, chew and swallow and drink from a cup, say US doctors.
Before the stimulation, done through electrodes implanted in his brain, he could only make slight eye or finger movements, the team report in Nature.
Experts said more studies were needed to assess which patients may benefit.

Now, my son can eat, express himself and let us know if he is in pain. He enjoys a quality of life we never thought possible
Patient's mother

Deep brain stimulation is already used in the treatment of tremors associated with Parkinson's disease.
The procedure involves electrodes implanted with millimetre accuracy to specific areas of the brain.
Badly beaten
The man involved in the study was badly beaten six years ago, leaving him severely brain injured and in a minimally conscious state, in which patients show intermittent signs of awareness.
Over a period of six months the researchers alternated periods of electrical stimulation with fake stimulation to assess whether it was having an effect.
Within 48 hours of the first stimulation, the patient was able to keep his eyes open, turn his head, and utter words.
After several treatments he is now able to perform complex tasks such as brushing his hair, although with difficulty due to severe immobility caused by his condition.
And can chew and swallows his food where before he needed a feeding tube.
Further tests on 12 patients have gained FDA approval. The researchers say if these results are replicated, it could change the standard of care for such patients, most of whom have to be cared for in long-term nursing facilities.
Dr Ali Rezai, the neurosurgeon at Cleveland Clinic's Center for Neurological Restoration who carried out the procedure said the changes in the man had been "remarkable and sustained".
Study leader, Dr Nicholas Schiff, associate professor of neurology and neuroscience at Weill Cornell added: "The work challenges the existing practice of early treatment discontinuation and also changes the approach to assessment and evaluation."
Communicate
His mother, who does not wish to be identified said it had been very hard for her to see her son lying in the nursing home, unable to communicate with them.
"I'll never forget the words the doctor said to us: 'if your son recovers from this in the next 72 hours, and we don't know if he will, he will be a vegetable for the rest of his life.'
"Now, my son can eat, express himself and let us know if he is in pain. He enjoys a quality of life we never thought possible.
"And the most important part is he can say 'I love you mommy'."
Professor Paul Matthews, an expert in clinical neurosciences at Imperial College London, said the study offered hope.
"The causes and severity of brain injury vary between minimally conscious state patients," he said.
"More experience with the approach is needed to understand which patients may be expected to benefit."
Professor Tipu Aziz, expert in neurosurgery at the University of Oxford, added there had been cases of patients recovering spontaneously after being in a minimally conscious state for a long time and no firm conclusions could be made.
"Much more needs to be done into the research of the best management of such patients but there is little funding to do so."

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Nature
Published online: 1 August 2007; | doi:10.1038/448522a
Implant boosts activity in injured brain
Deep-brain stimulation offers hope for minimally conscious patients.

Michael Hopkin
Brain function has been improved in a patient who was in a minimally conscious state, by electrically stimulating a specific brain region with implanted electrodes. The achievement raises questions about the treatment of other patients who have been in this condition for years, the researchers say.



Deep-brain stimulation might help trauma patients regain consciousness.
CLEVELAND CLINIC
Patients in a minimally conscious state, often the result of severe brain trauma, show only intermittent evidence of awareness of the world around them. Typically, they are assumed to have little chance of further recovery if they show no improvement during their initial 12-month rehabilitation programme.

In the latest case study, neuroscientists describe how they implanted electrodes in the brain of a 38-year-old man who had been in a minimally conscious state for more than six years following a serious assault. By electrically stimulating a brain region called the central thalamus, they were able to help him name objects on request, make precise hand gestures, and chew food without the aid of a feeding tube (see 'Behavioural improvements with thalamic stimulation after severe traumatic brain injury'). The thalamus is involved in motor control, arousal and in relaying sensory signals ― from the visual systems, for example ― to the cerebral cortex, the part of the brain involved in consciousness.

There will be a subset of patients who are responsive to this approach.

Nicholas Schiff of Weill Cornell Medical College in New York, and his colleagues chose the patient because they believed his condititon was due to impairment of the arousal system, and that despite considerable damage to his cerebral cortex, many essential areas were preserved.

"There will be a subset of patients who are responsive to this approach," says Schiff. But he adds that patients with different brain injuries may not benefit from electrostimulation. "Not every patient in a minimally conscious state will fit this profile," Schiff says, and it is difficult for neurologists to identify those patients who will show recovery.

Nevertheless, the case shows that many patients currently seen as beyond hope of rehabilitation might benefit from the results of further research. "Severe brain injury is not an uncommon problem, and the number of people doing research on this is shockingly small," Schiff says. "It's very rare to find a programme that will take a patient in a minimally conscious state even straight out of acute care. If they don't respond in a lively enough way and can't communicate and interact with people at the bedside, they go to a nursing home directly."

"The report does not suggest that deep-brain stimulation [DBS] 'cures' the minimally conscious state," says Paul Matthews, a clinical neuroscientist at Imperial College, London. "Although based on a study of only a single patient, it suggests that DBS may be adapted to benefit at least some patients in the minimally conscious state. And it emphasizes that improvements can be made by patients even long after an injury.

"Although we do not know precisely which brain connections are important, we may expect that some specific connections must be intact for DBS to have a beneficial effect."

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