This is your brain after super-magnets ....

[Guest guest]

> Zap!

>

> Scientist bombards brains with super-magnets

to edifying

> effect

>

> By Carey Goldberg, Globe Staff, 1/14/2003

>

> Just by pointing his super-magnets at the

right spots

> on your head, Dr. Alvaro Pascual-Leone can

make you go

> momentarily mute or blind.

>

> He can disrupt your working memory or your

ability to

> recognize faces. He can even make it harder

for you to

> say verbs while nouns remain as easy as ever.

>

> Weird, yes. Fringe, no.

>

> Pascual-Leone is one of the premier scientific

pioneers

> exploring a new technique called transcranial

magnetic

> stimulation, or TMS, which shuts down or revs

up the

> electrical doings inside the brain by sending

a potent

> magnetic field through the skull.

>

> This is no try-it-at-home parlor trick and no

''Relieve

> your Pain!'' magnetic bracelet or insole.

>

> Invented in 1985, modern-day magnetic

stimulators charge

> up to a whopping 3,000 volts and produce peak

currents of

> up to 8,000 amps - powers similar to those of

a small

> nuclear reactor.

>

> That pulse of current flowing from a capacitor

into a

> hand-held coil creates a magnetic field

outside the

> patient's head. The field painlessly induces a

current

> inside the brain, affecting the electrical

activity that

> is the basis for all it does.

>

> The promise of TMS as a scientific tool seems

similarly

> powerful. And it has generated a range of

intriguing

> practical effects as well, from improving

attention to

> combating depression, that have been published

in

> reputable, peer-reviewed journals.

>

> ''From the point of view of cognitive

neuroscience -

> understanding how brain activity relates to

behavior - it

> is, in a way, a dream come true for all of us,

because it

> provides a way to create our own patients, as

it were,''

> said Pascual-Leone, director of the Laboratory

for

> Magnetic Brain Stimulation at Beth Israel

Deaconess

> Medical Center. ''You can create a very

transient

> disruption of the brain. For a few

milliseconds, it is as

> if those cells were not there. So you are able

to ask

> questions about what role a particular brain

part plays

> in a particular behavior.''

>

> More and more, TMS also appears to hold the

potential for

> therapy to help with brain problems, including

> depression, Parkinson's Disease and stroke.

>

> Evidence, including a seminal paper by

Pascual-Leone in

> 1996, has been mounting that repeated sessions

of TMS can

> alleviate recalcitrant cases of depression,

and without

> the nasty side effects of electroshock

treatment.

>

> Hundreds of studies in the past decade have

explored

> myriad potential TMS targets, including

schizophrenia and

> post-traumatic stress disorder. Most recently,

a small

> study published last month found that applying

TMS to

> parts of the brain involved in processing

sound could

> temporarily reduce the endless

buzzing-in-the-ears of

> tinnitus.

>

> Pascual-Leone and his colleagues plan to try

TMS next

> month on patients whose ability to speak has

been damaged

> by stroke. Preliminary work indicates that

their brains,

> in trying to repair the damage, may have

rewired

> themselves wrong. So blocking certain areas

can actually

> help the patients speak better, he said.

>

> He has a full shopping list of other projects

held up

> only by lack of money, including plans to

expand on work

> using TMS to relieve chronic pain and to speed

up the

> learning of physical skills. For all his own

obvious

> excitement, Pascual-Leone's talk is constantly

punctuated

> by caveats that TMS is too unproven for other

people to

> get too excited.

>

> For the most part in those hundreds of

studies, he said,

> he hears ''a premature ringing of the bells.

It may help

> some people but it risks creating a lot of

premature

> expectations that may not hold true in the

end.''

>

> Still, he's not against a few flights of

fancy. What if,

> he asked, TMS could block the brain activity

associated

> with lying, and witnesses would get zapped

before taking

> the stand? ''It opens up all kinds of cans of

worms,'' he

> said.

>

> Or take the question of mental enhancement.

Pascual-Leone

> was the first to demonstrate that TMS can not

only block

> brain functioning, it can temporarily enhance

it as well.

> In some studies, TMS has appeared to improve

subjects'

> working memories, speed up their

problem-solving, and

> sharpen their attention.

>

> Might it be possible, he wondered, to

pre-activate a

> person's brain with TMS and enable them to

learn faster?

> What if some day a student could rev up one

part of his

> brain before French class and another before a

piano

> lesson?

>

> TMS is far too crude and little-tried at this

point to

> allow for such specific interventions. Still,

the

> military is already aiming for TMS

enhancement.

> Researchers at the Brain Stimulation

Laboratory at the

> Medical University of South Carolina announced

last year

> that they had received a $2 million government

grant to

> develop a TMS device - probably a helmet - to

sharpen the

> minds of sleep-deprived soldiers while they

wore it.

>

> Ultimately, Pascual-Leone said, the field will

likely

> move in the direction of developing such

longer-term TMS

> devices. Already, repeated stimulations can

apparently

> produce effects lasting for weeks afterward,

by revving

> up underactive areas or quieting down

overactive spots

> for long enough that the changes linger even

after the

> stimulation stops.

>

> But these are still very early days. TMS is

conveniently

> noninvasive - years ago, it took electrodes

inserted in

> an open brain to produce similar results - and

it appears

> to have virtually no side effects. But there

is always

> risk with something so new, Pascual-Leone

cautioned, in

> particular, risk that it could cause some

unexpected

> long-term harm.

>

> Dr. John A. Cadwell of Cadwell Laboratories in

Kennewick,

> Wash., which began producing a commercially

viable TMS

> machine back in 1990, agreed: ''I think it's a

good tool,

> but it's not one that should be sold at

Wal-Mart just

> yet.''

>

> Inventors had been tinkering with the

application of

> powerful magnets to the human brain since the

end of the

> 19th century. But it was only in 1985 that Dr.

Anthony T.

> Barker, a professor of medical physics at the

University

> of Sheffield in England, finally created the

first

> effective transcranial stimulator.

>

> Barker is a skeptic about any other medical

claims for

> garden-variety magnets, he said, but he no

longer doubts

> that TMS can affect mood, at the very least.

>

> ''I think it's going to be useful,'' he said.

''Whether

> it will be very, very useful, only time will

tell.''

>

> Many of the initial volunteers for TMS

experiments were

> the researchers themselves, on the principle

that they

> should not ask subjects to do what they would

not do

> themselves.

>

> ''I've probably had more zaps to my brain than

anybody

> else on the planet,'' Barker said blithely.

>

> The beginning was not so blithe: There were

real

> questions about whether TMS might induce some

of the

> complications - memory loss, seizures - that

electroshock

> can bring.

>

> Cadwell recalled that in the early days of

testing a TMS

> machine, ''No one knew if we were going to be

the next

> one to have a seizure, or if 12 years of

medical

> residency would suddenly get blown away.''

>

> TMS did induce several seizures in

participants in the

> early years, but researchers have since worked

out

> technical safety rules that prevent them and

established

> that no significant memory loss occurs.

>

> Pascual-Leone, 41, who did the first TMS

safety study and

> wrote the first paper on TMS ethics, has

zapped himself

> countless times, too. The zapping looks

strange but not

> scary: When a post-doctoral student, Yukiyasu

Kamitani,

> sat for a dress rehearsal of a TMS experiment

the other

> day, it sounded like nothing more than a bag

of microwave

> popcorn on its final pops, and felt, Kamitani

said, like

> someone was lightly flicking his scalp.

>

> Still, though TMS is already starting to be

offered in

> Canada (see www.mindcarecentres.com), it

appears unlikely

> that it will arrive soon in American clinics.

>

> Cadwell, the American manufacturer, said that

TMS devices

> are approved for clinical use in most other

countries,

> but not by the FDA. So, he said, pronouncing

the ultimate

> clinical death knell, ''It's not a billable

procedure.''

>

> Carey Goldberg can be contacted at

goldberg.

>

> This story ran on page E1 of the Boston Globe

on

> 1/14/2003.

> © Copyright 2002 Globe Newspaper Company.

>

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