I Knew It Was Too Early for Senior Moments

Chron­ic pain may per­ma­nent­ly shrink the brain

The North­west­ern Uni­ver­si­ty team had pre­vi­ous­ly shown patients with back pain had decreased activ­i­ty in the same brain region called the thalamus.

This area is known to be impor­tant in deci­sion-mak­ing and social behaviour.

The team’s cur­rent study in the Jour­nal of Neu­ro­science sug­gests some of the changes may be irre­versible and ren­der pain treat­ment inef­fec­tive. More research is need­ed, they say.

Shrink­age

If true, it makes it all the more impor­tant to treat pain ear­ly to pre­vent any per­ma­nent change, say Dr Vania Apkar­i­an and colleagues.

They scanned the brains of 26 patients with chron­ic back pain and 26 healthy people.

The patients with chron­ic pain caused by dam­age to the ner­vous sys­tem showed shrinks in the brain by as much as 11% — equiv­a­lent to the amount of gray mat­ter that is lost in 10–20 years of nor­mal aging.

Dr Nigel Lawes, senior lec­tur­er in bio­med­ical sci­ence at St Georges Med­ical School
The decrease in vol­ume, in the pre­frontal cor­tex and the thal­a­mus of the brain, was relat­ed to the dura­tion of pain.

Every year of pain appeared to decrease gray mat­ter by 1.3 cubic centimetres.

What the researchers now need to find out is whether this loss is per­ma­nent or whether it can be reversed with treatment.

Dr Apkar­i­an said: “It is pos­si­ble that some of the observed decreased gray mat­ter shown in this study reflects tis­sue shrink­age with­out sub­stan­tial neu­ronal loss, sug­gest­ing that prop­er treat­ment would reverse this por­tion of the decreased brain matter.”

Per­ma­nent loss?

But Dr Apkar­i­an said oth­er research in rats had shown that spinal cord neu­rons die, which sug­gests the brain changes could be irreversible.

Dr Nigel Lawes, senior lec­tur­er in bio­med­ical sci­ence at St Georges Med­ical School, Lon­don, said: “This is a very inter­est­ing study.

“Oth­er imag­ing stud­ies have shown in chron­ic pain con­di­tions these areas of the brain are less active, so it does cor­re­spond with what oth­er peo­ple have found.”

He said the brain areas involved, which con­trol deci­sion mak­ing such as how to con­scious­ly move the body, might be important.

He said peo­ple with chron­ic back pain tend­ed to move in auto­mat­ic ways that per­pet­u­ate the pain.

Ther­a­pies to teach peo­ple how to pay atten­tion to and con­trol their move­ment to lim­it this pain might help, he said.

“Stud­ies could look at whether any of these ther­a­pies improve the way they cope with their pain, do you reverse the under­ac­tiv­i­ty in that part of the brain and, after you have reversed it for long enough, will that then change the brain volume?

“It might well be that it is reversible, but that depends on whether they get the right treat­ment or not.”