IN PUR­SUIT OF MEM­ORY

Cosmos - - Spectrum - — DREW TUR­NEY

is a jour­ney of dis­cov­ery for Bri­tish neu­ro­sci­en­tist Joseph Je­belli. Hav­ing watched his Ira­nian grand­fa­ther suc­cumb to Alzheimer’s dis­ease, this book is part of his ef­fort to learn (and tell) the story of every­thing we know about the ill­ness, from the Ger­man physi­cian who iso­lated it to the lat­est treat­ments in­volv­ing gene ther­apy.

It’s an ur­gent and long­stand­ing prob­lem. As the world’s pop­u­la­tion ages, 135 mil­lion peo­ple are ex­pected to have Alzheimer’s by 2050, beat­ing cancer as the sec­ond lead­ing cause of death.

There’s a lot that might go over the head of the ca­sual reader. Alzheimer’s in­volves pro­teins called beta-amy­loids, struc­tures called plaques, tan­gles that de­velop in the brain, and genes, pri­ons, mi­croglia and sev­eral other el­e­ments that have been iden­ti­fied and in­ves­ti­gated, most of which only con­firm how lit­tle we ac­tu­ally know about what causes it.

The cur­rent the­ory is that be­taamy­loids op­er­ate at the sur­face of cells, fa­cil­i­tat­ing the en­try and exit of other ma­te­rial. If that process goes wrong, mal­func­tion­ing beta-amy­loids drift off from neu­rons and build up as char­ac­ter­is­tic Alzheimer’s plaques. They in­ter­fere with com­mu­ni­ca­tion be­tween neu­rons, caus­ing them to die off fur­ther and faster. But that de­scrip­tion is far from de­fin­i­tive, and even if it was then treat­ment would still be far from sim­ple. Don’t be­lieve any diet or ex­er­cise regime that claims to pro­tect you. All we know is that ex­er­cise helps the im­mune sys­tem, which might fight the build-up of Alzheimer’s-re­lated neu­ron dam­age. It also light­ens mood, and depressed peo­ple are more prone to the dis­ease, but that’s far from an em­pir­i­cal med­i­cal path­way.

In fact, the field is ripe for snake oil sales. Brain train­ing videos and games might be fun, but Je­belli and the ex­perts he in­ter­views re­mind us that there’s no sci­en­tific mea­sure of “smarter”. As one neu­ro­sur­geon says wryly, do­ing Sudoku puzzles will make you great at Sudoku, but that doesn’t mean they’re pro­tect­ing you from cog­ni­tive de­cline.

Like cancer, Alzheimer’s is not even a sin­gle dis­ease. A vis­ual vari­ant, the bizarre con­di­tion pos­te­rior cor­ti­cal at­ro­phy (also known as Ben­son’s syn­drome), leaves mem­ory and sense of self mostly in­tact, in­stead caus­ing hal­lu­ci­na­tions and the sud­den loss of the abil­ity to read or recog­nise faces and en­vi­ron­ments. One suf­ferer even saw every­thing com­pletely up­side-down.

Not long af­ter the first de­cod­ing of the hu­man genome in the 1990s, sci­en­tists found a mu­ta­tion that seemed to cause Alzheimer’s in a cer­tain fam­ily, but com­pet­ing the­o­ries about cau­sa­tion in­di­cate there’s no sin­gle trig­ger.

More re­cent ef­forts at treat­ment have gen­er­ated hope – plenty of it false. Some drug com­pounds and regimes have been shot down for ap­par­ently po­lit­i­cal rea­sons, with harder than usual test re­sults im­posed. Other ex­per­i­men­tal treat­ments al­most seem to be in the realm of alchemy, like the blood plasma trans­fer from a healthy donor that al­most wiped out symp­toms in one suf­ferer, but then couldn’t be repli­cated.

There’s a lot of med­i­cal sci­ence here about beta-amy­loids, but just as much about the sto­ries and ex­pe­ri­ences of suf­fer­ers. Je­belli spins a tale a cen­tury or more long, about a bat­tle we have no idea when we’ll win.

NON- FIC­TION In Pur­suit of Mem­ory: The Fight Against Alzheimer’s by JOSEPH JE­BELLI Ha­chette Australia (2017) RRP $29.95

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