Media Releases

Potential genetic cause of severe sleep disorder discovered, implications for Parkinson’s disease research

June 15, 2011

TORONTO, ON – Researchers at the Uni­ver­si­ty of Toron­to are the first to inden­ti­fy a poten­tial cause for a severe sleep dis­or­der that has been close­ly linked to Parkinson’s dis­ease and oth­er neu­rode­gen­er­a­tive dis­eases.

“Our research is the first to estab­lish a poten­tial genet­ic link to human REM sleep behav­iour dis­or­der (RBD).  That’s impor­tant because between 60 and 80 per cent of peo­ple diag­nosed with human RBD devel­op Parkinson’s dis­ease or oth­er neu­rode­gen­er­a­tive dis­or­ders lat­er in life,” says Dr. John Peev­er, lead author of the study that recent­ly appeared in The Jour­nal of Neu­ro­science.

Rapid-eye-move­ment sleep behav­iour dis­or­der (RBD) is most often char­ac­ter­ized by vio­lent move­ments that occur dur­ing dream­ing sleep, also called rapid-eye-move­ment sleep.  Peo­ple who suf­fer from RBD do not expe­ri­ence nor­mal mus­cle paral­y­sis that pre­vents them from enact­ing their dreams and they often hurt them­selves or their bed part­ners with their rapid, force­ful move­ments. In some cas­es, patients need to be tied to their bed to pre­vent seri­ous injury to them­selves or their bed­part­ners.

Peever’s team focused on inves­ti­gat­ing a genet­ic cause of RBD because the under­ly­ing cause of this dis­or­der is unknown. There is evi­dence indi­cat­ing that reduced brain inhi­bi­tion could cause RBD, so Peever’s team genet­i­cal­ly reduced brain inhi­bi­tion in mice and then record­ed their sleep and mus­cle activ­i­ty.

“We found that mice with reduced brain inhi­bi­tion act­ed just like human RBD patients and they moved vio­lent­ly dur­ing REM sleep,” says Peev­er. “This link strong­ly sug­gests that patients with RBD may also have impaired brain inhi­bi­tion.”

They also found that RBD symp­toms in mice could be alle­vi­at­ed by giv­ing them clon­azepam – a drug used to treat human RBD.

Peever’s research under­scores the impor­tance of iden­ti­fy­ing a cause of RBD as 60 – 80 per cent of RBD suf­fer­ers sub­se­quent­ly devel­op Parkinson’s.

“Treat­ing RBD could have direct impli­ca­tions for under­stand­ing and per­haps treat­ing Parkinson’s dis­ease,” says Peev­er.

 

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For more infor­ma­tion, please con­tact:

 

John Peev­er
Asso­ciate Pro­fes­sor
Depart­ment of Cell and Sys­tems Biol­o­gy
Work: 416–946-5564
Cell: 647–207-7920
john.peever@utoronto.ca

 

Michael Kennedy
Media Rela­tions Assis­tant
416–946-5025
m.kennedy@utoronto.ca