ObjectiveTo determine whether transplanting olfactory ensheathing cells(OECs)is effective in controlling or re.versing the deterioration caused by amyotrophic lateral sclerosis(AtS). MethodsUetwcen February 2003 and April 2006,327 pa-fients(241 males and 86 females)with probable or definite ALS(diagnosed according to the El Escorial criteria)received dle oECstransplantation.Their ages ranged from 20 to 84 years(51.6±11.1 years).The duaration of sympltoms before surgical trealment wit84.8months to 13 years(2.9±2.0 years).OECs were cultured and.injected into palllological regions of the spinal cord and/or bilateralcoroila radiata of the brain;the patients were divided into three groups,group A(cord only,n=29),group B(cord and brain,,n=6),and group C(brain only,n=292)based on the transplant sites.ResultsThe patient's neurological function was assessedboth before and at4 weeks after transplantation by using the Amyolrophic Lateral Sclerosis Functional Rating Scale(ALSFRS)of the ALSCNTF Trealment Study(ACTS).The$cores were increased from 17.2±8.6 pre-operation to 20.1±9.7 post-operation in group A(P<0.05),from 24.2 4-6.8 to 25.7±6.6(P>0.05)in group B,and from 20.3±8.6 to 22.0±9.4(P<0.001)in group C.There were no significant difference inincreased ALSFRS scores amongthe three groups(P>O.05).The total improvement rate of neurological function was 77.1%(252/327).The result of electramyographic examination showed that spontaneous potential diminishedand/or disappeared,the amplitude of the motor unit action potential decreased remarkably andthe numbers of motor unitaction potentialgreatly increased in 261 cases(79.8%).Sixteen patients(4.9%)experienced the various complications including headache.short-term fever,seizure attack,central nerve system infection,pneumonia,respiratory failure,urinary tract infection,heartfailure,and pos-sible pulmonary embolism;of them,there were 4 deaths(1.2%). ConclusionThese preliminary results suggest that the OECs trasplantafion is effective in controlling or reversing the physiological deterioration caused by ALS.