Organic solvent induced chronic toxic encephalopathy: extent of recovery, and associated factors, following cessation of exposure.
OBJECTIVE
to determine extent and nature of recovery of solvent induced chronic toxic encephalopathy (CTE).


METHODS
21 confirmed cases had repeat neuropsychological and clinical assessments 6-42 (mean 27) months after ceasing exposure. An exposure score was calculated for each.


RESULTS
less than half (42.8%) showed evidence of improvement, which showed no association with time away from solvents or exposure score. The more severely affected at first diagnosis were nearly four times more likely to improve (RR 3.85 (95%CI 1.03, 14.38), p = 0.03). Those with no subjective improvement were five times more likely to have been on antidepressants (RR 5.25 (95%CI 0.83, 33.2), p=0.02).


CONCLUSIONS
The largely irreversible nature of Type 2 CTE is confirmed. The study results suggest that severity of effect and partial recovery are not dose related but multifactorial, with individual susceptibility probably important. Concomitant depression may also adversely influence recovery.
Dryson
E W
EW
Occupational Safety and Health, Department of Labour, Auckland, New Zealand. evan.dryson@osh.dol.govt.nz
Ogden
J A
JA
D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use; D002908:Chronic Disease; D003071:Cognition; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009483:Neuropsychological Tests; D020258:Neurotoxicity Syndromes / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology*; D016273:Occupational Exposure; D012997:Solvents / Q000633:toxicity*; D013997:Time Factors
D000928:Antidepressive Agents; D012997:Solvents