Muscular strength and vibration thresholds during two years after acute poisoning with organophosphate insecticides.
OBJECTIVE
To evaluate the association of acute organophosphate (OP) poisoning with chronic sensory and motor neurological impairment.


METHODS
This study concerns the third of a series of three examinations of hand strength and vibration thresholds in a two year period after acute OP poisoning among 48 Nicaraguan men. The first two examinations were performed at hospital discharge and seven weeks after poisoning, and the present examination two years later. Twenty eight cattle ranchers and fishermen who had never experienced pesticide poisoning were examined as controls, also three times over the two year period. The poisonings were categorised as caused by "non-neuropathic" OPs and "neuropathic" OPs, each subdivided in moderate and severe poisonings.


RESULTS
Men poisoned with OP insecticides had persistent reduced hand strength. We previously reported weakness at hospital discharge for OP poisoned in all categories that worsened seven weeks later for those severely poisoned with neuropathic OPs. Strength improved over time, but the poisoned were still weaker than controls two years after the poisoning, most noticeably among the subjects most severely poisoned with neuropathic OPs. Also, index finger and toe vibration thresholds were slightly increased at the end of the two year period, among men with OP poisonings in all categories, but patterns of onset and evolvement of impairment of vibration sensitivity were less clear than with grip and pinch strength.


CONCLUSIONS
Persistent, mainly motor, impairment of the peripheral nervous system was found in men two years after OP poisoning, in particular in severe occupational and intentional poisonings with neuropathic OPs. This finding is possibly due to remaining organophosphate induced delayed polyneuropathy.
Miranda
J
J
Department of Preventive Medicine, National Autonomous University, León, Nicaragua. jamilette.miranda@smd.sll.se
McConnell
R
R
Wesseling
C
C
Cuadra
R
R
Delgado
E
E
Torres
E
E
Keifer
M
M
Lundberg
I
I
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D002908:Chronic Disease; D005500:Follow-Up Studies; D018737:Hand Strength; D006801:Humans; D007306:Insecticides / Q000506:poisoning*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced*; D016273:Occupational Exposure / Q000009:adverse effects; D009943:Organophosphorus Compounds; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced*; D012678:Sensation Disorders / Q000139:chemically induced*; D012684:Sensory Thresholds
D007306:Insecticides; D009943:Organophosphorus Compounds