Organophosphate-induced delayed neuropathy: case report

Abstract

-Organophosphate induced delayed neuropathy (OPIDN) is an uncommon clinical condition. It occurs in association with the ingestion of great amounts of organophosphate after the stimulation of cholinergic receptor. The clinical picture is characterized by a distal paresis in lower limbs associated with sensitive symptoms. Electrodiagnostic studies show a motor axonal neuropathy. Involvement of the central nervous system may occur. We describe a 39 years-old female patient who developed hyperesthesia associated with lower limbs paresis, fourteen days after she had ingested a Dichlorvos-based insecticide. Electrophysiological study was characterized by an axonal polyneuropathy pattern. Pyramidal tract dysfunction was observed later in upper limbs. Considering that both peripheral and central nervous systems are involved we believe that the more appropriated term would be organophosphate induced delayed neuropathy (OPIDN) instead of organophosphate induced delayed polyneuropathy (OPIDP).KEY WORDS: neuropathy, polyneuropathy, organophosphate. Neuropatia tardia por organofosforado: relato de casoRESUMO -A neuropatia tardia dos organofosforados (NTOF) é condição clinica incomum. Geralmente ocorre após a intoxicação aguda por organofosforados, seguindo-se a fase de hiperestimulação colinérgica. O quadro clínico é caracterizado por déficit motor distal nos membros inferiores associado a sintomas sensitivos. O estudo eletroneuromiográfico tem demonstrado padrão axonal motor na maioria dos casos. Podem ocorrer sinais de comprometimento do sistema nervoso central. Descrevemos o caso de uma paciente de 39 anos que ingeriu inseticida a base de Dichlorvos e quatorze dias após apresentou quadro de hiperestesia associado a paresia distal nos membros inferiores. Realizou eletroneuromiografia que se caracterizou por padrão compatível com polineuropatia axonal. Sinais piramidais, de aparecimento mais tardio, foram observados nos membros superiores. Diante do comprometimento do sistema nervoso periférico e central, também consideramos o termo neuropatia tardia por organofosforado (NTOF) mais adequado do que tão somente polineuropatia tardia por organofosforado (PTOF).

Organophosphate induced delayed neuropathy: a case report

“…After the early progressive phase, the stationary phase begins with predominant clinical manifestation as paraplegia or quadriplegia. [5,7] In our case the first symptoms of OPIDN arose four weeks after chlorpyrifos ingestion with bilateral drop foot following with intense spasticity at the proximal part of lower extremities. By the time there is regeneration of the peripheral nerve, the signs of CNS involvement may be predominant, including hyperreflexia, increased muscle tone and spastic gait.…”

“…Intermediate syndrome evaluated as a junction dysfunction due to the depolarization block characterized by prolonged overstimulation. [5,6] After the ingestion of OP, the progressive phase follows the latent period. [7] Organophosphate induced delayed neuropathy is a rare neurodegenerative disorder which develops due to the loss of function of distal parts of motor and sensory axons in both peripheral nerves, and ascending, descending tracts of spinal cord.…”

In vitro evaluation of the effect of botanical formulations used in the control of Aedes aegypti L. (Diptera: Culicidae) on liver enzymes.

“…In the human body, true cholinesterases are classified as those present in red blood cells, the lungs, spleen, neurons, and in the brain, while pseudocholinesterases are those present in the liver plasma, pancreas, and intestine. In humans, the inhibition of acetylcholine hydrolysis caused by the presence of anticholinesterase substances leads to disorders of muscarinic (in smooth muscle, cardiac fi bers, and exocrine glands) and nicotinic activity (in skeletal muscles and autonomic ganglia) (18) (19) . When poisoning by anticholinesterase agents occurs with inhibition exceeding 50% of the activity of the pool of cholinesterase, it is commonly accompanied by a severe acute cholinergic crisis, although stimulation of the parasympathetic nervous system with nicotinic receptor response is observed (20) .…”

Epidemiological Studies of Anticholinesterase Pesticide Poisoning: Global Impact

“…According to some researchers, the declining availability of OPs might be among the reasons for the reduced occurrence of acute OP poisonings in the developed world (Aardema et al, 2008). Lotti et al (1986) Dichlorvos (2-dichlorovinyl dimethyl phosphate) 5 (4 suicide attempts, 1 accidental) Sevim et al (2003); Vasilescu and Florescu (1980); Vasconcellos et al (2002); Wadia et al (1985) …”