Extra-pyramidal parkinsonism complicating organophosphate insecticide poisoning

We present a 1 7-year-old female with acute extra-pyramidal parkinsonism complicating a suicidal attempt with the organophosphate insecticide chlorpyrifos, who was initially suspected to have developed severe depression or psychosis. On admission she was stupurous, with diarrhoea and massive salivation lapsing into respiratory failure and coma. Following atropine and toxogonin treatment along with mechanical ventilation she developed overt extrapyramidal parkinsonism and encephalopathy, characterized by impaired sensorium and agitation, mask facies along with a muffled voice and swallowing impairment, a resting tremor with cogwheel rigidity switching to bradykinetic choreoathetotic movements. Once a parkinsonian syndrome was diagnosed, she was given amantadine therapy with complete recovery. The patient is presently maintained on amantadine therapy; there was mild worsening of her extrapyramidal signs following unplanned discontinuation of this medication, and on follow-up assessments after 9 months she is virtually asymptomatic. A parkinsonian extrapyramidal syndrome, complicating organophosphate intoxication, should therefore also be taken into account in any patient with organophosphate poisoning, presenting with marked behavioural alterations, rigidity or akinetic mutism, and beneficial response to amantadine.