title: Extrapyramidal effects of acute organophosphate poisoning.
abstract: BACKGROUND
  There is limited information on extrapyramidal symptoms in acute organophosphate (OP) poisoning. We describe the course and outcome of severely poisoned patients who develop extrapyramidal manifestations.
  
  
  METHODS
  In this prospective observational study, spanning 8 months (Apr-Nov 2013) adult patients (>18 years) admitted with OP poisoning were enrolled. Patients on anti-psychotic therapy, those refusing consent or presenting with co-ingestions were excluded. Treatment included atropine and supportive care (e.g. ventilation and inotropes as indicated); oximes were not administered. The presence of rigidity, tremors, dystonia and chorea were assessed daily till discharge using modifications of the Unified Parkinson's Disease rating scale and the Tremor rating scale. The presence of extrapyramidal manifestations was correlated with length of ventilation and hospital stay and mortality.
  
  
  RESULTS
  Of the 77 patients admitted with OP poisoning, 32 were enrolled; 17 (53.1%) developed extrapyramidal manifestations which included rigidity (94.1%), tremors (58.8%) and dystonia (58.8%). None developed chorea. The median (inter-quartile range) time of symptom onset was 8 (5-11) days; extrapyramidal features resolved in 11 (6-17) days. The median duration of intensive care stay in patients not developing extrapyramidal symptoms was 6 (2-8) days, indicating that most of these patients had recovered even before symptom onset in patients who developed extrapyramidal manifestations. Overall, 27/32 (84%) were ventilated. Hospital mortality was 6.25% (2/32). When compared with patients not developing extrapyramidal signs, those with extrapyramidal manifestations had significantly prolonged ventilation (5 versus 16 median days; p = 0.001) and hospitalization (8 versus 21 days; p < 0.001), reduced ventilator-free days (23 versus 12 days; p = 0.023) and increased infections (p = 0.03). The need for ventilation and mortality were not significantly different (p > 0.6). Extrapyramidal symptoms were not observed in non-OP poisoned patients with prolonged ICU stay.
  
  
  CONCLUSIONS
  In this small series of acute OP poisoning, extrapyramidal manifestations were common after 1 week of intensive care but self-limiting. They are significantly associated with longer duration of ventilation and hospital stay.
authors.affiliation: a Department of Neurology , Christian Medical College , Vellore , Tamil Nadu , India ;
authors.forename: Kent K
authors.initials: KK
authors.lastname: Reji
authors.affiliation: a Department of Neurology , Christian Medical College , Vellore , Tamil Nadu , India ;
authors.forename: Vivek
authors.initials: V
authors.lastname: Mathew
authors.affiliation: b Department of Medicine , Christian Medical College , Vellore , Tamil Nadu , India ;
authors.forename: Anand
authors.initials: A
authors.lastname: Zachariah
authors.affiliation: a Department of Neurology , Christian Medical College , Vellore , Tamil Nadu , India ;
authors.forename: Anil Kumar B
authors.initials: AK
authors.lastname: Patil
authors.affiliation: b Department of Medicine , Christian Medical College , Vellore , Tamil Nadu , India ;
authors.forename: Samuel George
authors.initials: SG
authors.lastname: Hansdak
authors.affiliation: b Department of Medicine , Christian Medical College , Vellore , Tamil Nadu , India ;
authors.forename: Ravikar
authors.initials: R
authors.lastname: Ralph
authors.affiliation: c Medical Intensive Care Unit , Christian Medical College , Vellore , Tamil Nadu , India.
authors.forename: John Victor
authors.initials: JV
authors.lastname: Peter
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001285:Atropine / Q000627:therapeutic use; D001480:Basal Ganglia Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000628:therapy*; D003422:Critical Care; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000627:therapeutic use; D062025:Organophosphate Poisoning / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D053717:Pneumonia, Ventilator-Associated / Q000453:epidemiology; D011446:Prospective Studies; D012121:Respiration, Artificial; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018727:Muscarinic Antagonists; D001285:Atropine
keywords: Organophosphorus; parkinsonism; pesticide; rigidity; tremors