A rare neurological complication of acute organophosphorous poisoning

Physical Rehabilitation Crucial in Motor Axonal Neuropathy Following Organophosphorus Poisoning: A Case Study

In India, organophosphorus (OP) chemicals known as anticholinesterases cause a considerable amount of disease and mortality. While precise figures are unavailable, data from hospitals indicates that about 50% of acute poisoning episodes are attributed to organophosphates. Anticholinesterases, when accidentally or suicidally exposed, cause three different neurological disorders. The first is an acute cholinergic crisis that can be fatal and necessitates administration in an intensive care unit; the second is an intermediate syndrome that frequently results in cranial nerve palsies, proximal and respiratory muscle weakness, and respiratory support for patients; and the third is a delayed organophosphate-induced polyneuropathy. Together, these neurobehavioral alterations have been identified and are referred to as "chronic organophosphate-induced neuropsychiatric disorders" (COPIND). A 40-year-old male patient tried suicide by swallowing a significant dose of OP pesticide. He was breathing heavily, gasping for air, foaming at the lips, and smelled intensely of pesticide when he was brought to a private hospital. Investigations like nerve conduction velocity (NCV) were done, which revealed motor axonal polyneuropathy.

Serum creatinine phosphokinase: A potential prognostic marker in assessing clinical severity with organophosphorus poisoning

INTRODUCTION

Organophosphorus compound (OPC) poisoning undoubtedly being a major concern in cultivation sites of the developing world, including Bangladesh. Two potential biomarkers, for example, serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH), are widely used in OPC poisoning severity indicators in patients. In this study, we sought to correlate the severity score of acute OPC poisoning with CPK or LDH level and subsequently explore their prognostic value.

METHODS

This study was performed on a total of 70 patients with OPC poisoning admitted to the inpatient care unit at a territory-based hospital in Bangladesh. Sociodemographics and poison types were recorded, and severity was assessed according to Peradeniya Organophosphorus Poisoning (POP) scale. Serum CPK and LDH levels were measured and recorded.

RESULTS

A total of seventy OPC patients were included with male to female ratio of 1.33:1, respectively, with a mean age of 28.7 ± 12.8 years. Chlorpyrifos and methylparathion were the most commonly utilized OP compounds, accounting for 42.9% and 28.6%, respectively. Among the OPC patients, the majority were married homemakers from rural areas. According to POP score, 55.7% and 37.1% of patients were categorized as mild and moderate, whereas very few were found to be severe. The mean serum CPK and LDH of OPC-patients at admission time were 235.6 ± 79.8 IU/L and 348.3 ± 154.1 IU/L, respectively. Serum CPK, atropine dose and hospital stay strongly correlated with clinical severity.

CONCLUSION

We conclude that the serum CPK level strongly correlates with the degree of OPC poisoning and can be used as a predictor of the clinical intervention approaches.

Delayed myelopathy in a child following organic phosphate poisoning

We report a rare manifestation of delayed organophosphate (OP) poisoning in a male patient in his early childhood. After initially presenting with a cholinergic crisis after OP exposure, the patient returned 3 weeks later with paraparesis and difficulty with bladder control. The results of the MRI of the spine and brain as well as the nerve conduction studies were normal. Myelopathy induced by OP poisoning should be considered in any patient with a history of OP exposure and a presentation of paraparesis. At most recent follow-up, the patient had full bladder control and could walk without assistance. However, he demonstrated circumduction while walking with upper motor neuron signs. Furthermore, he had mild Achilles tendon contractures on both sides. To enable early detection, neurologists and paediatricians should be aware of this uncommon complication of OP poisoning which may influence neurological outcome.

Neurotoxicity evoked by organophosphates and available countermeasures

Organophosphorus compounds (OP) are a constant problem, both in the military and in the civilian field, not only in the form of acute poisoning but also for their long-lasting consequences. No antidote has been found that satisfactorily protects against the toxic effects of organophosphates. Likewise, there is no universal cure to avert damage after poisoning. The key mechanism of organophosphate toxicity is the inhibition of acetylcholinesterase. The overstimulation of nicotinic or muscarinic receptors by accumulated acetylcholine on a synaptic cleft leads to activation of the glutamatergic system and the development of seizures. Further consequences include generation of reactive oxygen species (ROS), neuroinflammation, and the formation of various other neuropathologists. In this review, we present neuroprotection strategies which can slow down the secondary nerve cell damage and alleviate neurological and neuropsychiatric disturbance. In our opinion, there is no unequivocal approach to ensure neuroprotection, however, sooner the neurotoxicity pathway is targeted, the better the results which can be expected. It seems crucial to target the key propagation pathways, i.e., to block cholinergic and, foremostly, glutamatergic cascades. Currently, the privileged approach oriented to stimulating GABA_AR by benzodiazepines is of limited efficacy, so that antagonizing the hyperactivity of the glutamatergic system could provide an even more efficacious approach for terminating OP-induced seizures and protecting the brain from permanent damage. Encouraging results have been reported for tezampanel, an antagonist of GluK1 kainate and AMPA receptors, especially in combination with caramiphen, an anticholinergic and anti-glutamatergic agent. On the other hand, targeting ROS by antioxidants cannot or already developed neuroinflammation does not seem to be very productive as other processes are also involved.

Quercetin plays protective role in oxidative induced apoptotic events during chronic chlorpyrifos exposure to rats

Chlorpyrifos (CPF), an organophosphate insecticide has a wider application throughout the world to protect agricultural crops and vegetables from insects. Polyphenolic compounds are considered as beneficial against toxicities induced by organophosphates. The present study was conducted to understand the neuroprotective role of quercetin in chlorpyrifos-induced apoptotic events in rats. Twenty-four male Sprague Dawley rats weighing 170 to 200 g were divided into four groups viz: Control, chlorpyrifos treated (13.5 mg/kg body wt. alternate day), quercetin treated (50 mg/kg body wt. every day) and combined chlorpyrifos + quercetin treated. All the treatments were carried out for a total duration of 60 days. Protein carbonyl content and acetylcholinesterase activity were estimated in serum along with cerebrum and cerebellum to ascertain neurotoxicity. Further, for appraisal of neurodegeneration as a consequence of apoptosis, protein expressions of Bcl-2, Bax, cytochrome c, caspase-8, and caspase-9 were assessed. The results showed that protein carbonyl contents were markedly increased in both serum and brain tissues (cerebrum and cerebellum) of chlorpyrifos-treated rats when compared with control group and were appreciably improved upon simultaneous supplementation with quercetin. Further, chlorpyrifos treatment revealed a significant decrease in the enzyme activity of acetylcholinesterase in serum as well as in cerebrum and cerebellum, which however was increased upon concomitant treatment with quercetin. In chlorpyrifos-treated animals, we have observed a significant decrease in the protein expression level of Bcl-2, but a remarkable increase in the expression levels of Bax, cytochrome c, caspase-8, and caspase-9 in both cerebrum and cerebellum. Interestingly, when chlorpyrifos-treated animals were supplemented with quercetin, a significant increase in the expression of Bcl-2 and an appreciable decline in the expression levels of Bax, cytochrome c, caspase-8, and caspase-9 was observed. In conclusion, the present study advocates that quercetin may prove to be a useful candidate in containing the oxidative-induced apoptotic events during chlorpyrifos exposure.

Extrapyramidal effects of acute organophosphate poisoning

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.

CONCLUSION

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.

Serum creatine phosphokinase as predictor of intermediate syndrome in organophosphorus poisoning

Background:

Organophosphorus (OP) compounds are commonly used pesticides. In OP poisoning, intermediate syndrome (IMS) manifests between the end of the acute cholinergic crisis and delayed neuropathy. Respiratory paralysis in IMS, if identified early can reduce the need for ventilator support, morbidity, and mortality. Serum creatine phosphokinase (CPK) is elevated in IMS. The objectives of our study were to measure serum CPK level, correlate CPK levels with severity of poisoning and estimate atropine dose used.

Materials and Methods:

A prospective, observational study was conducted for 1-year. Patients diagnosed with OP poisoning were included. Demographic characteristics, type of poison, time since poisoning, Peradeniya Organophosphorus Poisoning (POP) score, serum pseudocholinesterase, CPK levels, atropine dose, and outcome of treatment were documented.

Results:

Seventy-five patients were recruited of which 57% and 43% were males and females, respectively, with a mean age of 31.48 ± 11.76 years. The most common OP compound was chlorpyriphos followed by triazophos and methylparathion. The time required to reach hospital was 181.26 ± 89.53 min. About 73.3% and 26.7% of patients had mild and moderate poisoning, respectively, as per POP scale. Pseudocholinesterase level was 364 (205–2168) IU. The amount of atropine used was 190.66 ± 78.83 mg. Serial serum CPK values were 279.72 ± 350.21 IU, 389.78 ± 376.33 IU and 163.13 ± 155.15 IU at admission, 48 h, and 96 h after admission, respectively. A weak positive correlation between serum CPK levels and severity of poisoning (r = 0.352) was observed. All patients recovered completely within 10.69 ± 5.57 days. Three patients developed IMS, and their serial CPK levels were 1837.33 ± 243.19 IU/L, 1935 ± 97.41 IU/L, and 714.66 ± 394.82 IU/L; and recovered in 17 ± 5.6 days.

Conclusion:

Increased serum CPK levels at 48 h after poisoning was observed in all the patients, but three patients had more than 1500 IU/L, who manifested with IMS. Early diagnosis of IMS by serial estimation of CPK may help in timely intervention and reduce further life-threatening complications.

Organophosphate intermediate syndrome with neurological complications of extrapyramidal symptoms in clinical practice

Organophosphates (OPs) are ubiquitous in the world as domestic and industrial agricultural insecticides. Intentional poisoning as suicides attempts are clinical phenomena seen in emergency departments and clinics in agricultural areas. Intermediate syndrome with the neurological complication of extra pyramidal symptoms following acute OP ingestion may occur in pediatric and adult cases. While death is the most serious consequence of toxic OP doses, low levels of exposure and nonfatal doses may disrupt the neurobehavioral development of fetuses and children in addition to bring linked to testicular cancer and male and female infertility. These are disturbing. Chronic and acute toxicity from OPs are barriers to the health of our present and future generations. Symptoms and treatment of acute and chronic OP exposure are briefly referenced with inclusion of the intermediate syndrome. Suggestions for local and systemic reduction of the acute and long term consequences of OP ingestion are opined.