Medical Aspects of Chemical Warfare (2008) - The Black Vault

Medical Aspects of Chemical Warfarewithin 2 to 12 hours, depending upon the severity ofSTX intoxication. As with TTX poisoning, many patientsappear calm and remain conscious throughoutthe episode. 82Physical Examination. Fever has been associatedwith PSP, 85 hypothermia and sweating occur withTTX intoxication, 83,86–88 and both neurotoxins cause lipparesthesias. 89 TTX-induced circumoral paresthesia ofthe tongue and mouth occur within 10 to 45 minutes ofingestion. 90,91 Oral paresthesia, typically the first presentingsymptom of TTX intoxication, 92 is followed bydysphagia, 90 aphagia, and aphonia. 93 STX causes ocularsymptoms like temporary blindness, 61,94 nystagmus, 94,95ophthalmoplegia, and iridoplegia. 96 TTX producesophthalmoparesis, 97 blurred vision, 87,98 early stagemiosis, 92,99,100 late stage mydriasis, 92,101 and absenceof papillary light reflex. 91 TTX was reported to causelaryngospasm and dysgeusia. 36 PSP is associated withloss of the gag reflex, jaw and facial muscle paralysis,tongue paralysis, 96,102 dysphagia, and dysphonia. 94PSP can also cause tachycardia, T-wave changes onEKG, 94 hypertension, 103,104 or hypotension. 84 The cardiacenzyme creatine kinase MB has been shown to beelevated after PSP intoxication, 105 and mild tachycardiahas been reported. 106 Puffer fish toxin may cause bradycardia,hypotension or hypertension, 92 dysrhythmias,and conduction abnormalities. 92,97,107,108 Chest pain isa common feature of both toxins. 93,99,106 TTX can alsolead to cardiopulmonary arrest. 92,109Death from TTX or STX intoxication is caused by respiratorydepression and paralysis of effector musclesof respiration. 79,96,107,108,110,111 Both TTX and STX intoxicationcause dyspneic symptoms. 91,92,111,112 Apnea hasbeen noted to occur within the first 2 hours after TTXingestion 92,101 and even earlier with PSP, 113 suggestingthe need for endotracheal intubation and mechanicalventilation. TTX blocks neuromuscular transmission,leading to skeletal muscle paralysis. Ascendingparalysis may develop within 24 hours for eithertoxin. 91,99,106,114 Both toxins lead to the diminution of thegag reflex. 88,89,94 TTX has also been associated with acutepulmonary edema secondary to hypertensive congestiveheart failure 115 and aspiration pneumonia. 99In addition to respiratory effectors, all voluntarymuscles rapidly weaken with either toxin due totheir effect on neuromuscular transmission; typicallythe upper extremities become weak, followed by thelower extremities. 89,92 Ascending paralysis follows 99and patients may drop deep tendon reflexes, includingabsent Babinski signs. 90,91,100,112,113,116,117 Neurologicsymptoms, such as paresthesias of the lips, tongue,face, neck and extremities, are the hallmarks of earlyintoxication, occurring within the first 30 minutesof ingestion. 95,96,104,107,109,114,118 Paresthesias of the lips,tongue, and throat usually precede the spread to thefingertips, neck, arms, and legs. 79,81 Lack of coordination,progressing to ataxia and dysmetria, has beenreported for both toxins. 79,90,95,103 Seizures have beendocumented for puffer fish intoxication; these typicallyoccur later in the progression of toxicity. 92,99 STX hasalso been associated with generalized giddiness, dizziness,incoherent speech, aphasia, 104 headaches, 81,104,113asthenia, 79,113 and cranial nerve disturbances (eg, dysarthria,dipopia, dysphagia, fixed dilated pupils, absentciliary reflex, 95,113 temperature reversal dysesthesia, 60and neuropathies). STX-induced neuropathies consistof prolongation in distal motor and sensory latencies,decreased motor and sensory amplitudes, and reducedconduction velocities. 96 EEG abnormalities showingposterior dominant alpha waves intermixed withtrains of short duration and diffuse theta waves havebeen demonstrated in TTX intoxication. 91 TTX causescentral nervous neuropathies as well, manifested asblurred vision, ophthalmoplegia, dysphagia, anddysphonia. 93,97 Coma has been reported only after severeTTX poisoning but is less common. 112,117,119 Othersymptoms reported with TTX intoxication includedizziness, 99 headaches, 110 and diabetes insipidus. 86Similar gastrointestinal complaints are experiencedby patients early in TTX and STX poisoning by ingestion.Nausea, vomiting, diarrhea, epigastric pain,and hypersalivation are common to both TTX 83,88–90-,92,93,99,100,107,112,114,117and STX 96,103,104,120,121 intoxication.Xerostomia has been reported in up to 20% of STXpatients in one study. 103Hematologic abnormalities have been documentedwith puffer fish intoxication. Petechial hemorrhagesand hematemesis are attributed to increased intrathoracicand intraabdominal pressure from violentepisodes of emesis and wretching. 92,97 An isolated caseof leukocytosis has been documented following TTXingestion. 114 Hematologic abnormalities have not beenreported for STX.Laboratory findings and monitoring. BecauseTTX- and STX-intoxicated patients are diagnosedbased on a high index of suspicion, clinical signs, andsymptom presentation, laboratory findings and testsmay be useful to determine etiology when patienthistory is inadequate and to monitor recovery. As aminimum, hemodynamic, acid-base, and fluid status,as well as serum electrolytes, blood urea nitrogen,creatinine, calcium, magnesium, phosphorous, urineoutput, CPK, EKG, and pulse oximetry should bemonitored. Blood gases are helpful to monitor adequateoxygenation and ventilation. Lactic acidosis hasalso been reported in animals exposed to STX 105 andmay be a useful parameter to monitor. Electromyographymay show marked abnormalities and the cardiac626