Table 1.
Case reports of snake envenomation resembling brain death (13)
| Source | Age*/sex | Duration of loss of brainstem reflexes | Neurologic exam | Failed brain death prerequisites | Neuroimaging | EEG | Outcome |
|---|---|---|---|---|---|---|---|
| [7] | 45/M | 12 h | Absent pupillary, corneal, gag, and oculocephalic reflex. No DTR or plantar reflex. No response to painful stimulation. External and internal ophthalmoplegia. Absent motor responses. Negative cold caloric testing | NR | NR | NR |
Discharge at 72 h Recovery to baseline health |
| [8] | 6/F | 36 h | Absent pupillary, corneal, gag, oculocephalic, DTR, and plantar reflexes. Flaccid extremities, no response to painful stimulation | NR | NR | NR | Pupils mid-dilated, sluggish to light, truncal muscle weakness, 4/5 strength lower limbs |
| [9] | 12/M | ~ 24 h | Absent pupillary, corneal and oculocephalic reflex. “Areflexic”. “Apnea test was negative” | NR | NR | NR |
Extubated at 72 h Discharged day 5 |
| [10] | 12/M | 3 days | Absent pupillary reflex. Complete ptosis and external and internal ophthalmoplegia. Absent DTR, plantar reflex, or movement to noxious stimulation. Comatose | Systolic BP < 100 mmHg | NR | NR |
Extubated day 5 Recovery to baseline health |
| [11] | 4/F | 48 h | Absent pupillary, oculocephalic, superficial and DTR, Bilateral ptosis. Paralysis of limbs and facial muscles. Flaccid extremities | NR | NR | NR |
Extubated day 13 Recovery to baseline health |
| [12] | 10/M | 4 days | Absent pupillary, corneal, oculocephalic, DTR, plantar reflex. Generalized hypotonia. No response to painful stimuli | Neuroimaging; pH 7.125 | Normal CT | NR |
Hospital day 12: 5/5 strength Day 14 weaned from ventilator Discharged home |
| [13] | 35/M | 5 days | Absent pupillary, corneal, cough, vestibulo-ocular reflexes. Complete ophthalmoplegia. “Completely paralyzed”. Negative cold caloric testing | Neuroimaging | Normal MRI | Suggestive of diffuse encephalopathy |
Extubated day 12 Discharged day 19 Able to walk unaided |
| [14] | 18/M | 8 h | “Areflexia”; pupils fixed and dilated, absent oculocephalic, no respiratory effort | Neuroimaging | Normal CT | NR | On transfer to ward: 4/5 strength of extremities, truncal muscle weakness noted. Pupils mid-dilated and sluggishly reactive. |
| [14] | 38/M | ~ 24 h | “Areflexia”; pupils fixed and dilated, no respiratory effort | Neuroimaging |
Normal CT Normal MRI |
NR |
Extubated day 4 Transferred to ward day 5 |
| [14] | 30/M | 5 days | “No brain stem reflexes”. No motor response. Neurologist performed brain death exam and patient was apneic; diagnosed with brain death. Cold calorics and MRI after exam were normal | Neuroimaging; caloric testing | Normal MRI | NR |
Extubated day 15 Discharged day 29 |
| [15] | 38/M | 4 days | Absent pupillary, corneal, oculocephalic, gag, DTR and plantar reflex | Neuroimaging | Normal CT | NR |
Extubated day 8 Recovery to baseline health |
| [15] | 27/F | 26 h | Absent pupillary, corneal, oculocephalic, cough, gag. Generalized hypotonia. Depressed DTR. Extensor plantar response | Neuroimaging |
Normal CT Normal MRI Normal MRA |
Diffuse background slowing, no epileptiform changes |
Extubated at 36 h Discharged day 6 Recovery to baseline health |
| [16] | 26/M | 48 h | “Areflexia”. Absent pupillary, corneal, and oculocephalic reflexes. Atony | NR | NR | NR | Recovery to baseline health at 4-week follow up |
*Age in years; BP blood pressure, CT computerized tomography, DTR deep tendon reflexes, EEG electroencephalogram, F female, M male, MRI magnetic resonance imaging, MRA magnetic resonance angiogram, NR not reported