A Horned Viper Bite Victim with PRES

Abstract

Neurological complications of snake bites have been well documented in the literature as neuromuscular paralysis and cerebrovascular complications; posterior reversible encephalopathy syndrome was rarely described. A 23-year-old lady presented near full term of her pregnancy with a horned snake Cerastes cerastes bite; after successful delivery she started complaining of altered mental status and visual disturbance with ulceration over the site of the snake bite. On admission, the patient had Glasgow Coma Score of 12, blood pressure 130/80 mmHg, temperature 38°C, sinus tachycardia at 120 beats per minute, severe dehydration, and reduction in visual acuity to “hand motion” in both eyes with poor light projection and sluggish pupillary reactions. CT brain was not conclusive; MRI revealed features of PRES. Treatment was mostly supportive within one week; the patient regained consciousness; visual disturbance, however, persisted. This patient as well as the few previously described cases highlights PRES as a possible complication of snake bites.

Posterior Reversible Encephalopathy Syndrome in Clinical Toxicology: A Systematic Review of Published Case Reports

“…In this case of PRES induced by kratom, brain MRI showed multifocal areas of abnormal T2 FLAIR; restricted diffusion in the superior parietal lobes, both occipital lobes, and both cerebellar hemispheres; and minimal hemorrhage in the left superior parietal lobe consistent with atypical PRES (20). DWI positivity (20,25,26,29,30,36,37,39,(47)(48)(49) due to advanced edema was higher (12/20, 60%) than previously described in other PRES etiologies. The occurrence of cytotoxic edema (19%, 4/21) was consistent with the literature (15-30%) (3).…”

“…This may partially explain the difference in prevalence, especially since the whole brain MRI was not available for neuroradiological analysis. The atypical distribution involving the thalamus (18,19,21,34), basal ganglia (18,19,46), midbrain (18,19), and corpus callosum (39) was less commonly reported, as described in the literature. As with other PRES etiologies, atypical imaging appearances including hemorrhage, contrast enhancement, and restricted diffusion on MRI were reported in similar proportions (58).…”

“…Four patients had concurrent acute kidney failure with PRES (13,19,44,48). When performed (33,39,43), hypomagnesemia was found in one patient (39). Cerebral spinal fluid (CSF) analysis (20,21,23,24,34,36,37,45,47,49) showed elevated CSF protein in one patient (34).…”

“…DWI was positive in 60% of patients (12/20), totally or partially in correspondence with T2/FLAIR hyperintensities, with focal or larger extent (20,25,26,29,30,36,37,39,(47)(48)(49). When data related to ADC were provided, positive DWI due to vasogenic edema (i.e., no restricted ADC) (16, 17, 19, 21, 23, 25, 26, 28-31, 33, 34, 36, 45, 47-49) and cytotoxic edema (i.e., restricted ADC) (20,24,39,49) were found in 86 and 19% of cases, respectively. T2 * (gradient echo) or susceptibility weighted imaging revealed intracranial hemorrhage in 14% of patients (16,20,30,31,36,43).…”

“…In venom-induced PRES, snake bites [Cerastes cerastes (39), Bothrops asper (38), pit viper (42), Bungarus caeruleus (12)] were involved in four patients, scorpion stings in two cases [Tityus bahiensis (13), Androctonus mauretanicus (14)], and multiple wasp stings in two patients (40,48). PRES was associated with mushroom (46) and licorice (16,17,(43)(44)(45) in one and five patients, respectively.…”