Reversible corpus callosum lesion in ciguatera poisoning

Abstract

A 45-year-old woman presented with profound watery diarrhoea, abdominal cramp and vomiting, followed by dysthesiae and paraesthesiae, generalised myalgia, retro-orbital pain and generalised pruritus approximately several hours after eating the internal organs of Sphyraena barracuda. She denied a past history of medical disease, surgery, trauma, medication use, or allergy to drugs or food. Moreover, her elder sister (51 years old), brother-in-law (59 years old) and son (25 years old) also complained of similar but less severe symptoms after eating the internal organ of S barracuda 2 weeks ago. The neurological examination disclosed clear consciousness, intact cranial nerve function and well muscle strength. The neuropsychological examination of the patient did not show callosal syndrome, for example, hemialexia, unilateral agraphia, unilateral agnosia and unilateral apraxia, too. The peripheral nervous system evaluation revealed ''cold reversal'' (reverse cold as burning, tingling or unbearable heat) manifestation, mild impairment of vibration and position sensations and generalised hyporeflexia. A brain MRI, done 4 days after the date of admission, revealed the presence of hyperintensity of corpus callosum on T2-weighted and fluid attenuation inversion recovery images, and a markedly increased signal intensity on diffusion-weighted imaging (DWI) with a reduced apparent diffusion coefficient (ADC) value (0.28610 23 mm 2 /s) (fig 1A-D). Her neurological symptoms and signs recovered almost completely 1 month later, after conservative management. A follow-up brain MRI, 3 months after discharge, showed nearly complete resolution of the corpus callosum lesion (fig 1E,F). DISCUSSIONCiguatera is a marine food poisoning caused by the ingestion of fish contaminated with ciguatoxin. 1 2 Diagnosis of ciguatera poisoning remains clinical, based on history and exclusion. The pathophysiology of ciguatera intoxication is as yet still unclear. The proposed mechanism reported in previous experimental studies was to bind to and open voltage-gated sensitive Na + channels at resting membrane potential, resulting in neural hyperexcitability. Followed by continuous Na + influx, cells become swollen because water enters the cell throughout the effect to maintain the osmotic equilibrium between intra-and extracellular space. 1 3 The mechanism was proven partially by the finding of the sural nerve oedema on biopsy. 4 Although midline corpus callosum changes on MRI are not specific, vascular lesions, traumatic axonal injury, demyelination lesions, neoplastic lesions, infection, metabolic abnormalities, epilepsy, antiepileptic drugs, thiamine deficiency and alcoholism were excluded by the clinical history, physical and neurological examination and laboratory studies in our case. 5 To our knowledge, reversible DWI and ADC abnormalities in the corpus callosum after ciguatera poisoning have never been reported before. Our patient developed reversible areas of significantly restricted proton diffusion in the corpus callosum without any evidence...

An Updated Review of Ciguatera Fish Poisoning: Clinical, Epidemiological, Environmental, and Public Health Management

“…This supports the observation of central nervous system involvement in human clinical cases of CFP [77,136,137,138]. …”

“…In animals, mannitol reverses membrane excitability and nodal swelling caused by CTX [146,147]; and it is thought to have similar effects in humans [136]. Also, mannitol may act as a scavenger of free radicals generated by the CTX molecule and may reduce the action of CTX at the sodium and/or potassium channels [148].…”

Neurological Disturbances of Ciguatera Poisoning: Clinical Features and Pathophysiological Basis

“…The skin biopsy of a mild CFP case with typical neurocutaneous disorders revealed swelling of intraepidermal nerve fibers 2 months after CTX exposure [ 70 ]. Finally, three cases of intramyelinic cytotoxic edema in the corpus callosum revealed by brain MRI were reported [ 122 , 123 ].…”

Ciguatera Fish Poisoning in East Asia and Southeast Asia

“…The causative species identified included moray eel G. javanicus (April 2004), red grouper L. bohar (February 2006, December 2008). In addition, there were two outbreaks caused by ingestion of barracuda eggs or viscera [ 42 , 43 ]. There was one death from ciguatera in 1998 after ingestion of red grouper [ 38 ].…”

“…Possible risk factors for an increased likelihood of (severe) ciguatera [ 1 , 3 , 4 , 12 , 13 ], such as the consumption of CTX-rich fish parts (head, viscera, roe and skin), were observed in some of the outbreaks in Japan [ 20 ], Malaysia [ 30 ], South Korea [ 36 ] and Taiwan [ 42 , 43 ]. However, any concomitant use of alcohol and the fish size involved were not mentioned.…”