Article Text

Download PDFPDF
Methyl iodide rhombencephalopathy: clinico-radiological features of a preventable, potentially fatal industrial accident
  1. Ivan Iniesta1,
  2. Mark Radon2,
  3. Colin Pinder1
  1. 1Department of Neurology, The Walton Centre Foundation Trust, Liverpool, Merseyside, UK
  2. 2Department of Neuroradiology, The Walton Centre Foundation Trust, Liverpool, Merseyside, UK
  1. Correspondence to Dr Ivan Iniesta, Department of Neurology, The Walton Centre Foundation Trust, Lower Lane, Fazakerley, Liverpool, Merseyside CH64 9RS, UK; iniesta.ivan{at}

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


Methyl iodide or ‘Mel’ is a dense, colourless, volatile monohalomethane, which is rapidly metabolised in man (Ofigures 1 and 2); the organically bound iodine is converted to inorganic iodide and excreted in this form in the urine.1 It is used as a pesticide in the USA and in a variety of organic chemical reactions and for dye-works and detergents in the UK. Although methyl iodide is a rare intoxicant, its manifestations are similar to those of poisoning with the other more common monohalomethane agents. Indeed, methyl iodide intoxication resembles that of methyl bromide and methyl chloride. Characteristics of the poisoning include a delay between exposure and onset of symptoms with early systemic toxicity, including congestive changes in the lungs and oliguria; metabolic acidosis; prominent cerebellar and extrapyramidal neurological features; and in severe cases, seizures and coma. Psychiatric disturbances may persist for years.

Figure 1

Molecular structure of methyl iodide (CH3I).

Figure 2

Ball and stick model of methyl iodide.


A previously healthy 40-year-old man employed in a chemical factory manufacturing methyl iodide for detergents was admitted to the intensive care unit in status epilepticus. The previous day he had inhaled an unspecified amount of methyl iodide. On returning home his wife described him as ‘out of character’, incoherent at times and with visual hallucinations …

View Full Text


  • Contributors II has written this article, MR has contributed with the MRI images and legends and CP contributed with useful comments on following this patient from a neurorehabilitation perspective.

  • Competing interests None.

  • Patient consent Obtained.

  • Ethics approval This case report did not require ethics approval.

  • Provenance and peer review Not commissioned; externally peer reviewed. This paper was reviewed by Mark Manford, Cambridge, UK.

  • Data sharing statement We confirm that this article is an original contribution. As such, Dr I Iniesta (Consultant Neurologist) has been the main author and Dr M Radon (Consultant Neurorradiologist) and Dr C Pinder (Consultant in Neurorehabilitation) the collaborators. Yours faithfully, Ivan Iniesta (On behalf of all the authors).

Linked Articles

  • Editors' Choice
    Phil Smith Geraint N Fuller

Other content recommended for you