MedPix Medical Image Database COW - Case of the Week Case Contributor: James G. Smirniotopoulos, M.D. Affiliation: Uniformed Services University

MedPix No: History Pt Demographics: Age = 42 y.o. Gender = Man 42 y.o. alcoholic man who works as a carpenter, found down in his workshop on Monday morning. Downloaded by (-1)

MedPix No: EXAM & LABS Profound metabolic acidosis, depressed mental status, and bilateral (*cortical*) blindness.

Methanol Toxicity Bilateral hyperintensity in the lateral lenticular nuclei (putamen). Downloaded by (-1)

Methanol Toxicity Bilateral hyperintensity in the lateral lenticular nuclei (putamen - see arrows). Downloaded by (-1)

Methanol Toxicity Schematic overlay of lenticular nucleus on three MR images:T1 - PD - T2 Downloaded by (-1)

Normal Anatomy This is a comparable MR in a normal patient. Downloaded by (-1)

Methanol Toxicity Bilateral hemorrhagic necrosis of the lateral lenticular nuclei (putamen). Downloaded by (-1)

Methanol Toxicity Bilateral hemorrhagic necrosis of the lateral lenticular nuclei (putamen - arrows). Downloaded by (-1)

Methanol Toxicity Bilateral abnormal attenuation in the lateral lenticular nuclei (putamen), the caudate, and diffuse cortical lesions. Downloaded by (-1)

Methanol Toxicity The diffuse bilateral abnormalities make this is a potentially confusing image. What pulse sequence? CSF is bright and scalp fat is darker - so it is a T2W MRI. There are bilateral abnormal hyperintensities in the lateral lenticular nuclei (putamen) and the caudate. Downloaded by (-1)

Methanol Toxicity There are bilateral abnormal hyperintensities in the lateral lenticular nuclei (putamen) and the caudate. The hyperintensity is related to methemoglogin from hemorrhage. Downloaded by (-1)

Methanol Toxicity Bilateral hemorrhagic necrosis in the lateral lenticular nuclei (putamen), both caudate heads, as well as some cortical gray matter hemorrhages. Downloaded by (-1)

FINDINGS Bilateral abnormal hyperintensity in the lateral lenticular nuclei (putamen).

DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? Dilateral symmetric BG lesions ->Toxic-metabolic insult: - poisoning - organic alcohol (methanol, ethylene glycol, etc.) - hypoxia - hypoglycemia - non-ketotic hyperglycemia

Diagnosis: Methanol intoxication, putamen infarction Dx Confirmed by: Blood MeOH levels

DISCUSSION As a carpenter, this unfortunate patient might have ingested methanol - which is a common (but toxic) solvent used to dilute shellac for finishing wood cabinets. The mechanism of blindness is usually attributed to primary damage to the optic nerve and retina