ORIGINAL ARTICLE Methanol Intoxication Pathological Changes of Central Nervous System (17 Cases) Ferah Karayel, MD,* Arzu A. Turan,* MD, Aydin Sav, MD,† Isil Pakis, MD,* Elif U. Akyildiz, MD,‡ and Gokhan Ersoy, MD§ Abstract: The nervous system has increased susceptibility for methanol intoxication. The aim of this study is to investigate various central nervous system lesions of methanol intoxication in 17 cases autopsied in the mortuary department of the Council of Forensic Medicine in Istanbul, Turkey. The reasons of methanol intoxication in the cases was likely the unwitting ingestion of methanol while drinking illegal alcohol. Survival times ranged from several hours to days. In 8 cases (47%), cerebral edema and in 9 cases (53%) at occipital, temporal and parietal cortex, basal ganglia and pons, petechial bleeding was observed. In addition to these findings, hemorrhagic necrosis were observed in thalamus, putamen, and globus pallidus in 5 cases (29.4%) and, in cerebral cortex in another 3 cases (17.6%). In 3 of the cases (17.6%) in which cerebral edema was found, herniation findings accompa- nied to the situation and in 2 cases (11.7%), pons bleeding was observed. Around the basal ganglia, in 2 of the cases with hemorrhagic necrosis, the situation ended with a ventricular compression. In 7 cases (41%), the associated findings of chronic ischemic changes in cortical neurons, lacunae formation, degeneration of granular cell layer of the cerebellum, and reactive gliosis were considered as the results of chronic alcoholism. Key Words: forensic science, forensic pathology, brain, methanol intoxication (Am J Forensic Med Pathol 2010;31: 34 –36) M ethanol poisoning by ingestion is a world-wide problem, and in some regions it is connected with high morbidity and mortality. 1,2 Inhalation, topical exposure, and oral routes absorb methyl alcohol rapidly and well. 3 Methanol is found commonly in antifreeze, perfumes, solvents, in commercial formaldehyde, and in illegal alcohol. 3–5 Toxicity occurs as a result of intentional overdose or accidental ingestion. 5 Methanol is rapidly absorbed from the gastrointestinal tract and methanol toxicity is believed to be due to the formaldehyde and formic acid that are produced when it is oxidized in the liver. These 2 metabolites are more toxic than methanol itself. 1,3,5 Formic acid blocks cellular respiration and contributes to metabolic acidosis. 5 The manifestations of acute toxicity are delayed for several hours, until after the methanol has been metabolized to from formaldehyde and formic acid. 6 Symp- toms and signs of methanol intoxication occur after a latent period of 12 to 24 hours. 2,4 Patients develop headache, abdominal pain, nausea, vomiting, and generalized weakness. Loss of vision is a common, usually permanent complication. Severe intoxication may cause delirium, convulsions, coma, cardio-respiratory failure, and death. 4,5 The usual lethal dose is in the range of 100 to 250 mL. 5 Methanol toxicity can cause severe central nervous system lesions. Methanol affects the basal ganglia, and both hemorrhagic and nonhemorrhagic damage of the putamen occur commonly due to severe intoxication. 2,6 –10 The aim of this study is to investigate various central nervous system lesions of methanol intoxication in 17 cases autopsied in the mortuary department of the Council of Forensic Medicine in Istan- bul, Turkey. MATERIALS AND METHODS Whole brain specimens of 17 methanol poisoning cases were submitted. Coronal cross-sections were taken of the brains of 17 cases after being fixed for 2 weeks in 10% formalin. After the macroscopic examination, cortex samples from each lobe as well as samples from basal ganglia, cerebellum, and brain stem were taken. The samples were embedded in paraffin and then were stained with hematoxylin eosin and the 5 m cross-sections were examined under the light microscope. Histopathologic examination of the cases was done by the Department of Pathology in the Mortuary Department, both blood samples taken from the left chamber of the heart and tissue samples are collected for systemic toxicological analyses according to regular procedures. All samples are sent to the toxicology section of the Council of Forensic Medicine to determine drugs and ethanol/methanol. The cases were analyzed in terms of age, gender, survival time, systemic toxicological analyses, and pathologic findings of the brain. RESULTS Seventeen fatal victims were studied. There were 15 men (88%) and women (12%). The mean age of the cases is 42  2.24 years (range: 25– 60). The reasons of methanol intoxication were the accidental ingestion of illegal alcohol. Survival times ranged from several hours to days. All the cases included in the study were checked with regard to blood formic acid level, but no blood formic acid was found in any case that survived for 8 days or more. The blood formic acid level of the cases that could be determined varied between 10.21 to 95.90 uq/mL. Clinically, all cases suffered nausea, vomiting, uncon- sciousness and following comas. Eight cases were diagnosed with visual disorder. Macroscopically and microscopically, in 8 cases (47%) mod- erate cerebral edema, and in 9 cases (53%) at occipital, temporal and parietal cortex, basal ganglia, hypothalamus and pons, petecchial hemorrhages were observed (Figs. 1–3). In addition to these find- ings, hemorrhagic necrosis was seen in thalamus, putamen, and globus pallidus in 5 cases (29.4%) and, in cerebral cortex in another 3 cases (17.6%). Coronal sections of the brain showed acute hem- orrhage in the putamen in 4 cases (23.5%). In 3 (17.6%) of the cases in which cerebral edema was found, herniation findings accompa- nied to the situation and in 2 cases (11.7%), pons bleeding was observed. Around the basal ganglia, in 2 of the cases with hemor- Manuscript received October 4, 2007; accepted February 6, 2008. From the *Council of Forensic Medicine, Istanbul, Turkey; †Department of Pathology, University of Acibadem, Istanbul, Turkey; ‡Department of Pathol- ogy, University of Uludag, Brusa, Turkey; §Institute of Forensic Medicine, University of Istanbul, Istanbul, Turkey. Reprints: Ferah Karayel, MD, Adalet Bakanligi Adli Tip Kurumu Yenibosna Cobancesme, Istanbul, Turkey. E-mail: ferahkarayel@mynet.com. Copyright © 2010 by Lippincott Williams & Wilkins ISSN: 0195-7910/10/3101-0034 DOI: 10.1097/PAF.0b013e3181c160d9 Am J Forensic Med Pathol • Volume 31, Number 1, March 2010 34 | www.amjforensicmedicine.com