Headache and specific CT finding of bilateral pallidum

Abstract

A 46-year-old man without any previous history consulted to our hospital complained of delirium and headache. 2-week prior to visit, he noticed headache and general fatigue. 1-week prior, his family felt that content of his speech was irrational. Specific abnormal findings were not recognized on physical examination and laboratory data. Blood laboratory examination showed as following; white blood cell count 7,200/mL, hemoglobin 14.7 g/dL, platelet count 224,000/mL, total protein 6.9 g/dL, albumin 4.4 g/dL, AST 32 IU/mL, ALT 30 IU/ mL, LDH 202 U/mL (normal range: 106-211) fasting blood sugar level 107 mg/dL, Na 141 mEq/L, K 3.5 mEq/L, Cl 107 mEq/L, Ca 9.3 mg/ dL C-reactive protein 0.2 mg/dL, Vitamin B 1 31 ng/mL (normal range: 24-66), Vitamin B 12 780 pg/mL (normal range: 24-66), and folic acid 7.5 pg/mL (normal range: 3.6-12.9). And, atrial blood gas analysis showed as following; pH 7.44, PaCO 2 34 mmHg, PaO 2 95 mmHg, HCO 3 -22.4 mmol/L, base excess 0.1 mmol/L, and COHb 0.4% (normal range 0-0.8). Cerebral CT showed symmetrical low-density area on bilateral pallidum (Figure 1a), and cerebral MRI (T2-weighted image) showed high intensity area on the same lesion (Figure 1b). When recognizing bilateral basal ganglia abnormalities on MRI, causes should be considered as following, toxic diseases, metabolic diseases, vascular diseases, chronic infectious diseases, and degenerative diseases [1]. After careful medical interview, we diagnosed this case as his having chronic carbon monoxide intoxication. 4-week ago, he used wooden stove in closed-room. Since arterial COHb showed normal range in chronic carbon monoxide intoxication like this case, diagnosis of chronic intoxication is difficult without information of exposure of carbon monoxide [2]. Although incidence of carbon monoxide intoxication is not rare, diagnosis of chronic intoxication is difficult without information of exposure of carbon monoxide [2,3]. The diagnosis of acute carbon monoxide intoxication is based on known CO exposure and blood COHb level [3], but arterial COHb showed