各種水頭症例における髄液中メラトニン値の検討

The Studies of Melatonin Values in the Cerebrospinal Fluid of Hydrocephalic Patients

　各種水頭症例の髄液メラトニン（MLT）を測定して比較検討し，その意義について検討した。先天奇形由来3例，炎症性4例，松果体以外の腫瘍9例，松果体部腫瘍6例，正常圧水頭症（NPH）5例の合計27例を対象とした。午前10時前後に髄液を採取し，クロロフォルムでMLT抽出後HPLC法で測定した。先天奇形例では，2歳で高値を示し以後加齢とともに漸減し，20歳前後で15pg/ml以下となった。炎症性の例は20歳でも高値を示す例があった。松果体近傍腫瘍例では，腫瘍の松果体への浸潤などによってMLTが高値を示した0しかし，40歳以上のNPH例や腫瘍例では，髄液MLTが15pg/ml以下の低値を示した。髄液MLTは生理学的にサーカディアンリズムに従って分泌調節されているため，水頭症の治療予後判定や腫瘍マーカーとして利用する場合には，採取時刻を一定とし，炎症や腫瘍の松果体への影響や腫瘍の性質を熟知し，日内変動リズムを注意深く観察することが大切である。

　The changes in daytime levels of melatonin (MLT) in the cerebrospinal fluid (CSF) of twenty seven hydrocephalic patients were studied by the high-performance liquid chromatography (HPLC) method. Patients comprised three with congenital hydrocephalus (spina bifida 1, Chiari type II malformation 2), four postmeningitic hydrocephalus, fifteen brain tumors (chiasmal germinoma 3 ; malignant glioma of frontal 3, and temporal lobes 1 ; germinoma 1, teratoma 2, yolk sac tumor 1, epidermoid 1 in pineal region) and five cases of normalpressure hydrocephalus. CSF was collected between 0930 and 1030h through puncture of the flushing device of shunt system or the lateral ventricle. The lowest value of MLT detected by HPLC was 15 pg/ml.

　Melatonin values were higher in patients aged under 10 years than over 20 years in the absence of meningitis or tumor in the pineal region. Even at ages over 15 years, higher CSF MLT values were obtained in the patients with meningitis or tumors in the pineal region. These results suggest that the inflammation or invasion of tumor into the pineal gland may stimulate the secretion of MLT by thepineal gland. However, lower MLT values were obtained in all patients over 40 years old. For these reasons, if one may use the changes of MLT values in CSF as a tumor marker or for determination of the treatment modality, time of CSF collection, age of patient, location or character of the tumor and presence of meningitis should be given due cosideration.

　Also, the presence or absence of the rhythmical changes of melatonin values in a day following circadian rhythm are very important in determination of the treatment modality.