脳梁腫瘍の臨床症状に関する検討

THE CLINICAL ANALYSIS OF SYMPTOM OF THE CALLOSAL TUMOR

I．はじめに

　脳梁腫瘍は多彩な精神症状を呈し，しかも特徴的な神経症状を有さなく，臨床症状による診断が困難であるとされている。このように脳梁腫瘍が特有な神経症状に乏しいことは事実であるが，神経症状が少ないのではなく大脳半球内へ拡がっている脳梁放線にそって腫瘍が発育して大脳半球各部内に腫瘍を形成するために多種の神経症状を発現して臨床症状を複雑化しているのであり，これが臨床症状による診断を困難にしている原因である。

　著者らは腫瘍が脳梁放線にそうて大脳半球内に発育することが脳梁腫瘍の特徴であると考え，このような見地から自験5例を検討したので，その結果について報告するとともに，最も短い脳梁放線によって到達する大脳半球内側面の神経症状としての両側下肢の筋力低下が脳梁腫瘍の臨床症状として極めて価値が大であることを知ったので報告する。

Many authors had described that the tumor of the corpus callosum shows various mental symptom, while on the other hand, because the callosal tumor do not shows characteristic neurological symptoms, it has been pointed that these tumors are difficult to diagnose from clinical symptoms and signs, While the authors agrees with other authors in that they recognizes the scarcity of characteristic neurological symptoms in callosal tumors but the authors' opinion are that clinical symptoms of the callosal tumor are highly complicated because callosal tumor grows along the radiation of the corpus callosum which extends from the corpus callosum to the cerebral hemisphere and because the tumor are formed at various site of cerebral hemisphere These facts also cause difficulty in the diagnosis from clinical symptoms. From a view point that the characteristic feature of callosal tumor lies in its growing along the radiation of the corpus callosum into the cerebral hemisphere, the authors have analysed the clinical symptoms of the author' 5 cases of the callosal tumor.

The site of the tumor in the corpus callosum in the authors' series are genu and truncus, while no tumor growth was found in the splenium.

1. The initial symptoms of the callosal tumor may be divided into 3 types which show one of following 3 symptoms, namely seizure, mental symptoms, and symptom of increased intracranial pressure. The time from the initial symptom to admission was within 6 months.

2. The clinical symptom when first examined inhe authors' clinic, of 5 cases of the callosal tumor, all showed mental symptoms and symptoms of increased intracranial pressure and pyramidal symptoms were seen in 3 cases out of 5 cases.

3. The main mental symptoms were loss of ac-tivity and indifference to the environment. These symptoms arises from tumor development in the corpus callosum itself and may also make their appearance by growth in the frontal lobe.

4. Regarding symptom of increased intracranial pressure, in some cases it appears as the initial symptoms while in others it appears as secondary symptoms. In case of initial symptoms, this iscaused by obstruction of the anterior part of the third ventricle and the interventricular foramina due to the tumor of the genu of the corpus callosum. In case of secondary symptoms, this is caused by the tumor infiltrating and growing in the cerebral hemisphere.

5. Since the most short fiber groups of the radi-ation of the corpus callosum reaches the medial snrface of the cerebral hemisphere, weakness of the bilateral lower limbs appears as the initial symptoms, and the authors emphasized that it is the main point of chronology of the callosal tumor.