症状と病態よりみた小頭症及びその外科的考察について 第1報

CLINICAL STUDY AND NEURORADIOLOGICAL INVESTIGATION OF MICROCEPHALUS (PART I) POSSIBILITY FOR SURGICAL APPROACH

Ｉ．緒言

　脳神経外科の立場から言って，「頭が小さい」という症候は，「頭が大きい」という症候より従来軽く見られてきた感がある。

　実際，頭蓋拡大を示す疾患群の中に含まれる脳神経外科疾患は，頭蓋狭小を示す疾患群よりも多い（第1表）。

In this paper, the authors investigated the pos-sibility for surgical approach to the secondary mi-crocephaly by neuroradiological methods, especially by the cisternography. Our observations dealed with 22 cases of microcephalus (secondary type were obtained in 17 cases), aged from 0 to 7 years (about half of them, 1-2 years old), consisted of 10 males and 12 females.

Head circumference was measured below 2 stand-ard deviation from mean length of normal head growth by Nellhaus. Plain X-ray examination, PEG, PVG and CAG were performed in all cases in order to check up closure of sutures, space oc-cupying lesions, dilation of CSF system, and other pathological changes except for 3 chronic subdural hematomas. Furthermore, to the purpose of inves-tigation of CSF hydrodynamic change, cisternogra-phy by ^99mTc and ¹³¹IHSA was also carried out in 8 cases of secondary microcephalus.

In the almost cases of secondary types, demon-strable symmetrical dilatation of the lateral ven-tricles were visualized moderately in contrast with little dilatation of the genetic types. On cisterno-gram, delayed RI distribution rate from the spinal subarachnoidal space to the parasagittal areas was appeared and also asymmetrical abnomal RI con-centration was visualized on the intracranial cav-ities in 5 cases.

In another 7 cases of the secondary microcepha-lus, RI clearance were measured by means of the direct injection of ^99mTc to the anterior horn of the lateral ventricle monitered by Dina Camera Scin-tigraph continuously.

Consequently, in 5 out of 7 cases, retention rate of CSF flow from the lateral ventricle to the basal cisterns revealed more than 43% which was exact-ly distinguishable from the normal level (less than 25%). Therefore, this fact seemed to be important and infomative of us to understand the nature of the secondary microcephalus. The ventriculo-atrial shunt was done in 6 cases for the purpose of re-pair of CSF cirulating disturbance.

The postoperative 3 cases resulted in disappear-ance of clinical convulsion and elimination of spas-tic paraplegia. Our experience was small but sat-isfactory. It is believed for us that this results in our observation suggested some possibility of operative indication for these microcephaly andcisternography might be much value as clinical diagnostic aid.