The morphogenesis of experimental malformations of the central nervous system in laboratory animals, if the malformations originated from abnormalities in the early developmental stage, will present useful information for understanding human cerebral malformations, since the brains during their organogenesis and early histogenesis are similar among different species of mammals. The experimental malformations of the brain in the rat and mouse which are compatible with those in human are 1. organogenetic malformations: exencephaly, encephalocele, holoprosencephaly, 2. histogenetic malformations: microcephaly, dysgenetic hydrocephalus, absent corpuscallosum, heterotopic gray matter, disorganized cortical architecture. The morphological states of the dysraphic malformations apt to be altered by sequential def ects of the skull bones and secondary degeneration of the brain tissue. The brains with histogenetic malformations are also easily involved in destructive changes due to abnormal vascularity, circulatory disturbance in the brain or failure of absorption of the cerebrospinal fluid, which occur as secondary changes of developmental abnormalities and growth retardation of the brain mantle. Consequently, the original maldevelopments fade out and are occasionally concealed by predominant destructive changes. These findings in laboratory animals suggest that the developmental disorder of the brain in the early gestational period is probably one of the important causal factors of human cerebral lesions, which manifest themselves in the late gestational or perinatal period and cause cerebral palsies and mental deficiency after birth.
Recent advance in experimental teratology has induced a rapid progress in clinical studies of the congenital malformations of central nervous system, enabling those diagnosis and prognosis to determine more accurately by using the various methods of neuroradiological investigation, such as pneumoencephalography, carotid angiography, together with brain scanning. The author summarized clinical signs and symptoms and neuroradiological findings of three instructive cases. In each case, both clinical and anatomo-histological studies were made as carefully and extensively as possible. Hans Kundrat was the first to define arhinencephaly. Yakovlev pointed out in his pathoarchitectonic studies of cerebral malformation that the term “arhinencephaly” is a misnomer and he proposed the term “holotelencephaly”. However more inclusive term “holoprosencephaly” has recently been suggested by DeMyer & Zeman. The author prefers the last mentioned term, considering his own results. The causation of holoprosencephaly is disccused.
The etiologies of congenital cerebral palsy are varied and very complicated. Medical evidence shows that anoxic brain damage accounts for a very high proportion of all cases of cerebral palsy. During the years 1963 to 1970, 1088 cases with cerebral palsy between 1 and 9 years were admitted to Kyushu University Hospital. 376 cases (34.3%) gave a history of neonatal asphyxia. 160 cases (14.7%) gave a history of severe neonatal jaundice, which was complicated further by premature birth in 52 cases. 283 cases (26.3%) were premature at birth. The patients with cengenital malformations which did not appear to be directly related to the abnormalities of the nervous system were found in 43 cases (12.8%), in contrast to 3% in the control group. There was evidence in some cases of an abnormal family history, suggesting a genetic factor. Areliable history of cerebral palsy occurring in sibs was obtained in 9 families. The risk to subsequentsib of congenital cerebral palsy was 17 per 1, 000. On the other hand, there was a raised frequency of parental consanguinity in the cases with no history of birth abnormality (11.9% in contrast to 5-6% in the control group). Prenatal, perinatal and postnatal cares are needed equally in order to prevent cerebral palsy.
On the basis of experiences of chromosome aberrations and some established embryopathy, the association of several minor structural anomalies may indicate an disorder of organogenesis. However, the fact that some structural abnormalities occur as a result of neurological disturbance should be kept in mind. In some of structural anomalies, the significance as an aid of suggesting embryopathy may be varied by age and genetic background of the patients, or criteria of the examiners. Then, one should be careful and experienced enough to check the structural anomalies of prenatal origin in order to avoid a risk of over-diagnosis.
Relationship between the clinical states in a series of 29 cases with childhood diabetes and their EEG findings is presented. The EEGs were recorded during all-night sleep. The EEG changes in this group of patients were as follows. 1) 14&6/sec Positive spiking-“14+6”-…12/29 (41%) 2) 6/sec Spike-and-wave complex (Wave and spike rhantom, Petit mal phantom)-“WSP”-…1/29 (3%) 3) Bursts of bilateral theta activity…9/29 (31%) 4) Bursts of bilateral 4-5/sec Spike-and-wave complex…7/29 (24%) No correlation of the occurrence of the EEG changes to blood sugar value was shown in all-nightecordings. Much higher incidence of the EEG changes was found in the fair to poor control cases, than in the patients with good control of diabetes. The EEG examinations were repeated every 4 to 6 months since the initial EEG during natural nocturnal sleep, in order to observe a transition of the EEG abnormalities which can be seen in the serial recording. The follow-up EEG study disclosed a phenomenon where an increase in the occurrence of “14+6” is recognized in contrast with the decrease in “WSP” for the same period. On the other hand, the increasing of “WSP” and the decreasing of “14+6” for other period were pointed out.
The results of follow-up studies on 38 cases of myasthenia gravis in infancy and childhood were reported. The duration of observation in this study ranged from three to 17 years (eight years in average) after the onset of the disease. In 22 cases the myasthenic symptoms remained locally in the extraocular muscles throughout the course, while in other 16 cases bulbar, trunk and extremity muscles were involved at some occasions during the course. The spreading of symptoms in these cases occured at various stages from two weeks to four and half years after the onset of ocular symptoms. The condition of patients at the last observation was considered as complete cure in 5 cases, remarkably ameliorated in 31, not changed in 1, and aggravated in 1. The disturbance of ocular movement was the most frequent symptom persisting at the last observa tion, followed by ptosis, double vision, reduced visual acuity and photophobia in frequency, but no bulbar nor extremity symptoms were observed at that time. Based on both clinical findings and the Tensilon response, symptoms present at the last follow-up observation were considered to be myasthenic as yet only in 25 out of 33 cases, while in other 5 cases symptoms became stationary and not myasthenic.
A 13 month old infant is reported in whom prolonged twilight states, frequent psychomotor seizures, and brief generalized motor seizures occurred over a period of 3 weeks after vaccination with Japanese encephalitis vaccine. The patient, whose family history is negative for epilepsy and never had any serious illness prior to the present disorder, began to have attacks of apathy and inactivity several times a day 19 hours after the vaccination. He had several episodes of circling around and tapping his bed, each lasting about 10minutes. Thereafter, he remained stuporous with staring eyes, occasionally regaining consciousness for a short time. On the 8 th day of his illness a few brief generalized convulsions occurred which reccured occasionally thereafter. He then went into a state of prolonged stupor which lasted succeeding 3 days. On the 10 th day numerous attacks of staring eyes, between which disturbed consciousness improved to some degree, appeared with their durations ranging from several seconds to 15 minutes. Thereafter he gradually regained consciousness over a period of following 10 days, during which he had decreasing number of psychomotor seizures with motion arrest, staring eyes, salivation and masticatory activity. EEG's were repeatedly taken, the chief finding of which were high voltage rhythmic theta waves seen in the frontal areas. The EEG findings paralleled very well with clinical manifestations. The last record performed five years later was entirely normal. The validity of calling this codition psychomotor seizure status is dicussed.
Patterns of MVEP (mean visual evoked potential) and the latency time of Peaks II, III, IV, V and VI of the MVEP were studied on 200 children under the age of 3 years. They consisted of 150 healthy children and 50 children with any history suggesting of central nervous system disorders. Patterns of the MVEP were divided into 3 groups according to the polarity of Peak V and the form of the evoked potential waves: group A consisted of cases with the Peak V of the same polarity as that described by Gastaut, group B included cases with the Peak V of the reversed polarity; and group C included cases with wave forms which were not classified into group A or B. In the MVEP patterns of the 150 healthy children under 3 years of age, it was found that the patterns of groups A and B were observed in approximately equal number, and that the patterns of group B showed a tendency to increase in incidence with advance in age. In the MVEP patterns of the 50 children with a history suggestive of central nervous system disorders, an incidence of the MVEP patterns of group C was found to be significantly higher. The mean values of the peak latency time showed a tendency to decrease with advance in age. However, they were not suitable for a method of evaluation of the brain maturation because of large range of variation in the latency time at each of the evoked potentials.
Effects of pyridoxine administration on the EEG were studied in a 7 month-old boy with Vitamin B6 dependent convulsive disorder. Soon after the administration of 20mg pyridoxal phosphate i. m., paroxymal discharges such as spikes and sharp waves disappeared. However, the basic rhythm became slower transitorily. The frequency spectrum showed a dominancy in delta wave band and the autocorrelogram revealed a marked dysrhythmia of the basic pattern. These changes remained for 24 hours after the drug administration. After a long term administration of Vitamine B6, normal pattern both in the frequency spectrum and in the auto-correlogram was observed.
63 polygraphic recordings were performed in 14 premature infants at 3-6 days after birth and every two weeks thereafter longitudinally, until their expected date of delivery. At 40 conceptional weeks, four different EEG patterns, i. e., trace alternant, moderately deep sleep. REM and drowsy REM patterns, were distinguished. Clinically two sleep stages, quiet and active sleeps, were observed in all recordings. Trace alternant and moderately deep sleep constitute the quiet sleep while REM and drowsy REM the active sleep. Quiet and active sleeps form the one sleep cycle which has the duration of about 90 minutes and is constant from 32 conceptional weeks through 40 weeks. The duration of four EEG patterns in one sleep cycle were quantitatively analysed every week. Percentage of REM and drowsy REM (active sleep) among the whole sleep cycle shows no change during maturation, that is about 60%. At 36 conceptional weeks drowsy REM was distinguished in active sleep from real REM with low amplitude fast wave EEG and this occupies about 10% in one sleep cycle. That means, real REM stage decreases from 36 conceptional weeks and finally constitutes 45.6% at 40 conceptional weeks. Absolute duration of trace alternant also decreases with conceptional weeks, namely 27.7 minutes at 32 conceptional weeks to 14.8 minutes at 40 weeks. Percentage of moderately deep sleep which is obscure before 35 weeks and perhaps same as slow wave sleep in adults, increases from 10.8% of quiet sleep at 35 weeks to 42. 2% at 40 weeks.