A desire to study congenital malformations of the CNS originated several years ago. It was found necessary first to acquire sufficient knowledge of anatomy of the normal adult human brain as well as of the morphogenesis of the developing human brain. The results of the work done in this field formed the subject for my M.Sc. thesis at the McGill University: Anatomical and Developmental Study of the Human Thalamus, 1951. This was subsequently published in the J. Comp. Neurology 1953 and 1954.

Many methods of gradually occluding blood vessels have been developed over the past Century. Some of these methods have withstood the effects of trial in time, and are still in use for clinical and experimental purposes. However, all of these methods have drawbacks of one sort or another. At present, there is need for a more efficient and less cumbersome means of occluding certain arteries for investigative and clinical purposes. One need has arisen from the desire to reproduce as realistically as possible many ominous disease states which result from aging and catastrophic vascular events.

Pavlov (1928) described the establishment of a conditioned salivary secretion to a non-specific stimulus as a “temporary connection” between the center responding to the conditioned stimulus (for example, the auditory "'center"' 'when a metronone was used) and that responding to the unconditioned stimulus, i.e. the “food center”. Since stimulation of the food center results normally in salivation, this same response may be produced by any stimulus which in turn activates the food center. A connection so formed is, in the true sense of Pavlov’s term, conditional.

Our clinical interest in the peripheral neuropathies has prompted the present study of metabolism of peripheral nerves. Our experiments were designed to investigate possible metabolic defects in various conditions of disturbed nerve function and to consider their relevance to clinical problems. As is well known, demyelinating lesions of nerves can be caused by a wide variety of etiological agents and conditions, resulting in fairly similar clinical disturbances. The mechanism by which interference with normal function occurs is not fully understood.

This study was begun at the suggestion of Dr. Arthur Elvidge while the author was a Fellow in the Tumour Registry and Follow-Up Clinic. It was thought that by analyzing carefully the material gathered over a period of thirty years, and comprising the medulloblastomas and cerebellar sarcomas seen at the Montreal Neurological Institute during that time, pertinent information could be obtained concerning a) the difference in survival time in medulloblastomas and cerebellar sarcomas and b) types of treatment leading to prolongation of useful life in patients suffering from this disease.

It was in 1862 when William John Little so aptly quoted Shakespeare's description of Richard III., "who was born feet forward from the Duchess of Gloucester who had much ado in her travail". For the first time in medical history, Little delivered before the London Obstetrical Society his classical paper on the influence of abnormal parturition, difficult labours, premature birth and asphyxia neonatorum on the mental and physical condition of the child, especially in relation to deformities. Before this, others seemed quite unaware that abnormal parturition besides ending in recovery or death not infrequently had another termination which was then fully described by Little for the first time.

Interest in the role of the Nucleus Caudatus (N.C.) on neural processes started when in 1873 Ferrier obtained strong contralateral pleurothotonos in animals upon stimulation of this structure (Ferrier, 1873 and 1876). For years research was concerned with the contribution of the N.C. to motor output. Results have suggested that the N.C. is a regulatory structure. Reports are at variance to some extent. Some claim an inhibitory action, ethers a facilitatory action and still others claim to have demonstrated both. Among the first authors to report on an inhibitory action of the N.C. on the motor system were Mettler et al. (1939).

It was known from ancient times that some men suffered from a disease that periodically threw them to the ground and caused a convulsion. The earliest mention of epilepsy of which we are now aware occurs in the Code of Hammurabi (2080 B.C.) in which may be found laws regulating the marriage of epileptic persona and the validity of their court testimony. Ancient Hebrew writings (2000 B.C.) found in the Talmud contain references to epilepsy in the precepts of the sanitary laws (Pirkner, 1929). It is understandable that the attention of the earliest observer of epilepsy should have been arrested by the prominent and awesome aspect of the generalized convulsion, and it is to this part or form of the disease that most consideration was given.

In recent years increasing interest has been aroused in short-term memory processes and their anatomical substrate. There have been numerous reports, some based mainly on clinical observations and others on experimental findings, but these are not all in agreement, and analysis of the results obtained by different investigators is rendered particularly difficult by the lack of uniformity of methods and by the lack of comparable studies in man and experimental animal. In man. bilateral medial temporal-lobe lesions appear to cause a grave, persistent, and generalized defect of recent memory (Scoville and Milner, 1957; Penfield and Milner, 1958; Milner, 1959; Milner, 1962b) but attempts to produce an analogous deficit in the monkey by similarly placed lesions have been largely unsuccessful (Orbach, Milner, and Rasmussen 1960), although loss of recent memory in both auditory and visual modalities has been reported after bilateral medial temporal-lobe removal in one study (Stepien, Cordeau, and Rasmussen, 1960).

It is obvious that while blindness results from bilateral section of the optic nerves, the complex function of vision does not reside in these tracts to the exclusion of all other parts of the nervous system. What can be stated confidently, however, is that the circuitry which is the indispensable anatomical basis of vision does run in these tracts. Similarly, the occurrence of unconsciousness subsequent to a local lesion in the brain does not prove that consciousness resides in that area to the exclusion of any other area, but only that the integrity of the damaged region is essential to consciousness. An analysis of the anatomy of lesions which produce short, prolonged or permanent loss of consciousness is helpful in deciding which areas are reversibly and paroxysmally inactivated in petit mal epilepsy.