720 



NERVOUS SYSTEM. (NERVOUS CENTRES. ABNORMAL ANATOMY.) 



mentary parts of the organ, has yet to be deter- 

 mined by microscopical examination. 



It is most probable that the disease consists 

 not merely in an increased, but also in a per- 

 verted nutrition, and that new material is depo- 

 sited between or in the proper anatomical ele- 

 ments of the brain. 



In some instances there is, along with the 

 signs of increased nutrition in the brain, evidence 

 of a similar condition of the cranial walls. 

 The bones of the skull are, in such cases, much 

 thicker than usual. In others, however, the 

 bones seem to yield under the pressure from 

 within, and they become thin, and more or less 

 transparent in parts. 



There appear to be two classes of cases in 

 which an hypertrophic state of brain occurs. In 

 one class the functions are carried on well, and 

 the only sign of the morbid change is derived 

 from the undue enlargement of the head, which 

 becomes almost too large for the body, and too 

 heavy for the muscles of the neck to support 

 conveniently ; in the other there may or may 

 not be enlargement of the head, but there are 

 marks of cerebral disturbance in more or less 

 dullness of intellect, and in the frequent re- 

 currence of epileptic fits. 



Dr. Watson has placed upon record two in- 

 stances of this enlargement of the brain's sub- 

 stance which are highly interesting and will 

 serve to illustrate the varieties above alluded to. 



One case was that of a young woman aet. 19. 

 Her countenance was sallow, lips pale. She 

 complained of pain in her chest and limbs, of 

 great and increasing debility and wasting, and 

 of nightly perspirations, and she was subject to 

 attacks of epilepsy. She died in a prolonged epi- 

 leptic paroxysm. The following appearances 

 were observed at the post-mortem examination. 



" When the surface of the brain was exposed 

 by the removal of the skull-cap and dura mater, 

 it was observed that the convolutions were re- 

 markably flattened, so that the little furrows be- 

 tween them were nearly effaced, and the sur- 

 face of the arachnoid membrane was perfectly 

 dry. These are not very unusual, although 

 they are unnatural appearances. I had often 

 seen such before ; and I ventured to say we 

 should find some cause of strong pressure in 

 the central part of the brain, effusion of serum 

 into the ventricles, or a large extravasation of 

 blood. But to my great surprise, and much to 

 the discredit of my prophecy, we found nothing 

 of the kind. The ventricles were even smaller 

 than natural, and contained scarcely any 

 moisture. The skull-cap was afterwards exa- 

 mined, and the bone was found to be uncom- 

 monly thick, dense, and heavy; and its inner 

 surface without being rough was very irregular." 

 The state of tlie bloodvessels of the brain was 

 not noticed. It is to be regretted likewise that 

 the weight of the brain has not been stated, for 

 it is obvious that a gradual and pretty uniform 

 diminution of the cranial cavity by the thick- 

 ening of the bone might have produced the flat- 

 tening and condensation of the brain described. 



A second case recorded by Dr. Watson oc- 

 curred in the practice of the late Dr. Sweatman. 

 The patient was a little boy two years old ; his 



head had been gradually increasing from the 

 age of six months until it had become so large 

 as to prevent the child from continuing long in 

 the upright posture. The boy was active and 

 lively although thin. He never had any con- 

 vulsion, but occasionally seemed uneasy, and 

 then would relieve himself by laying his head 

 upon a chair. He had never squinted, nor 

 was he subject to drowsiness or starlings during 

 sleep, and his pupils contracted naturally. His 

 appetite was good, and all the animal functions 

 were properly performed. The head measured 

 from ear to ear twelve inches, from the super- 

 ciliary ridges to the occipital thirteen inches, 

 and in circumference twenty-one inches. The 

 brain was sound. The convolutions were dis- 

 tinct and retained their shape. The surfaces of 

 the medullary matter, exposed by different 

 sections, presented very unusual vasculanty.* 



In this case the yielding of the cranial walls 

 prevented compression of the brain, whilst it 

 admitted of the growth of the organ within. 

 Hence, no doubt, the absence of any symptoms 

 of compressed or irritated brain. 



Hypertrophy of the brain sometimes coexists 

 with hydrocephalus, and is congenital, and 

 prevents by the great size of the organ the de- 

 velopement of the cranial bones. (Otto, Ro- 

 kitansky.) 



Hypertrophy may affect only particular parts 

 of the brain, as the optic thalami, the pons, and 

 the medulla oblongata, instances of which have 

 been placed on record. 



Atrophy of the brain. At the advanced 

 periods of life we generally meet with more or 

 less of wasting of the brain, resulting from a 

 change in the nutrition of that organ which it 

 experiences in common with all other organs, 

 and whicli is only the natural result of the pro- 

 gress of age. It is remarkable, however, how 

 much more of this senile atrophy is observed in 

 some individuals than in others. 



In cases of epilepsy of long standing I have 

 invariably noticed wasting of the brain, affect- 

 ing chiefly the convolutions, or sometimes the 

 corpora striata, optic thalami, &c. The brain 

 wastes likewise in cases of long-continued 

 intemperance, the patient generally dying of 

 delirium tremens. In such instances all parts 

 of the brain waste, but the convolutions expe- 

 rience the most marked change. 



The following are the marks of an atrophied 

 state of brain. There is a considerable quantity 

 of fluid in the subarachnoid cavity, indicating an 

 increase in the interval between the surface of 

 the brain and the interior of the skull. The 

 brain has a shrunk appearance. Its texture 

 feels firm, and in cutting the knife grates against 

 it as in cutting cartilage. In point of colour 

 the grey matter is frequently extremely pale, 

 and scarcely to be distinguished from the adja- 

 cent white substance ; in some instances, how- 

 ever, it is of a dark brownish hue. In all 

 cases the layer of grey matter which covers the 

 convolution is much less deep than is natural. 

 The convolutions are evidently shrunk, and 

 the sulci between them have greatly increased 



* Lectures on tho Practice of Physic, vol. i. 



