NERVO-MUSCULAR EXPRESSION. 589 



The movements of the head aside from those due to movements 

 of the cervical spine may be classified as those of flexion and exten- 

 sion ; the bending forward and backward of the head ; of rotation, in 

 which the head remains erect ; and of inclination or the depression of 

 one or the other side. Flexion and extension of the head are of frequent 

 necessity and physiological import ; rotation is frequently necessary 

 to move the eyes toward an object looked at, or to direct the ear to- 

 ward a source of sound. Inclination is, I think, often of other signifi- 

 cance : it sometimes indicates weakness, it is more frequently seen in 

 young girls and weakly persons than in strong men. Inclination, with 

 rotation to the same side, with slight flexion, is a position of the head 

 very commonly seen in choreic girls, and then often accompanies an awk- 

 ward, ill-balanced position of the spine. Inclination of the head, with 

 rotation to the opposite side, and slight extension, is indicated by Sir 

 Charles Bell in his figure in " Adoration." In seeking general informa- 

 tion as to the signs of cerebral adequacy in an infant that is, whether 

 the infant has a good sound brain, probably capable of development 

 we always notice whether it can hold its head up, whether it usually 

 keeps its head erect while sitting up. 



Tooth-grinding, which is common in nervous children and among 

 lunatics, champing of the jaws, and trismus, are signs of disordered 

 conditions of the fifth nerve. The violent motions of the tongue seen 

 in chorea and whooping-cough, the tremulous tongue of alcoholism 

 and paralyses, indicate affections of the seventh nerve. Affections 

 of the pneumogastric may produce palpitations, irregularities of organic 

 action, the bronchial spasm of asthma, and functional aphasia. 



It is a matter of very common experience that children and adult 

 patients " hold themselves awkwardly " ; stoop, or otherwise give the 

 spine and trunk an ill-balanced position, due to want of nerve-muscular 

 energy, and characteristic of the condition of exhaustion and weak- 

 ness. Doubtless there is much expression in a torso ; in many cases a 

 weakly condition is indicated by a stooping attitude, with a lolling 

 over to one side. It is difficult to indicate in precise terms the posi- 

 tions and movements of the spine, and perhaps this is one reason why 

 so little is known about the action of the muscles of the back. "With 

 regard to the lower extremities, the gait and manner in walking may 

 be characteristic of brain or cord disease. Conditions affecting the 

 muscles of both lower extremities are usually dependent upon disease 

 of the cord, and most of the signs by which spinal disease may be 

 localized are derived from examination of the muscles of the legs. 

 Reflex actions are also used as a means of localizing: and ascertaininsr 

 the condition of the nerve-centers, and here, again, visible muscular 

 conditions are the indices. 



The significance of the action of muscles as indicating brain con- 

 ditions has long been dwelt upon by writers. Camper, who wrote in 

 1821, has shown that the Laocoon presents evidence of how deeply the 



