Search

The abnormal plantar response that occurs in disease of the pyramidal tract, as described by Babinski,1 consists of a group of simultaneously occurring movements, the most conspicuous of which are dorsiflexion of the big toe, separation—generally associated with plantar flexion of the other toes and eversion of the foot. The reflexes with which the phenomenon should properly be identified are, therefore, the coordinate or purposive reflexes. These reflexes, in addition to exhibiting themselves in simultaneous contraction of a large number of muscles, are like the Babinski response in that they occur exclusively or are especially prominent after the cerebral influence has been removed. Sherrington2 and Riddoch3 give details concerning these reflexes in the "spinal" animal and "spinal" man. PREVIOUS INTERPRETATIONS OF THE BABINSKI TOE RESPONSE Among the explanations of the origin and mechanism of the toe response are: Knapp4 attributed the dorsiflexion of the big toe

In a recent communication1 I reported the results obtained by graphically recording the gait of an animal after two different types of experimental lesions of the cerebellum. The records obtained indicated changes, characteristic of the type of lesion, which could not be detected by ordinary observation. This led me to believe that the graphic study of locomotion, which Marey truthfully designated "the microscope of movement," might be useful in the study of cerebellar disease in men: It might indicate not only the presence, but also the location of a lesion. For this method I had to consider:First. The type of locomotion should be one in which all the limbs are in action. Even in the ordinary progression of man, there is simultaneous activity of all the extremities, each arm swinging forward with the advance of the contralateral leg.2 But this activity of the arms is rudimentary, inconstant

This paper is based on a study of twenty-four cases of abscess of the brain which came under my observation during the last two years. These include eight cases of abscess of the temporal lobe, six of abscess of the frontal lobe (four in the prefrontal region, and two in the posterior part of the lobe), two of abscess of the parietal lobe, one of abscess of the occipital lobe and seven of abscess of the cerebellum. These cases, with the exception of four private cases, were seen by me in the neurologic service of the Los Angeles County General Hospital, to which they were referred, chiefly for diagnosis, by the eye, ear, nose and throat service and the meningitis division of the contagious disease department.In all of these cases the final diagnosis, on which this paper is based, was established either by operation or by postmortem examination, in

Unlike the doctrine of cerebral localization, which was founded on direct experimental evidence, the motor responses being obtained on stimulation of the cerebrum, the theory of cerebellar localization was evolved through studies in embryology and comparative anatomy. It was first formulated, in 1903, by the Dutch anatomist Bolk1 who, from a study of the cerebellum in numerous types of mammals, deduced the theory that the developmental variations of its different lobules bear a relationship to the various muscle complexes in the body.It is obvious that the theory requires for its verification experimental proof. The theory also presupposes that the function of the cerebellum is to coordinate muscle groups in their synergistic action. This is a supposition which is still subject to dispute, a point raised by Van Rynberk.2 PREVIOUS METHODS OF STUDYING CEREBELLAR LOCALIZATION STIMULATION EXPERIMENTS. —The striking success that has attended the electric method of excitation

The object of this study has been to ascertain, if possible, the mechanism of the cerebellar function, as deduced from the phenomena consequent to its lesions. It will be necessary, therefore to formulate at the outset a clear conception as to which of such phenomena are essentially cerebellar in origin. The cerebellum is adjacent to so many important structures and forms such intimate connections with the vestibular system and its oculomotor tracts that many of its lesions, experimental, as well as clinical, but especially the latter, very frequently implicate these other structures, producing their corresponding symptoms. On reviewing the literature we find, therefore, that a number of symptoms have from time to time been ascribed to this organ which have not had their genesis in it at all. THE CEREBELLUM AND SENSORIUM Lesions of the cerebellum do not produce disturbances of sensibility, and if these are present, they are invariably

Graphic records of the movements of the eyes in nystagmus can be obtained by means of the electrocardiograph. The records, like the electrocardiogram, are based on the fact that a muscle under the influence of a stimulus, including a nerve impulse, is traversed by a wave of negativity, the so-called action current, immediately preceding its contraction. The current, if led off through a string galvanometer, produces a deflection of the suspended thread between its magnetic poles, the direction of the deflection varying with the direction of the current. A photograph of the deflection when obtained on a moving film thus furnishes a record not only of activity in the muscle but of the origin and course along which the current is propagated. The current flows from the point of higher to that of lower potential and, accordingly, the point at which it enters the galvanometric arc of the circuit is

The temporal lobe is generally designated as a "silent area" owing to the fact that, aside from the superior temporal convolution which, as indicated by the experimental studies of Ferrier1 and Munk,2 is the center for the perception of auditory stimuli, this part of the brain is not known to represent a specific function. Extirpation of this part in animals (the dog and the ape) is found to produce, not a loss of motor or sensory functions, but only a state of mental torpor, the animal losing its initiative and becoming tardy in reactions to environmental stimuli. In other words, the animal apparently does not lose an individualized function, but only fails to perform properly the functions presided over by other parts of the brain.Clinicopathologic studies in man have likewise localized a specific function in the superior convolution of the lobe only. This convolution, in addition to

The phenomena of Magnus and De Kleijn1 occur with striking regularity and in a pronounced degree in the so-called decerebrate state of both animal and man; that is, in the animal after ablation of both hemispheres of the cerebrum and in man when disease of the cerebrum is of such extent as to eliminate more or less completely its influence on the periphery. In this state the limbs, always the anterior, less constantly the posterior, change posture as a result of passive displacement of the head. These reactions vary with the type of head displacement. They may be bilaterally identical, the limbs on both sides undergoing flexion or extension, or the limbs on one side undergo flexion, while those on the other side undergo extension. The first type of reaction may be one of two: the anterior limbs may flex and the posterior extend or vice versa; or all