A system of practical medicine. By American authors. Vol. 5

by Unknown

Apoplectiform attacks sometimes take place suddenly during the progress of cases of brain tumor. A patient who has been suffering for months with the general symptoms of tumor, and who may or may not have had some paresis of the limbs or face, has an attack of unconsciousness, from which he arouses after a time, and is then found to be almost completely hemiplegic. After such attacks, in some cases, the symptoms of brain-irritation, particularly the headache and vomiting, subside or greatly improve. Such attacks may be explained in several ways—from the occurrence of congestion with œdema, of intercurrent hemorrhage, or of softening from obliteration of blood-vessels by the advancing growth; and the temporary subsidence or more permanent disappearance of the headache and other symptoms is probably, in some cases at least, owing to the diminution of tension because of the breakdown of tissue in the neighborhood of the growth. Sometimes the seizures which occur during the progress of the case are both epileptiform and apoplectiform in character.

Sometimes in cases of intracranial tumor there are present in the cranial nerve-trunks and the muscles supplied by them the changes known as the reactions of degeneration. These changes are characteristic of the peripheral palsies, and indeed sharply distinguish them from paralyses of central origin. The exception to this rule in cases of intracranial growths is, of course, only apparent and not real, because these palsies, when caused by the pressure of a tumor on a nerve-trunk, even within the cavity of the skull, and not upon their proper centres or intracerebral tracts, are as much peripheral as though the injury was caused by compression of these nerve-trunks outside of the skull. These reactions of degeneration are briefly as follows: The nerve-trunk gradually, sometimes rapidly, loses its response to both the galvanic and faradic currents. The muscle loses its response to faradism coincidently with the nerve-trunk, but to galvanism it is apt to exhibit first increased excitability, then gradually lessening excitability: and with this lessening response it puts on the so-called qualitative changes. These consist of the serial alterations—i.e. the negative pole, instead of exciting the more active reaction at closure, gives a less response than the positive pole at closure, and also calls forth a response at opening which may be greater than the opening contraction of the positive pole, which may be abolished. In health the positive pole causes often an active response, and the negative pole none, or almost none, at opening. Finally, occur modal alterations in the affected muscles, which consist of a slow, lazy contraction instead of a quick, lively one as in health, and a tendency in the muscle to remain contracted (tetany) while the current is passing. The many modifications—or, better, the partial exhibitions of these changes and the conditions underlying them—are to be sought in detail in special treatises. It is sufficient to say that they have been reported in a number of cases of brain tumor, and that the nerves in whose distributions they would be especially seen are the motor oculi, or third, the abducens, or sixth, and the facial, or seventh. It is doubtful if a very exact electrical examination could be made of many muscles supplied by these nerves, except in the case of the facial, and possibly the elevator of the upper eyelid. It is in the case of the seventh nerve that the recorded observations have been made. It will be noticed, by reference to the table, that the third, sixth, and seventh nerves are frequently involved in tumors of the crus and pons-medulla region, and that the paralysis is usually on the side of the lesion. These are the cases which would exhibit the reactions of degeneration. It has been said that in ordinary hemiplegia, and also in paralyses from tumors of the brain high in the motor region, the affected side exhibits simply a qualitative increase to electrical excitation; and this may be explained by the increased excitability to all stimuli of the lower or spinal-cord centres when cut off from the brain. The statement, however, which has been made, that in tumors of the cerebellum the sound side exhibits a quantitative decrease, sounds like a paradox, and requires further tests before being accepted as a fact in electro-diagnosis.

Ataxia has been observed in cases of brain tumor situated in various locations. The symptom described as ataxia, staggering, or staggering backward, is more particularly observed in cases of tumor of the cerebellum, pons, and corpora quadrigemina.

Changes in the state of the reflexes are somewhat frequent. Usually the skin and tendon reflexes will be increased on the side opposite the lesion, although some striking exceptions, probably due to the positions of the growth, occur.

Atrophy of the limbs is sometimes present, but usually in brain tumor, as the lesions are above the nutritive connection of the nerve, true atrophies do not occur.

True neuralgias are frequent, particularly in the distribution of the trigeminal. Trigeminal neuritis also undoubtedly occurs in lesions involving this nerve at its origin, in its course, or in the Gasserian ganglion.

Anæsthesia, either in the form of local or hemianæsthesia, was observed in about 20 per cent. of the cases. It is rarely present as an isolated symptom, but frequently accompanies unilateral paresis. In a partial or variable form it most frequently is seen in connection with tumors of the Rolandic region. It is a marked symptom in postero-parietal growths and those involving the posterior part of the internal capsule. It may take the form of loss of sensation to pain, touch, pressure, temperature, etc.

Hyperæsthesia occurs so commonly as to be almost regarded as a general symptom of brain tumor. Sometimes it is confined to the head; sometimes it is generally diffused; more frequently it is present in the limb or limbs affected with the paralysis. With hyperæsthesia the patients often complain of spontaneous pain in the limbs.

Diplopia or double vision is a somewhat frequent symptom, occurring most commonly, of course, when the ocular nerves are involved directly or indirectly by the tumor; hence tumors of the floor of the skull, of the crus cerebri, of the pons, or of the cerebellum are most likely to give rise to this symptom. A close study of the character of diplopia and of other symptoms which go with it will usually enable a local diagnosis to be made. Diplopia, however, does sometimes occur in tumors situated remotely from the base, either because of pressure, because of general nervous weakness, or possibly because of involvement of cortical oculo-motor centres.

Ptosis is another symptom, generally unilateral, and most frequently present in connection with strabismus, diplopia, and dilatation of the pupil from involvement of the third nerve. Dilatation of the pupil and contraction of the pupil may be present as general symptoms of tumors. The latter is most probably due to meningeal irritation.