Undoubtedly the length of time the disease lasts is especially influenced by two circumstances, nourishment and increase in infra cranial pressure. This explains why the course of the disease is often extraordinarily slow in breast-fed infants, since, in the first plaee, suckling at the breast, which is the result of a deep-seated reflex mechan ism, becomes interfered with very late and, in the second place, the yielding cranium keeps the increasing cerebral pressure below the fatal limits for a long, time. tio the disease is occasionally seen to drag on for four to six weeks or longer, with a comatose stage persisting for weeks.
On the other hand, individuals in tvhom meningitis presents the termination of an extensive general tuberculosis, usually succumb a few days or a week after the onset of the disease. The gradual develop ment of the disease, as we have already remarked, is usually absent in these cases; coma sets in early and dominates the symptoms of motor irritation. The development of tubercles on the meninges is usually trifling in comparison with the amount of gelatinous exudate.
In conclusion those atypical cases are to be mentioned in which spinal symptoms are more prominent than usual. While we are well aware that participation of the spinal meninges is the rule (although perhaps less frequent with miliary tuberculosis than with nonspecific inflammatory processes), still there may be no clinical signs of it. Excep tionally however we observe severe radiating pains in various segmental divisions and early loss of the tendon reflexes, which indicate disease of the nerve roots: and occasionally undoubted retention of urine, ischuria paradoxa, which is not caused by the dulness of the senses and demands artificial evacuation by expression or catheterization.
Having thus briefly sketched the atypical forms (it is impossible to exhaust the variety of possibilities), we shall discuss the individual symptoms to complete what has been said.
The temperature follows no definite curve; measuring it twiee daily it tnay be found normal for a long time or even throughout the attack or„ especially in young infants, it may become subnormal shortly before death. In other cases there may be continuous fever similar to that of typhoid: most frequently, however, there is a low fever, 3S°-38.5° C. (100°-101° F.) often slightly and irregularly remitting, which in the last days of life first shows gradual a rise to 40°--11° C. (104°-106° F.) or higher and which probably Is duc to complicating bronchitis and bron chopneumonia.
Frequently a fall in temperature occurs with the onset of menin gitis if a disease with high fever, e.g., advanced pulmonary tuberculosis,
preceecled the meningitis. The cause of this behavior is not apparent but it should be called to mind that frequently purulent processes in ValiOUS parts of the body, e.g., ulcerating lymph-glands, etc., also severe weeping cczemas, tend to subside quickly under the influence of menin gitis. Probably a similar process occurs when pulmonary tuberculosis and the like are concerned in which a mixed infection no doubt causes the high fever.
The behavior of the pulse is of far greater diagnostic value than the temperature curve. The previously mentioned irregularity of the pulse as a rule begins early and is seldom absent; it is, however, in itself, not pathognomonic of meningitis, since an identical pulse occurs occasionally with digestive disturbances and other non-cerebral diseases. But when there is associated with this irregularity a palpable slowing of the pulse, in connection with other symptoms, the strongest suspicion is justified. The diminution of pulse rate may be very pronounced, to 60-50 beats a minute and may persist continuously for tnany (lays: as a rule however as indicative of the great instability of the pulse, there occurs a transitory jerky rise in the rate on change of position or with painful irritations. The stage of bradyeardia cloes not invariably occur. This is especially the case in children less than a year old and is probably accounted for by a still faulty action of the inhibitory vagus fibres at this age.. As the case advances the slow pulse uniformly disap pears being replaced by tachycardia (160 to 200 pulsations per minute), which indicates vagus paralysis, and persists till death. The pulse rate seems to be absolutely independent of the temperature.
Respiration is much less characteristically influenced by meningitis than is the pulse. It may early become irregular; after a deep noiseless inspiration and its succeeding sighing expiration, a lengthened pause ensues. But. we see this also in other patients, whose minds being disturbed, suffer pain. The periodieity of respiration which occurs as the end approaches is more significant. The periodicity may be of the pure Cheyne-Stokes type; it inay however be such that a series of equally deep respirations is suddenly interrupted hy a considerable pause, in which ease the gradual ascent and descent characteristic of Cheyne-Stokes respiration is absent. This type is called meningeal respiration.