There are finally certain secondary changes of nerve-tissue that may de velop. These affect only such nerve fibres as have either been directly sev ered by the effusion or so much involved as to be unable to recover even their trophic function. Then the portions of these neurons that have been cut off from their respective cells undergo de creneration the same as do severed fibres in peripheral nerves. In the case of the pyramidal or spinal motor tracts this degeneration may extend down the cord to the anterior horns; but the terminal, or spinal, motor neurons, being inde pendent structures, are not generally involved in this process. Of course, fibres going to other parts of the brain will degenerate in like manner if sev ered from their parent-cells. While in the peripheral nervous system there may be a regeneration of severed or degen erated fibers, nothing of the kind is known to occur in the central nervous system.
Prognosis.—This must be based on the following factors and on the accuracy with which we can determine them. There are, however, two separate ques tions in the matter of prognosis: one has regard to the continuation of life and the other to the extent of recovery from the attack.
The age of the patient. In childhood the rare cases that do occur are usually severe; but, if the attack itself is out lived, the natural recuperative power is so great that the person will Jive on indefinitely. Improvement may be ex pected for some years, but entire recov ery is unusual.
In middle life the outcome depends on the causal trouble and the severity of the apoplectic attack. Where the motor involvement is not great or is due to indirect pressure, practically complete restitution of all functions is occasion ally observed. More often some impair ment of the involved area remains. If the primary cause still obtains, this also interferes with recovery and the general outlook.
In senile conditions (tortuous or cal cified arteries, dry and wrinkled skin, arcus senilis, etc.) but limited recovery is to be expected. Life may be pro longed, but most depends on the promptness with which the attack is checked. The subsequent length of life depends much on the kindness and care with which the chronic invalid is sur rounded.
Nephritis. Here we must distinguish between unimportant secondary or cas ual albuminuria and real kidney disease. The latter, when present, limits recov ery and determines the eventual dura tion of life. Even with this complica tion, however, if the site and extent of the effusion be favorable, the paralytic condition may be fully recovered from.
Syphilis. The existence of this sys temic infection is principally of etio logical importance. It may constitute
an indication for treatment, but other wise bas little significance.
Severity and nature of the attack. This is the great guide to prognosis.
Coma, stertor, vomiting, prolonged semiconsciousness, extensive and com plete paralysis, etc., indicate a large effusion with much damage to the brain, both in local destruction and general shock. Consequently there is immediate danger to life and much less chance of functional recovery when life is pro long.ed. In proportion as these features are less prominent the chances for pres ervation of life and for recovery are increased.
Prolonged high temperature, or a rise to 104° or 106° F., makes a fatal prog nosis probable.
General convulsions, as indicative of ventricular rupture (barring urminia), are a particularly-bad omen, death usu ally resulting in from a. few hours to a few days.
Location and size of the lesion. These two features are complementary. For, though much depends on the site, still a large outpour by its mere volume may include temporarily all the effects of the smaller, and certain general effects in addition.
Pantile luemorrhages are more often promptly fatal, doubtless from the im portance of the local centres and passing tracts. The outpour is also more rapid because from relatively large vessels and close to the parent-tncnk. On the con trary, litemorrhages of the pallium (that part of the cerebral hemisphere above the central ganglia) commonly become vast in size before inducing as serious symptoms.
Inequality of the pupils developing as a part of the attack, especially where the larger is on the side of the supposed lunmorrliage, suggests a large focus, and hence points to a more serious condition. This is, however, by itself quite inde cisive.
After the acute stage has been tided over the extent of presumable recovery is the main matter for prognosis. Here, besides the points already presented, other manifestations have to be consid ered. _The state of the tendon-refiexes in the involved area must be determined; if there is any increase compared with the other side, we can pretty safely con clude that some permanent injury of nerve-tracts will remain, though a slight local increase is not incompatible with apparent functional recovery. Any marked increase of these reflexes—as ankle-clonus or wrist-clonus or a knee jerk of ten inches, say—means lasting paralysis. The occurrence of cedema or contractures in the paralyzed part signi fies so grave a lesion of the motor path as to preclude hope of recovery.