ative.
Operation is indicated only when the "signal symptom" indicates a
limited and accessible portion of the brain as the seat of the lesion,
or when there is a depression of the skull or other definite evidence
of cranial injury. The more recent the injury the better is the
prospect, as secondary changes are less likely to have taken place,
and the peculiarly irritable state of the brain--sometimes referred to
as the "epileptic habit"--has not developed. The operation consists in
opening the skull freely, and removing any discoverable cause of
irritation--depressed bone, thickened and adherent membranes, a cyst,
or sclerosed patch of cortex; it may be necessary to interpose a layer
of tissue, a flap of fascia lata, for example, between the bone and
the cortex of the brain. The point at which the skull is opened is
determined by the seat of the injury and the focal brain symptoms.

The return of fits within a few days of the operation does not
necessarily mean failure, as they often pass off again. Complete and
permanent cure is not common, but the number and severity of the
attacks are usually so far diminished that life is rendered bearable.

#Traumatic insanity# may follow injury to any part of the brain, and
it may come on either immediately or after an interval. It may or may
not be associated with epilepsy. Any form of insanity may occur,
either as a direct result of the trauma, or from the resistance of the
brain being lowered by the injury in a patient predisposed to
insanity. When insanity follows as a direct consequence of injury, the
organic lesion is usually a superficial one, and the disturbance of
brain function is generally due to reflex irritation of the dura mater
(Duret). These facts possibly explain the immediate improvement which
occasionally follows the opening of the skull at the point of injury
and removal of the exciting cause. Cases occurring within a few days
of the injury usually recover within a month or two. The later the
condition is in developing the less obvious is the relationship
between the trauma and the insanity, and therefore the worse is the
prognosis.

_Meningitis_, _sinus thrombosis_, and _cerebral abscess_ may follow
upon any form of head injury attended with infection. The clinical
features--save for the history of a trauma--correspond so closely with
those of the same conditions occurring apart from injury, that they
are most conveniently considered together (p. 374).