ningitis. In
meningitis the optic discs are highly oedematous and are more swollen
than in abscess, and the condition is equally marked on the two sides.

_Localisation of Cerebral Abscess--Temporal Abscess._--The existence
of middle ear disease is always presumptive evidence that the abscess
is in the temporal lobe on the same side. A small abscess in this lobe
may produce no localising symptoms; one of large size may press
indirectly on the motor cortex, on the fibres passing through the
internal capsule, or on individual cranial nerves.

It is important to observe the order in which paralysis of the
opposite side of the body comes on. When it begins in the face and
passes successively to the arm and leg, the pressure is on the
cortical centres. When the paralysis progresses in the opposite
direction--leg, arm, face--the pressure is on the nerve fibres passing
through the internal capsule (Fig. 195). The paralysis may be spastic
in lesions of the cortex or internal capsule; if it is flaccid the
lesion is almost certainly cortical.

[Illustration: FIG. 195.--Diagram illustrating Sequence of Paralysis,
caused by abscess in temporal lobe. (After Macewen.)]

Motor aphasia may result from pressure on the left inferior frontal
convolution; auditory aphasia from abscess in the posterior part of
the superior temporal convolution. Ptosis and lateral squint, with a
fixed and dilated pupil, indicates pressure on the oculo-motor nerve
of the same side.

Abscess in the _parietal lobe_ gives rise to paralysis of the face and
limbs on the opposite side of the body. Abscess in the _occipital
lobe_ produces interference with the visual functions. An abscess in
the _frontal lobe_ may give rise to no localising symptoms, but if it
is on the left side, the power of making co-ordinated movements may be
lost--apraxia--or the motor speech centre may be implicated.

_Terminal Stage._--If left to itself, a cerebral abscess usually ends
fatally by causing gradually increasing stupor and coma, or by
bursting, either into the ventricles or into the sub-arachnoid space,
and setting up a diffuse purulent lepto-meningitis.

When the _abscess bursts into the ventricles_, the patient suddenly
becomes much worse and dies within a few hours. "The pupils become
widely dilated, the face livid, the respiration greatly hurried, and
either shallow or stertorous. The temperature rises within a few hours
with a bound from subnormal to 104 deg. to 105