us_), from its proximity to the middle ear and mastoid air
cells, is that most commonly affected, especially in young adults.
With the onset of the phlebitis the discharge from the ear stops;
there is severe pain in the ear and violent headache. The temperature
rises, but shows marked remissions, and rigors are common. Vomiting is
frequently present. Turgescence of the scalp veins draining into this
sinus, and oedema over the mastoid, are occasionally observed; but as
these signs may accompany various other conditions, they are of little
diagnostic value. Not infrequently phlebitis spreads to the internal
jugular vein, which may then be felt as a firm, tender cord running
down the neck, and the head is held rigid, sometimes in the position
characteristic of wry-neck.

Three clinical types of sinus phlebitis are recognised--pulmonary,
abdominal, and meningeal--but it is often impossible to relegate a
particular case to one or other of these groups. Many cases present
symptoms characteristic of more than one of the types.

In the _pulmonary type_ evidence of infection of the lungs appears
towards the end of the second week, in the form of dyspnoea, cough,
and pain in the side, coarse moist rales, and dark foetid sputum.
Death usually takes place from gangrene of the lung. The brain
functions may remain active to the end.

In the _abdominal type_ the symptoms closely resemble those of typhoid
fever, for which the condition may be mistaken. The absence of a rash
and the coexistence of middle ear disease are important factors in
diagnosis.

When the disease is of the _meningeal type_, symptoms of general
purulent lepto-meningitis assert themselves, and soon come to dominate
the clinical picture. Evidence of the presence of meningitis may be
obtained by lumbar puncture. The mind at first is clear, but the
patient is irritable; later he becomes comatose.

The _prognosis_ is always grave, on account of the risk of general
infection.

_Treatment._--The primary focus of infection must first be removed,
and this usually involves clearing out the middle ear and mastoid
process. The sigmoid sinus is then exposed, and after any granulation
tissue or pus that may be in the groove has been cleared away, the
sinus is opened and the thrombus removed. With the object of
preventing the dissemination of infective material, a ligature should
be applied to the internal jugular vein in the neck before the sinus
is opened, as was first