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 dyspnœa, cough, and pain in the side, coarse moist râles, and dark fœtid 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 recommended by Victor Horsley. If the phlebitis is accompanied by other intra-cranial infections, these are, of course, treated at the same time.
The superior sagittal or longitudinal sinus is liable to be infected from pyogenic lesions of the scalp. There are no symptoms that are pathognomonic, but œdema of the scalp with turgescence of its veins, epistaxis, and convulsions followed by paralysis, are those most likely to be met with.
The cavernous sinus is usually implicated by spread of the process from other sinuses—for instance, from the petrosal or transverse (lateral) sinuses—or from the ophthalmic veins in cases of orbital cellulitis. Although at first unilateral, the thrombosis usually spreads across the middle line to the sinus of the opposite side. The special symptoms—exophthalmos, œdema of the eyelids, and paralysis of the ocular nerves—are due to pressure on the structures entering the orbit.
Operative interference is seldom feasible in phlebitis of the superior sagittal (longitudinal) or cavernous sinuses.
Intra-cranial Tuberculosis.—Tuberculous meningitis is most frequently met with in patients below the age of twenty, and the infection takes place by the blood stream from some focus elsewhere in the body or from the spinal membranes. In cases of tuberculous disease of the middle ear infection may spread to the membranes by way of the internal auditory meatus (Macewen). The arachno-pia, especially at the base, is studded over with miliary tubercles, and an excess of fluid collects in the arachno-pial space and in the ventricles (acute hydrocephalus).