#Phlebitis of Individual Sinuses.#--The _transverse_ (_lateral_ or _sigmoid sinus_), 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 œdema 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 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.