When the process spreads outwards along the course of the mastoid emissary vein, œdema, and dilatation of veins in the post-auricular region are observed, associated with tenderness on palpation. This is most apparent at the upper and posterior border of the mastoid process.
When the thrombus spreads downwards along the course of the posterior condyloid vein, there may be some œdema and pain on pressure in the upper part of the posterior triangle of the neck, associated with glandular enlargement in the region. These symptoms are dependent on the connexion established by the posterior condyloid vein between the sigmoid sinus and the deep veins of the neck.
When the thrombus extends inwards along the meningeal veins, meningitis, meningo-cerebritis, and cerebral abscess result.
2. Symptoms resulting from toxic absorption or dependent on the transmission of infected material to other parts of the body.
Optic neuritis is present, according to Hunter Tod, in about 50 per cent. cases. It develops rapidly and attains a high degree of intensity.
Headache is usually intense in character, persistent, but little remedied by drugs and presenting marked exacerbations. It is often most acute over the affected region.
The mental condition of the patient is subject to variation. In the average case mental symptoms are quite disproportionate to the severity of the disease. Sometimes the patient is cheerful, perhaps rather excited, retaining his faculties to the last, in other cases—as the result of excessive toxic poisoning—he lies in a stuporose, typhoid-like state. When the thrombus is associated with meningitis, meningeal symptoms predominate.
Vomiting is often a conspicuous feature, generally of the so-called ‘cerebral’ type, a regurgitation without nausea and retching.
The pulse is rapid, the rhythm irregular, and the tension lowered.
The temperature. The formation of the thrombus is usually notified by the advent of one or more severe rigors, the temperature rising to 103° or more. During the height of the illness the temperature is high but remittent, and rigors are frequent. The occurrence of a series of rigors is almost certainly indicative of sinus thrombosis. Any marked remission of temperature is succeeded by profuse sweating, but, with this exception, the skin remains dry and burning.