In addition to the severity of disease, discussed below, sinusitis can be classified by the sinus cavity it affects:

Maxillary – can cause pain or pressure in the maxillary (cheek) area (e.g., toothache, or headache) (J01.0/J32.0)
Frontal – can cause pain or pressure in the frontal sinus cavity (located above the eyes), headache, particularly in the forehead (J01.1/J32.1)
Ethmoidal – can cause pain or pressure pain between/behind the eyes, the sides of the upper part of the nose (the medial canthi), and headaches (J01.2/J32.2)
Sphenoidal – can cause pain or pressure behind the eyes, but is often felt in the top of the head, over the mastoid processes, or the back of the head. Complications
Complications are thought to be rare (1 case per 10,000).The proximity of the brain to the sinuses makes the most dangerous complication of sinusitis, particularly involving the frontal and sphenoid sinuses, infection of the brain by the invasion of anaerobic bacteria through the bones or blood vessels. Abscesses, meningitis, and other life-threatening conditions may result. In extreme cases, the patient may experience mild personality changes, headache, altered consciousness, visual problems, seizures, coma, and possibly death.Sinus infection can spread through anastomosing veins or by direct extension to close structures. Orbital complications were categorized by Chandler et al. into five stages according to their severity (see table). Contiguous spread to the orbit may result in periorbital cellulitis, subperiosteal abscess, orbital cellulitis, and abscess.
Recovery from the psychotic symptoms seems to be rare, and in most cases paraphrenia results in in-patient status for the remainder of the life of the patient. Patients experience a slow deterioration of cognitive functions and the disorder can lead to dementia in some cases, but this development is no greater than the normal population. Epidemiology
Studies suggest that the prevalence of paraphrenia in the elderly population is around 2–4%. Sex differences
While paraphrenia can occur in both men and women, it is more common in women, even after the difference has been adjusted for life expectancies. The ratio of women with paraphrenia to men with paraphrenia is anywhere from 3:1 to 45:2. Age
It is seen mainly in patients over the age of 60, but has been known to occur in patients in their 40s and 50s. Personality type and living situation
It is suggested that individuals who develop paraphrenia later in life have premorbid personalities, and can be described as “quarrelsome, religious, suspicious or sensitive, unsociable and cold-hearted.” Many patients were also described as being solitary, eccentric, isolated and difficult individuals; these characteristics were also long-standing rather than introduced by the disorder. Most of the traits recognized prior to the onset of paraphrenia in individuals can be grouped as either paranoid or schizoid. Patients presenting with paraphrenia were most often found to be living by themselves (either single, widowed, or divorced). There have also been reports of low marriage rate among paraphrenics and these individuals also have few or no children (possibly because of this premorbid personality).