Mohamed Zaki Helal, M.D.
Professor of ORL,
Web Page: www.mzhelal.com
Sinusitis is an inflammation of the mucoperiosteal lining of the PNS. Extension of infection beyond the sinus mucoperiseum (into its bony walls or outside the sinus) is considered as a complication. Due to the use of antibiotics, acute exacerbations of chronic sinusitis became the first cause of these complications followed by severe acute sinusitis (in children and immunocompromized patients) and lastly, chronic sinusitis without acute exacerbations.
· Osteitis (compact bones of ethmoid and sphenoid sinuses) or osteomyelitis (cancellous bones of frontal and maxillary sinuses).
· Congenital bony defects (dehiscence).
· Preformed pathways in the bony walls as traumatic defects or fractures or postsurgical defects.
· Thrombophlebitis of diploic veins.
· Retrograde thrombophlebitis of the draining veins.
· Perivascular and perineural spread: For example infection may spread along the olfactory nerves into the subarachnoid space.
It occurs in the frontal bone or maxilla: i.e. inflammation of the diploic bone. Frontal bone is more frequently affected compared to maxilla. Osteomyelitis may lead to the formation of a sub-periosteal abscess (in case of frontal osteomyelitis, it is called Pott’s puffy tumor). A sub-periosteal abscess may burst into the subcutaneous tissues forming a subcutaneous abscess, which in turn may open to the outside producing a sinus fistula (through the skin in frontal sinus and oro-antral in maxillary sinus).
A mucocele is a cystic expansion of a sinus as a result of retention of mucoid secretions.
Pyoceles are similar to mucoceles but contain pus not mucus.
They include the orbit, teeth or intracranial structures.
These are the commonest to occur especially in children and usually complicate ethmoiditis (the lamina papyracea is a very thin bone). Pyoceles and frontal and maxillary sinusitis come next in this domain.
It is collection of edema fluids in the orbital soft tissues and eye lids due to venous obstruction with no manifestations of orbital infection.
It is inflammation of the orbital soft tissues without pus formation. It causes proptosis, limited eye mobility and diminution of vision. All of these manifestations are reversible with treatment.
Pus is collected between bone and the periosteum of the medial orbital wall. It causes throbbing pain, proptosis (forward and laterally) and diminution of vision. These are reversible with treatment too.
Inflammation occurs with pus collecting in the orbit leading to severe throbbing pain, chemosis, marked proptosis, ophthalmoplegia and diminution of vision. Ophthalmoplegia and visual affection may be partially or totally irreversible.
Osteomyelitis of maxilla may destroy non-erupted teeth in children. Maxillary sinus infection or osteomyelitis may affect the roots of upper teeth (in adults) leading to their destruction. An oro-antral fistula may follow the rupture of a maxillary subperiosteal abscess into the canine fossa.
Extension of infection into the cranial cavity may produce:
1. Extradural abscess.
3. Subdural empyema.
4. Frontal lobe abscess.
5. Cavernous sinus thrombosis:
It is thrombophlebitis of the cavernous sinus of the dura.
Sources of infection:
i. Skin of the dangerous area of the face.
ii. Sinus infection (frontal via supraorbital and ophthalmic veins, and sphenoid sinus via direct spread that may lead to bilateral cavernous sinus involvement).
iii. Orbital infections via ophthalmic veins.
iv. Pharyngeal suppurations as quinzy may reach cavernous sinuses via the pterygoid plexus of veins.
v. CSOM may be complicated by lateral sinus thrombophlebitis that may extend to the cavernous sinus via the superior or inferior petrosal sinuses.
The cavernous sinus receives the ophthalmic veins and contains the 3rd, 4th, 5th and 6th cranial nerves passing through it. Therefore, its infection and thrombosis will obstruct venous drainage of the orbit together with paralysis of these cranial nerves. Showers of infected emboli may separate and reach the circulation. The other sinus may be involved through intercavernous communicating sinuses.
· General manifestations: as remittent high fever, rigors and severe headache.
· Orbital manifestations (ipsilateral) as:
o Edema and chemosis of the upper eye lid together with ptosis.
o Chemosis of the eye “black eye”!
o Forward proptosis that may be pulsating.
o Both external and internal ophthalmoplegia.
o Drop of vision that may proceed to total loss of vision.
o Papilledema seen on fundus examination.
· Paralysis of the 6th cranial nerve of the opposite eye is the earliest manifestation of contralateral cavernous sinus thrombosis.
One should not wait till getting the full blown picture!
ü CT scan of the brain with contrast is diagnostic.
ü MRI and MRA (MR angiography) show better visualization of the sinus.
ü Blood picture will show marked leucocytosis.
It should be started immediately after clinical diagnosis i.e. before getting the results of the investigations. It includes:
i. Massive antibiotic therapy: Using antibiotics that can cross the blood brain barrier, and should be given IV.
ii. Anticoagulants: Heparin is given IV.
iii. Surgical treatment of the source of infection is done as soon as the general condition of the patient permits general anesthesia and surgery.
Prognosis and morbidity:
Cavernous sinus thrombophlebitis has high morbidity and mortality rate specially when neglected. The case may end with permanent loss of vision and ophthalmoplegia. In untreated cases mortality rate is about 30% due to septicemia, meningitis or cerebral thrombophlebitis.
It includes infection to the pharynx, larynx, ears, chest and GIT.
Chronic sinusitis may be accompanied by muscle and joint pains.