This syndrome was first described by Gradenigo in 1907. He was an Italian Otologist. Maurice Lannois added vital data to those already described by Gradenigo. Gradenigo classically described the following as the classic features of this syndrome:
Retro orbital pain
Adbucent nerve paralysis causing diplopia
Epidural abscess following mastoiditis
This syndrome has been known to occur due to spread of ear infection to involve air cells around petrous apex. It is hence also known as “Petrous apex syndrome” / “Petrous apicitis”. Infection & inflammation of petrous apex involves 6th cranial nerve at the Dorello's canal and 5th cranial nerve in the Meckel's cave. Meckel's cave lies close to Dorello's canal. Retro orbital pain is caused due to the involvement of trigeminal ganglion (Gessarian ganglion) at the level of Meckel's cave.
Intense head ache (most commonly retro orbital pain)
6th nerve palsy & diplopia
Horner's syndrome rarely if sympathetic plexus around internal carotid artery is involved at the level of petrous apex
Pain could be caused by any of the following mechanisms:
Dural irritation in the tegmen area
Inflammation of Gessarian ganglion
It is clearly not known how long it takes for infection to spread from mastoid air cells to petrous apex. Studies have shown that this interval can vary between 1 week to 3 months. The spread of infection from mastoid air cell system to petrous apex depends on the following factors:
Type and virulence of the infecting organism
Pneumatization of petrous apex area – If this area is not pneumatized then infection from mastoid air cell system cannot spread to this critical area.
Children are commonly involved because the common infecting organims in them is H. Influenza which is known to spread rapidly.
Role of Imaging:
High resolution CT scan and MRI studies help in clinching the diagnosis. CT scan reveals clouding of mastoid and petrous air cells. MRI is useful in patients with suspected lateral sinus thrombophlebitis which may be an associated condition in these patients.
The proximity of various venous sinuses to the petrous apex has been attributed to be the cause for various complications following Gradenigo syndrome. These complications include:
Thrombosis involving various venous sinuses
Palsies involving various cranial nerves
Prevertebral and parapharyngeal abscesses
Intravenous broad spectrum antibiotics should be started immediatly. If there is associated lateral thrombophlebitis then anticoagulants should be considered. After a week of antibiotic therapy if the patient does not show any signs of recovery then mastoidectomy should be resorted to. In children with gradenigo syndrome with associated lateral sinus thrombophlebitis surgery should be resorted to at the earliest.
Intravenous antibiotic regimen:
Vancomycin 60 mg /kg/day – 10 days
Cefotaxime 275 mg /kg / day – 7 days
Role of steroids:
Injection dexamethazone has been administered in these patients during acute phase in parenteral dose of 0.8 mg/kg/day. This dose of course should be tapered.
Acute pain can be best managed by use of anti inflammatory drugs.