Initial stages. Sedation with labyrinthine sedatives is required, dimenhydrinate

(Dramamine), promethazine hydrochloride (Pipolphen) or prochlorperazine

(Novamine) being useful. Parenteral antibiotics in adequate dosage are required.

A combination of penicillin and a sulphonamide can be used empirically until

swab results are known. Most patients settle on this regime. If the

precipitating cause were an acute exacerbation of chronic otitis media this can

be dealt with subsequently. Occasionally a myringotomy will be required in acute

otitis media, and occasionally it is necessary to deal surgically with a

mastoiditis. In a few cases persistence of symptoms with evidence of

intracranial irritation may call for exploration and a labyrinthectomy.

Labyrinthectomy. This is now rarely done but may be required in suppurative

labyrinthitis. It is also indicated in an ear where the cochlear function has

been severely damaged by chronic otitis media and there is persistent vertigo.

Occasionally it is indicated in Meniere's disease. A radical mastoidectomy is

performed. The lateral semicircular canal is exposed and opened and the

membranous labyrinth removed. The oval and round windows are joined and the

contents of the vestibule removed by suction. Some authorities recommend opening

all three canals.

INTRACRANIAL COMPLICATIONS

There has been a marked reduction in incidence of these complications over the

past four decades, the reasons for this being the same as for extracranial

complications. When they do occur, however, their morbidity and mortality are

still high. Even today a person who has a brain abscess has a 40% chance of

dying from it. It is vital, in any suspected case of intracranial extension of

disease, to liaise closely with the neurosurgeons. The only exception to this

rule being a small extradural abscess where the diagnosis is made during the

course of exploratory mastoid surgery.

Extradural abscess

An extradural abscess consists of a collection of pus between the bone and the

dura mater. Unless it is opened and drained it is frequently followed by other

Intracranial complications. It is more common in the posterior than in the

middle cranial fossa, in some cases forming between the lateral sinus and the

bone of the posterior cranial fossa (perisinus abscess). Extradural abscess

occurs more commonly in acute than in chronic middle-ear suppuration. In chronic

purulent otitis media it is met with chiefly in cases of cholesteatoma and in

acute exacerbations of chronic suppuration. The extent of the abscess varies

greatly; it may be quite small or, in chronic cases, it may attain a

considerable size.

CLINICAL FEATURES. The symptoms are rarely characteristic and the majority of

extradural abscesses are only discovered at the time of operation. The condition

Is associated with deep-seated boring pain, tenderness on tapping over the

temporal region or posterior fossa, and rise of temperature. If the abscess is

large, there may be evidence of compression of the brain. There are rarely any

localizing symptoms although occasionally paresis of the VIth nerve may be

encountered.

DIAGNOSIS. This is not easy as a rule. The relief of pain by the spontaneous

evacuation of a large quantity of pus, or the aspiration of much pus by mopping

or aspiration through the external meatus, may suggest the diagnosis. The

continuation of pain, pyrexia and a raised pulse rate after operation for a

mastoid complication should suggest the probability of the presence of a

deeper-seated collection of pus.

TREATMENT. This consists in opening the abscess and evacuating its contents by

free removal of the bony wall. When the abscess is opened the pus flows out in a

pulsating manner. The affected dura mater may be covered with red "healthy"

granulations, or it may be greyish-green and slough-like. Removal of the

underlying bony wall should be continued until the whole abscess cavity has been

freely exposed. The cortical or the radical operation - according to

circumstances - is performed at the same time. The patient should be carefully

watched in order to detect the first signs of further intracranial

complications, e.g. sinus thrombosis, brain abscess or meningitis.

Lateral (sigmoid) sinus thrombosis

This condition used to account for about 30% of all cases of intracranial

complications in the pre-antibiotic era, but now it occurs much less frequently

and today makes up less than 10% of the total. About half of these are

associated with other intracranial complications, usually cerebellar abscess or

meningitis. It is still a dangerous condition which must be recognized as early

as possible and treated vigorously.

PATHOLOGY. The initial lesion is inflammation of the wall of the sinus secondary

to local infection. This can be due to local venous thrombophlebitis but it is

usually a result of an extradural perisinus abscess, which has sometimes been

present for a considerable time. It occurs in both acute and chronic mastoid