5Ml may be introduced is turbid. Surgery of the underlying ear disease should be

carried out when the patient's general state permits. Labyrinthectomy may be

required in the presence of concomitant suppurative labyrinthitis.

PROGNOSIS. An uncomplicated meningitis has a more favourable outlook than one

associated with a sinus thrombosis, brain abscess or labyrinthitis.

Brain abscess

Brain abscess is the commonest intracranial complication of ear disease making

up over one-third of the total numbers. Ear disease, on the other hand, is the

commonest cause of brain abscess and accounts in some series for about half the

total. Cerebellar abscesses nearly always arise from ear disease. Today the

overall mortality from brain abscesses is quoted at around 40%. The earlier the

diagnosis is made and treatment instituted, the more likely are the chances of

recovery, but there is a significant morbidity rate in the survivors in terms of

epilepsy. Suspicion and early diagnosis, therefore, are vital if the prognosis

is to improve.

PATHOLOGY. An abscess develops close to the site of the original infection, so

otogenic brain abscesses arise in the temporal lobes and the cerebellum. The

majority are associated with chronic otitis media although acute infections

account for a significant number. Cerebellar abscess is due to: (1) extension of

infection from the mastoid posteriorly and medially through the triangular area

bounded by the superior petrosal sinus above, the labyrinth and facial nerve

anteriorly, and the lateral sinus laterally - there is usually a preceding

extradural abscess; (2) septic thrombosis of the sigmoid sinus which is usually

associated with a perisinus abscess; (3) labyrinthitis.

Temporal lobe abscess, the more common abscess, is caused by spread of infection

through the roof of the middle ear or mastoid antrum, again frequently preceded

by an extradural abscess. The dura mater, pia arachnoid and brain become

adherent to the inflamed tissue, and after an initial local surface encephalitis

the infection spreads to the subcortical white matter. More rarely the abscess

is due to septic thrombosis of one of the pial veins of the temporal lobe or

cerebellum. Infection by this route, which is common in cases of acute

middle-ear suppuration, may result in multiple abscesses.

Once infection is established in the brain, if unchecked, it involves more

tissue which becomes necrotic and an abscess is formed. The presence of

infection stimulates oedema of the surrounding tissue and results in increased

intracranial pressure, distortion of surrounding structures and functional

disturbance of them. Continuing infection causes tissue destruction, a further

displacement of brain tissue across the midline and eventually death, usually

from mid-brain damage.

CLINICAL FEATURES. The symptoms and signs produced are due to three factors: (1)

increased intracranial pressure, (2) focal disturbance of function, (3) systemic

disturbance.

1. Increased intracranial pressure. Headache is the dominant symptom and is

usually generalized and worse in the morning. Vomiting often occurs, especially

in cerebellar lesions. Drowsiness, confusion and lethargy develop as pressure

increases and finally coma supervenes. Papilloedema may be present but its

absence does not rule out raised intracranial pressure. The temperature is often

subnormal in the early stages unless there is coexisting meningitis and the

pulse is often slow.

2. Focal signs. These are variable. Homonymous hemianopia is a valuable sign in

temporal lobe abscess, as is nominal dysphasia. Cerebellar abscesses give rise

to ataxia and nystagmus. In very ill patients these signs may be difficult to

elicit.

3. Systemic disturbance. Although there may be little initial systemic upset as

the infection progresses the patient becomes very ill and emaciated. There is

pyrexia, loss of appetite, exhaustion and a furred tongue. There is raised ESR

and a polymorphonuclear leucocytosis. A severe rise in temperature often occurs

if an abscess ruptures into the ventricular system.

Temporal Lobe Abscess

This is more common than cerebellar abscess and gives rise to a typical clinical

picture.

CLINICAL FEATURES. Headache is common and is usually generalized. If there has

been a preceding extradural abscess the headache may be more severe on the

affected side and be associated with tenderness over the temporal lobe. The

headache classically is worse in the morning and it is exacerbated by coughing,

sneezing or straining. Vomiting is occasionally seen. Mental changes may be

minimal initially and consist of subtle changes in personality and mild

confusion. As the intracranial pressure increases, however, the patient will

become lethargic and listless, and then drowsy. Drowsiness is a danger signal as

it indicates early tentorial herniation and mid-brain compression. Papilloedema

may be present at this stage.

Nominal dysphasia is a feature of temporal lobe abscesses and it suggests

involvement of the speech area of the dominant cerebral hemisphere. The speech

area is located in the frontotemporal region and is usually on the left side of

the brain in a right-banded person and on the right side in a left-banded

person. The earliest focal sign is usually a homonymous hemianopia. If this sign

is present the patient has visual field defects affecting the same sides of both

retinas, and he will be unable to see objects on one side, i.e. to the right if

there is a lesion of the left temporal lobe. The defect is due to interruption

of the fibres of the optic radiation as they pass near the temporal lobe and, if

the lesion is small, it may present early as a superior quadrantic visual

defect. This test is elicited by standing in front of the patient and comparing

his visual fields with the examiner's. In an unconscious or drowsy patient the

sign may be elicited by flashing a light or a handkerchief near the eye and

trying to elicit the blink reflex and comparing the sides. An expanding lesion

may cause contralateral paralysis of limbs and even a hemiplegia if the internal

capsule is affected. Pupillary abnormalities and oculomotor palsies are

suggestive of transtentorial herniation and are danger signs. Epileptic fits are

not uncommon but, unless they are focal, are of little localizing value. Sudden

onset of coma associated with a high fever indicates that the abscess has

ruptured into the lateral ventricle and is of a grave prognostic significance.

Cerebellar Abscess

This abscess is less common than temporal lobe abscess by a ratio of 1 to 4 or

5.

CLINICAL FEATURES. Headache is again a feature and tends to be suboccipital and

may be associated with nuchal rigidity. Vomiting is common and papilloedema is

seen more often than in temporal lobe lesions. Confusion and drowsiness occur if

the intracranial pressure increases and will progress to coma and death if

untreated.

Truncal and limb ataxia gives rise to unsteadiness, and Romberg's test is

positive. Other signs of cerebellar disease are past-pointing and

dysdiadokokinesia. In the latter test the patient is asked to pronate and

supinate his forearms alternately. If there is unilateral cerebellar disease

present he will be unable to do the test efficiently on that side. Nystagmus is

usually present and is coarser and of greater amplitude than that due to

labyrinthitis. As a rule it is directed towards the affected side. Later signs

consist of a VIth nerve palsy and dysarthria.

DIAGNOSIS. Once suspected it is essential to obtain neurosurgical advice as the

investigation and treatment are neurosurgical. Lumbar puncture is

contra-indicated, even if a concomitant meningitis is suspected, because of the

risk of coning. The investigations carried out depend on local facilities but

they must be done with utmost urgency.

1. Plain skull radiography. This is useful as it may show a midline shift if the

pineal gland is calcified.

2. Computerized transverse axial tomography scan. A CT scan is the best

investigation if available. It is quick, non-invasive and extremely accurate in

localizing abscesses, especially when it is combined with iodine enhancement. As

well as delineating the abscess, intracranial shift, cerebral oedema and

hydrocephalus can all be demonstrated.

3. Electroencephalography. This can be of use.

4. Brain scan. Radio-active technetium is injected intravenously and the brain

scanned by a gamma camera. It is very valuable in supratentorial lesions and is

non-invasive.

5. Arteriography. This is still recommended as an important investigation

because it shows intracerebral shifts, avascular areas and areas of increased

vascularity. It is not without risk, needs a general anaesthetic, unless the

patient is comatose, and its accuracy can be doubtful.

TREATMENT. This is primarily neurosurgical. High doses of antibiotics which

cross the blood brain barrier are given parenterally. Some help may be obtained

from swabs from the offending ear. Once the abscess is localized it is drained

via a burrhole and this may be followed by repeated aspiration and instillation

of antibiotic. In some cases a craniotomy is performed and the abscess with its

capsule, if well defined, is removed.

In an emergency if there is no immediate neurosurgical help available and the

patient is deteriorating rapidly a temporary improvement may be obtained by

giving 500 ml of 20% mannitol intravenously combined with 4 g of dexamethasone.

This may reduce the cerebral oedema sufficiently to prevent coning and allow the

patient to be transported to a neurosurgical unit.

The causative ear infection should be dealt with as soon as the patient's

general condition permits. A radical mastoidectomy is recommended for chronic

disease and a cortical mastoidectomy for acute infections.

COURSE AND TERMINATION. If untreated a brain abscess ends fatally with

increasing drowsiness, stupor and eventually coma which continues until death.

PROGNOSIS. Even today the mortality for brain abscesses may be as high as 40%. A

further 40% are left suffering from some degree of permanent disability, usually

epilepsy. If there is meningitis associated with the brain abscess the prognosis

is worsened.

Subdural abscess

This is an extremely rare complication of otogenic infection and it is serious,

with a poor prognosis. The mode of spread is similar to other intracranial

infections but pus collects in the subdural space. This causes increased

intracranial pressure, midline shift and transtentorial herniation. The patient

is extremely ill, has severe headache and, as infection spreads to involve the

cerebral cortex, develops focal signs of hemiplegia or hemi-anaesthesia.

Drowsiness progresses rapidly to coma. Epileptic fits may start. Neurosurgical

referral is a matter of urgency and investigations are similar to those for

brain abscess.

The treatment consists of draining the subdural space and in some acute cases

this may have to be done on a presumptive diagnosis in order to save the

patient's life.

Part 6

DISEASES OF THE NOSE AND PARANASAL SINUSES

Deviation of the nasal septum

Very few individuals have a completely straight nasal septum. Deviations and

spurs vary from being slight and causing no trouble, to being gross and causing

complete obstruction of one nostril. People vary greatly in the degree to which

they suffer from deviations of the septum, some complaining bitterly of

unilateral nasal obstruction when only a slight abnormality is found, and not

infrequently a gross deviation is encountered as a chance finding, the patient

having no symptoms whatsoever. It is therefore necessary to be guided by

subjective symptoms when deciding on the advisability of operative interference.

Deviations may be of developmental or traumatic origin. The latter group may

additionally show displacement of the tip of the nose, and there may also be an

untreated fracture of the nasal bones. In most septal deviations, the convex

surface is towards the narrow side and the concave towards the other. The

inferior and middle turbinates on the concave side may be enlarged to compensate

for the widening of the airway, and this enlargement may in turn give rise to

symptoms such as secondary sinusitis. due to reduced airflow through the middle

meatus.

The caudal end of the septal cartilage should be inserted into the columella in

the midline. If there is caudal dislocation of the septum into one nostril,

there is frequently a convex displacement into the other nostril more

posteriorly. The inferior surface of the septal cartilage should be inserted

into the crest of the maxilla. If it is dislocated a spur is formed.

SYMPTOMS. Deviations of the nasal septum give rise to unilateral or bilateral

symptoms. If the presenting complaint is of nasal obstruction, this will usually

be found on the convex side. If the presenting symptom is of catarrh, or of

facial pain due to obstruction or infection of the sinuses, it may be associated

also with the concave side, where the enlarged turbinates are causing

obstruction. The patient may also present with chronic otitis media due to

malfunction of the auditory (Eustachian) tube, secondary to a deformed septum.

CLINICAL FEATURES. Inspection of the nose will easily reveal the pathology, and

note should be taken of whether there is caudal dislocation, whether a spur is

present and whether there is any compensatory enlargement of the turbinates. The

external nose should be examined, and an assessment made of whether it is truly

midline, and if not whether the displacement is of the nasal bones alone, of the

nasal bones and the tip combined or of the tip alone. An X-ray of the sinuses

may reveal radiological changes suggestive of infection, which could account for

increasing symptoms in middle age.

TREATMENT. An assessment should be made of the degree of the patient's symptoms,

correlated with the appearance of the septal deformity. If it is decided that

surgery is indicated, the choice is between a submucosal resection and a

septoplasty operation. The essential feature of the former is removal of the

deviated section of cartilage and bone. This can be safely achieved only if it

is possible to retain an adequate depth of septal support superiorly and

caudally to maintain the position of the nasal tip. This operation therefore

remains the one of choice when there is no caudal dislocation of the septum, and

the deviation is confined to the inferior two-thirds of the cartilage.

The essential features of a septoplasty operation are to free all the

attachments of the quadrilateral (septal) cartilage, to remove the "spring" of

the deflection and to reposition it in the midline, with minimal removal of

cartilage or bone. It is therefore indicated in patients with caudal dislocation

of the cartilage, and as a cosmetic procedure where there is associated

displacement of the tip of the nose. When deviation of the nasal bones is also

present, or a hump or saddle deformity is present, it forms part of a

septorhinoplasty. A septoplasty can be safely carried out in children, whereas a

submucosal resection operation is contra-indicated until growth of the facial

skeleton has ceased.

Folliculitis of the nasal vestibule (sycosis) and nasal furuncle.

SYMPTOMS. Increasing pain, marked sensitivity to pressure, and feeling of

tension in the tip of the nose is followed by reddening and swelling of the tip

of the nose, of the nasal ala, and of the upper lip. The area becomes edematous,

and the patient may have a fever. The swelling may begin to resolve before

suppuration occurs. Otherwise, a typical furuncle forms, containing pus and a

central necrotic cove.

PATHOGENESIS. A pyodermia, usually due to staphylococcal infection, arises from

the hair follicles of the nasal vestibule of the upper lip, often close to the

nasal tip. The disease is always limited to the skin and never affects the

mucosa.

TREATMENT. Antibiotic creams are applied to the nasal vestibule as long as the

disease remains a circumscribed folliculitis. Manipulation on the nose is

forbidden. If it is suspected that a furuncle is forming, high-dose oral or

parenteral antibiotics are given, possibly combined with local antibiotics. They

must be continued for several days after the symptoms have subsided (do not

discontinue too early or use too low dosage)! It may be necessary to prescribe a

fluid diet and voice rest to immobilize the tip of the nose and upper lib. Soaks

of alcohol or ice water are used on the external nose. It may be necessary to

admit to the hospital in severe cases.

A furuncle on the nose or upper lip must never be squeezed because of the danger

of spreading of the infection and of complications such as thrombophlebitis and

cavernous sinus thrombosis. The veins of the nose and upper lip drain to the