Intracranial Suppuration Leslie Oliver, M.B.(Lond.), F.R.C.S., F.A.C.S

POSTGRAD. MED. j. (I96I), 37, 534 Postgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from

INTRACRANIAL SUPPURATION LESLIE OLIVER, M.B.(LOND.), F.R.C.S., F.A.C.S. Neurosurgeon, Charing Cross Hospital, West London Hospital and Royal Northern Hospital, London

ALTHOUGH the introduction of the sulphonamides to the exterior or into septic nasal sinuses or and the antibiotics has reduced the incidence of mastoid cells. Infected subdural effusions not intracranial suppuration, it can still cause con- infrequently complicate the convalescence in cases siderable anxiety to the medical practitioner. of acute purulent meningitis, especially in child- hood (Hankinson and Amador, 1956). There are Extradural Abscess severe toxemia and pyrexia, with signs of raised An abscess may form between the skull and intracranial pressure (headache, vomiting and the dura mater as a complication of mastoiditis, papilledema). The infection spreads widely in osteomyelitis of the skull or fracture of the skull the subdural space producing contralateral hemi- (open to the exterior, or into an infected mastoid paresis, cortical sensory loss and hemianopia. If process or nasal sinus). The dura mater forming the dominant cerebral hemisphere is affected, the inner wall of the abscess is inflamed and dysphasia or aphasia may be found. Patients usually covered with granulations corresponding sometimes present with grand mal or Jacksonian to the extent of the abscess. there is severe epilepsy. Subdural empyemas sometimes occurProtected by copyright. toxemia and pyrexia. Localizing neurological bilaterally. signs are sometimes found and depend on the A subdural abscess is a localized collection- of site of the abscess. Rarely, osteomyelitis, blood- pus; it may form during the treatment of sub- borne or arising from an overlying carbuncle, dural empyema, or the infection may be localized affects the suboccipital region causing an extra- from the beginning. Subdural abscesses tend to dural abscess with cerebellar signs. The cerebro- form along the falx or between the occipital lobe spinal fluid shows a moderate increase in white and tentorium. A subdural abscess produces a cells but contains no organisms; its pressure may localized neurological effect. Thus an abscess on be raised. the medial aspect of the hemisphere involving When an extradural abscess is caused by osteo- the motor cortex causes paralysis of the contra- myelitis or mastoiditis, the operation appropriate lateral leg with sparing of the arm and face. to these diseases establishes the necessary drainage. Lumbar puncture in subdural infection shows When, however, an extradural abscess follows raised pressure, and the cerebrospinal fluid con-

fracture of the skull, a burr-hole is made over tains an increased number of white cells (ioo tohttp://pmj.bmj.com/ the site of the abscess and a drain inserted. 300 per cu. mm.) but no organisms. Although Appropriate antibiotics are administered. a variety of organisms may be grown from the primary focus, the commonest one found in Subdural Suppuration subdural pus is the non-h2emolytic streptococcus. (The synonym purulent pachymeningitis is a Burr holes are made to confirm the diagnosis bad term, for it equally well applies to extradural and to enable drainage to be carried out. In abscess which is associated with pachymeningitis subdural empyema small rubber catheters are secondary to overlying osteomyelitis.) Subdural insinuated between the dura and arachnoid for on September 27, 2021 by guest. empyema means a widespread collection of pus the instillation of penicillin, to which the organisms between the dura and arachnoid mater. It is an of subdural infection are usually sensitive (Schiller, uncommon but serious condition which before Cairns and Russell, 1948). The strength of the days of antibiotics was invariably fatal. The penicillin employed is 500 units per ml. of isotonic commonest cause is osteomyelitis of the skull saline. Although systemic penicillin passes into following an acute exacerbation of inflammation the subdural space, the greater concentration of the of the nasal air sinuses. Such an exacerbation drug obtained by the catheter method is desirable. may be brought about by operative interference Subdural abscesses are located with the aid of in sinusitis. Subdural infection may also be a brain cannula which is passed unhesitatingly caused by blood-borne osteomyelitis of the skull, through relatively silent parts of the brain, but it mastoiditis, or frac-tures of the skull which open is particularly important to avoid the motor cortex Postgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from Sept0mber I196 I OLIVER: Intracranial Suppuration 535 and the speech zones. Diodone is injected into the sinus through the angular and ophthalmic the'subdural empyema or abscess cavity to demon- veins; in (d)' it spreads through the superiof strate its extent radiologically. A subdural petrosal sinus. The onset occurs with headache, abscess, unlike a brain abscess, is shown to be rigors and a remittent temperature. The eyelids superficial to the brain. Ventriculography or become swollen, the conjunctivae (edematous, the angiography may be required to localize it. Anti- eyes fixed and proptosed, and the pupils dilated biotics are given from the beginning, and when and inactive. If the cornea is clear, retinal penicillin is indicated, 20,000 units in 5 ml. of hamorrhages and papilloedema' may be observed. -isotonic saline are given by lumbar puncture to Septic sinus thrombosis is rare in countries prevent meningitis arising after needling the brain, where sulphonamides and antibiotics are freely for systemic penicillin does not reach the cerebro- available for the treatment of the causal lesions. spinal fluid in sufficient concentration to be Formerly, the condition was fatal; patients died effective. Subdural abscess is treated by inter- from septicammia and metastatic infection of the mittent aspiration and usually the instillation of lungs, or from meningitis; nowadays the dis5ase penicillin. is usually cured with antibiotics. Nevertheless; septic lesions of the nose or upper lip-the' Sigmoid Sinus Thrombosis "danger area "-should not be squeezed 6r Since the introduction of sulphonamides and incised. There 'is nowadays no indication for antibiotics, the incidence of this condition has ligation o'f the angular veins in cavernous sinus been greatly reduced and the clinical picture infection when the primary lesion is in the danger modified. Now it is more often a complication area. of chronic than of acute suppurative otitis media and, whereas in the past, septicemia was the Meningitis

common presentation, today the manifestations Unless otherwise stated, the term meningitis' Protected by copyright. of the disease are due to spreading thrombosis refers to leptomeningitis (i.e. inflammation of the into other venous sinuses and the cerebral veins. arachnoid and pia mater). Infection may reach Formerly, the common -syndrome consisted of the meninges directly from the exterior: (a) by headache, rigors, swinging temperature, positive erosion of the skin over a cranial or spinal con- blood culture, and metastatic abscesses in the genital defect (e.g. meningocele); (b) as the result lungs and elsewhere; at the present time, the of open injuries of the head or spine; (c) following more usual features are headache, vomiting and cranial or spinal operations 'or lumbar puncture papilledema caused by thrombosis spreading into when aseptic technique has been defective.- the other venous sinuses; if it spreads into cortical Infection may also reach the meninges from the veins, focal effects may be produced such as following adjacent inflammatory diseases: (a) epilepsy or hemiparesis. If thrombosis spreads otitis media; (b) osteomyelitis of the skull; (c)' into the petrosal sinuses the fifth and sixth cranial infected dermoid sinus of the occiput or spine nerves may be affected producing paralysis of the (Logue and Till, I952); (d) cerebral abscess, by external rectus muscle and pain in the face rupturing into the ventricles or subarachndid space. (Gradenigo's syndrome). Extension of throm- Lastly, infection may occur through the blood' http://pmj.bmj.com/ bosis into the internal jugular vein produces a stream; tuberculous and meningococcal menin- tender swelling in the neck. gitis arise in this way whereas pneumococcal Opinion is divided about the extent of surgical meningitis can occur either as a blood-borne treatment that is necessary in these days of infection from pneumonia, or directly from otitis ,abundant antibiotics. There is a tendency to be media (by far the commonest cause) or nasal content with mastoidectomy and wide exposure sinusitis. In many cases of pneumococcal

of the sigmoid sinus, but some otologists still meningitis the source of infection cannot be traced. on September 27, 2021 by guest. advocate the classical triad of mastoidectomy, The symptoms of meningitis are frontal or evacuation of the clot from the sinus and ligation occipital headache, vomiting and in some cases of the internal jugular vein (Reading and Schurr, photophobia. Retention of urine may occur. I956). The physical signs are neck stiffness, positive Kernig's sign and sometimes a positive Brud- Cavernous Sinus Throm6osis zinski's sign (flexion of the hips and knees occurs Septic thrombosis of the cavernous sinus may when the patient's head is flexed). These signs arise from: (a) Boils or carbuncles of the nose or of meningeal irritation are accompanied by upper lip, especially after suigical interference; pyrexia and toxwemia. With the onset of coma, (b) erysipelas; (c) dental sepsis in the upper jaw, the signs of meningeal irritation may disappear, especially after extractions; or (d) middle-ear and in infants and young children they may be infection. In (a), (b) and (c) infection spreads to inconspicuous or absent from the beginning.' In- 536 POSTGRADUATE MEDICAL JOURNAL September i 96 IPostgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from meningococcal meningitis, which may occur mastoiditis and osteomyelitis of the skull. In sporadically or in epidemics, a petechial rash may tuberculous meningitis, a course of streptomycin be present on the trunk (' spotted fever '). In is given lasting several months. The drug is given tuberculous meningitis, the syndrome of menin- intramuscularly and intrathecally. Burr holes geal irritation may be absent, and thus the ' diag- may be needed for injection of the drug into the nosis ' of pyrexia of unknown origin may be made. lateral ventricles when adhesions have produced In all forms of leptomeningitis, the cerebro- a spinal block (the intrathecal or intraventricular spinal fluid pressure is raised. In pyogenic dose of streptomycin is So to ioo mg. in S ml. meningitis the fluid is opalescent because of the isotonic saline). Burr holes may also be required presence of a large number of polymorphs (i,ooo in pneumococcal meningitis when a spinal block to io,ooo per cu. mm.). The protein is increased occurs. When satisfactory progress is not being (Ioo to 500 mg. per ioo ml.), while the sugar is made by a patient suffering from pyogenic reduced below 40 mg. per ioo ml. The chlorides meningitis, the possibility of a coexistent brain are moderately reduced. abscess, subdural abscess or subdural hygroma In tuberculous meningitis, the cerebrospinal should be considered. fluid appears clear or slightly hazy and, after standing a few hours, a fine web-like fibrin clot Brain Abscess forms. The cell count is increased. In the Otitis media and mastoiditis may give rise to majority of cases there are between 50 and 500 an abscess in either the temporal lobe or the cells per cu. mm. Lymphocytes and mono- cerebellum. Abscess of the brain is much more nuclears predominate. The protein level is raised likely to be caused by chronic than acute infection with an average of 200 mg. per ioo ml. If in of the middle ear. Inflammatory diseases of the tuberculous meningitis the protein exceeds 500 lungs, especially following their surgical treatment, mg. per I00 ml. there is likely to be a subarachnoid are liable to cause metastatic brain abscesses; block. The sugar content is lowered but not to single abscesses occur much more frequently thanProtected by copyright. the same extent as in pyogenic meningitis. The multiple ones. Degeneration of a secondary chloride is usually reduced below 650 mg. per carcinoma, especially when there is no evident I00 ml. Although formerly thought to be a primary growth, may cause confusion in diagnosis reliable test for the presence or absence of tuber- when the lesion in the brain is aspirated. Nasal culous meningitis, the chloride test is now regarded sinusitis, with or without spreading osteomyelitis, as significant only when positive. Under the may cause a frontal lobe abscess. Open fractures microscope, tubercle bacilli may be seen in the of the skull, when the dura mater has been opened fluid or can be cultured from it. and the brain penetrated, have a strong tendency to cause intracranial suppuration (Fig. i). A Treatment of Meningitis brain abscess is almost certain to form if frag- In pyogenic meningitis, the organism should be ments of bone, hair or hat material have been identified as soon as possible and its antibiotic left in the brain. Fractures into the nasal air sensitivity determined. In the meantime, a wide sinuses, with or without cerebrospinal fluid spectrum antibiotic should be given. If the rhinorrhca, frequently cause meningitis and some-http://pmj.bmj.com/ organism is sensitive to penicillin, the drug should times a cerebral abscess. The presence of a be given intrathecally as well as intramuscularly, missile is much less likely to cause an abscess. for an effective concentration of penicillin does Osteomyelitis of the skull, caused either by not pass into the cerebrospinal fluid from the infection of the nasal air sinuses or by blood-borne blood stream. The dose injected into the cerebro- organisms, is liable to cause a brain abscess. spinal fluid must not exceed 20,000 units daily Occasionally an inflammatory lesion of the scalp without evidence of and it should be dissolved in not less than 5 ml. produces a cerebral abscess on September 27, 2021 by guest. of isotonic saline. Cases are on record in which osteomyelitis. Rarely, infection of an operation 500,000 units were given in error and the patients wound causes an abscess of the brain. Peripheral developed generalized convulsions and died within sepsis is responsible for an occasional brain 24 hours. Pneumococcal meningitis is usually abscess. Examples of such causal lesions are treated with penicillin and a sulphonamide, carbuncle, whitlow, to9sillitis, infected dental root whereas meningococcal meningitis requires only (especially after extraction), septic wounds and a sulphonamide in the majority of cases. Hcemo- osteomyelitis. Sometimes an abscess occurs philus influenza meningitis usually responds to without an evident focus of infection and may chloramphenicol alone, although there is a ten- thus be encountered unexpectedly. Cryptogenic dency to give it with sulphadiazine. In pyogenic brain abscess is particularly liable to occur in the meningitis, the focus of origin of the infection may presence of congenital heart disease, especially be known and can be treated surgically, e.g. when there is cyanosis (Campbell, 1957). More Postgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from September I 96 I OLIVER: Intracranial Suppuration 537

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FIG. 2.-A carotid arteriogram showing the charac- teristic upward sweep of the middle cerebral artery and the opening up of the carotid ' syphon' produced by a space-occupying lesion in the tem- poral lobe, in this case an abscess. Protected by copyright. usually immediately subjacent to the primary ...... lesion, but occasionally it may be well away from FIG. i.-Inflammation of the right upper lid at the site the area of osteomyelitis. A careful neurological of entry of a pencil through the root of the orbit. The pencil entered the brain and caused an abscess examination is therefore necessary. The com- in the frontal lobe. The abscess was successfully monest site for osteomyelitis is in the frontal treated by the aspiration method. region, although no part of the skull is exempt. Of particular importance in temporal lobe than 5o% of such abscesses have been found in abscesses is examination of the visual fieldswhich association with Fallot's tetralogy and some have commonly show an upper quadrantic homonymous followed operations for cardiac lesions. They are defect or, if the abscess is extensive, a complete not necessarily caused by paradoxical emboli, for hemianopia. Cerebellar abscesses produce mini- the shunt is not always from right to left. mal or moderate cerebellar signs (unilateral Bacteriology. Organisms isolated from abscesses hypotonia; incoordination of the upper ex- of the brain include Staphylococcus aureus or albus; tremity of the same side; nystagmus, which is http://pmj.bmj.com/ Streptococcus pyogenes, viridans or pneumonia? more marked and of greater excursion when the Pseudonomas pyocyanea; Proteus vulgaris; actino- patient fixes his gaze towards the side of the myces; diphtheroids; Haemophilus influenza? and abscess; and a tendency for the patient to deviate occasionally Entamcba histolytica. Not in- towards the side of the lesion when walking). frequently a mixed growth of organisms is A metastatic abscess may occur anywhere in the obtained. The nature of the responsible organisms brain. As much information as possible about

and their sensitivity to the various antibiotics is its location is obtained from the history and on September 27, 2021 by guest. ascertained. Often, however, no organism is neurological examination, as in the diagnosis of demonstrated in the pus although the infection intracranial tumnours, and help then obtained may still be active in the abscess capsule. from the investigations discussed below. The Diagnosis. An abscess of the brain behaves temperature is most likely to be slightly raised like a tumour, giving rise to increased intracranial (990 to ioo0F.) or subnormal. A high temperature pressure and localizing signs. Thus there are is not found with an uncomplicated brain abscess. headache, vomiting and, frequently, but not The pulse may show an increased rate or the always, a mild degree of papilledema. A meta- classical slowing of increased intracranial pressure. static abscess may begin with epileptic attacks Investigations. Lumbar puncture is avoided which, if of the Jacksonian type, are of localizing when possible for fear of producing a cerebellar value. When the infection arises in the skull or pressure cone. The cerebrospinal fluid is clear its air-containing cavities, the cerebral abscess is in uncomplicated cases, although there is usually 538 POSTGRADUATE MEDICAL JOURNAL S--ebtember i 96 i Postgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from

FIG. 3.-A temporal lobe abscess visualized radiologically by in- jection of 2 ml. diodone after aspiration of pus. Protected by copyright. a moderate increase in white cells. There should a closed abscess cavity is asking for persistence of be no organisms, either on direct examination of infection as plainly in the brain as it would be the fluid or after culture. When there is doubt anywhere else in the body. There is no primary about the presence or location of an abscess, reason to suppose that it may be any less provoca- ventriculography or arteriography should be tive of chronicity than is a sequestrum, or a knot carried out. The latter investigation is particularly of so-called absorbable catgut, in the depths of useful in demonstrating an abscess in the tem- a sinus. I cannot help thinking that the wide- poral lobe, because it may be difficult or impossible spread habit of demonstrating the existence of to fill the temporal horn with air in such cases abscesses radicilogically by this means may be (Fig. 2). Electroencephalography is likely to show a cause of the need to excise them later' (Taylor, slow waves of marked amplitude, and phase- I950). reversal in the region of a supratentorial abscess. When a brain abscess has been localized, its Treatment of Brain Abscess http://pmj.bmj.com/ extent can be demonstrated by positive contrast (a) Aspiration. A burr hole is made over the radiography. Diodone 2 to 3 ml. is injected into site of the abscess, unless it is secondary to the abscess cavity after some of the pus has been osteomyelitis of the skull when the dura mater is aspirated (Oliver and Leese, I949). The skull is already exposed by removal of infected bone. then X-rayed (Fig. 3). Many neurosurgeons A small incision, a few millimetres long, is made recommend Thorotrast (thorium dioxide), for it in the dura mater. An avascular point on the has the advantage of remaining in situ and thus surface of the brain is punctured with a pointed the progress of the abscess can be followed radio- tenotome, and a bluni-ended brain needle is on September 27, 2021 by guest. logically. But there is experimental evidence that 'passed into the abscess cavity. The pus is Thorotrast, acting as a foreign body, stimulates aspirated and replaced by 2 to 3 ml. penicillin capsule formation (Falconer, McFarlan and solution (ioo,ooo units per ml.). This small Russell, 1943). Therefore, if resolution of the volume of fluid is injected to avoid rupture of the abscess is desired, the rapidly absorbable contrast capsule which may be extremely thin. Sometimes medium, diodone, should be employed. Further- an abscess heals after one penicillin replacement, more, it is a violation of surgical principles to but the procedure may have to be repeated several leave an unabsorbable foreign body in a septic times. The cannula (brain needle) is then passed place. The late Julian Taylor had strong feelings through the original burr hole between the about this: ' I should like to point out that to sutures. Considerable judgment is needed in inject a foreign body such as Thorotrast . . . into spacing aspirations. Needling should be repeated Se-btember i 96 i OLIVER: Intracranial Suppuration ... 5,39 Postgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from

FiG. 4.-The probe indicates a large opening from the interior wall of a temporal abscess through which there was a free com- munication with the tympanic antrum. This type of abscess should be totally excised. Protected by copyright. if the patient's general and neurological state do may be life-saving for patients who are too ill to not improve; it should not be delayed until undergo a major operation. deterioration occurs. At first, aspiration and (b) Secondary Excision. Excision of the abscess penicillin replacement may be needed at intervals capsule is carried out when aspiration alone fails. of 24 to 48 hours, but when progress is satisfactory, Some neurosurgeons, however, excise the abscess the intervals become longer and longer until no capsule as a routine as soon as aspiration is more pus can be aspirated. Many abscesses can unproductive. After excision of the abscess be completely cured by this technique (Oliver capsule, the wound is closed without drain- and Leese, 1949) but if a patient's condition does age. not improve or deteriorates the possible causes (c) Primary Excision. This is another method are: (i) Persistent infection in the capsule asso- of treatment made possible by the discovery of ciated with brain swelling. The abscess should antibiotics (Le Beau, 1946). The advantage is then be excised' (vide infra, method b) and decom- that the anxious period of observation required pression The performed. edema may also be by the aspiration technique is'eliminated. Primary http://pmj.bmj.com/ reduced by intravenous injection of a solution of excision of the abscess is particularly indicated urea. (2) Loculation, in which aspiration only when it is situated in a relatively silent part of the drains part of the abscess. Other loculi may be brain, e.g. the frontal or cerebellar lobes where detected and drained by needling in new direc- a neurological deficit is unlikely to be caused by tions. (3) The presence of multiple abscesses excision. It is also the best method of treating which may occur when the primary infection is an abscess following an open head injury, for any in the lungs. Neurological examination alone indriven fragments of bone or foreign bodies are may not reveal the location of additional abscesses, automatically removed and the infection is thus on September 27, 2021 by guest. but they may be demonstrated by ventriculo- brought to an end. A brain abscess occasionally graphy. (4) A sinus which has become established follows a very slow course, and the onset of with the tympanic antrum in an otogenic brain increased intracranial pressure and localizing signs abscess (Fig. 4). Such an abscess will not heal are long delayed. Such an abscess develops into unless excised. (5) The presence of a foreign body a solid mass of fibrous tissue closely resembling in the abscess, e.g. bone fragments in post- a tumour, although there may be a small quantity traumatic cases. The aspiration technique is of pus in the centre. Primary excision is the only particularly applicable to abscesses which involve possible treatment in such a case. the motor cortex, the speech zones or the optic In the management of cerebellar abscess, com- radiations when other methods would cause severe pression of the medulla oblongata by the increasing neurological deficits. Furthermore, aspiration volume of the abscess and the surrounding cedema El 540- POSTGRADUATE MEDICAL JOURNAL September I96I Postgrad Med J: first published as 10.1136/pgmj.37.431.534 on 1 September 1961. Downloaded from of the cerebellum demands immediate decom- dura mater is opened over both cerebellar lobes, pression. A full exposure of the posterior fossa and the abscess is removed. The wound is is first carried out. The abscess is then aspirated closed without drainage, and 20,000 units of with a brain cannula through a small puncture penicillin in 5 ml. of isotonic saline are given by made in the dura mater on the side of the abscess, lumbar puncture. If the patient is very ill, the and penicillin (ioo,ooo units dissolved in i ml. of abscess is aspirated and its removal carried out isotonic saline) is instilled into the cavity. The a few days later.

REFERENCES CAMPBELL, M. (1957): Cerebral Abscess in Cyanotic Congenital Heart Disease, Lancet, i, ixiI. FALCONER, M. A., McFARLAN, A. M., RUSSELL, D. S. (1943): Experimental Brain Abscesses in the Rabbit, Brit. 7. Surg., 30, 245. HANKINSON, J., and AMADOR, L. V. (I956): Infected Subdural Effusions, Brit. med.J7. ii, I2z. LE BEAU, J. (1946): Radical Surgery and Penicillin in Brain Abscess, Y. Neurosurg., 3, 359. LOGUE, V., and TILL, K. (1952): Posterior Fossa Dermoid Cysts with Special Reference to Intracranial Infection, J7. Neurol. Neurosurg. Psychiat., 15, I. OLIVER, L. C., and LEESE, W. L. B. (1949): Treatment of Brain Absces3 with Special Reference to a Conservative Method, Lancet, ui, 828. READING, P. V., and SCHURR, P. H. (1956): Thrombosis of the Sigmoid Sinus, Ibid., ii, 473. SCHILLER, F., CAIRNs, H., and RUSSELL, D. S. (I948): The Treatment of Purulent Pachymeningitis and Subdural Suppuration with Special Reference to Penicillin, 3. Neurol. Neurosurg. Psychiat., xi, New Series, 143. TAYLOR, J. (1950): Intracranial Suppuration, Proc. roy. Soc. Med., 43, 129. Protected by copyright. http://pmj.bmj.com/ on September 27, 2021 by guest.