54ournal ofNeurology, Neurosurgery, and Psychiatty 1995;59:524-527

SHORT REPORT

Serial MRI in listeria mesenrhombencephalitis: a

case report

N Lever, L Haas

AbstractListeria mesenrhombencephalitis is arare disorder, especially in the non-immunocompromised host. The pre-dilection for brain stem involvement isunexplained. The anatomical correlationof brain stem signs with serial MRI overthree months is shown in a 64 year oldwhite man. The pathological lesionsseemed to be a combination of micro-abscesses and associated oedema.

(JNeurol Neurosurg Psychiatry 1995;59:524-527)

Keywords: magnetic resonance imaging; listeriamesenrhombencephalitis

It is an enigma why encephalitis due toListeria monocytogenes should have a predilec-tion for the brain stem. The true incidence isnot known but it is a rare condition.' 2Although the clinical picture has beendescribed, the clinicoanatomical correlationhas not. The purpose of this case report is toshow the correlation between physical signsand MRI abnormalities.

Department ofMedicine, WellingtonSchool ofMedicine,Mein Street,Newtown, PO Box7343, WellingtonSouth, New ZealandN LeverNeurologyDepartment,Wellington Hospital,Capital Coast HealthLtd, Private Box 7902,Wellington, NewZealandL HaasCorrespondence to:Dr Lever.Received 19 April 1995and in revised forn30 June 1995Accepted 1 1 July 1995

Case reportTwo days after a fish meal at a restaurant, a

64 year old immunologically competent man

experienced nausea and vomiting (but nodiarrhoea). His wife, who ate the same dish,was not affected. One day after the onset ofsymptoms ataxia, vertigo, and headacheoccurred. By day 3 of the illness, when admit-ted to hospital, he had become dehydrated.The only neurological abnormalities weremild gait ataxia and first degree nystagmus on

gaze to the left and right. He was afebrile.There was no meningism. White blood cellcount was 12-4 x 109/1. Treatment was sup-portive with intravenous fluids and anti-emetics. On the fourth day of his illness hebecame febrile and hypertensive (blood pres-sure 200/140 mm Hg) having previously beennormotensive. On day 5 he became confusedand had a convulsion associated with a respi-ratory arrest. The precise chronology of theseassociated events is unclear. He was intu-bated. Seizure control was obtained withdiazepam. Anexate (fluphenarazine) was

given to reverse possible respiratory sedationbut this was ineffective. Fever was believed tobe due to a chest infection associated withinhalation. A chest radiograph supported thispresumption. Ceftazidine, metronidazole,and amoxycillin antibiotics were given intra-venously.Computed tomography of the head and

posterior fossa on day 5, the day of the respi-ratory arrest, was normal. Cerebrospinal fluidobtained after the CT contained 298 x 109/lwhite cells (neutrophils 92%). Protein was0-69 g/l; CSF glucose and simultaneousblood glucose were 2-6 mmol/l and 6-6mmol/I respectively. Repeat CSF examinationwas performed on day 7. At that time whitecell count was 508 x 106/1 (90% lympho-cytes). Protein was 1'24 g/l and glucose 2-9mmol/I (serum 8'6 mmolI1). Blood and CSFcultures taken on day 5 grew Listeria monocy-togenes on day 8 of the illness. The diagnosiswas now listeria mesenrhombencephalitis.The isolates were sensitive to amoxycillin.The serotype was type 4.On day 9, when transferred to the neurol-

ogy service, there was no spontaneous respi-ratory effort. Continuous ventilation wasrequired. Cognitive function was normal andappropriate responses were obtained to verbaland written requests. There were strikingabnormalities of ocular movement (fig 1).Horizontal gaze was absent on attemptedgaze to left and right. By contrast, verticalgaze was unimpaired. Convergence andpupillary reaction to light were normal.Ocular bobbing or a slow downbeat nystag-mus was present. Optokinetic and vestibulo-ocular responses were normal for verticalstimulation but absent with horizontal test-ing. Bilateral caloric stimulation provokedenhanced bobbing movements. A dense rightlower motor neuron facial palsy and a partial(mild) left lower motor neuron facial paresiswas present. Gag response was absent bilater-ally and volitional palatal movement wasimpaired. Right hypoglossal lower motor neu-ron lesion was evident. Right hemianaesthesiato pinprick and touch was present withimpairment to position and vibration sensa-tion in the right hand and leg to the knee.Diffuse pronounced right upper and lowerlimb hemiparesis was present. Movement wasonly possible with the elimination of gravity.

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Serial MRI in listeria mesenrhombencephalitis: a case report

Figure 1 Clinicalphotographs ofgaze palsieson day 30. Centre of

figu!re: neutral gazeposttion. Left o centre:attempted gaze left withfailure to perform lateralgaze movement. Right ofcentre: failure to gain rightgaze. Note exposurekeratopathy and intactvertical eye movements(top and bottom centre).

Deep tendon reflexes on the right were ini-tially hyperreflexic, but then subsequentlybecame normal and symmetric. The rightplantar response became and remained exten-sor and the left plantar response became neu-

tral.Treatment with amocycillin continued.

The other agents were stopped. The dose of4 g amoxycillin per day was increased on day11 to 12 g per day until acute anuric renalfailure developed four days later (day 14).

This required temporary haemodialysis.Interstitial nephritis secondary to the amoxy-

cillin was considered the likely cause of theanuria. Antibiotic treatment was changed tocotrimoxazole (1920 mg per day).

Brain MRI on day 16 showed swelling inthe medulla oblongata, particularly in theregion of the right cuneate nucleus andoedema in the brainstem. Enchancementwith gadolinium suggested multiple foci ofinfection (fig 2).

Figure 2 MRI study onday 16. Right: Tl coronalview showing ring andpunctate lesions in the ponsand medulla. Left: T2coronal slice showingoedema throughout themedulla and pons.Bottom: Tl gadoliniumenhanced axial slice withring enhancement in theregions of the posteriorcolumns. I2

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Over the ensuing weeks ventilatory require-ments lessened and power in the right legimproved but his eye and cranial nerve signsremained unaltered. Repeat MRI was per-formed on day 33 of his illness. This showedincreased signal on TI weighting in the bedof the previous inflammatory change. Theamount of oedema was reduced but enhance-ment was now present in the right superiorcerebellar peduncle and behind the fourthventricle, and less obvious in the lowermedulla oblongata than had been seen in theearlier MRI. Antibiotic treatment was discon-tinued four weeks after this study.A further MRI study was performed at

three months (day 88) after the onset of hissymptoms (fig 3). This showed further reso-lution of the previous enhanced areas with nonew inflammatory changes. Examination ofCSF at that time showed 2 x 106/1 white cellswith normal protein and glucose concentra-tions. Eye movements remained abnormalbut the ocular bobbing was of smaller magni-tude.

At six months, horizontal eye movementshad largely returned but were slow, and therewas failure to gain full adduction or abduc-tion. Ocular bobbing was no longer present.His other cranial nerve signs were essentiallyunchanged. Inability to swallow remainedand he was fed by gastrojejunostomy tube.Despite residual weakness (MRC 4) in theright leg he was walking although with anataxic broad based gait requiring assistancefor safety. He was experiencing complex par-tial seizures and had developed a headtremor. An EEG showed diffuse slow activitymore prominently on the left with epilepto-genic changes in the right parieto-occipitalarea.He required continuous ventilation for the

first three months. At the time of writing hehad been in hospital for 18 months and forthe past 11 months had required respiratorysupport only at night. This is due to centralnocturnal hypoventilation with resultinghypercapnia. During the last period sponta-neous ventilatory effort has been adequatewhen awake and no additional ventilatorysupport has been required.

At 11 months a laryngectomy, and subse-quently a cricopharyngeal myotomy, were

performed to improve his swallowing.Tarsorrhaphy was performed to prevent fur-ther corneal damage to his right eye at theeight month and is still required at 18months.

Concluding commentsListeria monocytogenes is a widespread, yetgenerally non-pathogenic organism. The esti-mated incidence of CNS listerioses inEngland and Wales of one case per 5*3 mil-lion population underestimates the true inci-dence. The Institute of EnvironmentalScience and Research CommunicableDisease Centre in New Zealand has had fourcases (including ours) reported since January1992 in a population of 3-4 million (P Short,personal communication, CommunicableDisease Centre, New Zealand). We treated a

patient in 1992 who had listeria mesen-

rhombencephalitis and who recovered com-

pletely. Treatment was with amoxycillin. Theother cases reported were children and wehave no knowledge of the outcome. There isa greater awareness of its pathogenicity inimmunocompromised people but even then itremains uncommon.The predilection for the brainstem is an

acknowledged feature of this disorder anddistinguishes it generally from other cerebralinfections.236 Other organisms which mayinfect the brainstem include mycoplasma,legionella, Lyme disease, and viral illnesses.4The reason for the brainstem predilection isunknown.

Although the anatomical abnormalitieshave been shown at necropsy' there havebeen few reported cases with MRI correla-tion.257 Paresis of horizontal gaze suggests alesion of the parapontine reticular formation.Neurogenic respiratory arrest with the preser-vation of consciousness is uncommon. TheMRI has shown the clinical and anatomicalcorrelation remarkably well.

There was dispute among different clini-cians as to whether ocular bobbing or slowdownbeat nystagmus was present. This case

Figure 3 MRI study onday 88. Left: T2 coronalview showingfurtherresolution. Right: Tl axialview with gadoliniumillustrating furtherresolution of the ring lesion.

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shows that a movement similar to bobbingcan occur in this clinical situation. Mostreviews have commented on the presence ofabnormal eye movements with this illness. Toour knowledge ocular bobbing has not beenpreviously described. In Fisher's syndrome(ophthalmoplegia-ataxia-areflexia form ofGuillain-Barre syndrome) late central demyli-nation has been shown,8 but the blood andCSF cultures did not support that diagnosis,and in that condition the deep reflexes aregenerally lost at an early stage.9

Amoxycillin is considered first line antibi-otic treatment for this disorder. The recom-mendation is that high doses be used.'Cotrimoxazole, considered a second lineagent with uncertain clinical effectiveness,seemed to be effective in this man's case. Theefficacy of second line agents are likely to beless important than the predilection formicroabscesses to congregate in an area oftightly packed neurological structures.The case described here is consistent with

previous descriptions of this condition. Thehigh incidence of brain stem findings, respira-

tory depression, and potential for long termneurological sequalae2 should raise early sus-picion of this diagnosis so that treatment canbe instituted promptly.

1 Pollock SS, Pollock TM, Harrison MJG. Infection of thecentral nervous system by Listeria monocytogenes: areview of 54 adult and juvenile cases. Q_JMed 1984;211:331-40.

2 Armstrong RW, Fung PC. Brainstem encephalitis(rhombencephalitis) due to Listeria monocytogenes: casereport and review. Clin Infect Dis 1993;16:689-702.

3 Duffy PE, Sassin JF, Summers DS, Lourie H.Rhomboencephalitis due to Listeria monocytogenes.Neurology 1964;14: 1067-72.

4 Baker PCH, Price RP, Allen CD. Brain stem and cerebel-lar dysfunction with Legionnaire's disease. J NeurolNeurosurg Psychiatry 1981;44: 1054-6.

5 Soo MS, Tien RD, Gray L, Andrews PI, Friedman H.Mesenrhombencephalitis: MR findings in nine patients.AJRAm J Roentgenol 1993;160: 1089-93.

6 Frayne J, Gates P, Listeria rhombo-encephalitis. Clin ExpNeural 1987;24: 175-9.

7 Outin HD, Merrer J, Molho M, Rabault N, Simon N,Nouailhat F. Solitary listerial abscess of the brain stem.Cure with antibiotic treatment. Revue Neurol (Paris)1989;145: 153-6.

8 Ferrer X, Ellie E, Larriviere M, Deleplanque B, LaguenyA, Julien J. Late central demyelination after Fisher'ssyndrome: MRI studies. J Neurol Neurosurg Psychiatry1993;56:698-9.

9 Hughes RAC, ed. Clinical features of Guillain-Barre syn-drome. In: Guillain-Barri syndrome. London: Springer-Verlag, 1990:121-32.

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