We reviewed MR imaging appearance and medical records of patients with an unusual presentation of CNS neurolisteriosis managed at our hospital with challenging features and clinical course.
Rhomboencephalitis: uncommon neural pathway,
a solution of the oral mucosa is penetration site.
Therefore Listeria can invade the nerve fibers transcellularly and migrate in a retrograde way (transcellular and intra-axonal) along the cranial nerves branches,
in particular the V cranial nerve (V-CN).
Once brainstem reticular formation is reached,
usually the trigeminal sensory nuclei,
from here the diffusion along nerve bundles continues as transcellular (neurons and glia) or intra-axonal way thanks to actin-dependent motility.
In 17% of cases of neurolisteriosis infection of the brainstem and cerebellum can be observed.
Typically infection happens in healthy subjects through consumption of contaminated food,
often with epidemic manifestation [3,4].
It typically follows a biphasic course: onset with a headache,
fever,
nausea and vomiting and subsequent cranial nerve palsy,
cerebellar signs,
alterations in the state of consciousness,
sometimes epileptic seizures and hemiparesis.
Liquor analysis generally reveals only slight abnormalities with great risk of diagnostic delay.
Differential diagnosis with other infectious agents with the similar pathological event include:
- Herpes
- Tuberculosis
- Toxoplasmosis
- Cryptococcosis and other fungal infections
- Lyme disease
- Epstein-Barr virus
- Brucellosis
- JC virus
Case 1:
45-year-old immunocompetent female; following the intake of a non-pasteurized dairy product of local production,
she suffered from generalized malaise,
exhaustion and epigastralgia.
In the following days,
she had episodes of intense holocraneal headache partially responsive to drugs,
vomiting,
with the subsequent appearance of hypoesthesia in the right tongue and fever.
Few minutes lasting shocks appeared at right face (especially V2-V3) and right ear with right eye ptosis and right V3 hypoesthesia.
Pruritic symptomatology of the right ear with mastoid pain (a clinical suspicion of Ramsay-Hunt syndrome); no auricular vesicular eruptions.
Brain MR with contrast medium (Fig.1) showed periventricular white matter of the pons and right medulla signal alteration and linear contrastographic impregnation of V CN with nodular hyperintensity of its ipsilateral central nucleus [5-9].
The first hypothesis was right trigeminal neuritis associated with homolateral rhomboencephalitis of possible herpetic or inflammatory demyelinating nature.
Lumbar puncture: limpid and colorless fluid,
absent cells,
IgG increase.
Negative PCR analyses for HSV 1 and 2,
VZV.
She underwent acyclovir and steroid therapy with benefits; after decalage neuralgia,
paresthesias to the right body,
deficit and incoordination to upper and lower limbs appeared.
Brain and cervical spine MR with a contrast agent (Fig.2): reduction of signal alteration described at V CN and pons; white matter signal alteration was evident close to IV ventricle with leptomeningeal hyperintensity and small areas of ring enhancement.
Signal alterations extended from the left lateral and posterior portion of the bulb to the spinal cord at the C6 level; both gray and white matter involvement with specific focus in the the posterior cordons.
At the same site,
ring nodular enhancement areas were objected [10-12].
Corticosteroid therapy was started again after 2nd MRI.
Neurological symptoms persisted.
New cervical spine MR (Fig.3) showed progressive reduction of bilateral periventricular T2 hyperintense signal alterations,
espression of vasogenic edema,
and partial resolution of minute parenchymal focal lesions characterized by regular rim enhancement,
the latter now recognizable in the upper site of vermis and at the left periventricular bulbar region.
Nearly resolved pathological enhancement in the right trigeminal nerve,
while leptomeningeal enhancement in the brainstem and cerebellum was still present.
Progressive extension of T2 hyperintense signal alteration in the inferior bulb and spinal cord level due to oedema,
increase of leptomeningeal and ependymal enhancement,
with a necrotic-colliquative appearance at C3 level.
The neuroradiological framework was compatible with an inflammatory-infectious process of the rhombencephalon and cervical spinal cord,
with an appearance suggestive for granulomatous nature.
Definitive CSF culture examination showed the presence of Listeria monocytogenes.
Next brain and cervical MR (Fig.4) showed a slight increase in the edema and enhancement.
Intramedullary oedematous alteration was slightly more intense showing higher enhancement.
In clinical scenario inflammatory indices slowly decreased,
persistence of episodes of low-grade fever and otalgia.
Case 2:
21y Moldavian female; no ingestion of food at risk.
After returning from Moldova,
gastrointestinal disorders and fever.
Subjective vertigo and instability in walking; the following days intense gravative occipital headache,
hypoesthesia and dysaesthesia at the right face and right limbs (cold sensation).
Dysarthria and dysphonia,
dizziness,
persistence of a headache not responsive to paracetamol.
Brain CT: presence of a smooth hypodense bulbar lesion in the region of the right inferior cerebellum peduncle,
apparently extending to the region of the ipsilateral medium cerebellar peduncle (Fig.5).
She then developed a right ataxic hemisyndrome with facial spasm; corticosteroid therapy was started.
At brain MRI (Fig.6) obliteration of the right lateral recess of the IV ventricle.
Right median-lateral bulbar 15 mm lesion extended to inferior cerebellar peduncle,
with thin peripheric T2 hypointensity of probable hemosiderinic nature characterized by intense peripheric enhancement.
Perilesional edema extended from pons to C2 level.
Small enhancement foci in the spinal cord at the C2 level.
The first hypothesis was a primary heteroplastic lesion.
Headache and vertigo persisted,
with nystagmus with a rotary component in lateral right vision,
diplopia,
dysesthesia-hypoesthesia at right hemisome.
Antibiotic therapy was then introduced for a suspicion of presence of infectious disease.
Positive blood culture for Listeria was communicated.
At brain MRI (Fig.7) new lesions with the same morphological characteristics but of smaller size in the contralateral bulbar and pontine region,
at the base of the cerebellar peduncle as well as at the level of the cervical cord up to the height of C2 were described.
Spectroscopy showed aspecific aspects (Fig.
8).
Clinical left VI CN deficiency appeared,
brain CT was performed for suspected intracranial hypertension,
negative for obstructive causes.
In the following days,
improvement of the clinical and neuroradiological findings: total regression of the oculomotion disorders,
clear improvement of the balance and recovery of the autonomy of the march.
New MRI (Fig.9) showed a slight modification of the known laterobulbar right lesion,
which currently showed a slight increase in peripheral T2 hypointensity and minimal increase in central necrotic-cystic components; intralesional diffusion restriction and reduced linear enhancement of the V CN.
The targeted spectroscopic study showed a clear reduction of the ratio between NAA and choline and the presence of a high lactic acid peak.
Further recognizable cervical enhancing localizations were slightly reduced.
Clinical slight improvement of right hemisome dysaesthesia-hypoesthesia,
persistent vertigo,
nausea,
abdominal pain,
nystagmus and ataxic walking.
After therapy,
subsequent brain MR (Fig.
10 and 11) showed progressive and almost complete resolution of described lesions.
Case 3:
27y female; minimal known VII CN deficit.
Unprotected sexual intercourse about one month before.
Fever,
malaise and hyposthenia at the right hemisome with paresthesia.
Numerous episodes of emesis.
Incoercible hiccup.
Brain CT (Fig.
12) IV ventricle reduced size; faded hypodensity at the right cerebellar peduncle; dilation of ventricular temporal horns.
Brain MRI (FIG.13) showed multiple lesions in the posterior fossa.
In particular,
partially confluent lesions characterized by multiple small,
necrotic components with irregular enhancement with restricted diffusion.
T2 edemigenous hyperintensity involves both the cerebellum and the brainstem and the proximal portion of the medulla displayed at the right lateral site and there is a modest mass effect on the fourth ventricle,
globally in place.
The largest component is evident in the deep portion of the right cerebellar hemisphere extended to the middle cerebellar peduncle.
Lesion components extended inferiorly to the inferior-lateral recess of the IV ventricle and to right lateral-bulbar cisterna with an exophytic appearance involving inferiorly the lateral surface of the cervical cord up to C2.
Areas of enhancement of some diffuse small irregular central bulbar components; pial and ependymal enhacement.
Fig.14: At spectroscopy presence of a marked peak of lactates and lipids,
reduction of N-Acetyl aspartate/choline.
The first hypothesis is an infectious-opportunistic meaning with multiple micro-abscesses and pial - leptomeningeal involvement.
The patient underwent anterior ventricular shunt implantation.
Blood culture resulted positive for Listeria; she started a targeted therapy.
Brain CT (Fig.
15) done for shunt control confirmed multiple lesions characterized by a peripheral enhancement in the right bulbar side and in the ipsilateral cerebellar hemispheric site.
There is mass effect on the IV ventricle,
slightly displaced to the left.
The patient was after discharged for rehabilitation (no more dysphagia),
marked ataxia persisted.
Brain MRI (Fig.16): slow progressive normalization of the findings,
minimal dimensional reduction of the multiple small necrotic-like components with enhancement,
still characterized by a restricted diffusion [7].
Markedly reduced white matter edema; also reduced the mass effect on the fourth ventricle and engagement of the cerebellar tonsils at the level of the foramen.
Leptomeningeal enhancement in the posterior cranial fossa as well as in the V CN was reduced.
Meningoencephalitis: is more common,
typically in newborn and children,
in the elderly and immunocompromised subjects (in particular leukaemia - lymphomas and transplanted subjects) with hematogenous pathway [13].
After a direct invasion of endothelial cells’ cytoplasm through the cell's membrane Listeria activates cytoplasmic F-actin allowing intra and transcellular diffusion through glial and neuronal cells and liquoral spread.
Invasion of endothelial cells is facilitated by the entry into peripheral monocyte-macrophages ("monocytogenes") and hence by cell adhesion up to the endothelial CNS cells or direct migration of the infected monocytes into CNS.
In adults the subacute form is more frequent,
characterized by fever with signs of meningeal irritation; an encephalitic component with a focal neurological deficit is possible.
It shows cranial nerve palsy and liquor lymphocytic pleocytosis,
proteinorrhagia and reduced glucose; differential diagnosis includes tuberculous or fungal meningitis.
Case 4:
53y male; non specific symptoms of epidemic illness after eating contaminated cheese.
At brain MRI signs of meningitis with ventriculitis (Fig.17).
Case 5:
63 y male; he suffered from colon diverticulosis and had a recent diagnosis of ulcerative rectocolitis,
in therapy.
An episode of fever in the evening with a headache and slight earmold happened.
Then he was found by his wife walking confused and confabulant,
with fever,
soporous,
and with the tendency to crouch on the left side in the absence of rigor or other signs of meningism.
Ceftriaxone and dexamethasone therapy were administered and then acyclovir and ampicillin were added.
Lumbar puncture showed a clear liquor test with bacterioscopic Gram- variable bacilli (suspected Listeria). Gentamicin therapy was added.
Brain MRI (Fig.18): minimal meningeal enhancement exclusively at the vertex with bilateral parietal apparent obliteration of the subarachnoid spaces.
Case 6:
22y female; a headache,
fever and paresthesia.
at MRI (Fig.
19) pseudotumoral right lesion,
without evidence of meningeal enhancement in Patient affected by multiple sclerosis recently treated with monoclonal antibody; documented sepsis from Listeria.
Cerebritis: infrequent,
it can rarely progress into brain abscesses [14-17] (Fig.
20).