CONTRIBUTION OF IMAGING
IN CHRONIC MENINGITIS
A. BEN MILED, F. JABNOUN, M. BEN ALI, K.
BOUZAIDI, I. KECHAOU, A. KHELIL
NEURORADIOLOGY : NR 21
 The contribution of slice imaging in the chronic
meningitis diagnosis process is considerable allowing
often a confirmation of the positive diagnosis, and
an etiological orientation.
 Exclusion of abscess tumors and para meningeal
focus of infection in cranial sinusis or paravertebral
location are important objectives of imaging in the
setting of chronic meningitis.
 Most patients with a chronic meningitis, however
will have normal imaging or non specific findings.
 A retrospective study of 7 patient observations
comprising of 3 men and 4 women with a mean age
of 43 years.
 Investigated by CT scan and/or MRI for headaches
associated with polyuro-polydipsia syndrome (3
cases), convulsions (2 cases) and headaches with
fever (2 cases).
 In
this presentation, we are illustrating the
different CT scan and MRI aspects of these
chronic meningitis.
 The radiological explorations involving CT scan
and MRI show and conclude to:
 Metastatic leptomeningitis (3)
 Neuro sarcoidosis (2)
 Idiopathic hypertrophic pachymeningitis (1)
 Langerhans Cell histiocystosis (1)
CHRONIC MENIGITIS
SYMPTOMS
Pleomorphic clinical manifestations encompassing symptoms and signs
in 3 domains of neurologic function:
1.
The cerebral hemispheres: Headache, decrease in mental
abilities, confusion.
2.
The cranial nerves: loss of feeling in the face, diplopia,
trigeminal sensory or motor loss, cochlear dysfunction, and
optic neuropathy.
3.
The spinal cord and roots: disturbances in the ability use the
legs and arms, back pain, weakness, burning or prickling
sensations.
CHRONIC MENIGITIS
IMAGING FINDINGS
 MRI have a higher sensitivity than CT
 Better contrast resolution
 Avoid the artefact beneath the inner table that limits
the visualization of meningeal enhancement with CT.
 Imaging should be obtained preferably prior
to the lumbar puncture which may cause a
meningeal reaction
CHRONIC MENIGITIS
IMAGING FINDINGS
 MRI
 CT scan can be sufficient evidencing:
Hyper dense aspect of leptomeningis
Important enhancement, sometimes diffuse in
others nodular.
CHRONIC MENIGITIS
IMAGING FINDINGS
MRI
 Leptomeninges thikening and enhancement:
 Fine signal-intense layer that follows the gyri , superficial
sulci, ependymal lining and perivascular spaces (appearance
of intraparenchymal lesion)
 Cranial nerve enhancement in the subarachnoid cisterns.
 Enhancing dural based mass.
 Intradural extramedullary enhancing nodules on spinal MR
CHRONIC MENIGITIS
IMAGING FINDINGS
MRI
 Hydrocephalus:
 may the first
disease.
and only sign of leptomeningeal spread of
Axial T2 image shows hydrocephalus
with transependymal seepage of CSF.
CHRONIC MENIGITIS
IMAGING FINDINGS
MRI
 FLAIR images may depict evidence of leptomeningeal
lesion:
 An hyperintensity in the subarachnoid space resulting from
elevations in CSF cellularity and protein concentrations.)
FLAIR MR image shows extensive
sulcal hyperintensity.
CHRONIC MENIGITIS
 Imaging signs of leptomeningeal damage
are common regardless of the etiology
 Etiologic diagnosis is guided by:
 The clinical and biological context
 A particular distribution of leptomeningeal
damage
 Other brain locations non leptomeningeal
 Other non cerebral locations
Case n° 1
•
•
•
40 year old woman.
Antecedent of operated
breast cancer.
Consulting for seizures.
Axial without and with contrast CT images showing
widespread leptomeningeal enhancement involving surfaces of
cerebellum hemispheres in connection with metastatic origin.
Subarachnoid enhancement over
cerebral surfaces and contrast
gain in mass of the falx cerbri.
Case n° 2
 62 year old men.
 Antecedent of lung
cancer.
 Convulsions.
Axial enhanced CT images
showing diffuse linear and
nodular meningeal
enhancement.
Metastatic leptomeningitis
 Leptomeningeal carcinoma, is a form of metastatic cancer
that has spread to the lining of the brain and spinal cord.
 The most meningeal metastasing cancers: leukemia,
lymphoma, melanoma, breast, lung and gastrointestinal
cancers.
 Carcinomas of unknown primary constitute 1% to 7%
of all cases of leptomenigeal carcinoma.
 Diagnosis:
Detection
cerebrospinal fluid.
of
malignant
cells
in
the
Metastatic leptomeningitis
IMAGING FINDINGS
MRI
 Non specific
 Leptomeninges enhancement, Cranial nerve
enhancement, enhancing dural based mass.
 The leptomeninges of spinal cord damage is
most frequently seen in the cauda equina.
Case n° 3
 33 years old women
 Headaches
 Polyuro-polydipsia
syndrome
Axial, sagittal and
coronal Contrastenhanced T1-weighted
MR images:
Diffuse and nodular
leptomeninges thickening
and enhancement.
Reached basilar and
frontal leptomeninges.
Hypothalamus and
pituitary lesions
.
Contrast-enhanced sagittal T1-weighted image in the same
patient shows enhancing lesion in spinal cord and an abnormal
linear leptomeningeal enhancement
Neurosarcoidosis
 Sarcoidosis is an idiopathic systemic disease.
 Formation of non-caseating granuloma affecting all parts of the
body: lungs and lymph nodes+++.
 Women affected more than men.
 Third and fourth decades.

In the head and spin:
 The leptomeninges damage +++is specially observed in the
base of the brain+++
 May involve bone, dura mater, nerve roots and parenchyma,
individually or in combination.
Neurosarcoidosis
 Symptoms depend on the site of granuloma involvement, non
specific; we note specially:
nerve paralysis, vision loss, paresis, paresthesia, diplopia,
and dysarthria…
 Facial
 Diabetes insipidus (involvement of the hypothalamus or
pituitary gland).
 Hydocephalus is rare.
Neurosarcoidosis
IMAGING FINDINGS
 Leptomeningeal involvement :
 The most typical manifestation of central nervous system
sarcoidosis (40%)
 Diffuse or nodular
 Basilar meninges +++: suggestive of diagnosis
(cisterns around the base of the brain)
 Differential diagnosis: tuberculosis; lymphoma
Neurosarcoidosis
IMAGING FINDINGS
 May involve:
 Parenchyma of the brain and spine, nerve roots, dura
mater, hypothalamus and pituitary.
Case n°4
 26 year old man
 Headache, polyuro-
polydipsia syndrome,
visual disturbances
Coronal CT (A) and MRI (B) after injection of contrast through the facial mass. (A)Tissular lesion
developed at the upper wall of the maxillary sinus with intraorbital extension.
(B)Thickening of the frontal meninges enhanced with contrast.
He also has a marked pituitary infiltration and a lytic lesion of the skull base.
Bronchoalveolar lavage: positif CD1a .
Langerhans Cell hitiocystosis
 Langerhans Cell hitiocystosis (LCH) is a rare
disease
 Systemic Idiopathic granulomatous process,
composed of a particular histiocytic contingent:
the Langerhans cell .
 More common in children.
 Sites of involvement: Bone :90% (skull+++), Lung,
lymph nodes, Skin, Soft tissue.
Langerhans Cell hitiocystosis
 Sites of involvement: Bone :90% (skull+++), Lung, lymph
nodes, Skin, Soft tissue.
 The neuroimaging of LCH is, in most of the cases non
specific and it can vary depending to the location,
specially on MRI.
 The most common CNS locations are:

Hypothalamus and pituitary axis (diabetes insipidus)

Cerebellum
 Meninges, parenchyma, pineal gland, choroid plexus are
rarely included.
Case n° 5
•
•
•
41 year old woman
Chronic headache, polyuro-polydipsia syndrome
Anosmia, decrease in visual acuity.
Sagittal and Frontal T2-weighted images: Duremerien thickening spreading
form the frontal base of the crane up to the anterior fossa, next to the
clivus in a frank hyposignal T2.
Case n° 5
Sagittal and coronal contrastenhanced T1-weighted :
Peripheral enhancement of the
Dura thickening.
Idiopathic Hypertrophic
Pachymeningitis
 Hypertrophic
pachymeningitis is a clinical disorder
characterized by localized or diffuse enlargement of the
dura mater. The underlying and neighboring leptomeninges
(pia mater, arachnoidea mater) become opaque and
thickened as well.
 If an exhaustive work-up fails to identify the cause of
the meningeal changes, a diagnosis of IHP is made.
 Rare disorder, affecting men more often than women
 Peak prevalence occurring in the 6th decade of life.
Idiopathic Hypertrophic
Pachymeningitis
 Most common manifestations: cerebellar ataxia, seizures,
and neuroophthalmic symptoms (visual field loss, complete
blindness, optic neuropathy).
 Chronic headaches resembling chronic migraines: focal
meningeal irritation or possibly to localized arachnoiditis.
 Cranial nerve palsies (cranial nerves IV–VIII) attributed
to compression of cranial nerves at the skull base by
enlarged dura mater.
 Increased intracranial pressure with papill edema.
Idiopathic Hypertrophic
Pachymeningitis
Imaging Findings
 Smooth or nodular dural thickening isointense or
hypointense with both T1- and T2-weighted
sequences (fibrosis and necrosis of the dura mater).
 Avid enhancement after intravenous administration
of contrast material.
 Peripheral hyperintensity can be seen on T2-weighted
images active inflammation or increased vascularity
of the dura mater and underlying parenchyma).
Idiopathic Hypertrophic
Pachymeningitis
Complications
 Venous sinus thrombosis
 Obstructive hydrocephalus
 Cerebral edema
Associated syndromes:
o Tolosa-Hunt syndrome (granulomatous inflammation of the wall of
o
o
o
o
o
o
the cavernous sinus resulting in painful ophthalmoplegia).
Cranial polyneuritis (especially with involvement of the 7th–12th
cranial nerves),
Multifocal fibrosclerosis (chronic granulomatous inflammation
consisting of retroperitoneal fibrosis).
Riedel thyroiditis.
Sclerosing cholangitis.
Pseudotumor oculi
Diabetes insipidus.
 The contribution of slice imaging in the chronic
meningitis diagnosis process is considerable
 Allowing often a confirmation of the positive
diagnosis, and an etiological orientation.
 The MRI is the examination of choice, however the
CT scan could be sufficient in some particular
clinical contexts.