IMAGING CONTRIBUTION IN CEREBRAL EMPYEMA:ABOUT CASE 3.

E. GAMY; J. MAHLAOU., S. SEMLALI; S.CHAOUIR, T. AMIL; A.HANINE. M.MAHI, S. AKJOUJ

Medical Imaging. Military Instruction Hospital Mohamed V Rabat.

NR1

Introduction

Brain empyema = rare since the use of antibiotic

Often secondary to a sinus infection.

Neurosurgical emergency.

The modern imaging techniques, especially spiral CT and MRI

have significantly reduced mortality by allowing earlier

diagnosis.

We report 3 cases of extradural empyema complicating

sinusitis.

Materials and methods

Case 1: Patient, 17 years old , suffering from sinusitis and shuffling with

a sudden disturbance of the functions above type of confusion.

We performed emergency brain scans

The early establishment of a regimen including anti-coagulants

and anti-infective therapy were done

A rapid clinical improvement without neurological squeal were

shown

Case 2: Patient, 19 years old , with impaired consciousness feverCase 3: Child 15 years , well vaccinated, ATCD: RAS Medical history: since 2 months, vomiting, impaired general

condition and a fever of 40 ° C. No neurological disorders. Laboratory tests: Leucocytosis to 15,000 per mm3,

                               CRP 200 mg / l.                               The CSF analysis was normal.Blood cultures: Sreptocoque sp.IDR and HIV: normal.

Results

A BRAIN SCAN performed in emergency showed a:

Right frontal extra axial collection, heterogeneous with a spontaneously

hyperdensity posterior related bleeding.

There is also another collection in small controlateral frontal

(extradural).

In bone window: through the paranasal sinuses show a left frontal

sinusitis and ethmidale.

The additional MRI found both frontal extradural collections,

although limited medially by the dura mater in hypo T2 signal.

The subsequent hemorrhagic component is hyperintense T1

and T2 signal hypothesis.

The peripheral contrast enhancement is evident and the mass

effect on midline structures.

The MRI also found the heterogeneous aspect of superior

sagittal sinus.

The MR angiography confirmed the cerebral venous thrombosis .

The patient is put on triple antibiotic therapy and underwent

emergency surgery. We evacuated 200 ml of pus mixed with

blood and found a right frontal osteitis.

Also we realized drainage of the maxillary sinuses.

  Control is satisfactory postoperative

Figure 1: Axial CT scan after injection of the PC shows the existence of a left frontal sinus with lysis of the posterior wall of the latter (a), two collections of extra-cerebral, frontal hypodense, biconvex, associated with contrast enhancement and a thickening of the dura mater from them. This is suggestive of extra-dural empyema (b and c). Within the superior sagittal sinus, near the empyema, there hypodensity (arrowheads Fig 1b) visible in several sections (Fig. 1d) showing the existence of cerebral thrombophlebitis

AB

C D

Fig 2 a and b: Axial CT scan of the facial bone and brain window in (c): ethmoid and left frontal sinusitis associated with extradural empyema

A B C

Fig 3: MRI axial section T1-weighted (a), T1 gado (b) and 3D AMR venous (c)

A

B

C

Fig 4: CT scan without contrast in axial section of the PC.Fig 5: AMR vein: normalization of the signal of superior sagittal sinus..

DISCUSSION

Empyema is a collection tank perished brain, usually secondary to infection

neighborhood especially in contact aeric face cavities . It grows on the

convexities in 80% of cases, particularly the frontal lobes .

It can be inter hemispheric in 12% of cases .

The subdural empyema (ESD) represents 13-20% of all intracranial

suppurations, against 20 to 33% in the extradural empyema (EED) .

Empyema secondary to sinus infection symptoms are usually noisy with fast

installation .

Febrile headache, usually frontal, are prominent and visible signs of intracranial

hypertension and disorders of consciousness. The seizures are not uncommon .

Conversely, the ESD is soon threatened, because of a faster increase in

volume, as well as retrograde propagation through cortical veins

thrombophlebitis of explaining the parenchymal lesions.

The most frequent germs are anaerobic streptococci .

These collections are more visible in MRI than CT.

The protein content differentiates their signal from that of the LCR and

identifies them.

Compared to the brain collection appears hypointense signal on T1-

weighted sequences and hyperintense on T2-weighted images.

Gadolinium injection produces a contrast enhancement of the Dura and

leptomeninges and therefore shows a border of hyper signal between the

collection and parenchyma on the one hand, between the collection and

vault on the other.

Generally, there are signal changes parenchyma neighborhood and

sometimes a seeding of the brain with onset of an abscess

The EED is characterized by the image of the dura mater, T2 hypointense

signal, enhanced by gadolinium injection, and the collection between the

brain and by the topography and possible detachment of the venous sinuses.

Ultrasound in infants, according to the topography, can show a collection

perished brain and heterogeneous echogenic or transonic sometimes with

an echogenic inner boundary .

In CT, the existence of contrast uptake in the periphery of the collection is

characteristic

Differential diagnosis

May arise with: A chronic subdural hematoma in post traumatic stress disorder (hypo signal in

T1 and T2) or a hygroma (hypo T1 signal and hyperintense T2). While on the

scanner all the lesions are hypo dense [6].

Septic thrombosis of intracranial venous sinus is also secondary to infection

neighborhood. Their mortality is heavy, close 50% [10]. The MRI demonstrates

thrombosis, venous infarction and meningeal reactions accompanying [10].

The superior sagittal sinus thrombosis is the classical representation the most

telling, as is the case with our patient. When the clinic is raised (convulsion and

/ or increase of impaired consciousness), replaces the MRI scanner and, mostly,

to angiography [1].

It allows using the sequences of angio-MRI in phase contrast to detect direct

signs of venous thrombosis.

CONCLUSION

The sequence of sinusitis complications, empyema - thrombophlebitis is

classic.

At the initial stage of empyema diagnosis can be difficult on CT.

MRI more sensitive and specific, allows early diagnosis, therapeutic

monitoring post and helps improve the prognosis