Empyèmes sous-duraux de l’enfant : stratégie thérapeutique

Parafalcine subdural empyema: The unresolved controversy over the need for surgical treatment

Background:

Parafalcine subdural empyema (SDE) is a rare entity consisting of pus accumulating below the longitudinal sinus, between the falx cerebri and the arachnoid layer covering the medial surface of the cerebral hemisphere. Its treatment strategy is controversial, but most clinicians have the general belief that appropriate treatment consists of prompt surgery combined with long-term antibiotic therapy. Nevertheless, six reports published in the 1980s provided evidence that antibiotic therapy alone is a safe and suitable option. The treatment strategies and outcomes of the 31 well-described cases previously published, in addition to our own, are discussed.

Case Description:

We report a 21-year-old female with a right-side parafalcine SDE who presented with fever, headache, generalized tonic-clonic seizures, and contralateral hemiparesis 3 weeks after undergoing sinonasal surgery. Despite clinical symptoms almost entirely abating after starting treatment with broad-spectrum antibiotics, magnetic resonance imaging performed during the 2^nd and 3^rd weeks showed progressive enlargement of the interhemispheric collection (from 4 cm³ to 30 cm³). We reflect on the treatment strategy chosen for this patient, who experienced a total recovery.

Conclusion:

A nonsurgical strategy for parafalcine SDE might be contemplated for patients with a good clinical condition and no major midline shift on neuroradiological studies, given their usual indolent course and the relative difficulty in reaching the interhemispheric fissure. Conversely, surgery should be contemplated when the collection significantly enlarges despite antibiotic therapy. When surgical drainage is added to antibiotics, broad- range 16S ribosomal DNA polymerase chain reaction of the empyema is recommended to identify the causative organism as pus cultures are usually sterile.

Hollow screws: a diagnostic tool for intracranial empyema

BACKGROUND

Subdural (SDE) and epidural empyema (EDE) are life-threatening intracranial infections. They require immediate diagnosis and treatment. However, in some cases, magnet resonance imaging (MRI) is not able to contribute to diagnosis; therefore, surgical exploration is indicated. Hollow screws used for decompression of chronic subdural haematoma (cSDH) are valuable tools for minimally invasive biopsy in awake patients when SDE and EDE are suspected.

METHODS

Between 2006 and 2010, eight patients in our department underwent biopsy of a suspected SDE or EDE using hollow screws. In these cases, MRI or computed tomography (CT) were not able to provide sufficient diagnostic security to indicate primary craniotomy. Diagnostic and therapeutic efficacy was evaluated on preoperative and postoperative imaging. The focus was on qualitative parameters, such as contrast enhancement or impaired diffusion on diffusion-weighted images (DWI).

RESULTS

The application of the hollow screw under local anaesthesia permitted an exact diagnosis in all cases. In one case, the suspected diagnosis of cSDH could be refuted by diagnostic puncture. In four cases of uncertain diagnosis, the application of the hollow screw revealed a cSDH. Seven of eight patients previously received neurosurgical treatment; three of those cases were SDE or EDE and four were cSDH. Cases of SDE and EDE needed further craniotomy after diagnostic puncture, whereas patients with cSDH were sufficiently treated by hollow screws.

CONCLUSIONS

Given their comparably wide diameter, hollow screws allow a sufficient sample size and, therefore, lead to precise diagnosis of SDE and EDE without significant operative risks or strains for the patient.

Complicated subdural empyema in an adolescent

Little is known regarding typical neuropsychological outcomes of intracranial empyema, a rare complication of sinusitis marked by accumulation of purulent material adjacent to the brain. A 15-year-old, right-handed male presented with a 3-day history of congestion, lethargy, fever, headache, dizziness, unequal pupil dilation, and right-sided facial droop. Computed tomography revealed right-sided subdural empyema causing subfalcine, central, foraminal uncal, and tonsillar herniation. Postoperative inpatient neuropsychological consultation was requested 17 days postsurgery due to language deficits. Through comparison of neuropsychological and radiological findings, this case of subdural empyema demonstrates the anatomical and functional impact of mass effect on the brainstem and the vasculature of the contralateral hemisphere. Deficits were observed in expressive language, processing speed, and fine motor functioning, all of which lingered 6 months postacute. This case study reviews the pathophysiology of subdural empyema and illustrates its potential neuropsychological impact to inform clinicians encountering this rare condition.

Two surgical methods used in 90 patients with intracranial subdural empyema

We studied the efficacy of two surgical methods used for the treatment of intracranial subdural empyema (ISDE) at our centre. A cross-sectional study (1999-2005) of 90 patients with non-traumatic supratentorial ISDE revealed that the two surgical methods used for empyema removal were burr hole/s and drainage (50 patients, 55.6%) and a cranial bone opening procedure (CBOP) (40 patients, 44.4%). Patients in the CBOP group had a better result in terms of clinical improvement (chi-squared analysis, p=0.006) and clearance of empyema on brain CT scan (chi-squared analysis, p<0.001). Reoperation was more frequent among patients who had undergone burr hole surgery (multiple logistic regression, p<0.001). The outcome and morbidity of ISDE survivors were not related to the surgical method used (p>0.05). The only factor that significantly affected the morbidity of ISDE was level of consciousness at the time of surgery (multiple logistic regression, p<0.001). We conclude that CBOP and evacuation of the empyema is a better surgical method for ISDE than burr hole/s and drainage. Wide cranial opening and empyema evacuation improves neurological status, gives better clearance of the empyema and reduces the need for reoperation. Level of consciousness at the time of presentation is a predictor of the morbidity of ISDE. Thus, aggressive surgical treatment should occur as early as possible, before the patient deteriorates.