Decompressive craniectomy for encephalitis with brain herniation: case report and review of the literature

BACKGROUND

Decompressive craniectomy (DC) has been sporadically used in cases of infectious encephalitis with brain herniation. Like for other indications of DC, evidence is lacking regarding the beneficial or detrimental effects for this pathology.

METHODS

We reviewed all the cases of viral and bacterial encephalitis treated with decompressive craniectomy reported in the literature. We also present one case from our institution. These data were analyzed to determine the relation between clinical and epidemiological variables and outcome in surgically treated patients.

RESULTS

Of 48 patients, 39 (81.25 %) had a favorable functional recovery and 9 (18.75 %) had a negative course. Only two patients (4 %) died after surgical treatment. A statistically significant association was found between diagnosis (viral and bacterial encephalitis) and outcome (GOS) in surgically treated patients. Viral encephalitis, usually caused by herpes simplex virus (HSV), has a more favorable outcome (92.3 % with GOS 4 or 5) than bacterial encephalitis (56.2 % with GOS 4 or 5).

CONCLUSIONS

Based on this literature review, we consider that, due to the specific characteristics of infectious encephalitis, especially in case of viral infection, decompressive craniectomy is probably an effective treatment when brain stem compression threatens the course of the disease. In patients with viral encephalitis, better prognosis can be expected when surgical decompression is used than when only medical treatment is provided.

Craniectomy in severe, life-threatening encephalitis: a report on outcome and long-term prognosis of four cases

OBJECTIVE

To report the feasibility of craniectomy with duraplasty in four patients with life-threatening encephalitis and, in particular, their long-term outcome.

DESIGN

Report of four cases, analysis of the acute clinical course and neurological long-term sequelae.

RESULTS

Generous craniectomy with duraplasty was performed in four patients with life-threatening encephalitis leading to decortication and decerebration. This treatment approach reduced intracranial pressure. The long-term sequelae (1.5-8 years after craniectomy) confirmed its appropriateness, having led to full neurological (cerebral) function, resocialization, and reintegration into their professional life in all four patients.

CONCLUSION

Craniectomy with dural augmentation is a treatment approach in cases of severe space-occupying encephalitis, not only saving the patient's life but also leading to favorable long-term outcome.

Clinical findings, imaging characteristics and outcome in catastrophic post-encephalitic epilepsy

OBJECTIVES

The aim of this study is to characterize the clinical features and prognostic factors for intractable, post-encephalitic epilepsy.

METHODS

We studied retrospectively 42 patients (26 men) evaluated between 1982 and 1999. MRI, neuropsychological findings, interictal and ictal scalp EEG were reviewed for all patients. Fifteen patients had additional stereo EEG (SEEG) studies.

RESULTS

The mean age at encephalitis was 17 years (SD = 15.5); etiology was identified in 18 patients. During the acute illness, 79% had status epilepticus (SE) or recurrent seizures and 76% were in coma; mean Glasgow outcome scale (GOS) was 3.6 (SD = 0.8). The mean latency to seizure onset was 0.8 years (SD = 1.9). The majority (72%) presented with complex partial seizures with or without secondary generalization. According to interictal epileptiform findings and the predominant seizure onset pattern as found on scalp EEG, patients were unilateral temporal (UTLE) = 8, bilateral temporal (BTLE) = 12, and extratemporal/multifocal or generalized (ETMFE) = 22 patients. MRI atrophy and/or signal changes were unilateral temporal in 7 (18%), bilateral temporal in 5 (13%), multilobar/diffuse in 20 (51%), and absent in 7 (18%). ANOVA revealed significant differences in mean GOS between UTLE versus BTLE and ETMFE (4.7 versus 3.2 versus 3.6; p < 0.0001), but not in age at encephalitis. Latency to the first unprovoked seizure was shorter in patients with ETMFE compared to UTLE and BTLE (p < 0.01). Surgery was performed in 24 patients. The best outcome was obtained in UTLE (7/8 class I and II). In the others, outcome was poor in the majority (13/16 class III and IV).

CONCLUSION

There is a small subgroup of patients with postencephalitic UTLE for whom the outcome is favorable. The majority of our patients had multifocal seizure onset with BTLE and ETMFE, and poor outcome after surgical treatment.

Operative treatment of tentorial herniation in herpes encephalitis

Herpes simplex virus is the most common cause of acute viral encephalitis in children. Due to the variety of possible clinical manifestations the diagnosis is often overlooked in the early stages of the disease. Anti-viral therapy with acyclovir should be started whenever HSE is suspected. When there is further deterioration under virostatic therapy, a brain biopsy should be performed to verify the diagnosis. But even when the adequate medical therapy is established, massive brain edema and brain shift resulting in tentorial herniation can develop. Up to now the reported mortality of these patients is still around 30%. Here we report on a child with severe necrotizing herpes simplex encephalitis who developed severe tentorial herniation due to a right-sided mass lesion. The patient's status markedly improved after decompressive anterior temporal lobe resection. To our knowledge a similar case has not yet been reported in the literature. We suggest that anterior temporal lobe resection and decompressive craniotomy is of benefit in selected cases with tentorial herniation because both decompression and reduction of infectious material can be achieved.

Intractable seizure disorder associated with chronic herpes infection. HSV1 detection in tissue by the polymerase chain reaction

We describe the pathological findings and report the detection of herpes simplex virus 1 (HSV1) in the brain in three patients who presented with intractable seizures. All three patients had a previous history of HSV1 encephalitis and went on to develop a medically refractory seizure disorder necessitating surgical intervention. HSV1 encephalitis was clinically diagnosed and treated at 6 months, 3 years, and 7 months and surgical resection was done at 8.5 years, 6 years, and 3 years, in cases 1, 2 and 3, respectively. Pathological examination revealed chronic encephalitis in all three cases, with microglial nodules, intraparenchymal, perivascular and meningeal lymphocytic infiltrates, and gliosis. While immunohistochemical and ultrastructural studies were negative for viral pathogens, polymerase chain reaction (PCR) analysis revealed HSV1 genome. These cases represent examples of chronic herpes encephalitis and seizure disorder with presence of viral genome in the brain long after the initial episode of treated herpes encephalitis.

Pediatric Rasmussen encephalitis: social communication, language, PET and pathology before and after hemispherectomy

This prospective case study examined social communication (i.e., formal thought disorder, cohesion), language, positron emission tomography glucose utilization, and neuropathology in four children with Rasmussen encephalitis who achieved seizure control following right hemispherectomy. Prior to hemispherectomy, all four children had illogical thinking, loose associations, cohesive deficits, and impaired performance on formal language tests. Their postoperative improvement in social communication and language appeared to be related to age of onset, duration of illness, and postsurgical reversibility of hypometabolism in the nonresected prefrontal cortex. These changes were not associated with increase in IQ scores. The variability in the type and extent of pathologic change across subjects reflected the severity and duration of the illness. The study's findings imply that early surgical intervention might have mitigated certain aspects of the social communication and linguistic deficits found in these children.

[A case of herpes simplex encephalitis requiring surgical management]

The authors report about surgical treatment of herpes simplex encephalitis, although conservative management of this disease is the method of choice in the first place. They draw a lesson from this case that certain cases of large space occupying lesions of infectious origin leading to brain stem compression may require surgical management, even if they customary treatment is conservative.

Pathology of chronic herpes infection associated with seizure disorder: a report of two cases with tissue detection of herpes simplex virus 1 by the polymerase chain reaction

Although uncommon, the association of chronic encephalitis with epilepsy is well recognized. While a viral etiology has been suspected based on the morphology, to date no virus has been successfully cultured from the brain in patients with Rasmussen's encephalitis. We describe the pathologic findings and report the detection of herpes simplex virus 1 (HSV1) in the brain in two patients who presented primarily with intractable seizures. In the first patient, an intrauterine infection was suspected as the underlying basis for the seizure disorder and the extensive cerebral calcification and gliosis. The second patient (with presumed HSV1 encephalitis at age 7 months) underwent a temporal lobectomy for medically refractory seizures at the age of 3 years and pathologic examination revealed a chronic encephalitis. While immunohistochemical, ultrastructural, and culture studies were negative for viral pathogens, molecular analysis by the polymerase chain reaction (PCR) revealed HSV1 DNA sequences in both cases. Thus our cases represent two examples of chronic encephalitis associated with a seizure disorder, where a definitive viral etiology was documented by PCR.