EEG and pathologic findings in patients undergoing brain biopsy for suspected encephalitis

doi:10.1016/0013-4694(90)90060-W

Electroencephalography and Clinical Neurophysiology

Volume 76, Issue 1, July 1990, Pages 86-89

https://doi.org/10.1016/0013-4694(90)90060-W Get rights and content

Abstract

Previous studies have suggested that EEG may be helpful in the diagnosis of herpes encephalitis (HE). To further define the value of EEG in an acutely ill, febrile, encephalopathic patient suspected as having encephalitis, we reviewed initial preoperative EEGs with the results of cerebral biopsies in 24 consecutive patients suspected of having encephalitis. Statistical analysis demonstrated that EEG patterns have only limited association with biopsy results. Since diseases which mimic encephalitis may also generate identical EEG changes, this is not an unexpected finding.

EEG is useful in the evaluation and management of patients with encephalitis. However, the absence of specific wave forms or focal EEG abnormalities in the proper clinical setting should not deter consideration of HE or delay treatment.

References (18)

P.C. Gupta et al.
Periodic complexes in herpes simplex encephalitis. A clinical and experimental study
Electroenceph. clin. Neurophysiol.
(1973)
L.S. Illis et al.
The electroencephalogram in herpes encephalitis
Lancet
(1972)
M. Rappel
Treatment of herpesvirus encephalitis
Lancet
(1971)
A. Upton et al.
Electroencephalograpy in diagnosis of herpes-simplex encephalitis
Lancet
(1970)
J.H. Adams et al.
Acute necrotizing encephalitis: a problem in diagnosis
J. Neurol. Neurosurg. Psychiat.
(1967)
M. Barza et al.
The decision to biopsy, treat or wait in suspected herpes encephalitis
Ann. Intern. Med.
(1980)
L.R. Caplan
Brain biopsy in herpes encephalitis
New Engl. J. Med.
(1980)
L.T. Ch'ien et al.
Characteristic early electroencephalographic changes in herpes simplex encephalitis
Arch. Neurol.
(1977)
D.A. Drachman et al.
Herpes simplex and acute inclusion body encephalitis
Arch. Neurol.
(1962)

There are more references available in the full text version of this article.

Cited by (27)

Herpes Simplex Type 2 Encephalitis after Craniotomy: Case Report and Literature Review
2016, World Neurosurgery
Citation Excerpt :
MRI demonstrates typical changes that include hyperintense signals on T2 and fluid attenuation inversion recovery sequences, most commonly in the cortex of the temporal lobes.1,15 In addition, electroencephalographic studies may show typical encephalitic changes, such as slowing of background activity with periodic localized delta discharges, mainly involving the temporal lobes.1,16 Stereotactic brain biopsy is an optional diagnostic modality for suspected cases of HSE, which are PCR negative and do not improve with empirical acyclovir treatment.
Herpes simplex encephalitis (HSE) after neurosurgical procedures is extremely uncommon, and the few published case reports mainly described herpes simplex virus type 1 (HSV-1) as being culpable. We present a rare case of HSV-2 encephalitis after craniotomy and describe its pathophysiology and optimal management.
A 70-year-old woman underwent an elective resection of a recurrent left sphenoid wing meningioma and clipping of a left middle cerebral artery aneurysm, the latter having been found incidentally. She returned to our department with clinical findings suggestive of meningitis 12 days after the operation. Her lack of response to empiric antibiotic treatment, taken together with the lymphocyte-predominant initial cerebrospinal fluid obtained by lumbar puncture and the electroencephalographic indications of encephalopathy, led to the suspicion of a diagnosis of HSE, which was later confirmed by a polymerase chain reaction test positive for HSV-2. The patient was then successfully treated with intravenous acyclovir for 2 weeks followed by another week of oral acyclovir treatment before being discharged.
The present case stresses the importance of recognizing the relatively rare entity of HSE after craniotomy. Timely correct diagnosis will expedite the initiation of appropriate treatment.
Management of suspected viral encephalitis in children - Association of British Neurologists and British Paediatric Allergy, Immunology and Infection Group National Guidelines
2012, Journal of Infection
Citation Excerpt :
In HSV encephalitis EEG abnormalities include non-specific diffuse high amplitude slow waves, sometimes with temporal lobe spike-and-wave activity and periodic lateralised epileptiform discharges (PLEDs).158 Even though PLEDs occur in many cases of HSV encephalitis33 and were at one stage considered pathognomonic, they are now recognised in other viral encephalitides36 and non-infectious conditions, and it is accepted that there are no EEG changes diagnostic of HSV encephalitis.159 For example when PLEDS are identified in patients with a sub-acute or chronic encephalopathy this would be suggestive of SSPE.77,160
In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to-day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines.
In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.
Management of suspected viral encephalitis in adults - Association of British Neurologists and British Infection Association National Guidelines
2012, Journal of Infection
Citation Excerpt :
In HSV encephalitis, EEG abnormalities include non-specific diffuse high amplitude slow waves, sometimes with temporal lobe spike-and-wave activity and periodic lateralized epileptiform discharges (PLEDs). Even though PLEDs occur in many cases of HSV encephalitis and were at one stage considered pathognomonic, they also occur in other viral encephalitides and non-infectious conditions, and it is accepted that there are no EEG changes diagnostic of HSV encephalitis.7,89–93 For many years brain biopsy was the preferred method for diagnosing HSV encephalitis, because clinically many conditions mimic HSV encephalitis, the chances of culturing the virus from the CSF were low, and a biopsy was one of the few reliable means of making the diagnosis, although its sensitivity was low.
In the 1980s the outcome of patients with herpes simplex encephalitis was shown to be dramatically improved with aciclovir treatment. Delays in starting treatment, particularly beyond 48 h after hospital admission, are associated with a worse prognosis. Several comprehensive reviews of the investigation and management of encephalitis have been published. However, their impact on day-to day clinical practice appears to be limited. The emergency management of meningitis in children and adults was revolutionised by the introduction of a simple algorithm as part of management guidelines.
In February 2008 a group of clinicians met in Liverpool to begin the development process for clinical care guidelines based around a similar simple algorithm, supported by an evidence base, whose implementation is hoped would improve the management of patients with suspected encephalitis.
The spectrum of herpes simplex encephalitis in children
2008, European Journal of Paediatric Neurology
Citation Excerpt :
Indeed, the initial EEG is abnormal and/or localising in 65–100% of patients with HSE.6,10,11,13,16,30 It is recognised that there is no pathognomonic EEG pattern in HSE.58–61 Indeed, focal or diffuse EEG slowing, focal sharp waves or spikes have been described in patients with HSE (children and adults).58–61
Clinical and basic science research carried out in recent years into herpes simplex encephalitis (HSE) have shown that the concept of a “classical” picture of HSE in children is now outdated and that our current knowledge of the disease is probably only the tip of an iceberg. Indeed, increasing evidence supports the existence of a wider range of pathophysiological mechanisms, clinical presentations and disease progressions in paediatric HSE. This paper reviews the clinical, biological and radiological data available and redefines the spectrum of HSE in children. Full understanding of the condition should improve the management of suspected cases and decrease the morbidity and the mortality associated with this disease.
Is EEG useful in assessing patients with acute encephalitis treated with acyclovir?
1998, Electroencephalography and Clinical Neurophysiology
EEG has been used widely in diagnosing encephalitis, as it demonstrates rather typical abnormalities, especially in herpes simplex virus encephalitis (HSVE). We analysed 204 EEG recordings from 98 consecutive acyclovir-treated patients with acute encephalitis between 1984 and 1994. Periodic complexes (PC) in the acute phase predicted poor outcome (Kendall tau 0.40, P<0.001). However, unlike in many other diseases, e.g. stroke and intracerebral haemorrhage, the diffuse slowing of the background activity at acute phase did not predict outcome (Kendall tau −0.6, P=0.35). At follow-up, the emergence of diffuse slow background activity was significantly associated with a less favourable outcome (Kendall tau 0.33, P=0.0016). Among clinical variables, only epileptic seizures early during the course of the disease correlated significantly with outcome. EEG does have value as a prognostic indicator in acute encephalitides, but it seems that diffuse slowing of background activity or irritative features acutely are not as important as previously thought, based on the experiences of the pre-acyclovir era.
Neuromagnetic sequelae of herpes simplex encephalitis
1998, Electroencephalography and Clinical Neurophysiology
Spontaneous cortical activity and auditory evoked responses were recorded with a whole-scalp 122-channel neuromagnetometer from 4 patients after left-hemisphere dominant herpes simplex encephalitis and associated memory disorders. Spontaneous activity of one patient contained periodic sharp waves over the left hemisphere; the background activity was attenuated. The sources of periodic sharp waves clustered close to the sources of auditory evoked fields in the temporal lobe. In controls, dominant rhythmic activity over the parieto-occipital region had spectral maximum at 10.6±0.6 Hz; in patients the dominant rhythmic activity peaked at 8.6±1.8 Hz. The suppression of the parieto-occipital activity in eyes-open versus eyes-closed condition was smaller in patients than in controls. The patients' peak spectral frequency was correlated with neuropsychological tests reflecting deficient attentional capacity. The observed changes probably reflect decreased subcortical control of the cortical electric activity.

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^☆: Presented in part at the 41st Annual Meeting of the American Academy of Neurology, April 1989, Chicago, IL, U.S.A.

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Short communicationEEG and pathologic findings in patients undergoing brain biopsy for suspected encephalitis☆

Abstract

Electroenceph. clin. Neurophysiol.

Lancet

Lancet

Lancet

Acute necrotizing encephalitis: a problem in diagnosis

J. Neurol. Neurosurg. Psychiat.

The decision to biopsy, treat or wait in suspected herpes encephalitis

Ann. Intern. Med.

Brain biopsy in herpes encephalitis

New Engl. J. Med.

Characteristic early electroencephalographic changes in herpes simplex encephalitis

Arch. Neurol.

Herpes simplex and acute inclusion body encephalitis

Arch. Neurol.

Short communication
EEG and pathologic findings in patients undergoing brain biopsy for suspected encephalitis☆