Evdoshenko
20.05.2007, 18:15
Peter Höllinger Lukas MatterMatthias Sturzenegger
Normal MRI findings in
herpes simplex virus
encephalitis
Received: 21 December 1999
Received in revised form: 13 April 2000
Accepted: 2 May 2000
Sirs: Signs and symptoms of herpes simplex virus encephalitis (HSVE)
are manifold and do not allow a firm diagnosis based on clinical findings
alone [10]. Diagnosis remains a challenge despite several refined methods
of investigation, including magnetic resonance imaging (MRI), electroencephalography (EEG), and analysis of cerebrospinal fluid (CSF) with
polymerase chain reaction (PCR) and antibody titers. The former gold standard of diagnosis was brain biopsy, which nowadays has largely been replaced by PCR [6]. Due to the ease of performance and widespread availability of the method, there is agreement that PCR analyses of CSF specimens will redefine the spectrum of HSV infections of the CNS [2, 5]. Cerebral MRI is believed to be the most sensitive neuroimaging method for the diagnosis of HSVE [1, 8, 9]. Definite diagnosis of HSVE relies on
a synopsis of clinical findings and additional investigations, which all have
limited sensitivity and specificity [6,10]. Establishing a firm diagnosis remains
an important issue, since the effective treatment of HSVE with
acyclovir is associated with remarkable costs [3]. On the other hand,
prompt initiation of treatment is essential for improvement in outcome
[10]. A 21-year-old farmer suffered
from bifrontal headache with slightly elevated body temperature and
malaise for approximately 2weeks.
One day before admission involuntary
jerking of the right cheek occurred
for about 30 s. The following
day he suddenly noticed myoclonic
jerks of his right arm with rapid progression
to a generalized tonic-clonic
seizure of about 1 min duration. On
admission he was febrile (up to
39°C), with slight somnolence and a
motor hemisyndrome on the right
side with mixed aphasia. Results of
laboratory investigations are listed in
Table 1. CSF essentially showed
mononuclear pleocytosis and a positive
PCR for HSV–1. This is an
unnested PCR amplifying a 200-bplong
fragment of 5-regulatory DNA
sequences of the thymidine kinase
gene with an analytical sensitivity of
five DNA-copies (Institute for Medical
and Molecular Diagnostics,
Zurich). In addition, normal values in
blood were obtained for antibodies
against Mycoplasma pneumoniae,
varicella zoster virus, cytomegalovirus,
human immunodeficiency
virus 1, Treponema pallidum, Borrelia
burgdorferi, rubella, measles, and
mumps. MRI (1.5T, Siemens, Germany)
of the brain was performed on
the second hospital day and included
the following sequences: T1 axial
(TR 528/TE 12) and sagittal
(440/12), T2 axial (3176/98) and
coronal (3640/96), proton weighted
axial (3176/16), contrast-enhanced
T1 in three planes and axial fluidattenuated
inversion recovery images.
Careful examination of temporal
lobes, opercular regions, and the
cingulate gyri revealed no signal abnormalities.
EEG on that day showed
bifrontotemporal delta waves with
preponderance on the left side without
periodic complexes.
Normal MRI findings in
herpes simplex virus
encephalitis
Received: 21 December 1999
Received in revised form: 13 April 2000
Accepted: 2 May 2000
Sirs: Signs and symptoms of herpes simplex virus encephalitis (HSVE)
are manifold and do not allow a firm diagnosis based on clinical findings
alone [10]. Diagnosis remains a challenge despite several refined methods
of investigation, including magnetic resonance imaging (MRI), electroencephalography (EEG), and analysis of cerebrospinal fluid (CSF) with
polymerase chain reaction (PCR) and antibody titers. The former gold standard of diagnosis was brain biopsy, which nowadays has largely been replaced by PCR [6]. Due to the ease of performance and widespread availability of the method, there is agreement that PCR analyses of CSF specimens will redefine the spectrum of HSV infections of the CNS [2, 5]. Cerebral MRI is believed to be the most sensitive neuroimaging method for the diagnosis of HSVE [1, 8, 9]. Definite diagnosis of HSVE relies on
a synopsis of clinical findings and additional investigations, which all have
limited sensitivity and specificity [6,10]. Establishing a firm diagnosis remains
an important issue, since the effective treatment of HSVE with
acyclovir is associated with remarkable costs [3]. On the other hand,
prompt initiation of treatment is essential for improvement in outcome
[10]. A 21-year-old farmer suffered
from bifrontal headache with slightly elevated body temperature and
malaise for approximately 2weeks.
One day before admission involuntary
jerking of the right cheek occurred
for about 30 s. The following
day he suddenly noticed myoclonic
jerks of his right arm with rapid progression
to a generalized tonic-clonic
seizure of about 1 min duration. On
admission he was febrile (up to
39°C), with slight somnolence and a
motor hemisyndrome on the right
side with mixed aphasia. Results of
laboratory investigations are listed in
Table 1. CSF essentially showed
mononuclear pleocytosis and a positive
PCR for HSV–1. This is an
unnested PCR amplifying a 200-bplong
fragment of 5-regulatory DNA
sequences of the thymidine kinase
gene with an analytical sensitivity of
five DNA-copies (Institute for Medical
and Molecular Diagnostics,
Zurich). In addition, normal values in
blood were obtained for antibodies
against Mycoplasma pneumoniae,
varicella zoster virus, cytomegalovirus,
human immunodeficiency
virus 1, Treponema pallidum, Borrelia
burgdorferi, rubella, measles, and
mumps. MRI (1.5T, Siemens, Germany)
of the brain was performed on
the second hospital day and included
the following sequences: T1 axial
(TR 528/TE 12) and sagittal
(440/12), T2 axial (3176/98) and
coronal (3640/96), proton weighted
axial (3176/16), contrast-enhanced
T1 in three planes and axial fluidattenuated
inversion recovery images.
Careful examination of temporal
lobes, opercular regions, and the
cingulate gyri revealed no signal abnormalities.
EEG on that day showed
bifrontotemporal delta waves with
preponderance on the left side without
periodic complexes.