An Unusual Stroke-Like Presentation of HSV Encephalitis

Abstract

HSV (Herpes Simplex Virus) encephalitis is a potentially life-threatening illness that can affect neonates as well as adults. 1 Despite improvement in diagnostic techniques such as magnetic resonance imaging (MRI) and cerebro-spinal fluid (CSF) examination, challenges and pitfalls remain in the diagnosis of this condition. 1 We are reporting a case of HSV encephalitis that presented like a stroke with atypical MRI and CSF findings. The possibility of HSV encephali-tis in a patient with fever and focal neurological deficit should always be kept in mind because a full-blown picture such as seizures, abnormal behavior, confusion, disorientation, etc., may not be seen in every patient. 2 Case Report A 69-year-old woman, otherwise healthy, presented to the emergency department with a sudden onset of headache, numbness, and weakness in the left upper extremity. Her presentation was suggestive of an acute ischemic stroke, but intravenous thrombolysis was not considered as she arrived outside of the window period. Neurologic examination revealed weakness and hyperreflexia in left upper extremity. MRI of the brain (stroke protocol) demonstrated hyperintensity on diffusion-weighted imaging (DWI) in the right frontal lobe corresponding with the area of weakness (Figure 1). On hospital day two, she developed a fever followed by urinary incontinence. Urinalysis revealed leukocyturia (50 white blood cells) and dipstick was positive for leukocyte esterase. Intravenous ceftriaxone was initiated empirically to treat urinary tract infection. On hospital day three, she had a generalized tonic-clonic seizure followed by recurrent focal seizures involving the right side of face and arm. Over the next few hours, her mental status worsened and she was barely responsive to stimuli. Her EEG showed bilateral independent periodic lateralized epileptiform discharges (BI-PLEDs). At this point, it was decided to repeat brain imaging and perform a lumbar puncture. CSF showed three white blood cells/µl, protein was 39 mg/dl, and glucose was normal. Cultures were negative for bacteria, fungi, and mycobacteria after six weeks of incubation. The detection of herpes simplex virus (HSV) type 1 DNA in CSF using polymerase chain reaction (PCR) confirmed the diagnosis of HSV encepha-litis. Brain MRI showed the new development of bilateral fluid attenuated inversion recovery (FLAIR) hyperintensities involving the parafal-cine frontal, temporal, anterior cingulate, and insular region (Figure 2). Complete blood count, lipid profile, hemoglobin A1c, blood culture, urine culture, and echocardiogram were either normal or negative. Autoantibodies in the serum against N-methyl-D-aspartate (NMDA) receptor, alpha-amino-3-hydroxy-5-methyl-4 isoxazolepropi-onic acid (AMPA) receptor, gamma-aminobutyric acid (GABAb) receptor, leucine-rich glioma in-activated-1 (LGI-1), and contactin-associated protein-like 2 (CASPR-2) were negative. After treatment with IV acyclovir, 10mg/kg every eight hours for 21 days combined with IV methylpred-nisolone, 1000 mg a day for five days, she improved dramatically, with only residual bilateral weakness in lower limbs and occasional partial seizures.

Full text

Abstract
HSV (Herpes Simplex Virus) en-
cephalitis is a potentially life-
threatening illness that can af-
fect neonates as well as adults.1 Despite
improvement in diagnostic techniques such as
magnetic resonance imaging (MRI) and cerebro-
spinal fluid (CSF) examination, challenges and
pitfalls remain in the diagnosis of this condition.1
We are reporting a case of HSV encephalitis that
presented like a stroke with atypical MRI and
CSF findings. The possibility of HSV encephali-
tis in a patient with fever and focal neurological
deficit should always be kept in mind because
a full-blown picture such as seizures, abnormal
behavior, confusion, disorientation, etc., may not
be seen in every patient.2
Case Report
A 69-year-old woman, otherwise healthy,
presented to the emergency department with
a sudden onset of headache, numbness, and
weakness in the left upper extremity. Her pre-
sentation was suggestive of an acute ischemic
stroke, but intravenous thrombolysis was not
considered as she arrived outside of the window
period. Neurologic examination revealed weak-
ness and hyperreflexia in left upper extremity.
MRI of the brain (stroke protocol) demonstrated
hyperintensity on diffusion-weighted imaging
(DWI) in the right frontal lobe corresponding with
the area of weakness (Figure 1). On hospital day
two, she developed a fever followed by urinary
incontinence. Urinalysis revealed leukocyturia
(50 white blood cells) and dipstick was positive
for leukocyte esterase. Intravenous ceftriaxone
was initiated empirically to treat urinary tract
infection. On hospital day three, she had a gen-
eralized tonic-clonic seizure followed by recur-
rent focal seizures involving the right side of face
and arm. Over the next few hours, her mental
status worsened and she was barely responsive
to stimuli. Her EEG showed bilateral independent
periodic lateralized epileptiform discharges (BI-
PLEDs). At this point, it was decided to repeat
brain imaging and perform a lumbar puncture.
CSF showed three white blood cells/µl,
protein was 39 mg/dl, and glucose was normal.
Cultures were negative for bacteria, fungi, and
mycobacteria after six weeks of incubation. The
detection of herpes simplex virus (HSV) type 1
DNA in CSF using polymerase chain reaction
(PCR) confirmed the diagnosis of HSV encepha-
litis. Brain MRI showed the new development
of bilateral fluid attenuated inversion recovery
(FLAIR) hyperintensities involving the parafal-
cine frontal, temporal, anterior cingulate, and
insular region (Figure 2). Complete blood count,
lipid profile, hemoglobin A1c, blood culture, urine
culture, and echocardiogram were either normal
or negative. Autoantibodies in the serum against
N-methyl-D-aspartate (NMDA) receptor, alpha-
amino-3-hydroxy-5-methyl-4 isoxazolepropi-
onic acid (AMPA) receptor, gamma-aminobutyric
acid (GABAb) receptor, leucine-rich glioma in-
activated-1 (LGI-1), and contactin-associated
protein-like 2 (CASPR-2) were negative. After
treatment with IV acyclovir, 10mg/kg every eight
hours for 21 days combined with IV methylpred-
nisolone, 1000 mg a day for five days, she im-
proved dramatically, with only residual bilateral
weakness in lower limbs and occasional partial
seizures.
Discussion
This patient presented with a sudden onset
of focal neurological deficit without any change
in the mental status. Her initial MRI and CSF
picture was not typical for HSV encephalitis. In
this case, the diagnosis of HSV encephalitis was
An Unusual Stroke-Like Presentation
of HSV Encephalitis
Harsh V Gupta, MD1; Samira Malhotra, MD1; Amit Batra, MD, DM1
1Department of Neurology, Max Super Specialty Hospital, New Delhi, India.
SCIENTIFIC ARTICLE
Keywords: encephalitis, stroke-like,
HSV, frontal lobe.
> Continued on page 40.
Figure 1. Demonstrates hyperintensity on DWI sequence (A and B) in the right parafalcine region.
Initially, HSV encephalitis affects
one hemisphere and involves
the contralateral side once it has
extended in the initially involved
hemisphere.4
38 • THE JOURNAL OF THE ARKANSAS MEDICAL SOCIETY VOLUME 115

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clinched by the amplification of HSV type 1 DNA
in CSF and improvement with Acyclovir. Earlier,
brain biopsy was considered to be the gold stan-
dard for the diagnosis of this condition, but this
has now been replaced by HSV PCR detection in
CSF.3 Despite being very sensitive, HSV PCR can
be negative if CSF is obtained very early in the
disease course; the testing should be repeated
if the suspicion is very high.3 The measurement
of intrathecal synthesis of immunoglobulin (IgG)
after one week into the disease course has been
suggested if the HSV PCR in CSF continues to
remain negative.3 Despite the fact that brain im-
aging can be initially normal in 5-10% of cases1,
Renard et al showed that DWI (diffusion-weight-
ed imaging) identified more areas of involvement
than FLAIR sequence when MRI is performed
early in the disease course.4 Initially, HSV en-
cephalitis affects one hemisphere and involves
the contralateral side once it has extended in
the initially involved hemisphere.4 Brain MRI is
not helpful to assess the response to therapy as
the lesions can progress despite treatment.1 The
temporal lobe is most commonly as well as ini-
tially affected with HSV encephalitis but isolated
extra-temporal forms of HSV encephalitis have
been reported.5 The frontal or parietal lobe can
also be initially involved with HSV encephalitis,
which can potentially delay the diagnosis of this
catastrophic condition.5 EEG when used alone is
not helpful for making a diagnosis as non-spe-
cific changes are seen.1 HSV encephalitis can
present with a sudden onset of symptoms which
can mimic a stroke.6 It is possible that sudden
deficits represent an ictal phenomenon or hypo-
perfusion of the involved area.
Early recognition of HSV encephalitis is im-
portant as it can unleash a variety of complica-
tions such as cognitive deficits, seizures, etc.1 It is
one of the neuroinfectious diseases where timely
institution of treatment can prevent morbidity and
mortality. There are several learning points in this
case, namely the sudden onset of symptoms, de-
layed appearance of fever and partial seizures,
initial frontal lobe involvement on brain imaging,
and atypical CSF findings. The combination of
brain MRI, CSF, and EEG should be used in cases
of diagnostic confusion because it improves the
sensitivity of diagnosis.1
References
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al. Managing atypical and typical herpetic
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Apr 13.
2. Vachalová I, Kyavar L, Heckmann JG. Pit-
falls associated with the diagnosis of her-
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3. Denes E, Labach C, Durox H, Adoukonou
T, Weinbreck P, et al. Intrathecal synthesis
of specific antibodies as a marker of her-
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negative PCR. Swiss Med Wkly. 2010 Oct
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4. Renard D, Nerrant E, Lechiche C. DWI and
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Figure 2. Demonstrates hyperintensity on DWI sequence (A and B) in bilateral parafalcine area. FLAIR
hyperintensity is also seen in bilateral temporal and parafalcine areas (C and D).
40 • THE JOURNAL OF THE ARKANSAS MEDICAL SOCIETY VOLUME 115