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A middle-aged woman with acute onset of fever, altered mental status, and movement disorder

Published:September 25, 2020DOI:https://doi.org/10.1016/j.ejim.2020.09.017

      Keywords

      1. Case description

      A 60-year-old woman was admitted in the emergency room with acute onset of fever, altered mental status, and movement disorder. The patient had well-controlled type 2 diabetes mellitus with hemoglobin A1c up to 6.0%. In addition, neither steroids nor immunosuppressive agents had been taken. Brain magnetic resonance imaging (MRI) was shown in Fig. 1. What is the diagnosis?
      Fig 1
      Fig. 1Magnetic resonance imaging showing asymmetrical signal abnormality in the left mesial temporal lobe (A: fluid-attenuated inversion recovery sequences, B: diffusion-weighted imaging).

      2. Discussion section

      The abovementioned clinical and radiographic findings suggested herpes simplex virus (HSV) encephalitis. Immediately, lumber puncture was performed, and empirical treatment with acyclovir was initiated. Since HSV polymerase chain reaction (PCR) was positive in the cerebrospinal fluid (CSF), the diagnosis was confirmed. Three weeks later, the patient recovered.
      Acute encephalitis is a neurological emergency which can cause severe impairment or death. HSV is the most common infectious cause of sporadic encephalitis [
      • Bradshaw MJ
      • Venkatesan A.
      Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
      ]. The annual incidence is estimated to be 2.3 cases per 1,000,000 persons [
      • Corey L
      Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
      ]. HSV encephalitis occurs in a non-seasonal pattern, and the age distribution appears to biphasic, with peaks at 5-30 and >50 years of age [
      • Corey L
      Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
      ].
      The clinical hallmark is the acute onset of fever and focal neurologic symptoms, especially in the temporal lobe [
      • Corey L
      Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
      ]. MRI is the most sensitive and specific imaging method for HSV encephalitis, particularly early in the course of the disease [
      • Bradshaw MJ
      • Venkatesan A.
      Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
      ]. Typical findings on MRI are asymmetrical hyperintensities on T2-weighted sequences in the mesiotemporal and orbitofrontal lobes and the insular cortex [
      • Bradshaw MJ
      • Venkatesan A.
      Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
      ]. Diffusion-weighted imaging is more useful for early diagnosis [
      • Bradshaw MJ
      • Venkatesan A.
      Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
      ]. Since PCR for detection of HSV DNA in CSF has high sensitivity and specificity [
      • Bradshaw MJ
      • Venkatesan A.
      Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
      ,
      • Corey L
      Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
      ], lumber puncture should be performed in patients with suspected HSV encephalitis.
      Antiviral therapy with acyclovir reduces the rate of death from HSV encephalitis [
      • Bradshaw MJ
      • Venkatesan A.
      Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
      ,
      • Corey L
      Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
      ]. Even with therapy, however, neurologic sequelae are common, especially among persons >50 years of age [
      • Corey L
      Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
      ].

      Declaration of Competing Interest

      I have stated explicitly that there are no conflicts of interest (COI) in connection with this article.

      References

        • Bradshaw MJ
        • Venkatesan A.
        Herpes simplex virus-1 encephalitis in adults: pathophysiology, diagnosis, and management.
        Neurotherapeutics. 2016; 13: 493-508
        • Corey L
        Herpes simplex virus infections. Harrison's Principles of Internal Medicine. 18th Edition.
        McGraw-Hill, New Yolk2012: 1453-1462