A 21-year-old woman presented to the emergency room at our hospital with a history of confusion, high fever, and headache. Six days before emergency consultation, she had fever in the 38°C range and had a loss of appetite. She had a history of mumps at the age of seven. Other than that, there was nothing remarkable about her medical or medication history. After admission on the same day, her level of consciousness worsened, and she could barely open her eyes when called, but she did not speak, did not get the instructions, and did not move her limbs (Glasgow Coma Scale; E3V1M1). In addition, tonic-clonic seizures that lasted for a few minutes began to occur. Her initial vital signs were as follows: heart rate, 128 beats/min; respiratory rate, 24 breaths/min; blood pressure, 130/81 mmHg; body temperature, 39.9°C; and oxygen saturation, 94% with room air. Neurological examination revealed no neck stiffness and no other gross focal neurological deficits. Results of laboratory investigations are shown in . Her white blood cell count and C-reactive protein concentration were 11530/µl (neutrophils, 47.0%; lymphocytes, 27.0%; monocytes, 3.0%; and atypical lymphocytes, 23.0%) and 3.34 mg/L, respectively. Also, many atypical lymphocytes were observed in the peripheral blood smear. Ferritin levels were mildly elevated in the serum (68 ng/ml). Liver dysfunction was observed with an elevated aspartate aminotransferase (AST) level (116 IU/L) and an elevated alanine aminotransferase (ALT) level (183 IU/L). Serum creatinine and electrolyte concentrations were normal. Serum levels of interleukin-6 (IL-6) were elevated to 10.3 pg/ml (normal range, <4.0 pg/ml). Both nasopharyngeal swab tests for SARS-CoV-2 RNA and influenza antigen (A and B) were negative results. Based on the presence of liver dysfunction by laboratory investigations at admission, abdominal computed tomography (CT) was performed. An abdominal contrast-enhanced CT revealed a splenohepatomegaly but no sign of neoplasia (Figures and ). Cerebrospinal fluid (CSF) analysis showed lymphocyte-dominant pleocytosis with 186 nuclear cells/mm3 (180 mononuclear cells/mm3 and 6 polymorphonuclear cells/mm3) and protein concentration (41 mg/dL) and glucose concentration (96 mg/dL, with a serum glucose concentration of 140 mg/dL). Fluid-attenuated inversion recovery (FLAIR) images of brain magnetic resonance imaging (MRI) showed high-intensity lesions at the left medial temporal lobe, bilateral caudate nucleus, and left lentiform nucleus (Figures and ). Based on the patient's clinical findings and the results of various laboratory and imaging tests, we diagnosed her with possible meningoencephalitis, including herpes simplex virus encephalitis. On the day of admission, the patient was started on meningoencephalitis treatment with acyclovir (10 mg/kg/IV q8h), ceftriaxone sodium (2 g IV q12h), and fosphenytoin sodium (IV q24h) as antiepileptic drugs and steroid pulse therapy with high doses of intravenous methylprednisolone (1,000 mg) for 3 days.\nOn the second day of admission, she became afebrile, was able to speak, and was shown to improve her disturbance of consciousness. Serial FLAIR images of brain MRI showed no abnormality and the improvement of previous MRI findings (Figures and ). In the results of laboratory investigations on admission, blood CMV pp65 antigenemia assay was found to be positive (17 pp65-positive cells per 5 × 105 cells) and herpes simplex virus (HSV) DNA was negative in the CSF. Thus, we suspected that encephalopathy was caused by CMV and started to administer ganciclovir (5 mg/kg/IV q12h) instead of acyclovir. As the possibility of CMV infection increased, she consulted an ophthalmologist. As fundus findings, white punctate exudate and petechiae were observed in the retina of the left eye, and a diagnosis of CMV retinitis and uveitis was made (Figures and ). However, symptoms such as decreased visual acuity and visual field impairment had not yet been developed. After that, her general condition recovered rapidly, and after two weeks, she was able to walk and talk normally. In other results of laboratory investigations on admission, blood CMV DNA was detected by polymerase chain reaction (PCR) (1.6 × 103 copies/ml), but CSF CMV DNA was negative (). The test for Epstein–Barr virus (EBV) DNA in blood was also positive. Anti-CMV IgM antibody levels were elevated (8.54 titers), as were anti-CMV IgG antibodies (15.5 titers) (enzyme-linked immunosorbent assay; positive titer >2.0), in the serum. The human immunodeficiency virus (HIV) antibody testing using rapid tests was negative, and HIV RNA was undetectable in the serum. The number of CD4+ cells was normal. Antinuclear antibody, anti-double-stranded DNA antibody, and hepatitis screening results were negative, and serum immunoglobulin levels (IgG, IgM, IgA, and IgE) were within normal limits. No other potential immunosuppressant factors were recognized in the patient in terms of clinical manifestation or laboratory findings. In addition, the IgM antibody levels of various viruses, including EBV, varicella-zoster virus, and mumps virus, were also elevated in serum. After two weeks of administration of ganciclovir, blood CMV pp65 antigenemia assay became negative and the administration of this drug was terminated. In addition, blood CMV DNA was also negative (). Two weeks after admission, a retest of CMV antibodies showed that IgM was still positive (7.49 titers), but IgG antibody titer was significantly higher (71.0 titers) than before (15.5 titers) (). Lower serum levels of IL-6 were observed (2.4 pg/ml). Considering the presence of CMV DNA and pp65 antigenemia along with IgM kinetics, CMV infection in the patient was suggestive of a primary infection. During the subsequent course, her liver function improved, and retinitis did not worsen. She recovered 20 days after admission and was able to leave our hospital without sequelae. After 4 months, follow-up laboratory investigations were performed, and blood CMV pp65 antigenemia was confirmed to be negative. The IgM antibody levels of all viruses, including CMV, EBV, varicella-zoster virus, and mumps virus, changed to negative or showed a significant decrease (). She is on outpatient follow-up and is doing well.\nRegarding the relative changes in the patient's IgM and IgG levels over time, CMV IgM four months after admission was observed to decrease to 2.99 titers. Conversely, CMV IgG levels four months after admission were 42.5 titers, which were not significantly different from the values (71.0 titers) two weeks after admission.
A 38-year-old Japanese man was admitted to our hospital because of muscle weakness in his lower extremities. His and his family’s histories were unremarkable. Fifteen days before admission, he had a mild fever with fatigue. Simultaneously, itchy skin rashes emerge on his foot and face, particularly around his mouth. The patient was tentatively diagnosed as having hand, foot, and mouth disease. Prior to admission, his fever, fatigue, and skin rash began to resolve, but the lower limb weakness progressively worsened within a few days. On admission, his general condition was unremarkable. A neurological examination showed that he was alert and oriented. His higher cerebral functions and cranial nerves were intact. The patient showed spastic paraparesis, with weakness of both lower extremities at approximately 4/5 strength. Deep tendon reflexes were brisk in all extremities, with ankle clonus in both legs. Babinski sings were bilaterally positive. He had paresthesia below the level of the T7-8 dermatome. Difficulty in micturition was noted. The patient had no sign of meningeal irritation. The results of his laboratory tests showed that his complete blood cell count, chemistry, immunoglobulin levels, C-reactive protein, erythrocyte sedimentation rate, and urinalysis were all within reference values. In particular, alterations in the liver function test results, suggestive of infectious mononucleosis, were not observed. Serological tests for syphilis, hepatitis B and C, HIV, and human T-lymphotropic virus type 1 were negative. The test results were also negative for anti-nuclear antibodies, anti-double stranded DNA, and cytoplasmic and perinuclear types of antineutrophil cytoplasmic antibodies, antiphospholipid antibodies, and anti-aquaporin-4 antibody. Antibody titers were not elevated for herpes simplex virus immunoglobulin M (IgM), varicella zoster virus IgM, Epstein–Barr virus IgM, and CMV IgM. CMV IgG was found elevated significantly. Additionally, the tests for coxsackie A16 and enterovirus were not significantly elevated, although we could not perform a serodiagnosis with paired serum samples. A malignancy survey, in which contrast-enhanced CTs of the chest, abdomen, and pelvis were included, was conducted in the present patient, and no cancer was identified. Additionally, tumor markers (alpha-fetoprotein, CEA, CA19-9, and soluble interleukin-2 antigen) were all within normal ranges. Examination of CSF showed elevated white blood cells, although protein (34 mg/dl) and glucose (57 mg/dl) levels were within normal ranges. The CSF IgG index 0.8 was found to be mildly elevated. The myelin basic protein (40.0 pg/ml) levels were not increased, and there were no oligoclonal IgG bands in the CSF sample. Nerve conduction velocity studies of the peripheral nerves indicated that they were intact. Sensory evoked potentials obtained by tibial nerve stimulation demonstrated no reproducible waves. Both brain and spinal cord magnetic resonance images (MRI) obtained at admission appeared normal (Figs. , , and ). Brain and spinal cord MRI examinations with gadolinium-enhancement were also performed, although no significant enhancement was demonstrated. After admission, the patient’s weakness and deep sensation disturbance of the lower extremities progressively worsened. He was tentatively diagnosed with transverse myelitis, and treatment was started with intravenous methylprednisolone at a dose of 1000 mg/day for 3 days, followed by oral prednisolone (PSL) (60 mg/day). After 7 days, the muscle weakness in his lower extremities continued to worsen, and we added intravenous immunoglobulin therapy (IVIG) at a dose of 0.4 mg/kg for 5 days. Ten days after admission, intravenous administration of ganciclovir (600 mg/day, 19 days) was initiated because CMV DNA was found in his CSF following polymerase chain reaction analysis (PCR) performed at admission. The deterioration of his symptoms ceased, and the weakness in his lower extremities gradually recovered. Other findings in his CSF also improved, including the results for white blood cells (13/mm3; all cells were lymphocytes), protein (23 mg/dL), and glucose (62 mg/dL). The CSF samples were also negative for CMV. However, MRI performed again on day 26 after admission demonstrated a spinal cord lesion of high signal intensity at cervical levels C2–C6, suggesting that the spinal cord was involved and may have been responsible for the paraplegia, although his paraplegia continued to improve with treatment (Fig. ). Additionally, a hyperintense signal was observed in the right frontal subcortical white matter (Figs. and ). On day 40 after admission, the weakness and numbness of his lower extremities again worsened, and myoclonic movements appeared in his lower legs. Subsequently, a loss of finger dexterity appeared bilaterally. In addition, the patient developed dysarthria and truncal ataxia, the latter of which resulted in his inability to maintain a sitting position. Brain MR images demonstrated faint, irregular-shaped lesions involving cerebral white matter with dense T2-weighted and fluid attenuated inversion recovery (FLAIR) hyperintensities in the internal capsules, suggesting that extensive disseminated demyelination was actively ongoing (Figs. and ). The CSF examination results showed re-elevation of protein (39 mg/dL), and MBP (58.9 pg/mL) was also increased compared with results from the initial CSF study, although both levels were within normal ranges. The white blood cell count in the CSF did not increase (7/mm3). We considered the possibility that the patient had ADEM, and intravenous methylprednisolone (1000 mg/day, 3 days) was administered again, followed by IVIG (0.4 mg/kg, 5 days). After this treatment, his neurological deterioration ceased, but he had residual neurological sequelae. Time course of clinical symptoms, CSF results, treatment, and MRI findings in the present patient are schematically shown (Fig. ).