Neurology International 2014; volume 6:5359

West Nile virus Introduction Correspondence: Chad J. Cooper, Department of induced opsoclonus- Internal Medicine, Texas Tech University Health syndrome West Nile virus (WNV) is an arthropod Sciences Center, 4800 Alberta Ave, El Paso, TX borne neurotropic single stranded RNA fla- 79905, USA. Chad J. Cooper, Sarmad Said vivirus.1 The virus is introduced into the host Tel. +1.915.543.1009. by the vector (Culex mosquito) during its blood E-mail: [email protected] Department of Internal Medicine, Texas meal. WNV originated in the Middle East and Tech University Health Sciences Center, Key words: West Nile virus, opsoclonus Africa but in recent years has reached the myoclonus syndrome, encephalitis. El Paso, TX, USA United States.2 From 1999 to 2011, a total of 31,414 cases of WNV were reported in the Contributions: the authors contributed equally. United States. The 2012 incidence of WNV neuroinvasive disease was 0.3 per 100,000 in Conflict of interests: the authors declare no Abstract the United States.3 Approximately 45% of WNV potential conflict of interests. cases were reported in Texas, USA.3 Seasonal West Nile virus (WNV) is an arthropod borne outbreaks occur annually but are often quite Received for publication: 18 February 2014. neurotropic single stranded RNA flavivirus focal and unpredictable in size and location. Accepted for publication: 19 February 2014. with <1% developing presenting with neuro- The majority of those infected with WNV are This work is licensed under a Creative Commons logical disease. Immunocompromised and eld- asymptomatic and only 20-30% will present Attribution NonCommercial 3.0 License (CC BY- erly patients are more prone to developing with flu like symptoms. Less than 1% of indi- NC 3.0). WNV meningitis or encephalitis. Definitive viduals will eventually develop neurological deficits. Neurological deficits associated with ©Copyright C.J. Cooper and S. Said, 2014 diagnosis of WNV meningoencephalitis is a Licensee PAGEPress, Italy combination of clinical suspicion and cere- WNV infection can be encephalitis, meningitis or flaccid paralysis. Immunocompromised and Neurology International 2014; 6:5359 brospinal fluid (CSF) serology. Forty-eight year doi:10.4081/ni.2014.5359 elderly patients are more prone to developing old Caucasian female presented with a sudden WNV meningitis or encephalitis compared to only onset of altered mental status after being the general population.4 WNV and other found unresponsive. She was confused with arboviral infections should be considered in Initial vital signs on admission included a intermittent bouts of alertness/lethargy and the differential diagnosis of aseptic meningitis rectal temperature was 41.1 degrees Celsius, unintelligible responses to questioning. Her or encephalitis, especially if the geographicalusetachycardia (heart rate of 108), stage 1 hyper- medical problems included endometrial cancer area is prone to WNV infection. The definitive tension (blood pressure of 140/61) and tachyp- that was in remission after undergoing a total diagnosis of WNV meningoencephalitis is a nea (respiratory rate of 34). Pertinent physical abdominal hysterectomy with bilateral salp- combination of clinical suspicion and CSF examination findings revealed a morbidly ingectomy and postoperative chemotherapy serology. Approximately 50% may have signifi- obese female that was alert but not oriented to with paclitaxel and carboplatin. Pertinent phys- cant postviral morbidity for a year following person, place or time and only able to answer ical examination revealed muscle strength that infection.4 Management of WNV infection con- yes or no to questioning. Her pupils were 3 mm was significantly decreased, nuchal rigidity sists of supportive measures. We are present- bilaterally, equal round and reactive to light and +2 pitting edema of both lower extremi- ing a very rare case of a immunocompromised with intact extraocular movements and no nys- ties. Computed tomography and magnetic res- patient that developed opsoclonus myoclonus tagmus noted. All cranial nerves were assessed onance imaging of the brain were negative for syndrome following WNV encephalitis. and normal on examination. No motor or sen- any intracranial pathology. CSF analysis was sory deficits to light, touch, pain, position consistent with aseptic meningitis with all CSF sense or vibration noted. All reflexes such as serology being negative except for positive biceps, knee tendon and Babinski sign were WNV antibody. A few days after being admitted Case Report normal. Muscle strength (3/5 all four extremi- she developed involuntary random movements ties) but no tremors, or myoclonus. Nuchal of her eyes and generalized jerking movementsNon-commercialForty-eight year old Caucasian female pre- rigidity was observed but Kernig and (myoclonus). This was determined to be opso- sented with a sudden onset of altered mental Brudzinski signs were both negative. She also had bilateral +2 pitting edema of lower myoclonus syndrome (OMS) induced by status after being found unresponsive. She extremities. The remainder of organ systems the WNV meningoencephalitis. She then was confused with intermittent bouts of alert- of examination was unremarkable. received five consecutive days of plasmaphere- ness/lethargy and unintelligible responses to questioning. Her medical problems included Initial laboratory work-up (Table 1) was sis with a significant improvement in her neu- endometrial cancer that was treated with a unremarkable except hyponatremia and rological status. Opsoclonus-myoclonus syn- total abdominal hysterectomy with bilateral thrombocytopenia. Brain computed tomogra- drome (OMS) is a rare neurological disorder salpingectomy and postoperative chemo - phy (CT) on admission was negative for any associated with chaotic multidirectional eye therapy. The endometrial adenocarcinoma was acute pathological abnormalities. CT of the movements, myoclonus and less frequently a stage 2 according to the International abdomen and pelvis was negative for any acute cerebellar ataxia. OMS affects as few as 1 in Federation of Gynecology and Obstetrics abdominopelvic pathology. The patient was 10,000,000 people per year. The pathogenesis (FIGO) staging: 8 cm tumor, grade 2, no lymph started on ceftriaxone 2 g IV daily, vancomycin is not fully understood with the majority of node involvement, and <50% invasion of the 2 g IV twice daily, and acyclovir 1.5 g IV every 8 cases of opsoclonus-myoclonus syndrome myometrium and cervical stroma. The patient hours due to our high suspicion of encephali- being idiopathic. According to current medical was currently in remission after receiving tis. A lumbar puncture with cerebrospinal fluid literature there have only been two previous chemotherapy (paclitaxel and carboplatin) and (CSF) analysis and CSF serology (Table 2) was case reports of opsoclonus myoclonus syn- dexamethasone. No history of tobacco, alcohol consistent with aseptic meningitis. The HIV drome associated with WNV encephalitis. or illicit drug use. screening test was negative. Magnetic reso-

[page 12] [Neurology International 2014; 6:5359] Case Report nance imaging (MRI) of the brain was unre- The onset of myoclonus may precede the opso- inhibitory projections of the Purkinje cells of markable for any acute intracranial abnormal- clonus. the deep cerebellar nuclei to the fastigial ities. Vancomycin and acyclovir were discon- The pathogenesis of opsoclonus is unknown nuclei.8 The pathogenesis is not fully under- tinued and fluconazole 400 mg PO daily was but, one hypothesis suggests that opsoclonus stood, however, an autoimmune pathophysiol- added to the management on the sixth hospital is due to damage of the omnipause cells in the ogy has been proposed. Autoimmune dysfunc- and ceftriaxone was continued until the tenth nucleus raphe interpositus of the pons.8 This tion of Purkinje cells in the dorsal vermis and hospital day. By the seventh hospital day, we prevents unwanted by inhibiting subsequent disinhibition of oculomotor fasti- noted involuntary random movements of her burst neurons in the paramedian pontine gial region seems to be the most probable eyes (see Video 1) and generalized jerking reticular formation and rostral interstitial mechanism.9 The majority of OMS cases are movements (myoclonus), mostly in lower nucleus of Cajal. However, these omnipause idiopathic. However, other common causes of extremities. An electroencephalography (EEG) neurons are spared in paraneoplastic opso- opsoclonus include paraneoplastic, viral brain- showed a severe and diffuse slowness, consis- clonus. Another explanation suggests that stem encephalitis and drugs.10,11 The onconeu- tent with encephalopathy. She was placed on opsoclonus may be generated by disinhibition ronal antibodies associated with OMS are anti- fosphenytoin 100 mg IV every 8 hours without of the oculomotor region of the fastigial nucle- Ri antibodies (gynecologic cancers) and, less any improvement. On the eighth hospital day, us by a process that interferes with the frequently, anti-Hu, anti-Yo, and anti-Ma-2 her GCS decreased to 3 and was subsequently intubated. A repeat brain CT did not reveal any new pathologic abnormalities. The platelet count continued to decrease during the hospi- talization and eventually reached its lowest Table 1. Initial laboratory work up. count of 21×103/uL by the tenth hospital day. White blood cell count 8.09×103 uL (4.5-11.0×103/UL) The West Nile virus (WNV) antibody IgM and IgG were noted to be positive on the twelfth Segmenters 53.1% hospital day. After determining that the Bands 11.3% encephalitis was due to the WNV we continued Metamyelocytes 1% supportive care and discontinued the flucona- Lymphocytes only24.4% zole. The neurology service was consulted for Monocytes 10.4% the myoclonus and erratic eye movements. Hemoglobin 13.2 g/dL (12.0-15.0 g/dL) They diagnosed her to have opsoclonus Hematocrit 39.5 (36.0-47.0%) myoclonus syndrome (OMS) induced by the use 3 WNV meningoencephalitis. Paraneoplastic Platelet count 109×10 uL (150-450×103/UL) antibodies anti-Yo, anti-Hu, anti-Ri and anti- Sodium 133 mmol/L (135-145 mmol/L) NMDAR were negative. Neurology recom- Potassium 4.4 mmol/L (3.5-5.1 mmol/L) mended a trial of either plasmapheresis or Serum glucose 119 mg/dL (70-100 mg/dL) IVIg. Therefore the patient had plasmaphere- BUN 21 mg/dL (7-22 mg/dL) sis on five consecutive days. A percutaneous Creatinine 1.50 mg/dL (0.60-1.30 mg/dL) endoscopic gastrostomy tube (PEG) and tra- AST 20 IU/L (15-37 IU/L) cheostomy were performed on hospital day 26. ALT 36 IU/L (12-78 IU/L) The patient continued to have improvement in her neurological status and was subsequently Alk. Phosphatase 128 IU/L (50-136 umol/L) discharge to a long term acute care (LTAC) facility for further rehabilitation. She under- Table 2. Cerebrospinal fluid analysis. went rehabilitation for six months and eventu- Appearance Clear and colorless ally had complete resolution of her neurologi- White blood cell count 67/ uL (0-5/uL) cal deficits on follow visit. Neutrophils 1% Non-commercialLymphocytes 97% Monocytes 2% Discussion and Conclusions Red blood cell count 399/uL (0-5/uL) Protein 131 mg/dL (15-45 mg/dL) Opsoclonus-myoclonus syndrome (OMS) is Glucose 38 mg/dL (41-70 mg/dL) a rare neurological disorder associated with Corresponding serum glucose 68 mg/ dL (70-100 mg/dL) chaotic multidirectional eye movements, CSF serology myoclonus and less frequently cerebellar atax- Cryptococcal antigen Negative ia. OMS affects as few as 1 in 10,000,000 peo- Cysticerosis IgG antibody Negative ple per year.5 The eye movements are charac- Coccidioides antibody Negative terized by multidirectional, high amplitude, Histoplasma antibody Negative arrhythmic and conjugate ocular saccadic Group B Streptococci Negative intrusions without intersaccadic latency caus- Haemophilus Negative Streptococcus pneumonia Negative ing oscillopsia.6 It should not be confused with Neisseria meningitides Negative which is usually unidirectional and Herpes simplex 1 & 2Negative Positive has a slow component.7 Myoclonus may affect West Nile Virus Negative any part of the body and may be evoked by CSF Culture Negative action, intention, auditory and visual stimuli. CSF cytology No malignancy

[Neurology International 2014; 6:5359] [page 13] Case Report antibodies.12 Paraneoplastic diseases associat- lines for either symptomatic or disease modify- 8. Wong A. An update on opsoclonus. Curr ed with OMS include small-cell lung, ovarian ing treatments. According to current medical Opin Neurol 2007;20;25-31. and breast cancer.13 Most infectious disease literature, only two other case reports have 9. Morales-Briceno H, Rodriguez-Violante M, causes involve the central nervous system or a reported opsoclonus myoclonus syndrome Cervantes-Arriage A, et al. Opsoclonus post infection immune mediated process. The induced by West Nile virus encephalitis. myoclonus syndrome associated with post infectious mechanism has been described GQ1b antibodies. Mov Disorders 2012;27: as a dysfunction of the cell mediated and 1615-6. humoral immune response. This immune 10. Scott KM, Parker F, Heckmann JM. mediated process was postulated because the References Opsoclonus-myoclonus syndrome and HIV- presence of autoantibodies and the response infection. J Neurol Sci 2009;284:192-5. of OMS to immunosuppressive therapy.14 1. Steiner I, Kennedy PG. West Nile virus 11. Khosla JS, Edelman MJ, Kennedy N, Reich These autoantibodies are directed towards cer- introduction into the new world. SG. West Nile virus presenting as opso- tain neural antigens. The specific microorgan- Neurology 2013;81:1441-2. clonus-myoclonus cerebellar ataxia. Neu - ism is rarely identified however OMS has been 2. Rossini G, Landini MP, Gelsomno F, et al. rology 2005;64:1095. reported to occur after infection with Innate host responses to West Nile virus: 12. Alshekhlee A, Sultan B, Chandar K. enterovirus, Borrelia Burgdorferi, streptococ- implications for central nervous system Opsoclonus persisting during sleep in cus, Coxsackie virus, Epstein-Barr virus, immunopathology. World J Virol 2013;2:49- West Nile encephalitis. Arch Neurol 2006; mumps or West Nile virus.15 56. 63:1324-6. Opsoclonus myoclonus syndrome can result 3. Centers for Disease Control and 13. Ertekin V, Tan H. Opsoclonus-myoclonus in significant long term neurological sequelae Prevention. West Nile Virus. 2013. syndrome attributable to hepatitis C infec- if either untreated or undertreated.16 There is Available from: www.cdc.gov/westnile/ tion. Pediatr Neurol 2010;42:441-2. no current established treatment for OMS. 4. Morita A, Ishihara M, Kamei S, Ishikawa Therapy options have been directed towards H. Opsoclonus-myoclonus syndrome fol- 14. Yiu VW, Kovithavongs T, McGonigle LF, the suppression of antibody formation and the lowing influenza an infection. Intern Med Ferrerira P. Plasmapheresis as an effective removal of the autoantibodies. Several thera- 2012;51:2429-31. treatmentonly for opsoclonus-myoclonus syn- peutic attempts can be utilized to remove the 5. Singh D, Sinha M, Kumar R, et al. drome. Pediatr Neurol 2001;24:72-4. autoantibodies in patients with OMS, such as Opsoclonus-myoclonus syndrome caused 15. Kanjanasut N, Phanthumchinda K, IVIG, plasmapheresis, and immunoadsorp- by varicella-zoster virus. Ann Indian Acad Bhidayasiri R. HIV-related opsoclonus– tion.16 Treatment of the underlying disease Neurol 2010;13:211-2. use myoclonus–ataxia syndrome: Report on process is the mainstay of management for 6. Guedes ME, Almeida AC, Patricio MS, two cases. Clin Neurol Neurosur 2010;112: OMS. However there is no available data from Costa JM. Opsoclonus-myoclonus syn- 572-4. clinical trials that suggest a definitive treat- drome. BMJ Case Rep 2011;28:2011. 16. Desai J, Mitchell WG. Acute cerebellar ment strategy. Because the opsoclonus- 7. Sahu JK, Prasad K. The opsoclonus- ataxia, acute cerebellitis, and opsoclonus- myoclonus syndrome is so rare, there are no myoclonus syndrome. Pract Neurol 2011; myoclonus syndrome. J Child Neurol 2012; randomized controlled trials to provide guide- 11:160-6. 27:1482-8.

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