SESSION TITLE: Critical Care Student/Resident Case Report Posters II
SESSION TYPE: Student/Resident Case Report Poster
PRESENTED ON: Tuesday, October 27, 2015 at 01:30 PM - 02:30 PM
INTRODUCTION: Encephalopathy can present in many forms. In the young, one must keep a broad differential.
CASE PRESENTATION: A previously healthy 19 year old woman presented with five days of frontal headache, forgetfulness, confabulation, insomnia, and right hand tremors. En route to the hospital, she had a tonic clonic seizure. On exam, she was afebrile, neurologically non-focal, and severely encephalopathic. She was admitted to the intensive care unit and intubated for airway protection. Lymphocytic pleocytosis on cerebrospinal fluid (CSF), clinical presentation, and mesiotemporal FLAIR signal change on MRI raised suspicion for autoimmune encephalitis and possibly infection. She started acyclovir. Computed tomography (CT) imaging showed an ovarian mass. Intravenous steroids were started immediately and plasmapharesis was initiated by the fifth day of admission. Seizures were controlled with versed, keppra, zonisamide, fosphenytoin, and phenobarbital. By day seven, her ovarian mass was removed and confirmed to be a 5.6 cm grade 3 teratoma composed of mature and immature cells. Eventually, antibody profiles in the CSF were positive for anti-NMDA (N-Methyl-D-aspartate) receptor and anti-AMPA (alpha-amino 3-hydroxy-5-methylisoxazole-4-propionic acid) receptor. Acyclovir was stopped. She was also given intravenous immunoglobulin and the germ cell tumor was treated with etoposide and cisplatin.
DISCUSSION: There are three different types of glutamate receptors that act by ligand-gated ion channels. These are NMDA, AMPA, and kainic acid receptors. Most glutamate receptors have both NMDA and AMPA channels. Encephalitis has been infrequently described with auto-antibodies against the NMDA or AMPA channels. However, there has not been a reported case with dual positive receptors as in this case. Autoimmune paraneoplastic encephalitis can present with symptoms of headache, confusion, behavior change, and seizures. Both antibody syndromes are seen in young adult women more than men and have been linked to teratomas. AMPA receptor antibodies have been described more with cancers of the lung and breast as well as thymomas. In cases associated with teratomas, treatment entails immunotherapy and tumor removal. Prognosis varies depending on cancer type (ability to remove or treat) and time to initiation of immunotherapy.
CONCLUSIONS: Encephalopathy in young patients may be due to paraneoplastic syndromes. Confirmation tests are not always readily available and diagnosis requires a prompt and aggressive evaluation with a high index of suspicion. Treatment involves immunotherapy, surgical resection, and may involve chemotherapy and aggressive seizure control.
Reference #1: Purves D, Augustine GJ, Fitzpatrick D, et al., editors. Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001. Glutamate Receptors.
Reference #2: Dalmau et. al. Anti-NMDA-receptor encephalitis: case series and analysis of the effects of antibodies. Lancet Neurol. 2008 Dec; 7(12): 1091-1098.
DISCLOSURE: The following authors have nothing to disclose: Emma Dishner, Abdulla Majid-Moosa, Sadat Shamim, Adan Mora
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