Paraneoplastic neurological syndromes associated with ovarian tumors

Refractory Anti- N -Methyl- d -Aspartate Receptor Autoimmune Encephalitis Induced by Ovarian Teratoma: A Case Report

OBJECTIVE

Teratoma is a type of germ cell tumor that derived from early embryonic stem cells and germ cell lines, which can lead to a rare complication known as paraneoplastic encephalitis syndrome. Delayed removal of teratoma allows for continuing antigen presentation, inducing affinity maturation of the antibody and the generation of long-lived plasma cells that infiltrate both bone marrow and brain, which makes the patient nonresponsive to later removal of teratoma and refractory to immunotherapy. We present this rare case to remind clinicians to be vigilant for the recognition and removal of teratoma during the treatment of autoimmune encephalitis.

METHODS

We retrospectively reviewed the clinical record of this 12-year 5-month-old female patient diagnosed with anti- N -methyl- d -aspartate receptor (anti-NMDAR) autoimmune encephalitis; her ovarian teratoma was unidentified on admission. She did not respond to immunosuppressive therapy until the mature ovarian teratoma identified 45 days after admission and removed the following day, nearly 2 months after symptom onset. This patient experienced nearly complete resolution of symptoms within the subsequent 2 weeks. In addition, we conducted a literature review of the clinical presentations and treatment of anti-NMDAR autoimmune encephalitis associated with ovarian teratoma in the pediatric population.

RESULTS

Our findings suggest that clinicians should be vigilant for the recognition and removal of teratoma during the treatment of autoimmune encephalitis.

CONCLUSION

Female pediatric patients with suspected anti-NMDAR encephalitis should be screened for ovarian tumors immediately and treated in a multidisciplinary setting including neurology and obstetrics and gynecology.

Paraneoplastic Syndrome Case Presented As Nystagmus and Ataxia

The incidence of paraneoplastic syndrome (PNS) is on the rise, attributed to the growing detection of antibody modalities in both the serum and cerebrospinal fluid (CSF). PNS can occur as different neurological symptoms. The revised guidelines streamline the diagnostic approach but identifying PNS still requires the detection of neurological manifestations concurrent with cancer, along with the presence of specific PNS autoantibodies.

Anti-NMDAR antibodies, the blood-brain barrier, and anti-NMDAR encephalitis

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an antibody-related autoimmune encephalitis. It is characterized by the existence of antibodies against NMDAR, mainly against the GluN1 subunit, in cerebrospinal fluid (CSF). Recent research suggests that anti-NMDAR antibodies may reduce NMDAR levels in this disorder, compromising synaptic activity in the hippocampus. Although anti-NMDAR antibodies are used as diagnostic indicators, the origin of antibodies in the central nervous system (CNS) is unclear. The blood-brain barrier (BBB), which separates the brain from the peripheral circulatory system, is crucial for antibodies and immune cells to enter or exit the CNS. The findings of cytokines in this disorder support the involvement of the BBB. Here, we aim to review the function of NMDARs and the relationship between anti-NMDAR antibodies and anti-NMDAR encephalitis. We summarize the present knowledge of the composition of the BBB, especially by emphasizing the role of BBB components. Finally, we further provide a discussion on the impact of BBB dysfunction in anti-NMDAR encephalitis.

Autoimmune and paraneoplastic neurological disorders: A review of relevant neuroimaging findings

INTRODUCTION

Paraneoplastic neurologic syndromes (PNS) and autoimmune encephalitis (AIE) are immune-mediated disorders. PNS is linked to cancer, while AIE may not Their clinical manifestations and imaging patterns need further elucidation.

OBJECTIVE/AIMS

To investigate the clinical profiles, antibody associations, neuroimaging patterns, treatments, and outcomes of PNS and AIE.

METHODS

A systematic review of 379 articles published between 2014 and 2023 was conducted. Of the 55 studies screened, 333 patients were diagnosed with either PNS or AIE and tested positive for novel antibodies. Data on demographics, symptoms, imaging, antibodies, cancer associations, treatment, and outcomes were extracted.

RESULTS

The study included 333 patients (mean age 54 years, 67% males) with PNS and AIE positive for various novel antibodies. 84% had central nervous system issues like cognitive impairment (53%), rhombencephalitis (17%), and cerebellar disorders (24%). Neuroimaging revealed distinct patterns with high-risk antibodies associated with brainstem lesions in 98%, cerebellar in 91%, hippocampal in 98%, basal ganglia in 75%, and spinal cord in 91%, while low/intermediate-risk antibodies were associated with medial temporal lobe lesions in 71% and other cortical/subcortical lesions in 55%. High-risk antibodies were associated with younger males, deep brain lesions, and increased mortality of 61%, while low/intermediate-risk antibodies were associated with females, cortical/subcortical lesions, and better outcomes with 39% mortality. Associated cancers included seminomas (23%), lung (19%), ovarian (2%), and breast (2%). Treatments included IVIG, chemotherapy, and plasmapheresis. Overall mortality was 25% in this cohort.

CONCLUSION

PNS and AIE have distinct clinical and radiological patterns based on antibody profiles. High-risk antibodies are associated with increased mortality while low/intermediate-risk antibodies are associated with improved outcomes. Appropriate imaging and antibody testing are critical for accurate diagnosis.

Mature Cystic Teratoma: An Integrated Review

Ovarian dermoid cysts, also called mature cystic teratomas (MCTs), account for 69% of ovarian germ cell tumors in young women. The tumors are formed by tissues derived from three germ layers, and sebaceous materials are most commonly seen. The origin of MCTs is widely considered to be the germ cell origin, which completes meiosis I. The clinical symptoms vary widely, but 20% of tumors could be asymptomatic. The diagnosis of MCTs is usually made without difficulty by ultrasound and confirmed by histopathology post-operatively. The imaging findings have a high diagnostic value. The typical characteristics present in the sonographic images, including a dermoid plug or Rokitansky nodule, are considered strong evidence for a teratoma. Although the malignant transformation of MCTs is rare, it can occur in some cases, especially in women of advanced age. The treatment of MCTs depends on the risk of malignancy, the age of the patient, and the patient's fertility reserve requirement. In this article, we review the epidemiology, clinical symptoms, diagnosis criteria, cellular origin, and treatment of mature cystic teratomas.

Neurology of Systemic Disease

Sex differences exist within the neurologic complications of systemic disease. To promote new avenues for prevention and develop novel therapeutics, we highlight the role of sex in differential outcomes to infectious disease and cardiac arrest and educate the reader in paraneoplastic presentations that may herald underlying malignancies in women.

Immunotherapy in Ovarian Cancer

Despite advances in surgery and chemotherapy, ovarian cancer remains one of the most lethal malignancies. Hence, the implementation of novel treatment approaches is required to improve the outcomes of the disease. Immunotherapy has been proven to be effective in many tumors and has already been incorporated into clinical practice. In this review, we describe key strategies in immunotherapy of ovarian cancer and summarize data from clinical studies assessing immunological prospects which could improve ovarian cancer treatment approaches in the future. The most notable current strategies include checkpoint blockade agents, the use of vaccines, adoptive cell transfer, as well as various combinations of these methods. While several of these options are promising, large controlled randomized studies are still needed to implement new immunotherapeutic options into clinical practice.

Ovarian Teratoma-Related Paraneoplastic Neurological Syndromes

Paraneoplastic neurological syndromes (PNSs) are a group of neurological disorders triggered by an underlying remote tumor. Ovarian teratoma (OT) is the most common histologic type of germ cell tumor in females. The most common PNSs associated with OT is anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. However, with the increasing number of new antibodies reported over the last decade, the clinical spectrum of OT-related PNSs is also expanding. Our knowledge of OT-related PNSs is still far from complete. Here, we provide a comprehensive review of the most recent findings in the field of OT-related PNSs, with a particular focus on their clinical and pathological characteristics. Overall, the description of neuronal antibodies in PNSs associated with OT strongly suggests that antibodies may be responsible for the clinical symptoms in some cases. OT-related PNSs are associated with various clinical manifestations, including anti-NMDAR encephalitis, limbic encephalitis, encephalomyelitis, progressive cerebellar syndrome and opsoclonus-myoclonus syndrome. The pathological characteristics of the OT suggest that the mechanism of PNSs is probably due to heteromorphic neurons in the tumor tissue, the ectopic expression of the antigens in neural tissue within the teratomas and patients' unusual immune response. Despite the severity of the neurological syndromes, most patients with OT-related PNSs showed good neurologic response to early tumor resection combined with immunotherapy. To further advance the management of OT-related PNSs, additional studies are needed to explore this complex topic.

The Association of Ovarian Teratoma and Anti-N-Methyl-D-Aspartate Receptor Encephalitis: An Updated Integrative Review

Ovarian teratomas are by far the most common ovarian germ cell tumor. Most teratomas are benign unless a somatic transformation occurs. The designation of teratoma refers to a neoplasm that differentiates toward somatic-type cell populations. Recent research shows a striking association between ovarian teratomas and anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, a rare and understudied paraneoplastic neurological syndrome (PNS). Among teratomas, mature teratomas are thought to have a greater relevance with those neurological impairments. PNS is described as a neurologic deficit triggered by an underlying remote tumor, whereas anti-NMDAR encephalitis is characterized by a complex neuropsychiatric syndrome and the presence of autoantibodies in cerebral spinal fluid against the GluN1 subunit of the NMDAR. This review aims to summarize recent reports on the association between anti-NMDAR encephalitis and ovarian teratoma. In particular, the molecular pathway of pathogenesis and the updated mechanism and disease models would be discussed. We hope to provide an in-depth review of this issue and, therefore, to better understand its epidemiology, diagnostic approach, and treatment strategies.

Trigeminal neuralgia leading to a diagnosis of ovarian cancer: a timely coincidence or a case of paraneoplastic syndrome?

A 51-year-old woman was referred to oral medicine with a 2-month history of progressive paraesthesia of the right lip, chin and oral mucosa. Examination revealed decreased sensation to the right dermatone of the inferior alveolar nerve and allodynia to light touch of the lower lip. An MRI of the head revealed bilateral cisternal trigeminal nerve pathological enhancement. While blood tests suggested a connective tissue disorder as the cause of the trigeminal neuralgia, a subsequent diagnosis of high-grade serous ovarian cancer gave a differential diagnosis of paraneoplastic syndrome.

Granzyme B in peripheral blood mononuclear cells as a measure of cell-mediated immune response in paraneoplastic neurological syndromes and malignancy

Background

Paraneoplastic neurological syndromes (PNS) may coexist with ovarian or lung cancers. Some tumors coexisting with PNS are smaller and have a better prognosis than tumors without PNS. PNS may constitute an opportunity to observe a natural immune antitumor response. We aimed to investigate a cytotoxic immune response by measuring granzyme B (GrB) in peripheral blood mononuclear cells (PBMC) in patients affected with ovarian or lung malignancy, with and without accompanying PNS.

Methods

We enrolled patients with: nonmalignant lesions (n = 21), ovarian cancer (n = 19), lung cancer (n = 57), and PNS (n = 30). PBMC were isolated by density gradient centrifugation with Ficoll–Paque. We evaluated the expression of GrB in PBMC lysates by ELISA and normalized to protein content as measured by the Lowry method.

Results

GrB levels in PBMC in the group with malignant tumors—median 1650 pg/mg protein (interquartile range 663–3260 pg/mg) and in patients with PNS—median 1890 pg/mg protein (range 1290–2640 pg/mg) was lower than in control group with nonmalignant lesions—median 5240 pg/mg protein (range 2160–7440 pg/mg), p = 0.0003 and p = 0.0038, respectively. The differences in GrB levels in PBMC between these groups were independent of epidemiological factors—age, sex, body mass index (BMI), and the number of immune cells, as confirmed by multiple regression analysis. Within the group of patients with malignancy and PNS, GrB levels in PBMC were elevated if onconeural antibodies were detected (2610; 2390–3700 pg/mg protein) as compared to patients without antibodies (1680; 970–1880 pg/mg protein, p = 0.035). GrB in PBMC was higher if the malignancy was diagnosed at the low (3060; 2120–5220 pg/mg protein) as compared to the high stage (1330; 348–2140, p = 0.00048). In patients with lung cancer, the expression of GrB in PBMC was lower (1430; 635–2660 pg/mg protein) than in the group with ovarian cancer (2580; 1730–3730, p = 0.02).

Conclusion

The cytotoxic response measured in peripheral blood by GrB in PBMC is impaired both in the course of malignancy and PNS. Levels of GrB in PBMC were higher if onconeural antibodies were detected. Tracking reactive immune responses, such as GrB in PBMC may have diagnostic and monitoring value in malignancy and PNS.

Electronic supplementary material

The online version of this article (10.1007/s00262-020-02750-1) contains supplementary material, which is available to authorized users.

Paraneoplastic Cerebellar Ataxia Can Affect Prognosis in High-Grade Serous Ovarian Cancer: A Case Report

The reported case is a 61-year-old woman, admitted for gradual onset of gait disturbances and dysphonia. The serum immunological panel revealed anti-Yo autoantibodies, suggestive of a paraneoplastic syndrome (PNS). A PET-CT revealed a suspicious left ovarian mass with retroperitoneal nodal involvement, and the histological assessment of surgical samples confirmed a FIGO IIIC high-grade serous ovarian cancer (HGSOC). Deemed inoperable at first, the patient was treated by carboplatin and paclitaxel chemotherapy, after which she refused surgical debulking. At the end of her systemic treatment, the patient only experienced a transient improvement of the cerebellar ataxia. Despite the suboptimal oncological treatment, the patient still presents stable disease and is free of progression 7 years from her diagnosis. This case study illustrates the favorable effect of PNS occurrence on oncological outcome in a patient with advanced HGSOC. The absence of recurrence despite the presence of residual disease after the systemic treatment is unusual and could be related to the PNS.

Surgical outcomes in patients with anti-N-methyl D-aspartate receptor encephalitis with ovarian teratoma

BACKGROUND

Anti-N-methyl-D-aspartate receptor encephalitis is an autoimmune encephalitis mediated by anti-N-methyl-D-aspartate receptor antibodies. Ovarian teratoma is closely related to anti-N-methyl-D-aspartate receptor encephalitis. However, the optimal treatment remains unknown, and strategies used for the diagnosis and therapy, including surgical intervention of ovarian teratoma, are debatable.

OBJECTIVE

The objective of the study was to study the clinical features of anti-N-methyl-D-aspartate receptor encephalitis with ovarian teratoma to further understand the disease.

STUDY DESIGN

This single-center prospective study included patients with anti-NMDAR encephalitis with ovarian teratoma from 2011 to 2016 who were admitted to Peking Union Medical College Hospital, Beijing, and discussed the clinical characteristics, treatment, and prognosis of the disease. The diagnosis of anti-N-methyl-D-aspartate receptor encephalitis was established preoperatively by identifying anti-N-methyl-D-aspartate receptor antibodies in the cerebrospinal fluid. Ovarian teratomas were suspected preoperatively by pelvic ultrasound and were diagnosed pathologically after laparoscopic detection and ovarian tumor resection. All patients were treated with first-line immunotherapy (steroids, intravenous immunoglobulin, and plasmapheresis), and when the therapy failed, they were treated with second-line immunotherapy (cyclophosphamide and rituximab). All patients were followed up regularly, and N-methyl-D-aspartate receptor antibodies, pelvic ultrasound, and neurological condition were monitored. Neurological symptoms were assessed using the modified Rankin Scale.

RESULTS

A total of 108 female patients with anti-N-methyl-D-aspartate receptor encephalitis were screened, of whom, 29 patients (26.9% of 108; mean age ± SD, 23.14 ± 6.59 years) had pathologically confirmed ovarian teratoma. The incidence of fever, decreased consciousness, arrhythmia, central hypoventilation, ventilator-assisted respiration, and intensive unit care (75.9%, 65.5%, 27.6%, 55.2%, 55.2%, and 58.6%, respectively) were significantly higher in patients with ovarian teratoma than in those without ovarian teratoma. The modified Rankin Scale at the acute onset in those 29 patients was 4.11 ± 1.20, which was also much higher than that in patients without ovarian teratoma (3.58 ± 1.08). Of the 29 patients with ovarian teratoma, 22 (75.9%) underwent laparoscopy during the acute onset of neurological symptoms. The mean diameter of the tumor was 4.61 ± 3.41 cm (SD), and the smallest tumor was only 1 cm in the unilateral ovary. All other cysts, except 4 bilateral cysts (13.8%), were unilateral. Only 1 patient was diagnosed pathologically with immature ovarian teratoma, while others had benign ovarian teratomas. In all, 28 patients (96.5%) had a good outcome (modified Rankin Scale ≤2) and 1 died. In the follow-up visit (mean duration, 37.69 months), the relapse rate of encephalitis in patients with ovarian teratoma undergoing laparoscopic cystectomy was 14.6%, whereas for those without ovarian teratoma, the relapse rate was 33.3%. The removal of ovarian teratoma was associated with reduced risk of relapse.

CONCLUSION

Patients having anti-N-methyl-D-aspartate receptor encephalitis with ovarian teratomas tend to present more severe neurological conditions. The diameter of the tumor in these patients is not very large and could be as small as 1 cm, and thus, careful exploration should be considered during surgery. Most of the ovarian teratomas in patients with anti-N-methyl-D-aspartate receptor encephalitis are mature. Early operative treatment is safe and effective because it is associated with reduced risk of relapse and complete recovery.

Clinical Features, Treatment, and Outcomes Among Chinese Children With Anti-methyl-D-aspartate Receptor (Anti-NMDAR) Encephalitis

Objective: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis in pediatric patients. In this study, we aimed to investigate the clinical features and long-term outcomes of pediatric patients with anti-NMDAR encephalitis in China.

Methods: We conducted a retrospective study of children (age range: 0–18 years) with anti-NMDAR encephalitis treated at Children's Hospital of Fudan University between July 2015 and November 2018. Demographic characteristics, clinical features, treatment, and outcomes were reviewed.

Results: Thirty-four patients with anti-NMDAR encephalitis were enrolled (age range: 5 months to 14 years; median age: 7 years; female: 18). The median follow- up duration was 20 months (range: 6–39 months). Eighteen (52.9%) patients initially presented with seizures and 10 (29.4%) with abnormal (psychiatric) behaviors or cognitive dysfunction. Thirty (88.2%) patients exhibited more than two symptoms during the disease course. No neoplasms were detected. Twelve (35.2%) patients had abnormal cerebrospinal fluid (CSF) findings, including leukocytosis, and increased protein concentration. Eighteen (52.9%) patients exhibited normal brain MRI findings. Electroencephalography revealed abnormal background activity in 27 (79.4%) patients, and epileptiform discharges in 16 (47.0%) patients prior to immunotherapy. All patients received first-line immunotherapy, with 30 (88.2%) and four (11.8%) patients achieving good (Modified Rankin Scale [mRS] score of 0–2) and poor outcomes (mRS score of 3–5), respectively. Initial mRS scores differed significantly between the good and poor outcome groups. Fourteen out of 18 patients (77.7%) with seizures accepted anti-epileptic drug (AED) administration, and seizure freedom was achieved in 12 out of 14 (85.7%) patients at the last follow-up. Ten of these 12 (83.3%) patients withdrew from AED treatment within 1 year.

Conclusions: Most patients achieved seizure freedom, so long-term use of AEDs may not be necessary for pediatric patients with anti-NMDAR encephalitis. Among our patients, 83.3% were sensitive to first-line immunotherapy and achieved good outcomes. Higher mRS scores before immunotherapy predicted poor outcomes, highlighting the need for a comprehensive assessment of patients with anti-NMDAR encephalitis.

Myasthenia as a paraneoplastic manifestation of ovarian Cancer

We describe the first case of myasthenia gravis as a possible paraneoplastic manifestation of ovarian cancer preceding its diagnosis.

•

Ovarian tumors account for 10% of paraneoplastic neurological symptoms.

•

Myasthenia gravis (MG) could be a rare paraneoplastic manifestation of ovarian cancer.

•

Cyclophosphamide is effective for MG crisis control and ovarian cancer treatment.

Genetic alterations and tumor immune attack in Yo paraneoplastic cerebellar degeneration

Paraneoplastic cerebellar degenerations with anti-Yo antibodies (Yo-PCD) are rare syndromes caused by an auto-immune response against neuronal antigens (Ags) expressed by tumor cells. However, the mechanisms responsible for such immune tolerance breakdown are unknown. We characterized 26 ovarian carcinomas associated with Yo-PCD for their tumor immune contexture and genetic status of the 2 onconeural Yo-Ags, CDR2 and CDR2L. Yo-PCD tumors differed from the 116 control tumors by more abundant T and B cells infiltration occasionally organized in tertiary lymphoid structures harboring CDR2L protein deposits. Immune cells are mainly in the vicinity of apoptotic tumor cells, revealing tumor immune attack. Moreover, contrary to un-selected ovarian carcinomas, 65% of our Yo-PCD tumors presented at least one somatic mutation in Yo-Ags, with a predominance of missense mutations. Recurrent gains of the CDR2L gene with tumor protein overexpression were also present in 59% of Yo-PCD patients. Overall, each Yo-PCD ovarian carcinomas carried at least one genetic alteration of Yo-Ags. These data demonstrate an association between massive infiltration of Yo-PCD tumors by activated immune effector cells and recurrent gains and/or mutations in autoantigen-encoding genes, suggesting that genetic alterations in tumor cells trigger immune tolerance breakdown and initiation of the auto-immune disease.

Paraneoplastic cerebellar degeneration secondary to ovarian carcinosarcoma: a cerebellar conundrum

We present a case of an elderly female patient who presented with a 6-month history of progressive slurred speech, vertigo, unsteadiness and falls. She underwent an extensive battery of neurological and cardiovascular investigations, none of which demonstrated a diagnostic cause for her symptoms. She was referred to the stroke and neurology teams and was started on treatment for presumed anxiety. As her symptoms continued to progress, she was referred to the falls service. Following a multidisciplinary team discussion, she was reviewed by the consultant geriatrician who felt this may be due to a malignancy so the consultant geriatrician arranged blood testsand CT scan of her chest, abdomen and pelvis. These demonstrated a large left adnexal mass and a raised Ca-125 level. The patient was diagnosed with an ovarian tumour, which was treated surgically. A provisional diagnosis of paraneoplastic cerebellar degeneration, secondary to ovarian carcinosarcoma, was made.

Anti-Yo positive and late-onset paraneoplastic cerebellar degeneration associated with ovarian carcinoma: A case report

RATIONALE

Paraneoplastic cerebellar degeneration (PCD) is a rare nonmetastatic neurological complication often associated with ovarian, breast, and other gynecologic cancers. Anti-Yo is one of the antionconeural antibodies found in patients with PCD. It primarily emerges before a malignancy is detected.

PATIENT CONCERNS

In this report, we describe an unusual case involving a patient who exhibited anti-Yo-positive PCD 1 year after being diagnosed with ovarian cancer.

DIAGNOSES

Histopathology of the resected tissues and Antineuronal antibody testing.

INTERVENTIONS

The patient was treated with intravenous immunoglobulin (IVIG, 1 g/d) for 1 week and a large-dose of methylprednisolone (0.4 g/kg/d) for 5 days. At the same time, underlying complications were prevented actively, and the peripheral nerves were protected.

OUTCOMES

Although most patients with anti-Yo-positive PCD do not improve after treatment, our patient significantly improved after receiving active and effective treatment.

Chronic Neuropsychological Sequelae in a Patient with Nontumorous Anti-NMDA-Receptor Encephalitis

Anti-N-methyl-D-aspartate receptor encephalitis is a neurological, autoimmune disorder tightly conceptualized only as recently as the mid-2000s. It presents itself in a combination of psychiatric, neurological, and autonomic features. We observe a unique case with probable earlier episode (prior to the mid-2000s conceptualization of the disease) and a later relapse, accompanying a comprehensive neuropsychological profile tracked after the relapse and subsequent improvement. Neurocognitive findings revealed residual frontal deficits with mood changes even in the state after plasmapheresis. This case is the first to describe posttreatment cognition in anti-NMDAR encephalitis after probable serial autoimmune episodes.

Anti-Yo Mediated Paraneoplastic Cerebellar Degeneration Associated with Pseudobulbar Affect in a Patient with Breast Cancer

Paraneoplastic cerebellar degeneration (PCD) is a rare anti-Yo mediated paraneoplastic syndromes rarely that is infrequently associated with breast cancer. We present a case of a 52-year-old female presenting with diplopia, gait instability, dysarthria, dysphagia, nystagmus, and, most notably, new onset paroxysmal episodes of uncontrollable crying concerning for pseudobulbar affect (PBA). Serologic testing showed anti-Yo antibodies. The patient was found to have stage IIIA breast cancer as the inciting cause of the paraneoplastic syndrome. The patient was treated with neoadjuvant chemotherapy, modified radical mastectomy, adjuvant Herceptin, and pertuzumab. She was given IVIG for paraneoplastic syndrome, antidepressants, and dextromethorphan-quinidine (Nuedexta), the first FDA-approved therapy for PBA. With multimodality therapy, she demonstrated significant improvement in neurologic and mood symptoms associated with PCD and PBA.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis in Children and Adolescents

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disease that is becoming increasingly recognized in the pediatric population. It may be the most common cause of treatable autoimmune encephalitis. The majority of cases of anti-NMDAR encephalitis are idiopathic in etiology, but a significant minority can be attributed to a paraneoplastic origin. Children with anti-NMDAR encephalitis initially present with a prodrome of neuropsychiatric symptoms, often with orofacial dyskinesias followed by progressively worsening seizures, agitation, and spasticity, which may result in severe neurologic deficits and even death. Definitive diagnosis requires detection of NMDAR antibodies in the cerebrospinal fluid. Optimal outcomes are associated with prompt removal of the tumor in paraneoplastic cases, as well as aggressive immunosuppressive therapy. Early detection is essential for increasing the chances for a good outcome. Close follow-up is required to screen for relapse and later onset tumor presentation. The nurse practitioner plays a major role in the research, screening, diagnosis, treatment, follow-up, and rehabilitation of a child or adolescent with anti-NMDAR encephalitis.