Pittock, Sean J.

11559 Background: Paraneoplastic neurologic disease (PND) is an aberrant immune-mediated response against the nervous system triggered by occult malignancy. Given the rarity of this disease, a paucity of data exists describing breast cancer (BC)-related PND; thus, we sought to further examine this specific population of patients. Methods: Using an institution specific clinical search tool, we identified all patients at our institution from 1997-2016 with a diagnosis of BC-related PND, verified by an international expert. Retrospective review was used to record tumor and treatment factors associated with PND and BC. A descriptive analysis was performed of the characteristics associated with BC-related PND. Results: BC-related PND was diagnosed in 58 female patients. Average age at BC diagnosis was 54.0±10.3 years. Most had invasive cancer of Stage II or higher [Stage 0 (10.3%), I (10.3%), II (44.8%), III (13.8%), IV (6.9%), unknown (13.8%)]. Most patients were hormone receptor (HR)+ (63.8%), while 4 (6.9%) were HR-, and 17 (29.3%) were unknown. Of the 34 patients where Her2/neu (Her2) data was available, 7 (20.6%) were Her2+ and 27 (79.4%) were Her2-. The majority (62.1%) had neurological symptoms prior to BC, 5.2% were concurrent, and 32.7% developed PND after initial BC. The interquartile range for time from PND to BC diagnosis was -8.5 to 10.5 months. Of the 58 patients, 29 (50%) had autoantibodies detected: Purkinje Cell Cytoplasmic Autoantibody Type-1 (PCA-1[anti-Yo]) (10), amphiphysin-IgG (n = 9), Anti-Neuronal Nuclear Autoantibody Type-2 (ANNA-2[anti-Ri]) (n = 5), and other (n = 5). The most common syndromes were cerebellar ataxia (n = 14), myelopathy (n = 11), and myopathy (n = 11). Immunotherapy was used for PND in 53 of 58 (91.4%) patients; benefit from immunotherapy was assessed as complete 0 (0%), robust 11 (20.8%), mild to moderate 28 (52.8%), none 9 (17%), and indeterminate 5 (9.4%). Conclusions: BC-related PND is rare, with only 58 cases over 20 years at a large academic institution. Paraneoplastic symptoms often present prior to BC diagnosis and BC characteristics are typical of the general population. Over 75% of patients benefit from immunotherapy. These data may provide helpful information to providers treating this population of patients.

The clinical phenotype of leucine‐rich glioma‐inactivated protein 1 (LGI1) and contactin‐associated proteinlike 2 (CASPR2) autoimmunity is well defined in adults. Data for children are limited (<10 cases). Among 13,319 pediatric patients serologically tested for autoimmune neurological disorders (2010–2017), 264 were seropositive for voltage‐gated potassium channel‐complex–IgG (radioimmunoprecipitation). Only 13 (4.9%) were positive by transfected cell‐binding assay for LGI1‐IgG (n = 7), CASPR2‐IgG (n = 3), or both (n = 3). This is significantly less than in adults. Encephalopathy, seizures, and peripheral nerve hyperexcitability were common, as was coexisting autoimmunity. No faciobrachial dystonic seizures or cancers were identified. Functional neurologic disorders were frequently the initial diagnosis, and immunotherapy appeared beneficial. Ann Neurol 2018;84:473–480

SummaryObjectiveTo characterize seizure semiology and the utility of antiepileptic drug (AED) therapy in leucine‐rich glioma inactivated‐1 ( LGI1‐Ab) autoimmune epilepsy (AE).MethodsPatients with voltage‐gated potassium channel complex (VGKCc) titers higher than 0.02 nmol/L who were evaluated between May 2008 and June 2016 at the 3 Mayo Clinic sites (Arizona, Florida, or Minnesota) were identified. We then performed a retrospective review of those who were LGI1‐Ab positive and were treated for seizures.ResultsA total of 1,095 patients with VGKCc titers higher than 0.02 nmol/L were identified, in which 77 were LGI1 positive. Of these, 56 patients with seizures were included in the analysis. Mean age at symptom onset was 62.9 years; 66% (n = 37) were male. The most common seizure semiology was focal faciobrachial dystonic seizures with preserved awareness (FBDS) (n = 35, 63%), followed by focal with impaired awareness (FIA) (n = 29, 52%), generalized tonic–clonic (GTCs) (n = 28, 50%), and focal non‐motor seizures with preserved awareness (n = 28, 50%). The majority had more than one seizure type (n = 49, 88%; median = 2.5). Thirty‐eight patients (68%) became seizure free: 29 (76%) with immunotherapy, 3 (5%) with AEDs alone, 2 (3%) with AEDs before any immunotherapy, and 4 (7%) with AEDs after immunotherapy. Levetiracetam (n = 47, 84%) and valproic acid (n = 21, 38%) were the most commonly used AEDs, but neither were associated with seizure freedom. Sodium channel blocking (NCB) AEDs were associated with seizure freedom in 4 patients compared to none treated with non‐NCB AEDs. Regardless of class, AEDs prior to or apart from immunotherapy were associated with seizure freedom in only five patients (9%). In patients with FBDS, seizure freedom was more often associated with immunotherapy than AEDs (20/30 vs. 3/34, p = 0.001).SignificanceAlthough FBDS are the most characteristic seizure type seen in LGI1‐Ab AE, other seizure types including FIA and GTCs also occur. Immunotherapy was the treatment most frequently associated with seizure freedom in LGI1‐Ab AE. In general, AEDs seemed to confer a very low chance for seizure freedom, although AEDs with NCB‐blocking properties were associated with seizure freedom in a limited number. Levetiracetam in particular appears to be ineffective in this patient population.