Aims: Neurotoxicity (NT) is a common complication of chimeric antigen receptor (CAR) T-cell therapy. Data on early clinical identifiers for impending severe NT are lacking. Methods: The authors performed a retrospective study on 26 adult relapsed/refractory diffuse large B cell lymphoma patients treated with commercial CAR T-cell therapy (December 2017 - September 2018). Results: NT of any grade and severe NT occurred in 88 and 31% of patients, respectively. Dysgraphia (p < 0.01), disorientation (p = 0.01) and inattention (p = 0.018) were associated with severe NT, with positive predictive values of 100, 87.5 and 87.5%, respectively. Dysnomia was not associated with severe NT. Conclusion: In the authors' limited cohort, the dysgraphia, disorientation and inattention components of the CAR T-cell therapy-associated toxicity 10 scoring system were significantly associated with and predictive of impending severe NT.

Neurological immune-related adverse events (irAEs) are rare toxicities that occur following immune checkpoint inhibitor therapy. We propose that patients with thymic malignancies and graft-versus-host disease (GVHD) are predisposed to irAEs. We present two asymptomatic patients, one with thymoma and another with GVHD, who developed abnormal brain MRIs after treatment with programmed cell death protein 1 inhibitors. The first patient, with thymic cancer and thymoma, developed pontine enhancing MRI lesions following treatment with pembrolizumab. The second patient, with prior GVHD, developed pachymeningeal enhancement following treatment with nivolumab. IrAEs with abnormal MRI studies, despite asymptomatology, have significant impact on the treatment strategy for these patients.

Neurological immune-related adverse events are potentially life-threatening complications of immune checkpoint inhibitors. Myasthenia gravis (MG) is a rare complication of treatment with inhibitors of programmed cell death protein 1 (PD)-1 and PD ligand 1 (PD-L1). We present a patient who developed seronegative MG resulting in respiratory failure while being treated with avelumab for metastatic, treatment-refractory ovarian cancer. Her MG went into remission following steroids and maintenance intravenous immunoglobulin treatment. We conclude that MG is a rare, but potentially life-threatening immune-related adverse event of avelumab therapy. This case provides support to the hypothesis that PD-1/PD-L1 signaling may have a protective role in MG.

RATIONALE: Primary central nervous system lymphoma (PCNSL) involving the choroid plexus is exceedingly rare. The differential diagnosis for choroid plexus enhancing lesions in addition to lymphoma includes infections, sarcoidosis, tuberculosis, papilloma, meningioma, subependymoma, and metastatic lesions. PATIENT CONCERNS: A 71-year-old man presented with 3 days of episodic memory loss and gait disturbance. Brain magnetic resonance imaging showed homogenously enhancing lesions with mildly restricted diffusion and T2 hypointensity in the lateral ventricles, as well as T2 hyperintensity and enhancement in the right hippocampus. His episodic memory loss was thought to be secondary to subclinical focal seizures, supported by EEG revealing right temporal lobe epileptiform discharges. DIAGNOSES: Large B-cell lymphoma, nongerminal center type was revealed on pathological examination. INTERVENTIONS: Stereotactic biopsy of his right thalamic lesion was performed. OUTCOMES: The patient underwent induction therapy with high-dose methotrexate, temozolomide, and rituximab, which resulted in complete resolution of the enhancing lesions. He then underwent conditioning chemotherapy with carmustine and thiotepa, followed by autologous stem cell transplantation. His PCNSL remains in remission 42 weeks after the onset of symptoms. LESSONS: We report a patient with multifocal PCNSL involving the choroid plexus, who presented with abnormal gait and episodic confusion and memory loss. PCNSL should be considered in the differential diagnosis of acute encephalopathy among immunocompetent older individuals who have choroid plexus enhancing lesions.

The augmented immune response caused by immune checkpoint inhibitors leads to the emergence of a class of side effects called immune-related adverse events (irAEs). Facial palsy (FP) is rarely reported as an irAE. In this retrospective study, we reviewed the records of 353 patients treated with immunotherapy in our center from 2015-2018. We identified 4 male patients and 1 female patient with FP. Four had metastatic melanoma and were treated with ipilimumab either as monotherapy or in combination with nivolumab or pembrolizumab. The remaining patient had metastatic bladder cancer, treated with atezolizumab. FP was unilateral and occurred 1-23 weeks after starting immunotherapy. FP was part of a more diffuse neuropathic process in 3 of our patients. Lymphocytic pleocytosis was seen in the cerebrospinal fluid of 3 patients who had lumbar punctures. Magnetic resonance imaging showed enhancement of the intracranial portion of the affected facial nerve in 4 patients. The outcome was favorable in all of the patients noting that 1 patient had incomplete recovery. We conclude that FP, in isolation or as a part of a polyneuropathy, is common among neurological irAEs associated with checkpoint inhibitors and generally has a good prognosis.

Cancer immunotherapy with checkpoint inhibitors may result in neuromuscular immune-related adverse reactions, including Guillain-Barré syndrome (GBS)-like disease. On the other hand, checkpoint inhibitor therapy may result in exacerbation of underlying autoimmune diseases such as myasthenia gravis and multiple sclerosis. We present a patient who developed a severe and fatal relapse of postvaccination GBS after he was treated with nivolumab, a monoclonal antibody directed to programmed death-1 (PD-1), during a GBS treatment-related fluctuation. We recommend that caution be exercised in starting treatment with PD-1 inhibitors in the acute stage or early in the recovery period of GBS.

OBJECTIVE: To describe the protocol of a prospective study to test the validity of intermuscular coherence (IMC) as a diagnostic tool and biomarker of upper motor neuron degeneration in amyotrophic lateral sclerosis (ALS). METHODS: This is a multicenter, prospective study. IMC of muscle pairs in the upper and lower limbs is gathered in ∼650 subjects across three groups using surface electrodes and conventional electromyography (EMG) machines. The following subjects will be tested: 1) neurotypical controls; 2) patients with symptomatology suggestive for early ALS but not meeting probable or definite ALS by Awaji Criteria; 3) patients with a known ALS mimic. The recruitment period is between 3/31/2021 and 12/31/2025. Written consent will be sought from the subject or the subjects legally authorized representative during enrollment. RESULTS: The endpoints of this study include: 1) whether adding IMC to the Awaji ALS criteria improve its sensitivity in early ALS and can allow for diagnosis earlier; 2) constructing a database of IMC across different ages, genders, and ethnicities. SIGNIFICANCE: This study may validate a new inexpensive, painless, and widely available tool for the diagnosis of ALS.