Neuronal toxicity of monoclonal antibodies (mAbs): an analysis of post-marketing reports from FDA Adverse Event Reporting System (FAERS) safety database.

BACKGROUND: Monoclonal antibodies (mAbs) are pivotal in treating various diseases, including cancers and autoimmune disorders. Despite their therapeutic benefits, mAb therapy has been associated with neurological toxicity. OBJECTIVES: This study aimed to assess the occurrence of neuronal toxicity associated with mAbs, utilizing data from the FDA Adverse Event Reporting System (FAERS) safety database. The study also sought to delineate the medical characteristics of the reported cases. METHODS: A comprehensive analysis of neurological adverse events reported in the FAERS database was conducted, employing computational methodologies such as proportional relative risk (PRR), information component (IC025), and chi-square (χ2). Individual case safety reports (ICSRs) pertaining to neurological disorders linked to mAbs from the date of first global marketing authorization until June 30, 2023, were meticulously examined. RESULTS: The FAERS safety database contains 79,022 ICSRs linking mAbs to nervous system disorders. Rituximab, bevacizumab, denosumab, nivolumab, and trastuzumab were frequently cited. Reported adverse events include headache, peripheral neuropathy, dizziness, and cerebrovascular accident. Most ICSRs (85.81%) were serious, mainly affecting females (57.04%) with a 14.09% fatality rate. Panitumumab, atezolizumab, bevacizumab, and trastuzumab showed strong drug-event associations. Signal disproportionate reporting (SDR) analysis flagged myasthenia gravis, peripheral neuropathy, and neurotoxicity across multiple mAbs, suggesting potential signals. CONCLUSIONS: Interdisciplinary collaboration between oncologists and neurologists is crucial for safe mAb use. Our study enhances understanding of mAb neurological safety. Disproportionality signal analysis provides valuable evidence for risk mitigation.

Comprehensive Review Regarding Mercury Poisoning and Its Complex Involvement in Alzheimer's Disease.

Mercury (Hg) is considered one of the most widespread toxic environmental pollutants, which seems to have multiple effects on organisms even at low concentrations. It has a critical role in many health problems with harmful consequences, with Hg primarily targeting the brain and its components, such as the central nervous system (CNS). Hg exposure was associated with numerous CNS disorders that frequently trigger Alzheimer's disease (AD). Patients with AD have higher concentrations of Hg in blood and brain tissue. This paper aims to emphasize a correlation between Hg and AD based on the known literature in the occupational field. The outcome shows that all these concerning elements could get attributed to Hg. However, recent studies did not investigate the molecular level of Hg exposure in AD. The present review highlights the interactions between Hg and AD in neuronal degenerations, apoptosis, autophagy, oxidative stress (OS), mitochondrial malfunctions, gastrointestinal (GI) microflora, infertility and altering gene expression.

Pembrolizumab-Related Side Effects: Acute Renal Failure and Severe Neurological Toxicity.

Immunotherapy with immune checkpoint inhibitors represents nowadays a marked improvement in cancer treatment. Nevertheless, they can cause severe toxicities that put the patient at high risk, often requiring aggressive treatment. We present the case of a female patient who developed a severe immune-related adverse reaction to Pembrolizumab prescribed for melanoma treatment. Her array of symptoms, which presented a few days after last drug administration, consisted of severe neurological deficit, severe renal failure, polymyositis, and hyperthyroidism. Treatment required the immediate interruption of the trigger drug, infusion of high dose steroids, renal replacement therapy, plasmapheresis, and methimazole, as will be further discussed.

The toxicity of cell therapy: Mechanism, manifestations, and challenges.

Adoptive cell therapy (ACT), including tumor-infiltrating lymphocytes (TILs), T cell receptor engineered T cell (TCR-T), and chimeric antigen receptor engineered T cell (CAR-T), has shown significant clinical benefits for cancer treatment. However, all of these ACT therapies are associated with toxicities from mild to life threatening in clinic. Common ACT-related toxicities include cytokine release syndrome (CRS) resulting from immune activation, neurological toxicity, on-target/off tumor or off-target toxicities, and toxicities associated with lymphodepletion preconditioning and high does IL-2 administration. This review summarizes clinical manifestations of adverse events associated with ACT treatment and discusses the underlying pathological mechanisms. Moreover, challenges and opportunities of managing ACT-related toxicities have been discussed to give an indication of how to improve the safety of ACT treatment without dampening the therapeutic effect.

Isolated Abducens Nerve Palsy Following Pembrolizumab.

Pembrolizumab is a checkpoint inhibitor targeting the programmed cell death 1 receptor of lymphocytes and is used in the treatment of solid tumours including melanoma. The authors report a 64-year-old man treated with pembrolizumab for stage IV cutaneous melanoma (primary cutaneous melanoma of the right lower back) with liver metastases. The patient developed a horizontal binocular diplopia due to an isolated unilateral cranial nerve VI palsy. Following 1 week of high dose oral steroid therapy and cessation of the drug, the patient's nerve palsy and associated diplopic symptoms improved dramatically, and after 6 weeks of oral steroid taper and drug cessation, the palsy resolved completely. Few reports of checkpoint inhibitor autoimmune-induced isolated cranial nerve palsies have been described, and this is the first report of drug-induced isolated cranial nerve VI palsy.

Suspected neurological toxicity after oral application of fluralaner (Bravecto®) in a Kooikerhondje dog.

BACKGROUND: Although the new isoxazoline drug fluralaner (Bravecto®) is generally well tolerated in dogs, adverse drug reactions involving neurological dysfunction occurred in individual dogs. However, most of these cases are documented inadequately and none of them is reported and discussed in the literature. As isoxazoline drugs target neuronal chloride channels with a clear preference for invertebrates, they are considered to have a good safety profile. However, pharmacodynamic effects in the nervous system of vertebrates cannot be ruled out completely. CASE PRESENTATION: A seven-month-old female Kooikerhondje dog was treated with Bravecto® at the recommended dose. About 24 h after administration, the dog exhibited signs of neurological toxicity, including generalized ataxia, myoclonic jerks, tremor of head and body, muscle twitching and oral dysphagia. All symptoms were transient and the dog fully recovered without any treatment after 10 h. CONCLUSION: This case report describes transient occurrence of neurological dysfunction after administration of Bravecto®. It may help to better classify adverse drug reactions after application of isoxazoline drugs and documents a good prognosis even after occurrence of severe neurological dysfunction in the present case.

Posterior Reversible Encephalopathy Syndrome Associated with Sorafenib and Successful Retreatment.

Posterior reversible encephalopathy syndrome (PRES) is a clinical and radiological syndrome characterized by acute hypertension, headache, decreased level of consciousness, visual disturbances and seizures associated with characteristic neuroimaging changes indicative of vasogenic edema of the posterior cerebral white matter. Several medical conditions have been associated with PRES including hypertensive encephalopathy and eclampsia. The use of cytotoxic and immunosuppressant drugs, such as those which target vascular endothelial growth factor (VEGF), have also been implicated. We report here the case of a 71-year-old woman with metastatic clear cell renal carcinoma who developed PRES 3 months after commencing sorafenib. Elevated blood pressure (BP) was recorded, and MRI of the brain) of the brain showed asymmetric areas of increased signal intensity within the supratentorial white matter suggestive of PRES. Clinical and radiological features rapidly improved with BP control and discontinuation of sorafenib. Sorafenib was resumed with no sign of PRES recurrence. The present case report supports the hypothesis that, in selected patients, the re-introduction of anti-VEGF therapies after PRES is feasible.

Neurotoxicity from immune-checkpoint inhibition in the treatment of melanoma: a single centre experience and review of the literature.

Background: Treatment with immune checkpoint inhibitors (ICPi) has greatly improved survival for patients with advanced melanoma in recent years. Anti-CTLA-4 and anti-PD1 antibodies have been approved following large Phase III trials. Immune-related neurological toxicity of varying severity has been reported in the literature. The cumulative incidence of neurotoxicity among ipilimumab, nivolumab and pembrolizumab is reported as <1% in published clinical trials. We aimed to identify the incidence of neurotoxicity in our institution across anti-CTLA4 and anti-PD-1 antibodies, including the combination of ipilimumab with nivolumab. We also review the existing literature and propose an investigation and management algorithm. Methods: All patients with advanced melanoma treated with ipilimumab, nivolumab, pembrolizumab or the combination of ipilimumab and nivolumab (ipi + nivo), managed at the Royal Marsden Hospital between September 2010 and December 2015, including patients on (published) clinical trials were included. Medical records for each patient were reviewed and information on neurotoxicity recorded. A systematic search strategy was performed to collate existing reports of neurological toxicity. Results: In total, 413 immunotherapy treatment episodes in 352 patients were included, with median follow-up of 26.7 months. Ten cases of neurotoxicity were recorded, affecting 2.8% of patients overall, ranging from grade 1 to 4, affecting both central and peripheral nervous systems. A rate of 14% was noted with ipi + nivo. Three of five patients commenced on corticosteroids responded to these. Six patients had made a full recovery at the time of reporting. A favorable radiological response was found in 7 of the 10 cases. Unusual presentations are described in detail. Conclusions: Neurological toxicity is not uncommon, and may be more frequent in patients treated with combination ipi + nivo. Patterns of presentation and response to treatment are varied. A prompt and considered approach is required to optimize outcomes in this group of patients.

Multifocal disseminated necrotizing leukoencephalopathy as severe central nervous system toxicity from nivolumab therapy for Hodgkin lymphoma: a case report.

Nivolumab, a monoclonal antibody approved in 2014 as an immune checkpoint inhibitor, offers benefits in cancer treatment but can cause serious neurological complications, including multifocal disseminated necrotizing leukoencephalopathy. We report a case of severe central nervous system toxicity in a 13-year-old boy with Hodgkin lymphoma who was treated with nivolumab following an inadequate response to multiple lines of chemotherapy. After six cycles of nivolumab, the patient developed multifocal disseminated necrotizing leukoencephalopathy, presenting with altered mental status, seizures, and neurological deficits with magnetic resonance imaging (MRI) findings of extensive white matter involvement, rendering him completely disabled. This case highlights the potential for disabling neurological complications associated with immune checkpoint inhibitors, emphasizing the importance of early detection through regular neurological assessment and MRI surveillance. The case also underscores the need for careful patient selection and monitoring when using nivolumab to mitigate the risk of severe central nervous system toxicity.

Facial palsy after administration of immune checkpoint inhibitors: case report, literature review and clinical care management.

Neurological immune-related adverse events (irAEs) due to immune checkpoint inhibitors (ICI) are rare complications of immunotherapy, particularly dreadful for patients and clinical teams. Indeed, neurological irAEs are potentially severe and their diagnosis require prompt recognition and treatment. Additionally, the spectrum of neurological irAEs is broad, affecting either neuromuscular junction, peripheral or central nervous system. Here, we described the case of a 55-year man with metastatic melanoma, facing a brutal right peripheral cerebral palsy after his third ipilimumab/nivolumab infusion. After the case presentation, we reviewed the literature about this rare complication of immunotherapy, and described its diagnosis work-up and clinical management.

Visual Hallucinations With Arsenic Trioxide Therapy in Acute Promyelocytic Leukemia.

A 68-year-old male with a history of diabetes and hypertension was diagnosed with acute promyelocytic leukemia (APML). He underwent induction therapy with all-trans retinoic acid (ATRA) and arsenic trioxide. He had a complete hematologic response and was initiated on consolidation therapy with arsenic trioxide (0.15 mg/kg/day intravenous (IV)) and ATRA (45 mg/per meter square of body surface area/day IV). He developed blurred vision and floaters after a few days. Soon after, he felt that his diabetic neuropathy had suddenly worsened. The floaters and flashing lights worsened and morphed into visual hallucinations. He reported seeing figures watching him from the corner of the room. He was admitted and head imaging was unremarkable. Routine labs did not show anything unusual. Arsenic trioxide therapy was held. The hallucinations gradually started decreasing and eventually subsided after around eight weeks. ATRA was continued but arsenic was permanently discontinued. Arsenic is known to cause poisoning if exposed in significant amounts. The arsenic dose used for APML is substantially low (0.15 mg/kg/day IV). We delineate this unanticipated case of arsenic toxicity leading to severe neurological symptoms like visual hallucinations which has not been previously reported in the literature. It is imperative to closely monitor patients who are on arsenic therapy and inform them about possible rare toxicities.

Mononeuritis multiplex following immune checkpoint inhibitors in malignant pleural mesothelioma.

Introduction: Mononeuritis multiplex is frequently related to vasculitic neuropathy and has been reported only sporadically as an adverse event of immune checkpoint inhibitors. Methods: Case series of three patients with mononeuritis multiplex-all with mesothelioma-identified in the databases of two French clinical networks (French Reference Center for Paraneoplastic Neurological Syndromes, Lyon; OncoNeuroTox, Paris; January 2015-October 2022) set up to collect and investigate n-irAEs on a nationwide level. Results: Three patients (male; median age 86 years; range 72-88 years) had pleural mesothelioma and received 10, 4, and 6 cycles, respectively, of first-line nivolumab plus ipilimumab combined therapy. In patient 1, the neurological symptoms involved the median nerves, and in the other two patients, there was a more diffuse distribution; the symptoms were severe (common terminology criteria for adverse events, CTCAE grade 3) in all patients. Nerve conduction studies indicated mononeuritis multiplex in all patients. Peripheral nerve biopsy demonstrated necrotizing vasculitis in patients 1 and 3 and marked IgA deposition without inflammatory lesions in patient 2. Immune checkpoint inhibitors were permanently withdrawn, and corticosteroids were administered to all patients, leading to complete symptom regression (CTCAE grade 0, patient 2) or partial improvement (CTCAE grade 2, patients 1 and 3). During steroid tapering, patient 1 experienced symptom recurrence and spreading to other nerve territories (CTCAE grade 3); he improved 3 months after rituximab and cyclophosphamide administration. Discussion: We report the occurrence of mononeuritis multiplex, a very rare adverse event of immune checkpoint inhibitors, in the three patients with mesothelioma. Clinicians must be aware of this severe, yet treatable adverse event.

Demyelinating polyradiculoneuropathy during dabrafenib and trametinib treatment for metastatic melanoma: A case report.

BACKGROUND: Melanoma is an aggressive malignancy, historically characterized with a poor prognosis and few treatment options. The advent of target therapy with BRAF and MEK inhibitors, as well as immunotherapy, changed this scenario and improved the prognosis of patients with BRAF V600E mutation. These therapies are generally well tolerated. Neurological toxicities, especially polyradiculopathy, are very rare with BRAF inhibitors and MEK inhibitors although some cases have been described in recent years, regardless of the type of target therapies combination used. CASE REPORT: We report the case of a patient with BRAF V600E-mutated metastatic melanoma treated with dabrafenib and trametinib who has developed a demyelinating polyradiculoneuropathy. CONCLUSION: This case, once more, should draw our attention to the possibility of rare, but potentially serious side effects, even in the case of generally well-tolerated treatments. Especially in the presence of side effects, it is important a close relationship between clinicians and patients for the management of adverse events and the choice of the best treatment strategy.

Neurological adverse events of mitotane in adrenocortical carcinoma: results of a pilot study.

Introduction: Mitotane, the only drug approved by the Food and Drug Administration (FDA) for the treatment of adrenocortical carcinoma, is associated with several side effects including neurotoxicity. The aim of our study is to investigate the relationship between mitotane plasma levels and neurological toxicity. Methods: We have considered five patients affected by adrenocortical carcinoma treated with mitotane. The neurological assessment included a neurological examination, an electroencephalogram, event-related potentials (P300), and a neuropsychological assessment. All of the patients were first considered at the onset of symptoms of neurotoxicity or when mitotanemia levels were above 18 mg/L, for the second time at mitotanemia normalization and subsequently at its further increase, or in case of persistent neurological abnormalities, some months after normalization. Results: At the first neurotoxicity, four patients showed impaired neurological examination, electroencephalogram, and P300; three patients had impaired neuropsychological assessment; one patient, only P300. At mitotanemia normalization, the neurological examination became normal in all patients and electroencephalogram normalized in one patient, improved in another one, continuing to be altered in the other three. P300 latency and neuropsychological assessment normalized in two patients and persisted altered in the patient experiencing long-term mitotane toxicity. At the third evaluation, in the patient with prolonged mitotane toxicity, the normal mitotanemia in the previous 9 months restored P300 and improved the electroencephalogram but not the neuropsychological assessment. In the two patients experiencing a further rise of mitotanemia, neurological examination was normal but P300 and electroencephalogram were altered. Conclusion: The results of our study highlighted the presence of neurophysiological and neuropsychological abnormalities associated with mitotane values above 18 mg/L.

Toxicities of CAR T-cell therapy: a review of current literature.

The chimeric antigen receptor (CAR) design, first invented by Zelig Eshhar, paved the way for the use of genetically modified T-cells in targeted therapy against cancer cells. Since then, it has gone through many generations, especially with the integration of co-stimulation in the second and third-generation CARs. However, it also mounts a hyperactive immune response named as cytokine release syndrome with the release of several cytokines eventually resulting in multiple end-organ toxicities. The severity of cytokine release syndrome depends upon certain factors such as the tumor burden, choice of co-stimulation, and degree of lymphodepletion, and can manifest as pulmonary edema, vascular leak, renal dysfunction, cardiac problems, hepatic failure, and coagulopathy. Many grading criteria have been used to define these clinical manifestations but they lack harmonization. Neurotoxicity has also been significantly associated with CAR T-cell therapy but it has not been studied much in previous literature. This review aims to provide a comprehensive account of the clinical manifestations, diagnosis, management, and treatment of CAR T-cell associated neurotoxicity.

Do peripheral neuropathies differ among immune checkpoint inhibitors? Reports from the European post-marketing surveillance database in the past 10 years.

Although the immunotherapy advent has revolutionized cancer treatment, it, unfortunately, does not spare cancer patients from possible immune-related adverse events (irAEs), which can also involve the peripheral nervous system. Immune checkpoint inhibitors (ICIs), blocking cytotoxic T-lymphocyteassociated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed cell death ligand 1 (PD-L1), can induce an immune imbalance and cause different peripheral neuropathies (PNs). Considering the wide range of PNs and their high impact on the safety and quality of life for cancer patients and the availability of large post-marketing surveillance databases, we chose to analyze the characteristics of ICI-related PNs reported as suspected drug reactions from 2010 to 2020 in the European real-world context. We analyzed data collected in the European pharmacovigilance database, Eudravigilance, and conducted a systematic and disproportionality analysis. In our study, we found 735 reports describing 766 PNs occurred in patients treated with ICIs. These PNs included Guillain-Barré syndrome, Miller-Fisher syndrome, neuritis, and chronic inflammatory demyelinating polyradiculoneuropathy. These ADRs were often serious, resulting in patient disability or hospitalization. Moreover, our disproportionality analysis revealed an increased reporting frequency of PNs with tezolizumab compared to other ICIs. Guillain-Barré syndrome is a notable potential PN related to ICIs, as it is associated with a significant impact on patient safety and has had unfavorable outcomes, including a fatal one. Continued monitoring of the safety profile of ICIs in real-life settings is necessary, especially considering the increased frequency of PNs associated with atezolizumab compared with other ICIs.

Whole genome sequencing across clinical trials identifies rare coding variants in GPR68 associated with chemotherapy-induced peripheral neuropathy.

BACKGROUND: Dose-limiting toxicities significantly impact the benefit/risk profile of many drugs. Whole genome sequencing (WGS) in patients receiving drugs with dose-limiting toxicities can identify therapeutic hypotheses to prevent these toxicities. Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting neurological toxicity of chemotherapies with no effective approach for prevention. METHODS: We conducted a genetic study of time-to-first peripheral neuropathy event using 30× germline WGS data from whole blood samples from 4900 European-ancestry cancer patients in 14 randomized controlled trials. A substantial number of patients in these trials received taxane and platinum-based chemotherapies as part of their treatment regimen, either standard of care or in combination with the PD-L1 inhibitor atezolizumab. The trials spanned several cancers including renal cell carcinoma, triple negative breast cancer, non-small cell lung cancer, small cell lung cancer, bladder cancer, ovarian cancer, and melanoma. RESULTS: We identified a locus consisting of low-frequency variants in intron 13 of GRID2 associated with time-to-onset of first peripheral neuropathy (PN) indexed by rs17020773 (p = 2.03 × 10-8, all patients, p = 6.36 × 10-9, taxane treated). Gene-level burden analysis identified rare coding variants associated with increased PN risk in the C-terminus of GPR68 (p = 1.59 × 10-6, all patients, p = 3.47 × 10-8, taxane treated), a pH-sensitive G-protein coupled receptor (GPCR). The variants driving this signal were found to alter predicted arrestin binding motifs in the C-terminus of GPR68. Analysis of snRNA-seq from human dorsal root ganglia (DRG) indicated that expression of GPR68 was highest in mechano-thermo-sensitive nociceptors. CONCLUSIONS: Our genetic study provides insight into the impact of low-frequency and rare coding genetic variation on PN risk and suggests that further study of GPR68 in sensory neurons may yield a therapeutic hypothesis for prevention of CIPN.

Identifying and managing CAR T-cell-mediated toxicities: on behalf of an Italian CAR-T multidisciplinary team.

INTRODUCTION: Chimeric antigen receptor (CAR)-T-cell therapy is a new treatment for patients with hematologic malignancies in which other therapies have failed. AREAS COVERED: The review provides an overview for recognizing and managing the most acute toxicities related to CAR-T cells. EXPERT OPINION: The development of immune-mediated toxicities is a common challenge of CAR-T therapy. The mechanism that determines this toxicity is still unclear, although an unfavorable tumor microenvironment and a pro-inflammatory state put patients at risk. The monitoring, diagnosis, and treatment of post-CAR-T toxicities must be determined and based on international guidelines and internal clinical practice. It is urgent to identify biomarkers that can identify patients at greater risk of developing complications. The adoption of consistent grading criteria is necessary to improve toxicity management strategies continually. The first-line therapy consists of supportive care and treatment with tocilizumab or corticosteroids. An early start of cytokine blockade therapies could mitigate toxicity. The plan will include cytokine release prophylaxis, a risk-adapted treatment, prevention of on-target/off-tumor effect, and a switch on/off CAR-T approach.

5-arylalkynyl-2-benzoyl thiophene: a novel microtubule inhibitor exhibits antitumor activity without neurological toxicity.

The composition of microtubules involving several steps, including the polymerization and depolymerization of α-tubulin and ß-tubulin heterodimers. Microtubule-targeting agents can increase or inhibit microtubule polymerization, thereby disrupting the dynamic process and stalling cells in G2/M phase. Microtubule-targeting agents are generally cytotoxic, which neurological toxicity being one of the significant adverse events associated. We recently reported a novel 5-arylalkynyl-2-benzoyl thiophene (PST-3) that exhibited broad-spectrum cellular cytotoxicity and in vivo potency with high safety. PST-3 was a substrate of p-gp, which could not cross the blood-brain barrier and lead to less neurotoxicity. The antitumor activities in vitro demonstrated that PST-3 combined with the colchicine-binding site on microtubule, induces morphological changes, disrupts microtubule networks, inhibits polymerization of tubulin, arrests breast cancer cells in the G2/M phase of the cell cycle and induces apoptosis. Evaluation of the antitumor effect in vivo demonstrated that PST-3 elicited MDA-MB-468 tumor %T/C of 11.75%, whereas elicited MCF7 tumor %T/C of 44.38% in breast cancer xenograft models. Besides, in vivo experiments of a higher dose (60 mg/kg) of PST-3 treatment for 21 days did not produce any significant neurotoxicity. These results provide evidence that PST-3 might possess the potential to be developed into a new microtubule inhibitor without neurological toxicity.

Immune checkpoint inhibitor-induced neurologic toxicity: a case report and literature review.

Immune checkpoint inhibitors (ICIs) are approved for the treatment of head and neck carcinoma. They have significantly improved survival in these patients but may cause immune-related adverse events (irAEs), some of which may be serious. The report presents a rare case of a neurologic adverse event associated with programmed death-1 inhibitor monotherapy. Neurologic irAEs (NirAEs) can occur in various and atypical forms, be potentially disabling and occur at various times during and after treatment. Prompt identification and drug withdrawal are essential to improve outcomes. A high dose of systemic corticosteroid has been recommended for the management of NirAEs, although optimal immunomodulatory treatment is still debated.

Current recommendations for head and neck squamous cell carcinoma treatments have been significantly modified after the introduction of immunotherapy. Indeed, immune checkpoint inhibitors (ICIs) are now recommended in localized and metastatic disease. Programmed death ligand-1 (PD-L1)-positive tumors can be treated with immunotherapy in the first and second lines regardless of PD-L1 expression. By increasing immune system activity, ICIs can have adverse effects. In most cases, these can be treated with the interruption of treatment and/or supportive therapy, which can include the administration of immunosuppressants. This report describes a case of suspected a neurologic adverse event characterized by trouble with balance and double vision in a person with head and neck cancer treated with nivolumab. This was adverse event was by pausing therapy and low-dose steroid treatment, leading to complete reduction of symptoms. Unfortunately, the laboratory and instrumental investigations could not determine an exact diagnosis or the area of neurological damage.