Motor polyradiculopathy during pembrolizumab treatment of metastatic melanoma

Pembrolizumab-Induced Isolated Cranial Neuropathy: A Rare Case Report and Review of Literature

Introduction: Anti-PD1 agents are widely used in the treatment of solid tumors. This has prompted the recognition of a class of immune-related adverse events (irAEs), due to the activation of autoimmune T-cells. Pembrolizumab is an anti-PD1 agent, which has been related to an increased risk of various neurological irAE (n-irAEs). Here, we present a rare case of pembrolizumab-induced neuropathy of cranial nerves. Case Report: A 72-year-old patient was diagnosed with a lung adenocarcinoma in February 2018 (EGFR-, ALK-, and PDL1 90%). According to the molecular profile, pembrolizumab was started. After three administrations, the patient developed facial paresis, ptosis, ophthalmoplegia, and dysphonia. As brain metastases and paraneoplastic markers were excluded, a drug-related disorder was suspected and pembrolizumab was discontinued. A nerve conduction study and electromyography excluded signs of neuropathy and myopathy at four limbs, and repetitive nerve stimulation was negative. However, altered blink reflex and nerve facial conduction were consistent with an acute neuropathy of the cranial district. Thus, the patient was treated with two cycles of intravenous immunoglobulins (IVIg), which rapidly allowed improvement of both symptoms and neurophysiological parameters. However, the patient died in October 2018 for a progression of lung tumor. Discussion: Only 16 cases of pembrolizumab-related neuropathies have been described so far. Our case is of particular interest for the isolated involvement of cranial nerves and the prompt response to IVIg. Conclusion: N-irAEs are insidious conditions that require solid knowledge of onco-immunotherapy complications: it is mandatory not to delay any treatment that would potentially modify the course of a neurological complication.

Inflammatory Myeloradiculitis Secondary to Pembrolizumab: A Case Report and Literature Review

Immune checkpoint inhibitors are the most important new medications in oncology and include inhibitors of programmed cell death protein-1 (PD-1) such as Pembrolizumab, Nivolumab, and Cemiplimab. These anticancer agents prevent tumour immune evasion and have been associated with a range of immune-related adverse events (irAEs) including those involving the nervous system. In this case report and literature review, we present the first case of inflammatory myeloradiculitis secondary to Pembrolizumab. We also summarise the characteristics, treatment, and outcomes of other cases reported in the literature which include a component of myelitis. Finally, we make general recommendations on management.

Polyradiculoneuropathy induced by immune checkpoint inhibitors: a case series and review of the literature

OBJECTIVE

The purpose of the present study is to report the clinical characteristics of polyradiculoneuropathy induced by immune checkpoint inhibitors (ICIs).

METHODS

We retrospectively reviewed lists of all inpatients with neurological immune-related adverse events (irAEs) treated at the neurology departments of three hospitals in January 2017 and December 2019. We also performed a review of the previous case reports with polyradiculoneuropathy induced by ICI therapy.

RESULTS

We had 4 patients with polyradiculoneuropathy following ICI therapy. We comprehensively reviewed our 4 patients and 32 previous case reports. There were 28 men and 8 women with a mean onset age of 61 years. ICI monotherapy was performed in 27 patients, whereas the combination of ICIs was administered in 9 patients. All patients except 2 showed limb weakness, which was observed symmetrically and predominantly in the legs rather than the arms. Bulbar involvement was observed in 7 patients. The laboratory findings were demyelination in electrophysiological studies and elevated protein with lymphocytes in the cerebrospinal fluid. Disease severity was ranked on the Hughes functional scale; 17 patients were grade 4 or greater. The treatment responses to corticosteroid and intravenous methylprednisolone were favorable. Intravenous immunoglobulin was also used in combination with steroids. Seven patients died, including 4 who on mechanical ventilation.

CONCLUSION

Polyradiculoneuropathy induced by ICIs has a distinct subset of neurological irAEs and requires early recognition.

Brucellosis causing subacute motor polyradiculopathy and the pathological correlation of pseudomyopathic electromyography: A case report

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Brucellosis may present with subacute polyradiculoneuropathy.

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Degeneration and regeneration of muscle fiber causes myopathy like features on EMG.

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Absence of sensory involvement does not exclude subacute polyradiculoneuropathy.

Introduction

Brucellosis is a rare cause of polyradiculopathy. We aim to present a case of subacute motor polyradiculopathy (SAMPR), along with the electromyographic pseudomyopathic changes, and their histopathological correlation.

Case presentation

A 24-year-old man presented with gradually progressive bilateral lower limb weakness for three weeks that progressed to a loss of ambulation in seven weeks. He had no ocular, facial, or sphincteric weakness and no sensory symptoms. He showed normal cognitive, cranial nerve, and upper limb exams. His lower limb power was medical research council (MRC) grade 3 proximally, and 4 distally. His reflexes were grade 2+ in the upper limbs and grade 0 in the lower limbs. The nerve conduction studies were normal. Electromyography (EMG) showed active denervation with a short-duration motor unit potential (MUP) and early recruitment. MRI showed a diffuse enhancement of the lumbosacral nerve roots. Cerebrospinal fluid (CSF) showed a protein of 2.7 g/L and a white blood cells (WBC) count of 420 cells per microliter. Muscle biopsy revealed neurogenic changes with secondary degenerating and regenerating fibers, explaining the small and short MUPs in the EMG. CSF grew Brucella after fourteen days of incubation. Serum showed high antibody titers for the Brucella species “Melitensis” and “Abortus”. The patient started to walk again, ten months after starting a course of antibiotics.

Conclusion

Neurobrucellosis can present primarily as SAMPR, sparing the sensory system. SAMPR, with ongoing degenerating and regenerating muscle fibers, may explain the pseudomyopathic changes found in electromyographic studies.

Severe Neurological Toxicity of Immune Checkpoint Inhibitors: Growing Spectrum

Expanding use of immune-checkpoint inhibitors (ICIs) underscores the importance of accurate diagnosis and timely management of neurological immune-related adverse events (irAE-N). We evaluate the real-world frequency, phenotypes, co-occurring immune-related adverse events (irAEs), and long-term outcomes of severe, grade III to V irAE-N at a tertiary care center over 6 years. We analyze how our experience supports published literature and professional society guidelines. We also discuss these data with regard to common clinical scenarios, such as combination therapy, ICI rechallenge and risk of relapse of irAE-N, and corticosteroid taper, which are not specifically addressed by current guidelines and/or have limited data. Recommendations for management and future irAE-N reporting are outlined. ANN NEUROL 2020;87:659-669.

Varied phenotypes and management of immune checkpoint inhibitor-associated neuropathies

OBJECTIVE

To describe the spectrum, clinical course, and management of neuropathies associated with immune checkpoint inhibitors (ICIs).

METHODS

Patients with ICI-related neuropathy (irNeuropathy) were identified and their clinical characteristics compared to neuropathy attributed to cytotoxic agents.

RESULTS

We identified 19 patients with irNeuropathies. ICIs included anti-programmed death-1 (PD1), 9; anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), 2; and combination of anti-CTLA4 and anti-PD1, 8. Median number of ICI doses prior to neuropathy onset was 4. Rate of neuropathies following ICI therapy was 0.7%. Underlying malignancies included melanoma (n = 15), lung adenocarcinoma (n = 3), and cholangiocarcinoma (n = 1). Neuropathy phenotypes were cranial neuropathies with or without meningitis (n = 7), nonlength-dependent polyradiculoneuropathies with and without cranial nerve involvement (n = 6), small-fiber/autonomic neuropathy (n = 2), ANCA-associated mononeuritis multiplex (n = 1), sensory neuronopathy (n = 1), length-dependent sensorimotor axonal polyneuropathy (n = 1), and neuralgic amyotrophy (n = 1). Immune-related adverse events involving other organ systems were common (58%). Corticosteroid use for management of neuropathy was associated with improvement in median modified Rankin Scale score (1 vs 0, p = 0.001) and Inflammatory Neuropathy Cause and Treatment Disability score (2 vs 0.5, p = 0.012) (Class IV). Significantly higher proportion of irNeuropathies had acute or subacute and nonlength-dependent presentations (p < 0.001) and rate of hospitalization for irNeuropathy was also higher (p = 0.002) compared to toxic neuropathy from chemotherapy.

CONCLUSION

Neuropathy is a rare complication of ICIs that often responds to immunosuppression. Recognition of its wide phenotypic spectrum and distinct clinical characteristics and prompt management with corticosteroids may lead to favorable outcomes.

Acute lumbar polyradiculoneuropathy as early sign of methotrexate intrathecal neurotoxicity: Case report and literature review

Acute paraplegia after treatment with intrathecal methotrexate requires a complete spinal cord neuroimaging as well as electrodiagnostic examination. The absence of lumbosacral F waves motor responses without demyelinating findings may indicate early direct root toxicity. Early electromyography (EMG) screening could be a valuable tool for detecting peripheral neurotoxicity.

Case Reports of Pembrolizumab-induced Acute Inflammatory Demyelinating Polyneuropathy

Pembrolizumab is a humanized monoclonal antibody that blocks the programmed cell death 1 (PD-1) pathway, thereby enhancing antitumor immunity. As the use of immune checkpoint inhibitors becomes more prevalent, so do immune-related adverse events associated with their use. The immune-related adverse events linked with this class of drugs are commonly seen and most of the time are classified as mild adverse events. These are easily treated with steroids if recognition of symptomatology and treatment are promptly established. However, neurologic immune-related adverse events are less understood and have been infrequently cited in the medical literature, thus representing a challenge for clinicians.

Neurological toxicities associated with immune-checkpoint inhibitors

PURPOSE OF REVIEW

Immune-checkpoint inhibitors (ICIs) constitute a novel class of agents recently approved to treat a number of human malignancies. Due to their immunomodulatory mechanism of action, ICIs can generate a wide range of immune-related adverse events (irAEs) of which neurological toxicities are of special interest because of their potential severity. The objective of this review is to examine the recent literature describing neurological irAEs and discuss their optimal management.

RECENT FINDINGS

As opposed to irAEs involving other organs, neurological complications of ICIs are uncommon. These complications encompass various toxicities of the central and peripheral nervous systems, including myositis, myasthenia gravis, demyelinating polyradiculoneuropathy, meningitis and encephalitis. Neurologic irAEs are often responsive to corticosteroids and other immune-modulating treatments (e.g. plasmapheresis, intravenous immunoglobulin), which have been used in patients presenting with severe neurologic irAEs or irAEs unresponsive to corticosteroids. Data from literature indicate that early treatment is critical for reducing the morbidity associated with neurologic irAEs.

SUMMARY

ICI-associated irAEs constitute a new group of neurologic complications of systemic anticancer therapies. Although potentially severe, these rare neurologic toxicities are often responsive to immune-modulating therapies. Early recognition and treatment is crucial for timely improvement of functional outcome and requires a multidisciplinary approach.