Neurologic aspects of plasma cell disorders

Bing-Neel syndrome with a paravertebral mass

Bing-Neel syndrome, a rare neurological complication of Waldenström macroglobulinemia, is caused by the direct infiltration of malignant lymphoplasmacytic cells into the central nervous system. We report a patient who presented with back pain, weakness, lower extremity numbness, and gait disturbance accompanied by immunoglobulin M paraproteinemia and lymphoplasmacytic lymphoma in the bone marrow. Thoracic and lumbar magnetic resonance imaging revealed a long paravertebral mass around the spinal column, but the direct infiltration could not be proven. The patient was diagnosed with possible Bing-Neel syndrome and managed with bendamustine and rituximab. After chemotherapy, the patient's neurological and radiological findings improved. Magnetic resonance imaging should be considered when the Bing-Neel syndrome diagnosis is unclear.

Leukoencephalopathy During Daratumumab-Based Therapy: A Case Series of Two Patients with Multiple Myeloma

Leukoencephalopathy in the setting of multiple myeloma (MM) is a rare demyelinating condition, with few reported cases in literature. Daratumumab is a CD38 targeted monoclonal antibody that has been widely used for the management of MM. In the absence of central nervous system (CNS) disease, many medication-induced leukoencephalopathy cases reported with MM, including daratumumab-induced, are associated with progressive multifocal leukoencephalopathy (PML) and John Cunningham (JC) virus. Currently, there are no reported cases of daratumumab-induced leukoencephalopathy among patients without CNS involvement or PML. We discuss 2 patients who developed leukoencephalopathy while receiving daratumumab-based therapy without evidence of PML or CNS disease. Both patients had baseline MRIs without significant white matter changes before daratumumab-based therapy. Patients began experiencing neurological deficits about 6 to 8 months after daratumumab-based therapy initiation. One patient passed away before being assessed for improvement of symptoms with daratumumab cessation. The second patient had some stabilization of symptoms after cessation; however, the leukoencephalopathy remained irreversible. As the class of anti-CD38 monoclonal antibodies expands in MM therapy, we highlight a potential treatment complication and the importance of detecting leukoencephalopathy early among patients receiving anti-CD38 therapy. We recommend vigilant monitoring of any new or worsening neurological symptoms to avoid serious complications of irreversible leukoencephalopathy.

Collet-Sicard syndrome due to concurrent extramedullary intracranial plasmacytoma and jugular venous sinus thrombosis in multiple myeloma

In a patient with Collet-Sicard syndrome and multiple myeloma, both extramedullary plasmacytomas and internal jugular vein-sigmoid sinus thrombosis should be considered as they can coexist.

Hypercalcemic Encephalopathy as an Initial Presentation of Multiple Myeloma

We report the case of an 84-year-old female presented to us with acute onset altered sensorium. On investigation, neurological and infectious causes were ruled out. On further evaluation, her serum calcium was found elevated (15.07 gm/dl). The diagnosis of hypercalcemic encephalopathy was made with the possibility of multiple myeloma due to raised total protein and globulin levels. Serum electrophoresis, immunofixation, and bone marrow examination confirmed the diagnosis of multiple myeloma. The patient was treated with bortezomib, dexamethasone, and lenalidomide. After 1 week, she improved with normalization of serum calcium. Herein, we highlight hypercalcemia as an important cause of encephalopathy. As our report suggests, metabolic encephalopathy can be the first presentation in multiple myeloma.

Phase I Trial of Autologous CAR T Cells Targeting NKG2D Ligands in Patients with AML/MDS and Multiple Myeloma

NKG2D ligands are widely expressed in solid and hematologic malignancies but absent or poorly expressed on healthy tissues. We conducted a phase I dose-escalation study to evaluate the safety and feasibility of a single infusion of NKG2D-chimeric antigen receptor (CAR) T cells, without lymphodepleting conditioning in subjects with acute myeloid leukemia/myelodysplastic syndrome or relapsed/refractory multiple myeloma. Autologous T cells were transfected with a γ-retroviral vector encoding a CAR fusing human NKG2D with the CD3ζ signaling domain. Four dose levels (1 × 10⁶-3 × 10⁷ total viable T cells) were evaluated. Twelve subjects were infused [7 acute myeloid leukemia (AML) and 5 multiple myeloma]. NKG2D-CAR products demonstrated a median 75% vector-driven NKG2D expression on CD3⁺ T cells. No dose-limiting toxicities, cytokine release syndrome, or CAR T cell-related neurotoxicity was observed. No significant autoimmune reactions were noted, and none of the ≥ grade 3 adverse events were attributable to NKG2D-CAR T cells. At the single injection of low cell doses used in this trial, no objective tumor responses were observed. However, hematologic parameters transiently improved in one subject with AML at the highest dose, and cases of disease stability without further therapy or on subsequent treatments were noted. At 24 hours, the cytokine RANTES increased a median of 1.9-fold among all subjects and 5.8-fold among six AML patients. Consistent with preclinical studies, NKG2D-CAR T cell-expansion and persistence were limited. Manufactured NKG2D-CAR T cells exhibited functional activity against autologous tumor cells in vitro, but modifications to enhance CAR T-cell expansion and target density may be needed to boost clinical activity.

Abducens Nerve Palsy as Initial Presentation of Multiple Myeloma and Intracranial Plasmacytoma

Central Nervous System (CNS) involvement in multiple myeloma and/or multifocal solitary plasmacytoma is rare. Although they are unique entities, multiple myeloma (MM) and plasmacytoma represent a spectrum of plasma cell neoplastic diseases that can sometimes occur concurrently. Plasmacytomas very often present as late-stage sequelae of MM. In this case report, we report a 53-year-old female presenting with right abducens cranial nerve (CN) VI palsy as an initial presentation secondary to lesion of the right clivus.

Monoclonal gammopathy with both nemaline myopathy and amyloid myopathy

Monoclonal gammopathies due to plasma cell dyscrasias can induce diverse rare neuromuscular disorders. Deposition of monoclonal antibody light chains in skeletal muscle causes amyloid myopathy. Monoclonal gammopathy is occasionally associated with sporadic late-onset nemaline myopathy. Here we report a monoclonal gammopathy patient with both sporadic late-onset nemaline myopathy and amyloid myopathy. The diagnoses were based on immunofixation electrophoresis of urine, and serum for free light chain assay, Congo red staining and Thioflavin S staining of muscle biopsies, as well as immunohistochemical staining and electron-microscopic observation. Nemaline myopathy and amyloid myopathy can present in the same patient with monoclonal gammopathy.

[Clinical characteristics of pain syndrome in patients with multiple myeloma]

AIM

To study pain syndrome characteristics in the trunk and extremities of patients with multiple myeloma (MM).

MATERIAL AND METHODS

The study involved 120 patients with MM, aged from 34 to 83 years. The duration of disease was 2-37 months.

RESULTS AND CONCLUSION

The pain syndrome of trunk and extremity localization was revealed in 94% patients, its intensity according to the VAS was 65.5±25.4 mm. At all stages of disease, moderate to severe pain, predominantly related to polyneuropathy (PNP), radiculopathy and osteodestruction, was more frequent. Radicular pain syndrome was revealed in 46% of all MM patients, and in the majority of cases (92%), there were bone destruction lesions. The character of pain in MM should be specified to optimize further management of the patient.

Managing treatment-related peripheral neuropathy in patients with multiple myeloma

Peripheral neuropathy is one of the most important complications of multiple myeloma treatment. Neurological damage can be observed at the onset of the disease, due to the effect of monoclonal protein or radicular compression, but more often is treatment related. Vinca alkaloids in the past era, and more recently, thalidomide and bortezomib are mainly responsible. Degeneration of dorsal root ganglion is common, prevalently related to angiogenesis inhibition and cytokine modulation in the case of thalidomide and inhibition of the ubiquitin proteasome system in the case of bortezomib. Sensory neuropathy and neuropathic pain are more common; motor neuropathy and autonomic damage are less frequently observed. Neurotoxicity often affects patient's quality of life and requires dose modification or withdrawal of therapy, with a possible effect on the overall response. A prompt recognition of predisposing factors (such as diabetes mellitus, alcohol abuse, vitamin deficiencies, or viral infections) and appearance of signs and symptoms, through a periodic neurological assessment with appropriate scales, is extremely important. Effective management of treatment at the emergence of peripheral neuropathy can minimize the incidence and severity of this complication and preserve therapeutic efficacy. Dose adjustment could be necessary during treatment; moreover, gabapentin or pregabalin, tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors, carbamazepine, and opioid-type analgesics are suggested according to the pain severity. Some authors reported that patients who develop peripheral neuropathy during their multiple myeloma treatments presented a particular gene expression profile; therefore, future studies could be helpful for a better understanding of possible biological pathways underlying neurotoxicity.

Lymphoma-associated dysimmune polyneuropathies

Lymphoma consists of a variety of malignancies of lymphocyte origin. A spectrum of clinical peripheral neuropathy syndromes with different disease mechanisms occurs in about 5% of lymphoma patients. There exists a complex inter-relationship between lymphoproliferative malignancies and autoimmunity. An imbalance in the regulation of the immune system presumably underlies various immune-mediated neuropathies in patients with lymphoma. This article reviews lymphoma and more-or-less well-defined dysimmune neuropathy subgroups that are caused by humoral and/or cell-mediated immune disease mechanisms directed against known or undetermined peripheral nerve antigens.