Recurrent Brachial Neuritis Attacks in Presentation of B-Cell Lymphoma

Paraneoplastic neuropathies and peripheral nerve hyperexcitability disorders

Peripheral neuropathy is a common referral for patients to the neurologic clinics. Paraneoplastic neuropathies account for a small but high morbidity and mortality subgroup. Symptoms include weakness, sensory loss, sweating irregularity, blood pressure instability, severe constipation, and neuropathic pain. Neuropathy is the first presenting symptom of malignancy among many patients. The molecular and cellular oncogenic immune targets reside within cell bodies, axons, cytoplasms, or surface membranes of neural tissues. A more favorable immune treatment outcome occurs in those where the targets reside on the cell surface. Patients with antibodies binding cell surface antigens commonly have neural hyperexcitability with pain, cramps, fasciculations, and hyperhidrotic attacks (CASPR2, LGI1, and others). The antigenic targets are also commonly expressed in the central nervous system, with presenting symptoms being myelopathy, encephalopathy, and seizures with neuropathy, often masked. Pain and autonomic components typically relate to small nerve fiber involvement (nociceptive, adrenergic, enteric, and sudomotor), sometimes without nerve fiber loss but rather hyperexcitability. The specific antibodies discovered help direct cancer investigations. Among the primary axonal paraneoplastic neuropathies, pathognomonic clinical features do not exist, and testing for multiple antibodies simultaneously provides the best sensitivity in testing (AGNA1-SOX1; amphiphysin; ANNA-1-HU; ANNA-3-DACH1; CASPR2; CRMP5; LGI1; PCA2-MAP1B, and others). Performing confirmatory antibody testing using adjunct methods improves specificity. Antibody-mediated demyelinating paraneoplastic neuropathies are limited to MAG-IgM (IgM-MGUS, Waldenström's, and myeloma), with the others associated with cytokine elevations (VEGF, IL6) caused by osteosclerotic myeloma, plasmacytoma (POEMS), and rarely angiofollicular lymphoma (Castleman's). Paraneoplastic disorders have clinical overlap with other idiopathic antibody disorders, including IgG4 demyelinating nodopathies (NF155 and Contactin-1). This review summarizes the paraneoplastic neuropathies, including those with peripheral nerve hyperexcitability.

Parsonage-Turner Syndrome and Hereditary Brachial Plexus Neuropathy

Parsonage-Turner syndrome and hereditary brachial plexus neuropathy (HBPN) present with indistinguishable attacks of rapid-onset severe shoulder and arm pain, disabling weakness, and early muscle atrophy. Their combined incidence ranges from 3 to 100 in 100,000 persons per year. Dominant mutations of SEPT9 are the only known mutations responsible for HBPN. Parsonage and Turner termed the disorder "brachial neuralgic amyotrophy," highlighting neuropathic pain and muscle atrophy. Modern electrodiagnostic and imaging testing assists the diagnosis in distinction from mimicking disorders. Shoulder and upper limb nerves outside the brachial plexus are commonly affected including the phrenic nerve where diaphragm ultrasound improves diagnosis. Magnetic resonance imaging can show multifocal T2 nerve and muscle hyperintensities with nerve hourglass swellings and constrictions identifiable also by ultrasound. An inflammatory immune component is suggested by nerve biopsies and associated infectious, immunization, trauma, surgery, and childbirth triggers. High-dose pulsed steroids assist initial pain control; however, weakness and subsequent pain are not clearly responsive to steroids and instead benefit from time, physical therapy, and non-narcotic pain medications. Recurrent attacks in HBPN are common and prophylactic steroids or intravenous immunoglobulin may reduce surgical- or childbirth-induced attacks. Rehabilitation focusing on restoring functional scapular mechanics, energy conservation, contracture prevention, and pain management are critical. Lifetime residual pain and weakness are rare with most making dramatic functional recovery. Tendon transfers can be used when recovery does not occur after 18 months. Early neurolysis and nerve grafts are controversial. This review provides an update including new diagnostic tools, new associations, and new interventions crossing multiple medical disciplines.

Neurolymphomatosis of the brachial plexus from atypical primary central nervous system lymphoma lesions: A case report and review of the literature

Background:

Primary central nervous system lymphoma (PCNSL) is an aggressive and extranodal non-Hodgkin lymphoma limited to the neuroaxis. In immunocompetent individuals, PCNSL is more common in older adults and lacks the association with the Epstein–Barr virus found in individuals with AIDS-associated PCNSL. Because the clinical presentation and radiographic findings of PCNSL are highly variable, stereotactic brain biopsy is typically required for definitive diagnosis. High-dose methotrexate, in combination with other chemotherapeutic agents with or without whole brain radiation, is the mainstay of treatment.

Case Description:

A 70-year-old HIV-negative woman presented with confusion, acute flaccid left arm weakness, and left hand numbness. Head computed tomography without contrast demonstrated a 1 cm hyperdense round lesion in the suprasellar cistern that prompted further evaluation. Gadolinium-enhanced brain magnetic resonance imaging demonstrated enhancing lesions with heterogeneous signal intensity in the suprasellar, pineal, and right periatrial regions that did not explain the limb weakness and numbness. Serum and cerebrospinal fluid (CSF) studies were unrevealing, and a diagnosis of PCNSL was made following stereotactic biopsy. The patient’s liver cirrhosis precluded chemotherapy, but treatment with whole-brain radiation was pursued.

Conclusion:

The myriad clinical presentations and insidious course of PCNSL contribute to diagnostic difficulties, delays in treatment, and poor outcomes. Stereotactic brain biopsy is the primary method of PCNSL diagnosis since malignant cells are typically not detected in CSF. PCNSL should be considered in the differential diagnosis when immunocompetent elderly patients present with multiple intracranial lesions, even in the presence of lower motor neuron findings.

Neurolymphomatosis; a case report

We present a case of indolent neurolymphomatosis in a 55-year-old male patient with worsening pain and weakness in his right leg over the past few months. The patient has a past medical history of type II diabetes mellitus, four-year history of worsening left foot drop, left lower limb pain and weakness attributed to diabetic amyotrophy, and back pain. The new right-sided symptoms prompted further imaging which revealed a left sciatic nerve mass which was biopsied. Initial biopsy results were inconclusive. ¹⁸F-FDG PET/CT revealed the full extent of this patient's disease and helped plan for a more representative biopsy site, which finally established a diagnosis of diffuse large B-cell lymphoma involving the lumbosacral nerve roots. The patient underwent a course of chemotherapy. ¹⁸F-FDG PET/CT was ordered again at the end of treatment showing partial response to therapy. He underwent radiation therapy to the site of residual disease, with complete metabolic response of lesions on follow up PET CT.