Guidance for resumption of routine electrodiagnostic testing during the COVID-19 pandemic.

As the world accommodates to the coronavirus disease 2019 (COVID-19) pandemic, routine in-person medical services are resuming. The resumption of non urgent electrodiagnostic (EDX) testing faces unique challenges due to the long duration of the procedure and direct close contact with patients, including studies with risk of exposure to oropharyngeal secretions. We provide consensus guidance for resumption of EDX testing, addressing scheduling, patient arrival and registration, use of personal protective equipment, COVID-19 screening and testing, the performance of EDX testing in outpatient and inpatient settings, cleaning and maintenance of the EDX equipment and laboratory, balancing trainee safety and training requirements, and patient care issues. These are broad recommendations that need to be adapted to local COVID-19 risks, institutional guidelines and policies, and changing federal, state, and local regulations, and to changes in the pandemic over time.

Worsening of anti-Hu paraneoplastic neurological syndrome related to anti-PD-1 treatment: Case report and review of literature.

We present an illustrative case of a 62-year-old woman with small cell lung cancer who developed progressive worsening of pre-existing anti-Hu antibody associated sensory neuronopathy after treatment with programmed cell death-1 (PD-1) inhibitor, nivolumab. We review the literature and identify 6 reported cases to understand the clinical outcomes of patients with anti-Hu paraneoplastic neurologic syndrome (PNS) treated with anti-PD-1 treatment. The PNS clinical spectrum comprised of encephalitis, a combination of sensory neuronopathy and anti-NMDAR encephalitis, isolated sensory neuronopathy, and encephalomyelitis. Immune checkpoint inhibitor have the potential to worsen pre-existing anti-Hu PNS and may promote the development of anti-Hu PNS.

Peripheral Vasculitic Neuropathy Associated With Minocycline Use.

We describe 2 patients presenting with multiplex mononeuritis, associated with skin manifestation, secondary to minocycline-induced vasculitis. One of the cases is associated neither with lupus nor polyarteritis nodosa. An extensive laboratory workup ruled out any possible underlying immunologic disorder. Electrodiagnostic studies were conducted to show axonal neuropathy in patchy and multifocal distribution consistent with multiplex mononeuritis. This diagnosis was confirmed with nerve biopsy. Withdrawing from the offending medication, minocycline, improved the patients' clinical condition and the quantitative serological measures.

Lambert-Eaton syndrome, an unrecognized treatable pediatric neuromuscular disorder: three patients and literature review.

BACKGROUND: Lambert-Eaton myasthenic syndrome, a presynaptic neuromuscular junction autoimmune disorder, rarely occurs in children. Patients typically present with proximal lower extremity weakness with areflexia. METHODS: We report three children presenting between ages 9 and 10 years diagnosed with Lambert-Eaton myasthenic syndrome 2 years, 1 year, and 5 months later, respectively. Their clinical attributes are correlated with nine other pediatric Lambert-Eaton myasthenic syndrome patients found in our literature review. RESULTS: These patients were identified as having Lambert-Eaton myasthenic syndrome during their evaluation for proximal weakness. Low-amplitude compound muscle action potentials classically facilitating >100% with voluntary exercise and/or 50 Hz stimulation were essential to diagnosis. Three of the 12 children had associated malignancies, two of them had lymphoproliferative disorders with onset of symptoms more rapid than the rest, and the third had neuroblastoma. The nine nonparaneoplastic Lambert-Eaton myasthenic syndrome patients responded to immunomodulatory therapy with close return to their baseline function. Complete remission no longer necessitating medication was reported in two patients. Follow-up up to 17 years was available on two patients previously reported. CONCLUSION: Lambert-Eaton myasthenic syndrome is a diagnosis that must be considered in children presenting with unidentified proximal muscle weakness. In most children, Lambert-Eaton myasthenic syndrome is a primary autoimmune disorder that is treatable. Nevertheless, a search for malignancy is recommended.

Pediatric sciatic neuropathy associated with neoplasms.

Seven children with sciatic neuropathy associated with an underlying neoplasm are reported. Clinical presentation, electrophysiological data, imaging, pathology, and/or autopsy results are described. Pain and weakness, primarily foot drop, were the most common presenting symptoms. The mechanism of sciatic neuropathy was varied and included: nerve infiltration by the adjacent neoplasm (neuroblastoma, rhabdomyosarcoma, and leukemic or lymphomatous infiltration); an expanding, intrinsic neurogenic tumor (perineurioma); or intraoperative stretch injury (osteosarcoma resection). The prognosis for sciatic nerve recovery was good among children who survived their associated cancer. Three children died from the cancer or complications of treatment. One child with perineurioma remained clinically stable, and two children improved after treatment of their neoplasm.

Rituximab and mycophenolate combination therapy in refractory dermatomyositis with multiple autoimmune disorders.

We report a case of dermatomyositis associated with rheumatoid arthritis, Hashimoto thyroiditis, and diabetes mellitus responsive only to combination of rituximab with mycophenolate. A 42-year-old woman presented with proximal muscle weakness, myalgias, fever, night sweats, and shortness of breath. Creatinine kinase was 8155 IU/L, and muscle biopsy was diagnostic of dermatomyositis. She was started on glucocorticoids; her systemic symptoms improved, but her muscle weakness persisted. She was serially treated with intravenous immunoglobulin, azathioprine, and mycophenolate mofetil without improvement in her weakness. She responded dramatically to combination therapy with rituximab and mycophenolate, with improvement in strength and normalization of creatinine kinase. She has been well controlled on rituximab infusion every 6 months and maintenance mycophenolate mofetil.

Immune-mediated necrotizing myopathy associated with statins.

We report patients from two neuromuscular centers who were evaluated between the years 2000 and 2008 and met the following criteria: (1) proximal muscle weakness occurring during or after treatment with statins; (2) elevated serum creatine kinase (CK); (3) persistence of weakness and elevated CK despite discontinuation of the statin; (4) improvement with immunosuppressive agents; and (5) muscle biopsy showing necrotizing myopathy without significant inflammation. Twenty-five patients fulfilled our inclusion criteria. Twenty-four patients required multiple immunosuppressive agents. Fifteen patients relapsed after being tapered off immunosuppressive therapy. Exposure to statins prior to onset was significantly higher in patients with necrotizing myopathy (82%) as compared to those with dermatomyositis (18%), polymyositis (24%), and inclusion-body myositis (38%) seen in the same time period. The lack of improvement following discontinuation of statins, the need for immunosuppressive therapy, and frequent relapse when treatment was tapered suggest an immune-mediated etiology for this rare, statin-associated necrotizing myopathy.

Achalasia, chronic sensory neuropathy, and N-type calcium channel autoantibodies: beneficial response to IVIG.

Autoimmune gastrointestinal dysmotility (AGID) can result from paraneoplastic onconeuronal antibodies. Patients may present with regional hypomotility anywhere along the gastrointestinal tract. We report a case of a woman who developed an insidious sensory neuropathy and achalasia. She was found to have a high-titer of N-type voltage gated-calcium channel (VGCC) antibodies. She demonstrated clinical and electrophysiological improvement of her neuropathy, as well as improvement of her swallowing and gait, after treatment with intravenous immunoglobulins.

Sensory polyneuropathy associated with paclitaxel-eluting coronary stent.

Paclitaxel is a microtubule-stabilizing chemotherapeutic agent used in ovarian and breast cancer; its principal adverse effect is sensory neuropathy. We describe the occurrence of sensory polyneuropathy after multiple paclitaxel-eluting stents in a patient who may have sub-clinical Sjogrens syndrome.

Pediatric sciatic neuropathies due to unusual vascular causes.

Four cases of pediatric sciatic neuropathies due to unusual vascular mechanisms are reported. Pediatric sciatic neuropathies were seen after umbilical artery catheterization, embolization of arteriovenous malformation, meningococcemia, and hypereosinophilic vasculitis. Electrophysiologic studies demonstrated abnormalities in motor studies of peroneal and tibial nerves. Sensory studies demonstrated abnormalities of sural and superficial peroneal nerves. Results of needle electromyography were abnormal in sciatic-innervated muscles. Prognosis was variable and depended on the severity of the initial nerve injury.

Inappropriate surgeries resulting from misdiagnosis of early amyotrophic lateral sclerosis.

Initial symptoms of amyotrophic lateral sclerosis (ALS) may mimic radiculopathy, myelopathy, mononeuropathy, or arthropathy. A retrospective review of 260 consecutive patients with ALS evaluated between 1996 and 2004 revealed that 55 (21%) had had surgery within the 5 years prior to ALS diagnosis. Thirty-four of these 55 (61%) had surgery for symptoms and signs that retrospectively were attributable to early manifestations of ALS. Misdiagnosis of early ALS may lead to unnecessary surgeries with their attendant potential complications.

Leprosy and the peripheral nervous system: basic and clinical aspects.

Leprosy is one of the most common causes of nontraumatic peripheral neuropathy in the developing world. The causative agent, Mycobacterium leprae, has a predilection for Schwann cells, where the organism multiplies unimpeded by organism-specific host immunity, resulting in destruction of myelin, secondary inflammatory changes, and destruction of the nerve architecture. The cardinal diagnostic features of leprosy are anesthetic skin lesions, neuropathy, and positive skin smears for the bacilli. However, patients may rarely present without skin lesions in pure neuritic leprosy. Electrodiagnostic findings early in the disease reveal demyelinating features, such as slowing of conduction velocity and prolongation of latencies, but as the disease progresses secondary axonal damage commonly ensues. Electrodiagnostic studies are also useful to monitor for toxicity secondary to therapy, particularly thalidomide-associated neuropathy. Nerve biopsy of a sensory cutaneous nerve is sometimes essential to confirm a diagnosis of leprosy. Significant advances in understanding of the pathogenesis, mapping of the genome, and other advances in molecular biology may result in better preventive and therapeutic modalities, and the goal of eradicating leprosy as a global problem may yet be realized.

Inflammatory myopathy associated with imatinib mesylate therapy.

We report a patient with chronic myelogenous leukemia (CML) who developed an inflammatory myopathy while being treated with imatinib mesylate. We found serum antibodies directed against a component of the human exosome. Similar antibodies have been demonstrated in patients with CML following immune-induced remission and also are occasionally found in patients with polymyositis. It is known that the previous use of alpha-interferon followed by imatinib leads to rapid apoptosis of leukemic cells. We speculate that the subsequent release of a large bolus of leukemia antigens could have crossreactivity with muscle antigens and generate an autoimmune response.