Evidence-based guideline: Neuromuscular ultrasound for the diagnosis of ulnar neuropathy at the elbow.

INTRODUCTION/AIMS: The purpose of this literature review is to develop an evidence-based guideline for the use of neuromuscular ultrasound in the diagnosis of ulnar neuropathy at the elbow (UNE). The proposed research question was: "In patients with suspected UNE, does ulnar nerve enlargement as measured with ultrasound accurately identify those patients with UNE?" METHODS: A systematic review and meta-analysis was performed, and studies were classified according to American Academy of Neurology criteria for rating articles for diagnostic accuracy. RESULTS: Based on Class I evidence in four studies, it is probable that neuromuscular ultrasound measurement of the ulnar nerve at the elbow, either of diameter or cross-sectional area (CSA), is accurate for the diagnosis of UNE. RECOMMENDATION: For patients with symptoms and signs suggestive of ulnar neuropathy, clinicians should offer ultrasonographic measurement of ulnar nerve cross-sectional area or diameter to confirm the diagnosis and localize the site of compression (Level B).

The Incidence of Amyotrophic Lateral Sclerosis in Ohio 2016-2018: The Ohio Population-Based ALS Registry.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a fatal, neuromuscular disease with no cure. ALS incidence rates have not been assessed specifically in Ohio, yet the state contains both metropolitan and rural areas with a variety of environmental factors that could contribute to disease etiology. We report the incidence of ALS in Ohio residents diagnosed from October 2016 through September 2018. METHODS: We engaged practitioners from 9 Ohio sites to identify newly diagnosed ALS patients and to complete case report forms with demographic and clinical information. ALS was diagnosed according to the Awaji criteria and classified as either definite, probable, or possible. We developed a method to estimate missing cases using a Poisson regression model to impute cases in counties with evidence of undercounting. RESULTS: We identified 333 newly diagnosed ALS patients residing in Ohio during the 2-year index period and found incidence rates varied in the 88 state counties. After incorporating the estimated 27% of missing cases, the corrected crude annual incidence was 1.96/100,000 person-years, and the age- and gender-standardized incidence was 1.71/100,000 person-years (standardized to the 2010 US census). DISCUSSION/CONCLUSION: The estimated Ohio incidence of ALS is overall similar to that reported in other states in the USA. This study reveals a geospatial variation in incidence within the state, and areas with higher rates warrant future investigation.

Risk factors for amyotrophic lateral sclerosis: A regional United States case-control study.

Most amyotrophic lateral sclerosis (ALS) cases are considered sporadic, without a known genetic basis, and environmental exposures are thought to play a causal role. To learn more about sporadic ALS etiology, we recruited n = 188 ALS patients from northern New England and Ohio and matched controls 2:1 from the general population of the same regions. Questionnaires evaluated the association between a variety of lifestyle, behavioral (ie, hobbies and activities), and occupational factors and the risk of ALS, including the duration of time between exposure and ALS onset, and exposure frequency. Head trauma was associated with increased ALS risk (adjusted odds ratio [OR] 1.60 95% confidence interval [CI] 1.04-2.45), with significantly greater effects for injuries occurring 10 or more years prior to symptom onset (P = .037). ALS risk was increased for those reporting severe electrical burns (adjusted OR 2.86, 95% CI 1.37-6.03), with odds ratios highest for burns after age 30 (OR 3.14), and for burns 10 or more years prior to symptom onset (OR 3.09). Hobbies involving lead were the most strongly associated with ALS risk (adjusted OR 2.92, 95% CI 1.45-5.91). Exposures to lead 20 or more years prior to diagnosis had larger effect sizes compared to those occurring more recently. Holding a job in mechanics, painting, or construction was associated with ALS. The identification of these specific environmental factors associated with ALS highlight the need for future prospective and laboratory studies to assess causality, biological mechanisms, and find prevention or treatment opportunities.

Randomized Trial of Thymectomy in Myasthenia Gravis.

BACKGROUND: Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone. METHODS: We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period. RESULTS: A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003). CONCLUSIONS: Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).

Chronic immune sensorimotor polyradiculopathy: Report of a case series.

INTRODUCTION: Chronic immune sensorimotor polyradiculopathy (CISMP) is a chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) variant affecting both sensory and motor nerve roots without evidence of peripheral nerve demyelination. METHODS: We report a case series of 9 patients with CISMP, identified from 2 tertiary centers. Clinical, electrodiagnostic, and neuroradiologic features, and treatment responses, were retrospectively reviewed. RESULTS: Patients presented with sensorimotor deficits and hypo-/areflexia, predominantly involving lower extremities. Three had cranial nerve involvement. Electrodiagnostic findings in all patients localized to roots proximal to dorsal root ganglia, without evidence of peripheral nerve demyelination. Cerebrospinal fluid examination revealed an albuminocytologic association. Eight patients exhibited gadolinium enhancement and thickening of multiple spinal nerve roots and/or cranial nerves. All patients demonstrated good responses to immunotherapies. DISCUSSION: CISMP is similar to CIDP in many aspects, but lacks typical electrodiagnostic findings of peripheral nerve demyelination. It is important to recognize this unusual and treatable entity. Muscle Nerve 59:658-664, 2019.

IgG4-related disease causing facial nerve and optic nerve palsies: Case report and literature review.

IgG4-related disease (IgG4-RD) is increasingly being recognized as an entity effecting the head and neck region. Although most commonly seen with salivary gland or paranasal sinus involvement, IgG4-RD may also involve the temporal bone and skull base. We report a rare care of a 61-year-old female with IgG4-RD presenting as synchronous lesions of the middle ear and middle cranial fossa with polyneuropathy of cranial nerves II, VI, and VII. Initial histopathological evaluation of her resected ear mass suggested a benign inflammatory process but no specific diagnosis. Her symptoms progressed over 10months prompting re-evaluation of the specimen and consideration of the IgG4-RD diagnosis. Key pathologic features included prominent lymphoplasmacytic population, storiform fibrosis, obliterative phlebitis, and IgG4 specific staining. The patient was treated with high-dose intravenous and oral steroids but was transitioned to azathioprine secondary to steroid-induced myopathy. Radiographic studies before and after treatment reveal marked improvement of the intracranial and extracranial disease. Correspondingly, her cranial neuropathies resolved. A high degree of clinical suspicion is necessary to diagnosis IgG4-RD. The diagnosis can be supported by elevated serum IgG, elevated IgG index, and pathognomonic histopathological findings. Primary treatment is with corticosteroids. However, immunotherapy using azathioprine or rituximab can be utilized in recurrent disease or patients with steroid intolerance.

Acute-onset chronic inflammatory demyelinating polyneuropathy: An electrodiagnostic study.

INTRODUCTION: Acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) is an increasingly recognized CIDP subtype. Differentiating A-CIDP from Guillain-Barré syndrome (GBS) is challenging but important, because there are different treatment outcomes. METHODS: We report 3 patients with A-CIDP who were initially diagnosed with severe GBS but were later confirmed to have CIDP based on their clinical course and electrodiagnostic (EDx) studies. We also report on the long-term treatment of these patients and review the literature on EDx studies in this syndrome. RESULTS: Three patients were initially diagnosed with GBS and responded to treatment. However, all 3 had arrest in improvement or deterioration during their rehabilitation phases. EDx studies showed prominent demyelinating changes many months after the initial presentation. All responded very well to immunotherapy. CONCLUSION: Although several features may suggest the diagnosis of A-CIDP at initial presentation, close follow-up of GBS patients during the recovery phase is also needed for accurate diagnosis. EDx studies may distinguish patients with A-CIDP from GBS patients.

Electromyographic diagnosis of multifocal pyomyositis.

INTRODUCTION: Multifocal pyomyositis is a rare inflammatory myopathy caused by bacterial infection and abscess formation in multiple skeletal muscles. To date, electromyography (EMG) of pyomyositis has not been reported. METHODS: We describe the EMG findings of a patient with pathologically proven multifocal pyomyositis. RESULTS AND CONCLUSIONS: Muscles affected by pyomyositis demonstrate EMG features similar to those of other inflammatory myopathies. Other features such as acute entrapment neuropathy may exist concomitantly due to nerve compression from muscle abscess formation.

Multiple muscle cell alterations in a case of encephalomyopathy.

Skeletal muscle from an encephalomyopathy was examined by morphological and biochemical modalities. Mitochondria displayed variability in size, numbers per myocyte, and morphology. Certain organelles had stacks of dense cristae, others contained variable numbers of crystalloids or several lipid droplets. In isolated skeletal muscle mitochondria, oxidative phosphorylation was reduced, but activities of the electron transport chain components were unaffected. This is the second case of adult onset encephalomyopathy with a phenotype overlapping MERRF and Kearns-Sayre syndrome associated with a heteroplasmic mtDNA 3255G > A mutation in the tRNA(UUR(LEU)). This study emphasizes the desirability of a multidisciplinary approach in the diagnosis of complex myopathies.

Gravity-dependent nystagmus and inner-ear dysfunction suggest anterior and posterior inferior cerebellar artery infarct.

Cerebellar lesions may present with gravity-dependent nystagmus, where the direction and velocity of the drifts change with alterations in head position. Two patients had acute onset of hearing loss, vertigo, oscillopsia, nausea, and vomiting. Examination revealed gravity-dependent nystagmus, unilateral hypoactive vestibulo-ocular reflex (VOR), and hearing loss ipsilateral to the VOR hypofunction. Traditionally, the hypoactive VOR and hearing loss suggest inner-ear dysfunction. Vertigo, nausea, vomiting, and nystagmus may suggest peripheral or central vestibulopathy. The gravity-dependent modulation of nystagmus, however, localizes to the posterior cerebellar vermis. Magnetic resonance imaging in our patients revealed acute cerebellar infarct affecting posterior cerebellar vermis, in the vascular distribution of the posterior inferior cerebellar artery (PICA). This lesion explains the gravity-dependent nystagmus, nausea, and vomiting. Acute onset of unilateral hearing loss and VOR hypofunction could be the manifestation of inner-ear ischemic injury secondary to the anterior inferior cerebellar artery (AICA) compromise. In cases of combined AICA and PICA infarction, the symptoms of peripheral vestibulopathy might masquerade the central vestibular syndrome and harbor a cerebellar stroke. However, the gravity-dependent nystagmus allows prompt identification of acute cerebellar infarct.

Clinical Reasoning: A 55-Year-Old Woman With Painless Hand Weakness and Atrophy.

Hand weakness is a frequent chief concern in neurology practice. We report a case of a 55-year-old woman presenting with a chronic, gradually worsening right hand weakness and atrophy, selectively affecting the thenar muscles, without any sensory symptoms. She had a history of carpal tunnel syndrome and previously underwent surgical carpal tunnel release. This case delves into the differential diagnosis of hand weakness and atrophy, emphasizing the significance of myotomal innervation in intrinsic hand muscles. Furthermore, it outlines a systematic approach to diagnosing an uncommon cause for a common clinical presentation, offering a comprehensive differential diagnosis, and exploring various possible causes.

Exacerbation of myasthenia gravis with voriconazole.

INTRODUCTION: We describe a patient with stable generalized myasthenia gravis who presented with new onset severe ophthalmoplegia and ptosis after initiation of voriconazole for aspergillosis. METHODS: Ligand-protein docking software was used to simulate the interaction of voriconazole with the acetylcholine receptor (AChR). We tested voriconazole binding to AChR in comparison to high affinity and neutral compounds. RESULTS: There was no clinical improvement after intravenous immunoglobulin infusion and plasmapheresis. However, the patient improved slowly after withdrawal of voriconazole. Based on our results, voriconazole binds favorably to AChR and may putatively block muscle nicotinic AChRs. Other theoretical explanations include blocking potassium channels and reducing their intracellular trafficking. CONCLUSIONS: The mechanisms involved in ocular exacerbation may be multi-factorial, reflecting the intricate dynamics of the neuromuscular junction. It is important to consider medications that harbor pyridine or pyrimidine moieties as potential causes of exacerbation in myasthenic patients, especially those who present with ocular symptoms.

Greater Number of Plasma Exchanges Does Not Improve Outcome in Myasthenic Crisis.

OBJECTIVES: To determine the relationship between the number of plasma exchanges and clinical outcome in patients experiencing myasthenic crisis. METHODS: We retrospectively reviewed all episodes of myasthenia gravis exacerbation/crisis who received plasmapheresis in patients admitted to a single-center tertiary care referral center from July 2008 to July 2017. We performed statistical analyses to determine whether the increased number of plasma exchanges improves the primary outcome (hospital length of stay) and the secondary outcome (disposition to home, skilled nursing facility, long-term acute care hospital, or death). RESULTS: There is neither clinically observable nor statistically significant improvement in length of stay or disposition on discharge in patients who received 6 or greater sessions of plasmapheresis. CONCLUSIONS: This study provides class IV evidence that extending the number of plasma exchanges beyond 5 does not correlate with decreased hospital length of stay or improved discharge disposition in patients experiencing myasthenic crisis.

Comparative analysis of therapeutic options used for myasthenia gravis.

OBJECTIVE: To compare clinical and economic outcomes following plasma exchange (PLEX) and intravenous immunoglobulin (IVIG) in U.S. patients with primary diagnoses of myasthenia gravis (MG). METHODS: Our cohort was identified from the Nationwide Inpatient Sample database for years 2000-2005 using codes from the International Classification of Diseases, 9th edition. Multivariate regression analyses were used to identify predictors of mortality, complications, length of stay, and total inpatient cost. RESULTS: Among 1,606 hospitalized patients, the unadjusted mortality rate of MG crisis remained higher than those without crisis (0.44% vs 4.44%, p < 0.001), as well as the unadjusted complication rate (26.36% vs 11.23%, p < 0.001). MG crisis patients receiving PLEX had significantly more complications than those receiving IVIG (30.06% vs 14.79%, p < 0.001). Among the whole cohort, adjusted mortality and complication rates were not significantly different between the treatment groups (p > 0.05). Acute respiratory failure, major cardiac complications, and acute renal failure were associated with an increased mortality rate (p < 0.001). Age and respiratory failure were associated with an increased complication rate (p < 0.001). Length of stay was significantly longer for MG (6 vs 4 days, p < 0.001) and MG crisis (10 vs 5 days, p < 0.001) patients receiving PLEX. Inpatient costs were higher for MG ($26,662 vs $21,124, p < 0.01) and MG crisis ($53,801 vs $33,924, p < 0.001) patients receiving PLEX. INTERPRETATION: Compared to PLEX, IVIG appears of similar clinical (mortality and complications) and perhaps of superior economic (length of stay and total inpatient charges) outcomes in the treatment of MG. Elderly and those with complex comorbid diseases including acute respiratory failure may be better treated with IVIG.

Neuropathy associated with IgA monoclonal Gammopathy. A harbinger of AL amyloidosis.

Peripheral neuropathy is seen in 15% of patients with IgA monoclonal gammopathy. Treatment and prognosis of dysproteinemic neuropathy is usually guided by the underlying plasma cell disorders, which could be either benign or malignant. The true incidence of hematologic malignancy in patients with neuropathy associated with IgA monoclonal gammopathy is not known. However, patients with IgA M-protein are generally at increased risk for malignant transformation. Since neuropathy may be the first and only organ involvement, neurologists are key contributors in identifying each patient's plasma cell dyscrasia. We report two patients who presented with severe progressive polyneuropathy, had a detectable low-level IgA lambda paraproteinemia dismissed as incidental. Both were diagnosed later with a combination of malignant plasma cell dyscrasia and AL amyloidosis resulting in multiorgan failure and death. Both patients demonstrated red flags for malignant progression including abnormal serum free light chain, rapidly progressive debilitating neuropathy refractory to immunotherapy, prominent autonomic dysfunction, and weight loss. In summary, patients with IgA monoclonal gammopathy presenting with polyneuropathy can be at risk for malignant transformation. Failure to investigate for hematologic malignancy and AL amyloidosis may cause significant delays in treatment and result in fatal outcomes.

Spinal cord injury level and Phrenic Nerve Conduction Studies do not predict diaphragm pacing success or failure- all patients should undergo diagnostic laparoscopy.

BACKGROUND: Diaphragm Pacing(DP) demonstrates benefits over mechanical ventilation(MV) for spinal cord injured(SCI) patients. The hypothesis of this report is that phrenic nerve conduction study(PNCS) results cannot differentiate success or failure in selection of patients for DP. Direct surgical evaluation of the diaphragm should be performed. METHODS: Observational report of prospective databases of patients undergoing laparoscopic evaluation of their diaphragms to assess for ability to stimulate to cause contraction for ventilation. RESULTS: In 50 SCI patients who could not be weaned from MV, PNCS results showed latencies in stimulated patients (n = 44) and non-stimulated(n = 6) overlapped (7.8 ± 2.5 ms vs 9.4 ± 2.8 ms) and the null hypothesis cannot be rejected (p-value>0.05). Amplitudes overlapped (0.4 ± 0.2 mV vs 0.2 ± 0.2 mV) and the null hypotheses cannot be rejected (P-value >0.05). In 125 non SCI patients with diaphragm paralysis, there were 78(62.4%) with false negative PNCS. CONCLUSION: PNCS are inadequate pre-operative studies. Direct laparoscopic evaluation should be offered for all SCI patients to receive the benefit of DP.

Acute motor axonal neuropathy in association with Sjögren syndrome.

Sjögren syndrome (SS) has been known to manifest with neurological complications, most frequently of the peripheral nervous system, and often in advance of xerostomia and xerophthalmia. There has been one case report of a patient with SS presenting with acute motor neuropathy similar to Guillain-Barré syndrome (GBS). We report the case of a patient who developed rapidly fulminant acute motor axonal neuropathy (AMAN) with positive anti-GM1 antibody at high titers in association with serological and pathological evidence of SS without xerostomia or xerophthalmia.