Positional Tremor and its Treatment.

BACKGROUND: Positional tremors arise when a patient's tremor is brought on during specific positioning of the involved body part. They can be distinguished from postural tremor, wherein a patient's tremor is elicited in any posture, and from task-specific tremor, wherein a patient's tremor occurs only during a certain task. CASES: We describe two cases of positional tremor that are markedly improved with botulinum toxin injection. DISCUSSION: The term "positional" is a valuable descriptor for tremors. In patients with positional tremor, botulinum toxin may be beneficial for treatment. Lidocaine injection provides a transient way to test for the appropriateness of botulinum toxin injection in these patients.

House staff communication training and patient experience scores.

OBJECTIVE: To assess whether communication training for housestaff via role-playing exercises (1) is well-received and (2) improves patient experience scores in housestaff clinics. METHODS: We conducted a pre-post study in which the housestaff for 3 adult hospital departments participated in communication trainingled by trained faculty in small groups . Sessions centered on a published 5-step strategy for opening patient-centered interviews using department-specific role-playing exercises. Housestaff completed post-training questionnaires. For one month prior to and one month following the training, patients in the housestaff clinics completed surveys with CG-CAHPS questions regarding physician communication, immediately following clinic visits. Pre-and post -intervention results for top-box scores were compared. RESULTS: Forty -four of a possible 45 housestaff (97.8%) participated, with 31 (70.5%) indicating that the role-playing exercise increased their perception of the 5-step strategy. No differences on patient responses to CG-CAHPS questions were seen when comparing 63 pre-intervention patients surveys to 77 post-intervention surveys. CONCLUSION: Demonstrating an improvement in standard patient experience surveys in resident clinics may require ongoing communication coaching and investigation of the "hidden curriculum" of training.

Durability of the Rituximab Response in Acetylcholine Receptor Autoantibody-Positive Myasthenia Gravis.

IMPORTANCE: Myasthenia gravis (MG), an autoimmune disorder of neuromuscular transmission, is treated by an array of immunotherapeutics, many of which are nonspecific. Even with current therapies, a subset of patients has medically refractory MG. The benefits of B-cell-targeted therapy with rituximab have been observed in MG; however, the duration of these benefits after treatment is unclear. OBJECTIVE: To evaluate the durability of response to rituximab in the treatment of acetylcholine receptor autoantibody-positive (AChR+) generalized MG. DESIGN, SETTING AND PARTICIPANTS: This retrospective case series study included 16 patients with AChR+ MG referred to an MG clinic from January 1, 2007, to December 31, 2015. The patients were treated with rituximab and followed up for 18 to 84 months after treatment. MAIN OUTCOMES AND MEASURES: Assessment of long-term clinical response, durability of response and/or relapse rate, AChR autoantibody levels, adverse effects, and inflammatory markers. RESULTS: In the 16 patients (6 men and 10 women; median age, 42 [range, 18-69] years), clinical improvement was observed in parallel with complete withdrawal or reduction of other immunotherapies, with all patients achieving complete stable remission, pharmacologic remission, or minimal manifestations based on the Myasthenia Gravis Foundation of America postintervention status criteria. Nine patients (56%) had a relapse during a mean follow-up of 36 (range, 24-47) months. Seven patients (44%) remained relapse free with a mean follow-up of 47 (range, 18-81) months since the last rituximab treatment. All values were normalized to a pretreatment anti-AChR antibody level of 100% and the mean levels after each rituximab cycle were calculated. A 33% decrease was seen after cycle 1 of rituximab treatment (100% vs 67%; P = .004); 20% after cycle 2 (compared with cycle 1) (67% vs 47%; P = .008); and 17% after cycle 3 (compared with cycle 2) (47% vs 30%; P = .02). However, the serum cytokine levels measured were found to be unchanged. CONCLUSIONS AND RELEVANCE: Rituximab therapy appears to be an effective option in patients with refractory AChR+ MG, who were observed to have a durable response after treatment. Identification of markers of disease relapse and sustained remission are critical next steps in the development of pathophysiology-relevant, evidence-based practice parameters for rituximab in the treatment of MG.

Relationship Between Cerebrospinal Fluid Protein Levels and Electrophysiologic Abnormalities in Guillain-Barré Syndrome.

OBJECTIVES: The cerebrospinal fluid (CSF) protein level is known to be elevated in patients with Guillain-Barré syndrome (GBS). This report correlates the degree of CSF protein elevation with the number of electrophysiologic abnormalities on nerve conduction study (NCS). METHODS: We reviewed 38 patients admitted to our institution with a diagnosis of GBS and had both a measured CSF protein level and a NCS within 24 hours of each other. RESULTS: CSF protein level correlates with the number of NCS demyelination criteria, as described by Cornblath, in patients with GBS. CONCLUSIONS: This retrospective study is the first to demonstrate a relationship between the CSF protein level and the electrophysiologic abnormalities that accompany GBS.

Novel mutations in the CLCN1 gene of myotonia congenita: 2 case reports.

INTRODUCTION: Myotonia Congenita is an inherited myotonia that is due to a mutation in the skeletal muscle chloride channel CLCN1. These mutations lead to reduced sarcolemmal chloride conductance, causing delayed muscle relaxation that is evident as clinical and electrical myotonia. METHODS: We report the clinical presentations of two individuals with Myotonia Congenita (MC). RESULTS: Patient 1 has been diagnosed with the recessive form of MC, known as the Becker variant, and Patient 2 has been diagnosed with the dominant form of MC, known as the Thomsen variant. In both patients, the diagnosis was made based on the clinical presentation, EMG and CLCN1 gene sequencing. Patient 1 also had a muscle biopsy. CONCLUSIONS: Genetic testing in both patients reveals previously unidentified mutations in the CLCN1 gene specific to Myotonia Congenita. We report the salient clinical features of each patient and discuss the effects and common types of CLCN1 mutations and review the literature.

Autoantibodies produced at the site of tissue damage provide evidence of humoral autoimmunity in inclusion body myositis.

Inclusion body myositis (IBM) belongs to a group of muscle diseases known as the inflammatory myopathies. The presence of antibody-secreting plasma cells in IBM muscle implicates the humoral immune response in this disease. However, whether the humoral immune response actively contributes to IBM pathology has not been established. We sought to investigate whether the humoral immune response in IBM both in the periphery and at the site of tissue damage was directed towards self-antigens. Peripheral autoantibodies present in IBM serum but not control serum recognized self-antigens in both muscle tissue and human-derived cell lines. To study the humoral immune response at the site of tissue damage in IBM patients, we isolated single plasma cells directly from IBM-derived muscle tissue sections and from these cells, reconstructed a series of recombinant immunoglobulins (rIgG). These rIgG, each representing a single muscle-associated plasma cell, were examined for reactivity to self-antigens. Both, flow cytometry and immunoblotting revealed that these rIgG recognized antigens expressed by cell lines and in muscle tissue homogenates. Using a mass spectrometry-based approach, Desmin, a major intermediate filament protein, expressed abundantly in muscle tissue, was identified as the target of one IBM muscle-derived rIgG. Collectively, these data support the view that IBM includes a humoral immune response in both the periphery and at the site of tissue damage that is directed towards self-antigens.

Response of patients with refractory myasthenia gravis to rituximab: a retrospective study.

INTRODUCTION: Myasthenia gravis, an autoimmune disorder of neuromuscular transmission, is treated by an array of immunomodulating therapies. A variable response is observed with certain patients being medically refractory. METHODS: We report the results of 14 refractory generalized myasthenia gravis patients (6 AChR+; 8 MuSK+) treated with rituximab. RESULTS: Sustained clinical improvement was observed in all patients as well as a reduction of conventional immunotherapies. Prednisone dose decreased a mean of 65.1%, 85.7%, and 93.8% after cycle 1, 2, and 3 of rituximab therapy, respectively. A statistically significant reduction in plasma exchange sessions was seen after cycle 1 with all patients being off of plasma exchange after cycle 3. Acetylcholine receptor antibody titers decreased a mean of 52.1% (p = 0.0046) post-cycle 2. CONCLUSION: Our results support the hypothesis that rituximab is beneficial and well tolerated in managing refractory myasthenia gravis and nearly doubles published cases. We propose that B-cell-directed therapies may become an attractive option and suggest pursuit of a prospective trial.

Expressive aphasia as a presentation of encephalitis with Bartonella henselae infection in an immunocompetent adult.

OBJECTIVE: To show the first clinically reported case of Cat Scratch Disease (CSD) presenting as a focal neurologic deficit in an immunocompetent adult. PATIENT: 59-year-old male with a history of a previous stroke. RESULTS: Examination showed an expressive aphasia, word substitution errors, and impaired repetition. A head CT and MRI showed no acute changes. The EEG findings were non-focal and did not show any epileptiform activity. The patient had a history of contact with stray kittens and previous axillary lymphadenopathy. Bartonella henselae serology titers were IgG positive 1:1024 (< 64) and IgM positive 1:20 (< 16). After antibiotic administration, the patient's symptoms and aphasia resolved. CONCLUSIONS: Focal presentations concerning for stroke or partial seizure activity may have underlying infectious etiology. We recommend consideration of CSD in the differential diagnosis of any adult with a history of lymphadenopathy, fever, and recent contact with a cat who presents with neurologic complications.