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Background There is no consensus on the management of incidental meningiomas. The literature on long-term growth dynamics is sparse and the natural history of these tumors remains to be illuminated. Methods We prospectively assessed long-term tumor growth dynamics and survival rates during active monitoring of 62 patients (45 female, mean age 63.9 years) harboring 68 tumors. Clinical and radiological data were obtained every 6 months for 2 years, annually until 5 years, then every second year. Results The natural progression of incidental meningiomas during 12 years of monitoring was growth (P Conclusion Active monitoring seems a safe and appropriate first-line management of incidental meningiomas. Intervention was avoided in > 40% with indolent tumors in this cohort. Treatment was not compromised by tumor growth. Clinical follow-up seems sufficient beyond 5 years if self-limiting growth is established. Steady or accelerating growth warrant monitoring until they reach a stable state or intervention is initiated.

Functional dependency in basic activities of daily living (ADLs) is a key outcome in Parkinson's disease (PD). We aimed to define dependency in PD, using the original and MDS versions of the Unified Parkinson's Disease Rating Scale (UPDRS).We developed two algorithms to define dependency from items of UPDRS Part 2 and MDS-UPDRS Part 2 relating to basic ADLs (feeding, dressing, hygiene and walking, and getting out of a chair). We validated both algorithms using data from 1110 patients from six community-based PD incidence cohorts, testing concurrent validity, convergent validity, and predictive validity.Our optimal algorithm showed high specificity and moderate to high sensitivity versus SchwabEngland80% (specificity 95% [95% confidence interval (CI) 93-97] and sensitivity 65% [95% CI 55-73] at baseline; 88% [95% CI 85-91] and 85% [95% CI 79-97] respectively at five-years follow-up). Convergent validity was demonstrated by strong associations between dependency defined by the algorithm and cognition (MMSE), quality of life (PDQ39), and impairment (UPDRS part 3) (all p 0.001). Algorithm-defined dependency status also predicted mortality: HR for mortality in those dependent vs independent at baseline was 1.6 (95%CI 1.2-2.1) and in those dependent vs independent at five-years' follow-up was 2.2 (1.6-3.0).We have demonstrated the concurrent validity, convergent validity, and predictive validity of a UPDRS-/MDS-UPDRS-based algorithm to define functional dependency in PD. This can be used for studying dependency in any study where UPDRS or MDS-UPDRS part 2 data have been collected.

We conducted a double-blinded phase I clinical trial to establish whether nicotinamide adenine dinucleotide (NAD) replenishment therapy, via oral intake of nicotinamide riboside (NR), is safe, augments cerebral NAD levels, and impacts cerebral metabolism in Parkinson’s disease (PD). Thirty newly diagnosed, treatment-naive patients received 1,000 mg NR or placebo for 30 days. NR treatment was well tolerated and led to a significant, but variable, increase in cerebral NAD levels—measured by 31phosphorous magnetic resonance spectroscopy—and related metabolites in the cerebrospinal fluid. NR recipients showing increased brain NAD levels exhibited altered cerebral metabolism, measured by 18fluoro-deoxyglucose positron emission tomography, and this was associated with mild clinical improvement. NR augmented the NAD metabolome and induced transcriptional upregulation of processes related to mitochondrial, lysosomal, and proteasomal function in blood cells and/or skeletal muscle. Furthermore, NR decreased the levels of inflammatory cytokines in serum and cerebrospinal fluid. Our findings nominate NR as a potential neuroprotective therapy for PD, warranting further investigation in larger trials. publishedVersion

The use of stereotactic radiosurgery (SRS) for brain metastases are increasing. Response assessment is challenging and the clinical significance of radiological response and retreatments are poorly defined. Ninety-seven patients with a total of 406 brain metastases were followed prospectively for 10 years or until death. Volume changes over time and clinical outcome in response to first time SRS and SRS retreatments were analyzed. Tumors grew significantly before (p = 0.004), but shrunk at 1 and 3 months (p = 0.001) following SRS. Four response-patterns of were observed; tumors either continuously reduced in size (A, 62%), pseudo-progressed (PP, B, 13%), temporarily reduced in size (C, 24%), or grew continuously (D, 2%); corresponding to 75% local control (LC) at initial SRS. Predictors for LC were primary cancer site (p = 0.001), tumor volume (p = 0.002) and target cover ratio (p = 0.005). Subsequent SRS for new lesions resulted in 94% LC (87% A) and repeat-SRS for local failures in 80% LC (57% B), predicted by higher prescribed dose, p = 0.001 and p = 0.042, respectively. Overall survival was only 4.5 months if A-response for all lesions, 13.3 months if at least one B-response, 17.1 months if retreated C- or D-response (p < 0.001), (7.5 and 4.7 months if untreated). Quality of life (p = 0.003), steroid use (p = 0.019) and prior whole brain radiotherapy (p = 0.026) were predictors for survival. There are 4 response patterns to SRS predicted by tumor size, primary cancer site, target cover ratio and prescribed dose. Long-term survivors experienced a higher incidence of PP and were more often retreated for new lesions and local failures. The immune response induced by PP seems beneficial but further studies are needed.

Background A major challenge in the follow-up of patients treated with stereotactic radiosurgery (SRS) for brain metastases (BM) is to distinguish pseudoprogression (PP) from tumor recurrence (TR). The aim of the study was to develop a clinical risk assessment score. Methods Follow-up images of 87 of 97 consecutive patients treated with SRS for 348 BM were analyzed. Of these, 100 (28.7%) BM in 48 (53.9%) patients responded with either TR (n = 53, 15%) or PP (n = 47, 14%). Differences between the 2 groups were analyzed and used to develop a risk assessment score (the Bergen Criteria). Results Factors associated with a higher incidence of PP vs. TR were as follows: prior radiation with whole brain radiotherapy or SRS (P = .001), target cover ratio ≥98% (P = .048), BM volume ≤2 cm3 (P = .054), and primary lung cancer vs. other cancer types (P = .084). Based on the presence (0) or absence (1) of these 5 characteristics, the Bergen Criteria was established. A total score 3 points were associated with 84% TR and 16% PP, P < .001. Conclusion Based on 5 characteristics at the time of SRS the Bergen Criteria could robustly differentiate between PP vs. TR following SRS. The score is user-friendly and provides a useful tool to guide the decision making whether to retreat or observe at appropriate follow-up intervals.

Background The number of incidental meningiomas has increased because of the increased availability of neuroimaging. Lack of prospective data on the natural history makes the optimal management unclear. We conducted a 5-year prospective study of incidental meningiomas to identify risk factors for tumor growth. Methods Sixty-four of 70 consecutive patients with incidental meningioma were included. Clinical and radiological status was obtained at 0, 0.5, 1, 1.5, 2, 3, 4, and 5 years. GammaPlan and mixed linear regression modeling were utilized for volumetric analysis with primary endpoint tumor growth. Results None of the patients developed tumor-related symptoms during the study period, although 48 (75%) tumors increased (>15%), 13 (20.3%) remained unchanged, and 3 (4.7%) decreased (>15%) in volume. Mean time to growth was 2.2 years (range, 0.5-5.0 years). The growth pattern was quasi-exponential in 26%, linear in 17%, sigmoidal in 35%, parabolic in 17%, and continuous reduction in 5%. There was significant correlation among growth rate, larger baseline tumor volume (P < .001), and age in years (75 y: 0.85 cm3/y). Conclusion The majority of meningiomas will eventually grow. However, more than 60% display a self-limiting growth pattern. Our study provides level-2 evidence that asymptomatic tumors can be safely managed utilizing serial imaging until persistent radiological and/or symptomatic growth.

Objective: We explored the effects of playing the piano on patients with cognitive impairment after mild traumatic brain injury (mTBI) and, addressed the question if this approach would stimulate neural networks in re-routing neural connections and link up cortical circuits that had been functional inhibited due to disruption of brain tissue. Functional neuroimaging scans (fMRI) and neuropsychological tests were performed pre–post intervention. Method: Three groups participated, one mTBI group (n = 7), two groups of healthy participants, one with music training (n = 11), one baseline group without music (n = 12). The music groups participated in 8 weeks music-supported intervention. Results: The patient group revealed training-related neuroplasticity in the orbitofrontal cortex. fMRI results fit well with outcome from neuropsychological tests with significant enhancement of cognitive performance in the music groups. Ninety per cent of mTBI group returned to work post intervention. Conclusion: Here, for the first time, we demonstrated behavioural improvements and functional brain changes after 8 weeks of playing piano on patients with mTBI having attention, memory and social interaction problems. We present evidence for a causal relationship between musical training and reorganisation of neural networks promoting enhanced cognitive performance. These results add a novel music-supported intervention within rehabilitation of patients with cognitive deficits following mTBI. publishedVersion

There is no consensus for the management of incidental meningiomas. To evaluate the natural history, we assessed tumour growth dynamics during 10 years of active monitoring of 62 patients (45 female and mean age 63.9) harbouring 68 tumours. Radiological and clinical data was obtained was obtained biannually for two years, then annually the following eight. Thirty-six patients (38 tumours) were referred to treatment and/or died of unrelated causes (n=5) within 5 years. The remaining were monitored for up to 10 years. Mean overall survival was at 128 months (95% CI: 118.8-136.7). Median progression free survival was 34 months (95% CI: 14.7-53.3). Median time for growth requiring intervention was 46 months (95% CI: 23.5-68.5). All tumours with self-limiting growth at 5 years (57.9 %) were still stable or reducing in size at 10 years. Mean growth rate decreased from 0.27 cm3/year (95% CI: 0.10-0.43) during the early observation period (0-5 years) to 0.09 cm3/year (95% CI: -0.02-0.21) in the late observation period. No tumours were referred to treatment during the late observation period. Two patients, both with verified WHO2 grade meningiomas succumbed to the disease, seven and eight years after diagnosis. No other patients developed symptoms and none other of the 18 total mortalities were meningioma related. Most clinical and radiological events occur within 5 years after diagnosis. Our findings suggests that if tumour growth slows down during the first 5 years of monitoring, this trend will continue. Clinical follow-up should be sufficient when a self-limiting growth pattern has been established.

Published version, available at http://dx.doi.org/10.1371/journal.pone.0221752 Previous research has demonstrated that people with Parkinson’s disease (PD) have difficulties with the perceptual discrimination of rhythms, relative to healthy controls. It is not however clear if this applies only to simpler rhythms (a so called “beat-based” deficit), or if it is a more generalized deficit that also applies to more complex rhythms. Further insight into how people with PD process and perceive rhythm can refine our understanding of the well known problems of temporal processing in the disease. In this study, we wanted to move beyond simple/complex-dichotomy in previous studies, and further investigate the effect of tempo on the perception of musical rhythms. To this end, we constructed ten musical rhythms with a varied degree of complexity across three different tempi. Nineteen people with PD and 19 healthy controls part-took in an internet based listening survey and rated 10 different musical rhythms for complexity and likeability. In what we believe is the first study to do so, we asked for the participants subjective ratings of individual rhythms and not their capacity to directly compare or discriminate between them. We found an overall between-group difference in complexity judgments that was modulated by tempo, but not level of complexity. People with PD rated all rhythms as more complex across tempi, with significant group differences in complexity ratings at 120 and 150bpm, but not at 90bpm. Our analysis found a uniform elevated baseline for complexity judgments in the PD-group, and a strong association between the two groups’ rank-ordering the rhythms for complexity. This indicates a preserved ability to discriminate between relative levels of complexity. Finally, the two groups did not significantly differ in their subjective scoring of likeability, demonstrating a dissimilarity between judgment of complexity and judgment of likeability between the two groups. This indicates different cognitive operations for the two types of judgment, and we speculate that Parkinson’s disease affects judgment of complexity but not judgment of likeability.

Source at https://doi.org/10.1038/s41598-019-48791-0. © The Author(s) 2019 Persons with Parkinson’s disease have general timing deficits and have difficulties in rhythm discrimination tasks. The basal ganglia, a crucial part of Parkinson’s disease pathology, is believed to play an important role in rhythm and beat processing, with a possible modulation of basal ganglia activity by level of rhythmic complexity. As dysfunction in basal ganglia impacts function in other brain areas in Parkinson’s disease during temporal processing, investigating the neuronal basis for rhythm processing is important as it could shed light on the nature of basal ganglia dysfunction and compensatory mechanisms. We constructed an auditory beat-omission fMRI paradigm with two levels of rhythm complexity, to investigate if and where persons with Parkinson’s disease showed abnormal activation during rhythm and omission processing, and whether such activations were modulated by the level of rhythmic complexity. We found no effect of complexity, but found crucial group differences. For the processing of normal rhythm presentations, the Parkinson-group showed higher bilateral planum temporal activity, an area previously associated with the processing of complex patterns. For the omissions, the Parkinson-group showed higher activity in an area in the right superior temporal gyrus previously associated with detection of auditory omissions. We believe this shows a pattern of “hypersensitive” activity, indicative of task-specific, compensatory mechanisms in the processing of temporal auditory information in persons with Parkinson’s disease.

Source at https://doi.org/10.1002/hbm.24421. Behavioral studies indicate that persons with Parkinson's disease have complexity dependent problems with the discrimination of auditory rhythms. Furthermore, neuroimaging studies show that rhythm processing activates many brain areas that overlap with areas affected by Parkinson's disease (PD). This study sought to investigate the neural correlates of rhythm processing in PD and healthy controls, with a particular focus on rhythmic complexity. We further aimed to investigate differences in brain activation during initial phases of rhythm processing. Functional magnetic resonance imaging was used to scan 15 persons with Parkinson's disease and 15 healthy controls while they listened to musical rhythms with two different levels of complexity. Rhythmic complexity had no significant effect on brain activations, but patients and controls showed differences in areas related to temporal auditory processing, notably bilateral planum temporale and inferior parietal lobule. We found indications of a particular sequential or phasic activation pattern of brain activity, where activity in caudate nucleus in the basal ganglia was time‐displaced by activation in the saliency network—comprised of anterior cingulate cortex and bilateral anterior insula—and cortical and subcortical motor areas, during the initial phases of listening to rhythms. We relate our findings to core PD pathology, and discuss the overall, rhythm processing related hyperactivity in PD as a possible dysfunction in specific basal ganglia mechanisms, and the phasic activation pattern in PD as a reflection of a lack of preparatory activation of task‐relevant brain networks for rhythm processing in PD.

A major challenge in the follow-up of patients managed with stereotactic radiosurgery (SRS) brain for metastases (BM) is to differentiate pseudoprogression (PP) from tumor recurrence (TR). A clinical score based on tumor and treatment related factors would be valuable when selecting appropriate treatment. Follow-up images of 97 consecutive patients treated with SRS for 406 BM were analyzed. We included 100 (24.6 %) BM in 42 (43.3 %) patients which responded either with TR (delayed growth; 53 (13.1 %) BM in 27 patients) or PP (temporary volume increase; 47 (11.6 %) BM in 15 patients). Differences between the 2 groups were analyzed and used to develop a PP risk assessment score (PP-RAS). Significant factors associated with a higher incidence of PP versus TR were: primary lung cancer vs. other primaries, BM volume < 2cc (or BM < 1.5 cm in diameter), Target cover ratio ≥ 98 % and prior radiation with SRS or WBRT. Based on the presence (0) or not (1) of these 5 parameters, a risk assessment score for PP versus TR was established. A PP-RAS score of 0 corresponds with high risk of PP vs.TR, whereas a score of 5 corresponds low risk of PP vs. TR. A score of ≤ 1 point was associated with 100 % PP, 2 points with 57 % PP and 43 % TR, 3 points with 57 % TR and 43 % PP whereas ≥ 4 points were associated with 84 % TR and 16 % PP, π=24.57, df =4, p < 0.001). Based on these 5 parameters at the time of SRS our risk assessment score could robustly differentiate between PP versus growth following SRS. The score is user-friendly and may be a useful tool to guide the decision making whether to retreat or observe at appropriate follow-up intervals.

Myasthenia gravis (MG) is an autoimmune disorder caused by autoantibodies that target the neuromuscular junction, leading to muscle weakness and fatigability. Currently available treatments for the disease include symptomatic pharmacological treatment, immunomodulatory drugs, plasma exchange, thymectomy and supportive therapies. Different autoantibody patterns and clinical manifestations characterize different subgroups of the disease: early-onset MG, late-onset MG, thymoma MG, muscle-specific kinase MG, low-density lipoprotein receptor-related protein 4 MG, seronegative MG, and ocular MG. These subtypes differ in terms of clinical characteristics, disease pathogenesis, prognosis and response to therapies. Patients would, therefore, benefit from treatment that is tailored to their disease subgroup, as well as other possible disease biomarkers, such as antibodies against cytoplasmic muscle proteins. Here, we discuss the different MG subtypes, the sensitivity and specificity of the various antibodies involved in MG for distinguishing between these subtypes, and the value of antibody assays in guiding optimal therapy. An understanding of these elements should be useful in determining how to adapt existing therapies to the requirements of each patient.

Mitochondrial complex I deficiency occurs in the substantia nigra of individuals with Parkinson's disease. It is generally believed that this phenomenon is caused by accumulating mitochondrial DNA damage in neurons and that it contributes to the process of neurodegeneration. We hypothesized that if these theories are correct, complex I deficiency should extend beyond the substantia nigra to other affected brain regions in Parkinson's disease and correlate tightly with neuronal mitochondrial DNA damage. To test our hypothesis, we employed a combination of semiquantitative immunohistochemical analyses, Western blot and activity measurements, to assess complex I quantity and function in multiple brain regions from an extensively characterized population-based cohort of idiopathic Parkinson's disease (n = 18) and gender and age matched healthy controls (n = 11). Mitochondrial DNA was assessed in single neurons from the same areas by real-time PCR. Immunohistochemistry showed that neuronal complex I deficiency occurs throughout the Parkinson's disease brain, including areas spared by the neurodegenerative process such as the cerebellum. Activity measurements in brain homogenate confirmed a moderate decrease of complex I function, whereas Western blot was less sensitive, detecting only a mild reduction, which did not reach statistical significance at the group level. With the exception of the substantia nigra, neuronal complex I loss showed no correlation with the load of somatic mitochondrial DNA damage. Interestingly, α-synuclein aggregation was less common in complex I deficient neurons in the substantia nigra. We show that neuronal complex I deficiency is a widespread phenomenon in the Parkinson's disease brain which, contrary to mainstream theory, does not follow the anatomical distribution of neurodegeneration and is not associated with the neuronal load of mitochondrial DNA mutation. Our findings suggest that complex I deficiency in Parkinson's disease can occur independently of mitochondrial DNA damage and may not have a pathogenic role in the neurodegenerative process.

Background Hypokalemic pareses are caused by low extracellular potassium levels which reduce the resting membrane potential of muscle cells and make them less excitable. It may be caused by an intracellular shift of potassium, renal potassium loss, reduced potassium intake or increased gastrointestinal loss. Case presentation A woman in her 60s presented with rapid-onset tetraparesis and hyporeflexia starting the day before admission. The patient history revealed several months of low food intake, increased alcohol consumption and diarrhoea. Laboratory tests showed severe hypokalemia (1.5 mmol/l) and hypomagnesemia (0.38 mmol/l), and ECG showed atrial fibrillation. She was admitted to the medical intensive care unit and treated with intravenous normal saline with added potassium and magnesium, with good effect on her symptoms. Urine tests showed high potassium-creatinine ratio (4.22 mmol/mmol creatinine) and increased fractional excretion of magnesium (18.6%). Abdominal CT scan revealed colonic wall thickening, and colonic biopsies showed mild inflammation. Faecal calprotectin was moderately elevated (294 mg/kg). Interpretation The patient had hypokalemic pareses for which there were several contributing factors. The renal causes were augmented excretion of magnesium and potassium, probably due to increased alcohol consumption. The extrarenal causes were increased gastrointestinal loss, with ulcerative colitis being the presumed explanation, and reduced food intake.

OBJECTIVELung cancer (LC) patients who develop brain metastases (BMs) have a poor prognosis. Estimations of survival and risk of treatment-related deterioration in quality of life (QOL) are important when deciding on treatment. Although we know of several prognostic factors for LC patients with BMs, the role of QOL has not been established. Authors of this study set out to evaluate changes in QOL following Gamma Knife surgery (GKS) for BMs in LC patients and QOL as a prognostic factor for survival.METHODSForty-four of 48 consecutive LC patients with BMs underwent GKS in the period from May 2010 to September 2011, and their QOL was prospectively assessed before and 1, 3, 6, 9, and 12 months after GKS by using the Functional Assessment of Cancer Therapy–Brain (FACT-BR) questionnaire. A mixed linear regression model was used to identify potential predictive factors for QOL and to assess the effect of GKS and the disease course on QOL at follow-up.RESULTSMean QOL as measured by the brain cancer subscale (BRCS) of the FACT-BR remained stable from baseline (score 53.0) up to 12 months post-GKS (57.1; p = 0.624). The BRCS score improved for 32 patients (72.3%) with a total BM volume ≤ 5 cm3. Mean improvement in these patients was 0.45 points each month of follow-up, compared to a decline of 0.50 points each month despite GKS treatment in patients with BM volumes > 5 cm3 (p = 0.04). Asymptomatic BMs (p = 0.01), a lower recursive partitioning analysis (RPA) classification (p = 0.04), and a higher Karnofsky Performance Scale (KPS) score (p < 0.01) at baseline were predictors for a high, stable QOL after GKS. After multivariate analysis, a high KPS score (p < 0.01) remained the only positive predictor of a high, stable QOL post-GKS.Median survival post-GKS was 5.6 months (95% CI 1.0–10.3). A higher BRCS score (p = 0.01), higher KPS score (p = 0.01), female sex (p = 0.01), and the absence of liver (p = 0.02), adrenal (p = 0.02), and bone metastases (p = 0.03) predicted longer survival in unadjusted models. However, in multivariate analyses, a higher BRCS score (p < 0.01), female sex (p = 0.01), and the absence of bone metastases (p = 0.02) at GKS remained significant predictors. Finally, the BRCS score’s predictive value for survival was compared with the values for the variables behind well-known prognostic indices: age, KPS score, extracranial disease status, and number and volume of BMs. Both BRCS score (p = 0.01) and BM volume (p = 0.05) remained significant predictors for survival in the final model.CONCLUSIONSPatient-reported QOL according to the BRCS is a predictor of survival in patients with BMs and may be helpful in deciding on the optimal treatment. Gamma Knife surgery is a safe and effective therapeutic modality that improves QOL for LC patients with a BM volume ≤ 5 cm3 at treatment. Careful follow-up and salvage therapy on demand seem to prevent worsening of QOL due to relapse of BMs.

OBJECTIVE: A major challenge in the follow-up of patients managed with stereotactic radiosurgery (SRS) for brain metastases (BM) is to differentiate pseudoprogression (PP) from tumor recurrence (TR). A clinical score based on tumor and treatment related factors would be valuable when selecting appropriate treatment. MATERIAL AND METHODS: Follow-up images of 97 consecutive patients treated with SRS for 406 BM were analyzed. Of these 100 (24.6 %) BM in 48 (49.5 %) patients responded either with TR (delayed growth; 53 (13.1 %) BM) or PP (temporary volume increase; 47 (11.6 %) BM). Differences between the 2 groups were analyzed and used to develop a PP risk assessment score (PP-RAS). RESULTS: Significant factors associated with a higher incidence of PP versus TR were: primary lung cancer vs. other primaries, BM volume ≤ 2cc (or BM ≤ 1.5 cm in diameter), Target cover ratio > 98 % and prior radiation SRS or WBRT. Based on the presence (0) or not (1) of these 5 parameters, a risk assessment score for PP versus TR was established. A PP-RAS score of 0 corresponds with high likelihood of PP vs. TR, whereas a score of 5 corresponds with a high risk of TR. A score of ≤ 1 point was associated with 100 % PP, 2 points with 57 % PP and 43 % TR, 3 points with 57 % TR and 43 % PP, whereas ≥ 4 points were associated with 84 % TR and 16 % PP, π=24.57, df =4, p < 0.001). CONCLUSION: Based on these 5 parameters at the time of SRS our risk assessment score could robustly differentiate between PP versus growth following SRS. The score is user-friendly and may be a useful tool to guide the decision making whether to retreat or observe at appropriate follow-up intervals.

The Joint Editors-in-Chief have retracted this article [1] at the request of the University of Bergen and the Norwegian Board of Health Supervision.

Introduction: Myasthenia gravis (MG) is an autoimmune disease. Patients without detectable antibodies against the nicotinic acetylcholine receptor or the muscle-specific tyrosine kinase are referred to as seronegative MG (SNMG). Because late-onset congenital myasthenic syndromes (CMSs) due to RAPSN or DOK7 mutations may be mistaken for SNMG, we investigated their frequency in a nationwide SNMG cohort. Methods: We performed sequencing of RAPSN and DOK7 in all Norwegian SNMG patients (n = 74) and 37 healthy controls, examining for the N88K and c.1124_1127dupTGCC mutations, respectively. Results: We found 1 patient homozygous for N88K and 2 carriers of the N88K mutation. Sequencing of DOK7 revealed no mutations. Conclusions: This study confirms that rapsn CMS can be mistaken for SNMG. In addition, the frequency of rapsn CMS in our nationwide SNMG cohort was found to be low. SNMG patients with an atypical clinical presentation and pediatric cases should be tested for the N88K mutation before initiation of immunosuppressive drug treatment or thymectomy. Muscle Nerve, 2011

Patients with autoimmune myasthenia gravis (MG) should be further classified before initiating therapy, as treatment response varies for ocular versus generalised, early onset versus late onset, and acetylcholine receptor antibody positive versus MuSK antibody positive disease. Most patients need immunosuppression in addition to symptomatic therapy. Prednisolone and azathioprine represent first choice drugs, whereas several second choice options are recommended and should be considered. Thymectomy should be undertaken in MG with thymoma and in generalised, early-onset MG. For MG crises and other acute exacerbations, intravenous immunoglobulin (IvIg) and plasma exchange are equally effective and safe treatments. Children and females in child bearing age need special attention regarding potential side effects of immunosuppressive therapy. MG pathogenesis is known in detail, but the immune therapy is still surprisingly unspecific, without a pin-pointed attack on the defined disease-inducing antigen-antibody reaction being available.

Background: Important progress has been made in our understanding of the autoimmune neuromuscular transmission (NMT) disorders; myasthenia gravis (MG), Lambert–Eaton myasthenic syndrome (LEMS) and neuromyotonia (Isaacs syndrome). Methods: To prepare consensus guidelines for the treatment of the autoimmune NMT disorders, references retrieved from MEDLINE, EMBASE and the Cochrane Library were considered and statements prepared and agreed on by disease experts. Conclusions: Anticholinesterase drugs should be given first in the management of MG, but with some caution in patients with MuSK antibodies (good practice point). Plasma exchange is recommended in severe cases to induce remission and in preparation for surgery (recommendation level B). IvIg and plasma exchange are effective for the treatment of MG exacerbations (recommendation level A). For patients with non-thymomatous MG, thymectomy is recommended as an option to increase the probability of remission or improvement (recommendation level B). Once thymoma is diagnosed, thymectomy is indicated irrespective of MG severity (recommendation level A). Oral corticosteroids are first choice drugs when immunosuppressive drugs are necessary (good practice point). When long-term immunosuppression is necessary, azathioprine is recommended to allow tapering the steroids to the lowest possible dose whilst maintaining azathioprine (recommendation level A). 3,4-Diaminopyridine is recommended as symptomatic treatment and IvIG has a positive short-term effect in LEMS (good practice point). Neuromyotonia patients should be treated with an antiepileptic drug that reduces peripheral nerve hyperexcitability (good practice point). For paraneoplastic LEMS and neuromyotonia optimal treatment of the underlying tumour is essential (good practice point). Immunosuppressive treatment of LEMS and neuromyotonia should be similar to MG (good practice point).

Of sera of patients with myasthenia gravis (MG), 30% contains titin and ryanodine receptor (RyR) antibodies. In early-onset MG (i.e., before 50 years of age), the presence of titin antibodies strongly suggests a thymoma. Late-onset MG comprises one MG group, characterized by a broad antimuscle immune response, including both titin and the acetylcholine receptor (AChR). Another group is preferentially associated with the HLA-A3, B7 and DRw2 antigens, representing a delayed early-onset of the disease that has a selective AChR immune response. The presence of titin and RyR antibodies is associated with more severe disease. Titin antibodies may, in some patients with rippling muscle disease, affect the contractile machinery of myofibers, thereby affecting their mechanical sensitivity. It is not known whether this occurs in MG. RyR antibodies may impair excitation–contraction coupling and contribute to muscle weakness in MG patients. Titin antibodies may serve as tumor markers in early-onset MG patients.

The collapsin response mediator protein 5 (CRMP5) antibody is usually associated with paraneoplastic neurological syndrome (PNS) and small-cell lung cancer (SCLC) or thymoma. The objective of this study was to assess the frequency of CRMP5 antibodies in patients with such tumours and to see if the presence of antibodies was associated with prognosis in these cancers. A multi-well adapted immunoprecipitation assay using radiolabelled recombinant CRMP5 protein, produced by coupled in vitro transcription/translation, was used for the detection of CRMP5 antibodies. Sera from 200 patients with SCLC, 73 patients with thymoma and myasthenia gravis (MG) and from 300 healthy blood donors were examined for CRMP5 antibodies. Positive sera were also examined by immunofluorescence and immune blots. The serological results were compared with disease severity of the patients with thymoma or SCLC. CRMP5 antibodies were detected in 10/200 (5%) of the SCLC, 9/73 (12%) of the thymomas and in 2/300 (0.6%) of the healthy controls by immunoprecipitation. The antibodies were less frequently detected by immunofluorescence or immune blots. There was no significant correlation between CRMP5 antibodies and disease severity. CRMP5 antibodies are more than twice as frequent, and the antibody levels are higher in patients with thymoma and MG than in patients with SCLC. The antibodies are correlated to these tumours, but not to disease severity.

Hypokalemic pareses are caused by low extracellular potassium levels which reduce the resting membrane potential of muscle cells and make them less excitable. It may be caused by an intracellular shift of potassium, renal potassium loss, reduced potassium intake or increased gastrointestinal loss.A woman in her 60s presented with rapid-onset tetraparesis and hyporeflexia starting the day before admission. The patient history revealed several months of low food intake, increased alcohol consumption and diarrhoea. Laboratory tests showed severe hypokalemia (1.5 mmol/l) and hypomagnesemia (0.38 mmol/l), and ECG showed atrial fibrillation. She was admitted to the medical intensive care unit and treated with intravenous normal saline with added potassium and magnesium, with good effect on her symptoms. Urine tests showed high potassium-creatinine ratio (4.22 mmol/mmol creatinine) and increased fractional excretion of magnesium (18.6%). Abdominal CT scan revealed colonic wall thickening, and colonic biopsies showed mild inflammation. Faecal calprotectin was moderately elevated (294 mg/kg).The patient had hypokalemic pareses for which there were several contributing factors. The renal causes were augmented excretion of magnesium and potassium, probably due to increased alcohol consumption. The extrarenal causes were increased gastrointestinal loss, with ulcerative colitis being the presumed explanation, and reduced food intake.

A right-handed woman of 90, taking aspirin 160 mg daily, suffered acute neck pain radiating to the shoulders, with right side hemiparesis and numbness occurring minutes thereafter. On admission 2.5 hrs later, examination showed paresis and hyporeflexia of the right limbs accompanied by neck stiffness and vertebral tenderness in level C7. Acute stroke was the initial working diagnosis. Cerebral CT was normal. Symptoms progressed with left arm numbness and left ancle clonus, and eight hours after symptom onset there was bilateral plantar inversion, reduced skin prick sensibility below C4, bladder paresis and anal sphincter hypotonia. CT myelography revealed an intraspinal mass extending from C2 to C6. 14 hours after symptom onset, a spinal epidural haematoma was removed by spinal laminectomy. Recovery and functional outcome was good. Symptoms, work-up and treatment are discussed with reference to previous publications.

Myasthenia gravis (MG) is caused primarily by autoantibodies against the nicotinic acetylcholine receptor (AChR), but autoantibodies to other muscle proteins may be present. Many of these proteins have structural or signalling functions, the disruption of which may affect muscle cell morphology or viability. In order to investigate the role of such autoantibodies in MG, we examined the effect of MG patient sera, of different autoantibody composition and obtained at different stages of disease severity, on primary human muscle cells. Sera from MG patients induced changes in cell morphology from typical elongated cells to an irregular phenotype, caused the formation of inclusion bodies and intracellular vesicles, and led to a disordered arrangement of actin microfilaments. Sera from the most severely affected patients also induced cell death, which did not occur via classic apoptosis. The effects were not complement-mediated and were dose- and time-dependent. As the effects observed in the cell culture system correlated with disease severity, a greater understanding of the individual factors responsible for these effects may improve our understanding of MG pathogenesis and be of value in the assessment of disease in individual patients.

Background: Myasthenia gravis (MG) is caused by autoantibodies to the acetylcholine receptor (AChR). NonAChR muscle autoantibodies are present in many MG serum samples, mainly from patients with thymoma or lateonset MG. The exact relationship between MG severity and several non-AChR muscle antibodies is unknown. Objective: To study the correlation between the severity of MG and the concentration of antibodies against striated muscle tissue sections, titin, citric acid antigen, ryanodine receptor, and AChR. Setting: The severity of MG was graded in 146 consecutive patients with MG, and their serum samples were tested for the presence of autoantibodies. Ten patients who were titin antibody positive were observed in longitudinal follow-up. Results: No significant difference was found in MG severity between late-onset and thymoma MG. Titin, citric acid antigen, and ryanodine receptor antibodies occurred significantly more often among patients with severe MG than among patients with less severe disease. Changes in MG severity correlated with changes in titin antibody titer in the individual patient. Titin antibodies showed a better longitudinal correlation with disease severity than the AChR antibodies. Conclusions: Non-AChR muscle autoantibodies occurred more frequently in severe MG regardless of MG subgroup. Thymoma per se does not generate a more severe MG. It may well be the presence of a humoral immune response to non-AChR muscle antigens such as titin, citric acid antigen, and ryanodine receptor that leads to a severe disease, not the presence of thymoma or a late age of onset. These antibodies can serve as important prognostic markers in MG regardless of the presence of thymoma. Arch Neurol. 2000;57:1596-1600

Background Tumor necrosis factor (TNF) α and TNF-β are proinflammatory cytokines thought to be involved in the pathogenesis of myasthenia gravis (MG). Objective To examine whether TNF polymorphisms are associated with MG, MG subgroups, and the presence of titin and ryanodine-receptor antibodies. Patients and Methods We did genotyping on 30 patients with MG and 92 healthy blood donors for 2 biallelic TNFA polymorphisms (G to A at positions −238 and −308) and 1 TNFB polymorphism ( Nco I digestive site) using methods based on the polymerase chain reaction. Results Patients with thymoma were typically homozygous for both the TNFA*T1 and the TNFB*2 alleles, but patients having an early onset of MG without thymoma were carriers of the TNFA*T2 and TNFB*1 alleles. Patients without thymoma who had the titin antibody had the same high frequency of TNFA*T1 and TNFB*2 as patients with thymoma, whereas patients without the titin antibody carried the same allele, TNFA*T2 and TNFB*1 , regardless of age and thymic disease. No association was found with acetylcholine-receptor levels or disease severity for any of the TNFA or TNFB polymorphisms. Conclusion Patients having MG, including those with thymoma, who have the titin antibody are most often homozygous for the TNFA*T1 and TNFB*2 alleles, whereas the presence of the TNFA*T2 and TNFB*1 alleles correlates with early-onset MG and the absence of titin antibodies.

Myasthenia gravis is an autoimmune disease caused, in most cases, by antibodies attaching to the acetylcholine receptor. Some myasthenia gravis patients have antibodies that bind in a cross-striational pattern to skeletal and heart muscle tissue sections (striational antibodies). These antibodies react with epitopes on the muscle proteins titin and ryanodine receptor, are found mainly in sera of patients with thymoma and late-onset myasthenia gravis, and may correlate with myasthenia gravis severity. Their presence may predict an unsatisfactory outcome after thymectomy. The detection of titin and ryanodine receptor antibodies provides more specific clinical information than the immunofluorescent demonstration of striational antibodies.