domenica 26 ottobre 2014

Complete remission of childhood-onset epilepsy: stability and prediction over two decades

The ultimate seizure outcome of childhood epilepsy is complete resolution of all seizures without further treatment. How often this happens and how well it can be predicted early in the course of epilepsy could be valuable in helping families understand the nature of childhood epilepsy and what to expect over time. In the Connecticut study of epilepsy, a prospective cohort of 613 children with newly-diagnosed epilepsy (onset age 0–15 years), complete remission, ≥5 years both seizure-free and medication-free, was examined as a proxy of complete seizure resolution. Predictors at initial diagnosis were tested. Information about seizure outcomes within 2 years and from 2–5 years after diagnosis was sequentially added in a proportional hazards model. The predictive value of the models was determined with logistic regression. Five hundred and sixteen subjects were followed ≥10 years. Three hundred and twenty-eight (63%) achieved complete remission; 23 relapsed. The relapse rate was 8.2 per 1000 person-years and decreased over time: 10.7, 6.7, and 0 during first 5 years, the next 5 years, and then >10 years after complete remission (P = 0.06 for trend). Six participants regained complete remission; 311 (60%) were in complete remission at last contact. Baseline factors predicting against complete remission at last contact included onset age ≥10 years (hazard ratio = 0.55, P = 0.0009) and early school or developmental problems (hazard ratio = 0.74, P = 0.01). Factors predicting for complete remission were uncomplicated epilepsy presentation (hazard ratio = 2.23, P < 0.0001), focal self-limited epilepsy syndrome (hazard ratio = 2.13, P < 0.0001), and uncharacterized epilepsy (hazard ratio = 1.61, P = 0.04). Remission (hazard ratio = 1.95, P < 0.0001) and pharmaco-resistance (hazard ratio = 0.33, P < 0.0001) by 2 years respectfully predicted in favour and against complete remission. From 2 to 5 years after diagnosis, relapse (hazard ratio = 0.21, P < 0.0001) and late pharmaco-resistance (hazard ratio = 0.21, P = 0.008) decreased and late remission (hazard ratio = 2.40, P < 0.0001) increased chances of entering complete remission. The overall accuracy of the models increased from 72% (baseline information only), to 77% and 85% with addition of 2-year and 5-year outcomes. Relapses after complete remission are rare making this an acceptable proxy for complete seizure resolution. Complete remission after nearly 20 years is reasonably well predicted within 5 years of initial diagnosis.

Brain 2014

Consistent abnormalities in metabolic network activity in idiopathic rapid eye movement sleep behaviour disorder

Rapid eye movement sleep behaviour disorder has been evaluated using Parkinson’s disease-related metabolic network. It is unknown whether this disorder is itself associated with a unique metabolic network. 18F-fluorodeoxyglucose positron emission tomography was performed in 21 patients (age 65.0 ± 5.6 years) with idiopathic rapid eye movement sleep behaviour disorder and 21 age/gender-matched healthy control subjects (age 62.5 ± 7.5 years) to identify a disease-related pattern and examine its evolution in 21 hemi-parkinsonian patients (age 62.6 ± 5.0 years) and 16 moderate parkinsonian patients (age 56.9 ± 12.2 years). We identified a rapid eye movement sleep behaviour disorder-related metabolic network characterized by increased activity in pons, thalamus, medial frontal and sensorimotor areas, hippocampus, supramarginal and inferior temporal gyri, and posterior cerebellum, with decreased activity in occipital and superior temporal regions. Compared to the healthy control subjects, network expressions were elevated (P < 0.0001) in the patients with this disorder and in the parkinsonian cohorts but decreased with disease progression. Parkinson’s disease-related network activity was also elevated (P < 0.0001) in the patients with rapid eye movement sleep behaviour disorder but lower than in the hemi-parkinsonian cohort. Abnormal metabolic networks may provide markers of idiopathic rapid eye movement sleep behaviour disorder to identify those at higher risk to develop neurodegenerative parkinsonism.

Brain 2014

Peripheral neuropathy predicts nuclear gene defect in patients with mitochondrial ophthalmoplegia

Progressive external ophthalmoplegia is a common clinical feature in mitochondrial disease caused by nuclear DNA defects and single, large-scale mitochondrial DNA deletions and is less frequently associated with point mutations of mitochondrial DNA. Peripheral neuropathy is also a frequent manifestation of mitochondrial disease, although its prevalence and characteristics varies considerably among the different syndromes and genetic aetiologies. Based on clinical observations, we systematically investigated whether the presence of peripheral neuropathy could predict the underlying genetic defect in patients with progressive external ophthalmoplegia. We analysed detailed demographic, clinical and neurophysiological data from 116 patients with genetically-defined mitochondrial disease and progressive external ophthalmoplegia. Seventy-eight patients (67%) had a single mitochondrial DNA deletion, 12 (10%) had a point mutation of mitochondrial DNA and 26 (22%) had mutations in either POLGC10orf2 or RRM2B, or had multiple mitochondrial DNA deletions in muscle without an identified nuclear gene defect. Seventy-seven patients had neurophysiological studies; of these, 16 patients (21%) had a large-fibre peripheral neuropathy. The prevalence of peripheral neuropathy was significantly lower in patients with a single mitochondrial DNA deletion (2%) as compared to those with a point mutation of mitochondrial DNA or with a nuclear DNA defect (44% and 52%, respectively; P < 0.001). Univariate analyses revealed significant differences in the distribution of other clinical features between genotypes, including age at disease onset, gender, family history, progressive external ophthalmoplegia at clinical presentation, hearing loss, pigmentary retinopathy and extrapyramidal features. However, binomial logistic regression analysis identified peripheral neuropathy as the only independent predictor associated with a nuclear DNA defect (P = 0.002; odds ratio 8.43, 95% confidence interval 2.24–31.76). Multinomial logistic regression analysis identified peripheral neuropathy, family history and hearing loss as significant predictors of the genotype, and the same three variables showed the highest performance in genotype classification in a decision tree analysis. Of these variables, peripheral neuropathy had the highest specificity (91%), negative predictive value (83%) and positive likelihood ratio (5.87) for the diagnosis of a nuclear DNA defect. These results indicate that peripheral neuropathy is a rare finding in patients with single mitochondrial DNA deletions but that it is highly predictive of an underlying nuclear DNA defect. This observation may facilitate the development of diagnostic algorithms. We suggest that nuclear gene testing may enable a more rapid diagnosis and avoid muscle biopsy in patients with progressive external ophthalmoplegia and peripheral neuropathy.

Brain 2014

Membrane-shaping disorders: a common pathway in axon degeneration

Neurons with long projections are particularly liable to damage, which is reflected by a large group of hereditary neurodegenerative disorders that primarily affect these neurons. In the group of hereditary spastic paraplegias motor axons of the central nervous system degenerate, while distal pure motor neuropathies, Charcot-Marie-Tooth disorders and the group of hereditary sensory and autonomic neuropathies are characterized by degeneration of peripheral nerve fibres. Because the underlying pathologies share many parallels, the disorders are also referred to as axonopathies. A large number of genes has been associated with axonopathies and one of the emerging subgroups encodes membrane-shaping proteins with a central reticulon homology domain. Association of these proteins with lipid bilayers induces positive membrane curvature and influences the architecture of cellular organelles. Membrane-shaping proteins closely cooperate and directly interact with each other, but their structural features and localization to distinct subdomains of organelles suggests mutually exclusive roles. In some individuals a mutation in a shaping protein can result in upper motor neuron dysfunction, whereas in other patients it can lead to a degeneration of peripheral neurons. This suggests that membrane-shaping disorders might be considered as a continuous disease-spectrum of the axon.

Brain 2014

Effects of long-term blood pressure lowering and dual antiplatelet treatment on cognitive function in patients with recent lacunar stroke: a secondary analysis from the SPS3 randomised trial

The primary outcome results for the SPS3 trial suggested that a lower systolic target blood pressure (<130 mm Hg) might be beneficial for reducing the risk of recurrent stroke compared with a higher target (130—149 mm Hg), but that the addition of clopidogrel to aspirin was not beneficial compared with aspirin plus placebo. In this prespecified secondary outcome analysis of the SPS3 trial, we aimed to assess whether blood pressure reduction and dual antiplatelet treatment affect changes in cognitive function over time in patients with cerebral small vessel disease.
In the SPS3 trial, patients with recent (within 6 months) symptomatic lacunar infarcts from 81 centres in North America, Latin America, and Spain were randomly assigned, in a two-by-two factorial design, to target levels of systolic blood pressure (1:1; 130—149 mm Hg vs <130 mm Hg; open-label) and to a once-daily antiplatelet treatment (1:1; aspirin 325 mg plus clopidogrel 75 mgvs aspirin 325 mg plus placebo; double-blind). For this analysis, the main cognitive outcome was change in Cognitive Abilities Screening Instrument (CASI) during follow-up. Patients were tested annually for up to 5 years, during which time the mean difference in systolic blood pressure was 11 mm Hg (SD 16) between the two targets (138 mm Hg vs 127 mm Hg at 1 year). We used linear mixed models to compare changes in CASI Z scores over time. The SPS3 trial is registered with, number NCT00059306.
The study took place between March 23, 2003, and April 30, 2012. 2916 of 3020 SPS3 participants (mean age 63 years [SD 11]) with CASI scores at study entry were included in the analysis, with a median follow-up of 3·0 years (IQR 1·0—4·9). Mean changes in CASI Z scores from study entry to assessment at years 1 (n=2472), 2 (n=1968), 3 (n=1521), 4 (n=1135), and 5 (n=803) were 0·12 (SD 0·83), 0·15 (0·84), 0·16 (0·95), 0·19 (0·99), and 0·14 (1·09), respectively. Changes in CASI Z scores over time did not differ between assigned antiplatelet groups (p=0·858) or between assigned blood pressure target groups (p=0·520). There was no interaction between assigned antiplatelet groups and assigned blood pressure target groups and change over time (p=0·196).
Cognitive function is not affected by short-term dual antiplatelet treatment or blood pressure reduction in fairly young patients with recent lacunar stroke. Future studies of cognitive function after stroke should be of longer duration or focus on patients with higher rates of cognitive decline.

lancet Neurology 2014

Vaccines and the Risk of Multiple Sclerosis and Other Central Nervous System Demyelinating Diseases

Importance  Because vaccinations are common, even a small increased risk of multiple sclerosis (MS) or other acquired central nervous system demyelinating syndromes (CNS ADS) could have a significant effect on public health.
Objective  To determine whether vaccines, particularly those for hepatitis B (HepB) and human papillomavirus (HPV), increase the risk of MS or other CNS ADS.
Design, Setting, and Participants  A nested case-control study was conducted using data obtained from the complete electronic health records of Kaiser Permanente Southern California (KPSC) members. Cases were identified through the KPSC CNS ADS cohort between 2008 and 2011, which included extensive review of medical records by an MS specialist. Five controls per case were matched on age, sex, and zip code.
Exposures  Vaccination of any type (particularly HepB and HPV) identified through the electronic vaccination records system.
Main Outcomes and Measures  All forms of CNS ADS were analyzed using conditional logistic regression adjusted for race/ethnicity, health care utilization, comorbid diseases, and infectious illnesses before symptom onset.
Results  We identified 780 incident cases of CNS ADS and 3885 controls; 92 cases and 459 controls were females aged 9 to 26 years, which is the indicated age range for HPV vaccination. There were no associations between HepB vaccination (odds ratio [OR], 1.12; 95% CI, 0.72-1.73), HPV vaccination (OR, 1.05; 95% CI, 0.62-1.78), or any vaccination (OR, 1.03; 95% CI, 0.86-1.22) and the risk of CNS ADS up to 3 years later. Vaccination of any type was associated with an increased risk of CNS ADS onset within the first 30 days after vaccination only in younger (<50 years) individuals (OR, 2.32; 95% CI, 1.18-4.57).
Conclusions and Relevance  We found no longer-term association of vaccines with MS or any other CNS ADS, which argues against a causal association. The short-term increase in risk suggests that vaccines may accelerate the transition from subclinical to overt autoimmunity in patients with existing disease. Our findings support clinical anecdotes of CNS ADS symptom onset shortly after vaccination but do not suggest a need for a change in vaccine policy.

JAMA Neurology 2014

Disease Penetrance of Late-Onset Parkinsonism A Meta-analysis

Objective  To compare penetrance of various mutations reported in published genetic studies to improve the understanding of late-onset parkinsonism.
Data Sources  Forty-nine previously published studies, including 709 participants, were included for all original and subsequent articles in ISI Web of Science, PubMed electronic databases, and extracted information about number of mutation carriers within families and sporadic cases worldwide for pathogenic mutations in SNCA, LRRK2VPS35, EIF4G1, and DNAJC13. The end-of-search date was January 31, 2014.
Study Selection  Published studies were included if there was information on the ethnicity of the patient or unaffected individual, confirmation of mutation, age of patient or unaffected individual, age at onset, and first motor symptom of patient. Autosomal recessive parkinsonism and genes implicated without significant genetic linkage were excluded from this study.
Data Extraction and Synthesis  The age-associated cumulative incidence was estimated using the Kaplan-Meier method with age at onset as the time variable; asymptomatic carriers were right censored at the age at last contact or age at death.
Main Outcomes and Measures  Comparative measures were obtained with log-rank tests, and each penetrance estimate was given separately with 95% confidence intervals.
Results  All the assessed autosomal dominant Parkinson disease mutations have significantly different age-dependent cumulative incidences (P < .001). In particular, penetrance of SNCAduplications was comparable to point mutations (log-rank P = .97) and driven by inclusion of SNCAp.A53T (mean age at onset, 45.9 years; 95% CI, 43-49 years). In addition, Israeli Ashkenazi JewishLRRK2 p.G2019S carriers (mean age at onset, 57.9 years; 95% CI, 54-63 years) were comparable to Tunisian Arab Berbers (mean age at onset, 57.1 years; 95% CI, 45.5-68.7 years) (P = .58), whereas Norwegian carriers (mean age at onset, 63 years; 95% CI, 51.4-74.6 years) were significantly different from the other groups (P < .001).
Conclusions and Relevance  Parkinson disease pathogenic mutations have an age-dependent penetrance that could be ameliorated or exacerbated by modifier genes or environmental factors in different populations.

JAMA Neurology 2014

Synaptic effects of cannabinoids

The discovery of (−)-Δ9-tetrahydrocannabinol (Δ9 THC) as the main psychoactive ingredient in cannabis (marijuana), the cloning of the cannabinoid receptors CB1R and CB2R, and the identification of the endocannabinoids as their endogenous ligands has stimulated extensive research on the role of the cannabinoid system in synaptic regulation in the CNS. The 2 major endocannabinoids in the nervous system are 2-arachydonoyl glycerol (2-AG) and N-arachidonoyl ethanolamide (also known as anandamide). They are lipid mediators that are released from neurons on demand in response to excitatory synaptic activity. Endocannabinoids function primarily as retrograde messengers that inhibit neurotransmitter release via presynaptic CB1Rs, which are distributed primarily in γ-aminobutyric acid (GABA)ergic and to a lesser extent glutamatergic and other presynaptic terminals. Retrograde endocannabinoid signaling participates in several mechanisms of short- and long-term plasticity (depression) of inhibitory and excitatory synapses. Endocannabinoids may also act via postsynaptic CB1Rs and, in the case of anandamide, also transient receptor potential, vanilloid type 1 (TRPV1) channels. Endocannabinoids also mediate interactions among neurons and different types of glial cells, regulating not only synaptic plasticity but also inflammatory responses in the CNS. By all these mechanisms, endocannabinoids affect the activity of neuronal networks involved in cognition, emotion, addiction and feeding behavior, motor control, and pain processing and participate in the mechanism of neuroprotection. The cannabinoid system thus provides a potential therapeutic target, with consequent increased interest in the use of cannabis for management of selected neurologic conditions. All these topics have been the subject of several comprehensive reviews.

Neurology 2014

Clinical spectrum of 4H leukodystrophy caused by POLR3A and POLR3B mutations

Objective: To study the clinical and radiologic spectrum and genotype–phenotype correlation of 4H (hypomyelination, hypodontia, hypogonadotropic hypogonadism) leukodystrophy caused by mutations in POLR3A or POLR3B.
Methods: We performed a multinational cross-sectional observational study of the clinical, radiologic, and molecular characteristics of 105 mutation-proven cases.
Results: The majority of patients presented before 6 years with gross motor delay or regression. Ten percent had an onset beyond 10 years. The disease course was milder in patients with POLR3B than in patients with POLR3Amutations. Other than the typical neurologic, dental, and endocrine features, myopia was seen in almost all and short stature in 50%. Dental and hormonal findings were not invariably present. Mutations in POLR3A and POLR3B were distributed throughout the genes. Except for French Canadian patients, patients from European backgrounds were more likely to have POLR3B mutations than other populations. Most patients carried the common c.1568T>APOLR3B mutation on one allele, homozygosity for which causes a mild phenotype. Systematic MRI review revealed that the combination of hypomyelination with relative T2 hypointensity of the ventrolateral thalamus, optic radiation, globus pallidus, and dentate nucleus, cerebellar atrophy, and thinning of the corpus callosum suggests the diagnosis.
Conclusions: 4H is a well-recognizable clinical entity if all features are present. Mutations in POLR3A are associated with a more severe clinical course. MRI characteristics are helpful in addressing the diagnosis, especially if patients lack the cardinal non-neurologic features.

Neurology 2014

Epilepsy-related clinical characteristics and mortality

Objective: We systematically synthesized the epidemiologic literature on mortality in patients with epilepsy (PWE) by epilepsy-related clinical characteristics with an aggregate data meta-analysis.
Methods: We systematically searched 15 electronic databases, browsed reference lists of pertinent publications, and contacted authors in the field. We were interested in cohort studies that reported the relative risk of death in representative epilepsy populations relative to the general population, with exclusion of highly selected subpopulations of PWE, such as patients with intellectual disabilities or epilepsy surgery series. Search, data abstraction, and study quality assessment with the Newcastle-Ottawa Scale were all performed in duplicate.
Results: Pooled mortality was threefold (relative risk 3.33, 95% confidence interval 2.83–3.92) in 38 epilepsy cohorts including 165,879 patients (79.6% from Nordic countries). Among incident cases, idiopathic epilepsies did not associate with materially increased mortality (1.29, 0.75–2.20; 4 studies), whereas mortality was almost twofold in cryptogenic epilepsy (1.75, 1.20–2.54; 5 studies), and highly elevated in patients with symptomatic epilepsy (4.73, 3.27–6.83; 12 studies) and especially in epilepsies due to congenital or developmental causes (10.3, 4.03–26.2; 2 studies). Newly diagnosed patients who attained seizure freedom did not have elevated mortality (0.97, 0.73–1.30; 2 studies).
Conclusion: Excess mortality was highly related to the etiology of epilepsy in all ages. In adult patients without neuroradiologic abnormalities or other identifiable cause of epilepsy, only patients with cryptogenic epilepsy exhibited excess mortality. Risk of premature death was lowest in idiopathic epilepsy and in PWE who attained seizure freedom.

Neurology 2014

sabato 18 ottobre 2014

Classifying neurocognitive disorders: the DSM-5 approach

Neurocognitive disorders—including delirium, mild cognitive impairment and dementia—are characterized by decline from a previously attained level of cognitive functioning. These disorders have diverse clinical characteristics and aetiologies, with Alzheimer disease, cerebrovascular disease, Lewy body disease, frontotemporal degeneration, traumatic brain injury, infections, and alcohol abuse representing common causes. This diversity is reflected by the variety of approaches to classifying these disorders, with separate groups determining criteria for each disorder on the basis of aetiology. As a result, there is now an array of terms to describe cognitive syndromes, various definitions for the same syndrome, and often multiple criteria to determine a specific aetiology. The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) provides a common framework for the diagnosis of neurocognitive disorders, first by describing the main cognitive syndromes, and then defining criteria to delineate specific aetiological subtypes of mild and major neurocognitive disorders. The DSM-5 approach builds on the expectation that clinicians and research groups will welcome a common language to deal with the neurocognitive disorders. As the use of these criteria becomes more widespread, a common international classification for these disorders could emerge for the first time, thus promoting efficient communication among clinicians and researchers.

Nature Reviews Neurology 2014

Brain connectivity in neurodegenerative diseases—from phenotype to proteinopathy

Functional and structural connectivity measures, as assessed by means of functional and diffusion MRI, are emerging as potential intermediate biomarkers for Alzheimer disease (AD) and other disorders. This Review aims to summarize current evidence that connectivity biomarkers are associated with upstream and downstream disease processes (molecular pathology and clinical symptoms, respectively) in the major neurodegenerative diseases. The vast majority of studies have addressed functional and structural connectivity correlates of clinical phenotypes, confirming the predictable correlation with topography and disease severity in AD and frontotemporal dementia. In neurodegenerative diseases with motor symptoms, structural—but, to date, not functional—connectivity has been consistently found to be associated with clinical phenotype and disease severity. In the latest studies, the focus has moved towards the investigation of connectivity correlates of molecular pathology. Studies in cognitively healthy individuals with brain amyloidosis or genetic risk factors for AD have shown functional connectivity abnormalities in preclinical disease stages that are reminiscent of abnormalities observed in symptomatic AD. This shift in approach is promising, and may aid identification of early disease markers, establish a paradigm for other neurodegenerative disorders, shed light on the molecular neurobiology of connectivity disruption and, ultimately, clarify the pathophysiology of neurodegenerative diseases.

Nature Reviews Neurology 2014

The phenotypic variability of amyotrophic lateral sclerosis

Classic textbook neurology teaches that amyotrophic lateral sclerosis (ALS) is a degenerative disease that selectively affects upper and lower motor neurons and is fatal 3–5 years after onset—a description which suggests that the clinical presentation of ALS is very homogenous. However, clinical and postmortem observations, as well as genetic studies, demonstrate that there is considerable variability in the phenotypic expression of ALS. Here, we review the phenotypic variability of ALS and how it is reflected in familial and sporadic ALS, in the degree of upper and lower motor neuron involvement, in motor and extramotor involvement, and in the spectrum of ALS and frontotemporal dementia. Furthermore, we discuss some unusual clinical characteristics regarding presentation, age at onset and disease progression. Finally, we address the importance of this variability for understanding the pathogenesis of ALS and for the development of therapeutic strategies.

Nature Reviews Neurology 2014

Maternal immune activation and abnormal brain development across CNS disorders

Epidemiological studies have shown a clear association between maternal infection and schizophrenia or autism in the progeny. Animal models have revealed maternal immune activation (mIA) to be a profound risk factor for neurochemical and behavioural abnormalities in the offspring. Microglial priming has been proposed as a major consequence of mIA, and represents a critical link in a causal chain that leads to the wide spectrum of neuronal dysfunctions and behavioural phenotypes observed in the juvenile, adult or aged offspring. Such diversity of phenotypic outcomes in the mIA model are mirrored by recent clinical evidence suggesting that infectious exposure during pregnancy is also associated with epilepsy and, to a lesser extent, cerebral palsy in children. Preclinical research also suggests that mIA might precipitate the development of Alzheimer and Parkinson diseases. Here, we summarize and critically review the emerging evidence that mIA is a shared environmental risk factor across CNS disorders that varies as a function of interactions between genetic and additional environmental factors. We also review ongoing clinical trials targeting immune pathways affected by mIA that may play a part in disease manifestation. In addition, future directions and outstanding questions are discussed, including potential symptomatic, disease-modifying and preventive treatment strategies.

Nature Reviews Neurology 2014

Neuroimmunology: Disease mechanisms in narcolepsy remain elusive

A pandemic influenza vaccine with a specific type of vaccine antigen has been linked to an increased incidence of narcolepsy in children from 2009–2010. However, the recent retraction of an article that reported a putative autoantigen means that the search for the mechanisms behind the vaccine–narcolepsy connection continues.

Nature Reviews Neurology 2014

Risk factors for multiple sclerosis, neuromyelitis optica and transverse myelitis

Background: Little is known about risk factors for neuromyelitis optica (NMO) or transverse myelitis (TM).
Objective: The objective of this paper is to evaluate whether established multiple sclerosis (MS) risk factors, including smoking history, a history of infectious mononucleosis (IM), anti-EBNA1 Ab titers and HLA-DR15 are associated with NMO or TM.
Methods: We conducted a case-control study among participants in the Accelerated Cure Project for Multiple Sclerosis (ACP) Repository, which includes patients with MS, NMO and TM. Controls include related and unrelated individuals without evidence of demyelinating disease. Analyses included 1237 cases of MS, 98 cases of NMO, 133 cases of TM and 488 healthy controls. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to assess the association between smoking, HLA-DR15, anti-EBNA1 Ab titers and a history of IM adjusting for gender, study site and ethnicity.
Results: Overall, the association between smoking, IM, HLA-DR15 and anti-EBNA1 Ab titers and odds of MS were as expected and no significant interactions were observed. However, there was little evidence of association between these MS risk factors and odds of NMO or TM.
Conclusions: Established MS risk factors do not appear to be associated with susceptibility to TM or NMO and, among MS patients, these risk factors appear to act independently

Multiple Sclerosis 2014

Neuropathology of multiple system atrophy: New thoughts about pathogenesis

Multiple system atrophy (MSA) is a fatal adult-onset neurodegenerative disorder of uncertain etiology, clinically manifesting with autonomic failure associated with parkinsonism, cerebellar dysfunction, and pyramidal signs in variable combination. The pathological process affects central autonomic, striatonigral, and olivopontocerebellar systems. These show varying degrees of neurodegeneration and underlie the stratification of the heterogenous disorder into MSA-P and MSA-C clinical variants, which correlate to the morphologic phenotypes of striatonigral degeneration and olivopontocerebellar atrophy (MSA-C). The lesions are not limited to these most consistently and severely affected systems but may involve many other parts of the central, peripheral, and autonomic nervous systems, underpinning the multisystem character of MSA. The histological core feature are glial cytoplasmic inclusions (GCIs, Papp-Lantos bodies) in all types of oligodendroglia that contain aggregates of misfolded α-Synuclein (α-Syn). In addition to the ectopic appearance of α-Syn in oligodendrocytes and other cells, oxidative stress, proteasomal and mitochondrial dysfunction, excitotoxiciy, neuroinflammation, metabolic changes, and energy failure are important contributors to the pathogenesis of MSA, as shown by various neurotoxic and transgenic animal models. Although the basic mechanisms of α-Syn–triggered neurodegeneration are not completely understood, neuron-to-oligodendrocyte transfer of α-Syn by prion-like spreading, inducing oligodendroglial and myelin dysfunction associated with chronic neuroinflammation, are suggested finally to lead to a system-specific pattern of neurodegeneration

Movement Disorders 2014

The harmony of the brain

Although something of a parlour game, the question can reasonably be asked: ‘which, in history, is the most important medical book ever written?’ High on the list of answers, probably the outright winner, is De humani corporis fabrica libri septem famous for the woodcuts portraying accurate anatomical structures, the many historiated initials and the frontispiece, written by Andreas Vesalius (1514–64) and published in 1543. The bodies dissected in Padua for specimens portrayed in the Fabrica include the mistress of a monk, exhumed by students, and the oarsman of a papal trireme. Vesalius wrote the book in only 2 years. The identity of the artist responsible for the images engraved and printed on 73 plates has been much debated: the most likely candidate is Jan van Calcar (1499–1545); possibly his teacher Tiziano Vecelli (Titian: 1485–1576); probably, Domenico Campagnola (1500–64); perhaps, Vesalius himself; and, beyond reasonable doubt, all four. Many of the flayed subjects are depicted by their artist in soothing landscapes. When aligned side-by-side, the back-drop to the 14 muscle plates is one continuous panorama of the Euganean Hills a few miles to the south and west of Padua.
We know much of Vesalius and his work through several publications: for example, A bio-bibliography of Andreas Vesalius, Harvey Cushing (1869–1939), 1943; A prelude to modern science being a discussion of the history, sources and circumstances of the Tabulae Anatomicae sex of Vesalius, Charles Singer (1876–1960) and C. Rabin (nk), 1946; The illustrations from the works of Andreas Vesalius of Brussels, J.B. deC M Saunders (1903–91) and C.D. O’Malley (1907–70), 1950; Vesalius four centuries later(Logan Glendening lectures on the history and philosophy of medicine), John Farquar Fulton (1899–1960), 1950; and Andreas Vesalius of Brussels 1514–1564, C.D. O’Malley, 1965.

Brain 2014

Immunotherapy alleviates amyloid-associated synaptic pathology in an Alzheimer’s disease mouse model

Cognitive decline in Alzheimer’s disease is attributed to loss of functional synapses, most likely caused by synaptotoxic, oligomeric forms of amyloid-β. Many treatment options aim at reducing amyloid-β levels in the brain, either by decreasing its production or by increasing its clearance. We quantified the effects of immunotherapy directed against oligomeric amyloid-β in Tg2576 mice, a mouse model of familial Alzheimer’s disease. Treatment of 12-month-old mice with oligomer-specific (A-887755) or conformation-unspecific (6G1) antibodies for 8 weeks did not affect fibrillar plaque density or growth. We also quantified densities of DLG4 (previously known as PSD95) expressing post-synapses and synapsin expressing presynapses immunohistochemically. We found that both pre- and post-synapses were strongly reduced in the vicinity of plaques, whereas distant from plaques, in the cortex and hippocampal CA1 field, only post-synapses were reduced. Immunotherapy alleviated this synapse loss. Synapse loss was completely abolished distant from plaques, whereas it was only attenuated in the vicinity of plaques. These results suggest that fibrillar plaques may act as reservoirs for synaptotoxic, oligomeric amyloid-β and that sequestering oligomers suffices to counteract synaptic pathology. Therefore, cognitive function may be improved by immunotherapy even when the load of fibrillar amyloid remains unchanged.

Brain 2014

Propriospinal myoclonus Clinical reappraisal and review of literature

Objective: Propriospinal myoclonus (PSM) is a rare disorder with repetitive, usually flexor arrhythmic brief jerks of the trunk, hips, and knees in a fixed pattern. It has a presumed generation in the spinal cord and diagnosis depends on characteristic features at polymyography. Recently, a historical paradigm shift took place as PSM has been reported to be a functional (or psychogenic) movement disorder (FMD) in most patients. This review aims to characterize the clinical features, etiology, electrophysiologic features, and treatment outcomes of PSM.
Methods: Re-evaluation of all published PSM cases and systematic scoring of clinical and electrophysiologic characteristics in all published cases since 1991.
Results: Of the 179 identified patients with PSM (55% male), the mean age at onset was 43 years (range 6–88 years). FMD was diagnosed in 104 (58%) cases. In 12 cases (26% of reported secondary cases, 7% of total cases), a structural spinal cord lesion was found. Clonazepam and botulinum toxin may be effective in reducing jerks.
Conclusions: FMD is more frequent than previously assumed. Structural lesions reported to underlie PSM are scarce. Based on our clinical experience and the reviewed literature, we recommend polymyography to assess recruitment variability combined with a Bereitschaftspotential recording in all cases.
Neurology 2014

DPPX potassium channel antibody

Objective: To describe the detection frequency and clinical associations of immunoglobulin G (IgG) targeting dipeptidyl-peptidase-like protein-6 (DPPX), a regulatory subunit of neuronal Kv4.2 potassium channels.
Methods: Specimens from 20 patients evaluated on a service basis by tissue-based immunofluorescence yielded a synaptic immunostaining pattern consistent with DPPX-IgG (serum, 20; CSF, all 7 available). Transfected HEK293 cell-based assay confirmed DPPX specificity in all specimens. Sixty-nine patients with stiff-person syndrome and related disorders were also evaluated by DPPX-IgG cell-based assay.
Results: Of 20 seropositive patients, 12 were men; median symptom onset age was 53 years (range, 13–75). Symptom onset was insidious in 15 and subacute in 5. Twelve patients reported prodromal weight loss. Neurologic disorders were multifocal. All had one or more brain or brainstem manifestations: amnesia (16), delirium (8), psychosis (4), depression (4), seizures (2), and brainstem disorders (15; eye movement disturbances [8], ataxia [7], dysphagia [6], dysarthria [4], respiratory failure [3]). Nine patients reported sleep disturbance. Manifestations of central hyperexcitability included myoclonus (8), exaggerated startle (6), diffuse rigidity (6), and hyperreflexia (6). Dysautonomia involved the gastrointestinal tract (9; diarrhea [6], gastroparesis, and constipation [3]), bladder (7), cardiac conduction system (3), and thermoregulation (1). Two patients had B-cell neoplasms: gastrointestinal lymphoma (1), and chronic lymphocytic leukemia (1). Substantial neurologic improvements followed immunotherapy in 7 of 11 patients with available treatment data. DPPX-IgG was not detected in any of the stiff-person syndrome patients.
Neurology 2014

Global investigation and meta-analysis of the C9orf72 (G4C2)n repeat in Parkinson disease

Objectives: The objective of this study is to clarify the role of (G4C2)n expansions in the etiology of Parkinson disease (PD) in the worldwide multicenter Genetic Epidemiology of Parkinson's Disease (GEO-PD) cohort.
Methods: C9orf72 (G4C2)n repeats were assessed in a GEO-PD cohort of 7,494 patients diagnosed with PD and 5,886 neurologically healthy control individuals ascertained in Europe, Asia, North America, and Australia.
Results: A pathogenic (G4C2)n>60 expansion was detected in only 4 patients with PD (4/7,232; 0.055%), all with a positive family history of neurodegenerative dementia, amyotrophic lateral sclerosis, or atypical parkinsonism, while no carriers were detected with typical sporadic or familial PD. Meta-analysis revealed a small increase in risk of PD with an increasing number of (G4C2)n repeats; however, we could not detect a robust association between the C9orf72(G4C2)n repeat and PD, and the population attributable risk was low.
Conclusions: Together, these findings indicate that expansions in C9orf72 do not have a major role in the pathogenesis of PD. Testing for C9orf72 repeat expansions should only be considered in patients with PD who have overt symptoms of frontotemporal lobar degeneration/amyotrophic lateral sclerosis or apparent family history of neurodegenerative dementia or motor neuron disease.
Neurology 2014