Showing papers in "Journal of Neurology in 2016"

Vestibular migraine: the most frequent entity of episodic vertigo

Abstract: Vestibular migraine (VM) is the most common cause of episodic vertigo in adults as well as in children. The diagnostic criteria of the consensus document of the International Barany Society for Neuro-Otology and the International Headache Society (2012) combine the typical signs and symptoms of migraine with the vestibular symptoms lasting 5 min to 72 h and exclusion criteria. Although VM accounts for 7% of patients seen in dizziness clinics and 9% of patients seen in headache clinics it is still underdiagnosed. This review provides an actual overview on the pathophysiology, the clinical characteristics to establish the diagnosis, the differential diagnosis, and the treatment of VM.

What is Menière's disease? A contemporary re-evaluation of endolymphatic hydrops.

Abstract: Meniere’s disease is a chronic condition with a prevalence of 200–500 per 100,000 and characterized by episodic attacks of vertigo, fluctuating hearing loss, tinnitus, aural pressure and a progressive loss of audiovestibular functions. Over 150 years ago, Prosper Meniere was the first to recognize the inner ear as the site of lesion for this clinical syndrome. Over 75 years ago, endolymphatic hydrops was discovered as the pathologic correlate of Meniere’s disease. However, this pathologic finding could be ascertained only in post-mortem histologic studies. Due to this diagnostic dilemma and the variable manifestation of the various audiovestibular symptoms, diagnostic classification systems based on clinical findings have been repeatedly modified and have not been uniformly used in scientific publications on Meniere’s disease. Furthermore, the higher level measures of impact on quality of life such as vitality and social participation have been neglected hitherto. Recent developments of high-resolution MR imaging of the inner ear have now enabled us to visualize in vivo endolymphatic hydrops in patients with suspected Meniere’s disease. In this review, we summarize the existing knowledge from temporal bone histologic studies and from the emerging evidence on imaging-based evaluation of patients with suspected Meniere’s disease. These indicate that endolymphatic hydrops is responsible not only for the full-blown clinical triad of simultaneous attacks of auditory and vestibular dysfunction, but also for other clinical presentations such as “vestibular” and “cochlear Meniere’s disease”. As a consequence, we propose a new terminology which is based on symptomatic and imaging characteristics of these clinical entities to clarify and simplify their diagnostic classification.

Vestibular compensation: the neuro-otologist’s best friend

Abstract: Why vestibular compensation (VC) after an acute unilateral vestibular loss is the neuro-otologist’s best friend is the question at the heart of this paper. The different plasticity mechanisms underlying VC are first reviewed, and the authors present thereafter the dual concept of vestibulo-centric versus distributed learning processes to explain the compensation of deficits resulting from the static versus dynamic vestibular imbalance. The main challenges for the plastic events occurring in the vestibular nuclei (VN) during a post-lesion critical period are neural protection, structural reorganization and rebalance of VN activity on both sides. Data from animal models show that modulation of the ipsilesional VN activity by the contralateral drive substitutes for the normal push–pull mechanism. On the other hand, sensory and behavioural substitutions are the main mechanisms implicated in the recovery of the dynamic functions. These newly elaborated sensorimotor reorganizations are vicarious idiosyncratic strategies implicating the VN and multisensory brain regions. Imaging studies in unilateral vestibular loss patients show the implication of a large neuronal network (VN, commissural pathways, vestibulo-cerebellum, thalamus, temporoparietal cortex, hippocampus, somatosensory and visual cortical areas). Changes in gray matter volume in these multisensory brain regions are structural changes supporting the sensory substitution mechanisms of VC. Finally, the authors summarize the two ways to improve VC in humans (neuropharmacology and vestibular rehabilitation therapy), and they conclude that VC would follow a “top-down” strategy in patients with acute vestibular lesions. Future challenges to understand VC are proposed.

Clinical features, pathogenesis, and treatment of myasthenia gravis: a supplement to the Guidelines of the German Neurological Society.

Abstract: Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder of neuromuscular synaptic transmission. The clinical hallmark of MG consists of fluctuating fatigability and weakness affecting ocular, bulbar and (proximal) limb skeletal muscle groups. MG may either occur as an autoimmune disease with distinct immunogenetic characteristics or as a paraneoplastic syndrome associated with tumors of the thymus. Impairment of central thymic and peripheral self-tolerance mechanisms in both cases is thought to favor an autoimmune CD4+ T cell-mediated B cell activation and synthesis of pathogenic high-affinity autoantibodies of either the IgG1 and 3 or IgG4 subclass. These autoantibodies bind to the nicotinic acetylcholine receptor (AchR) itself, or muscle-specific tyrosine-kinase (MuSK), lipoprotein receptor-related protein 4 (LRP4) and agrin involved in clustering of AchRs within the postsynaptic membrane and structural maintenance of the neuromuscular synapse. This results in disturbance of neuromuscular transmission and thus clinical manifestation of the disease. Emphasizing evidence from clinical trials, we provide an updated overview on immunopathogenesis, and derived current and future treatment strategies for MG divided into: (a) symptomatic treatments facilitating neuromuscular transmission, (b) antibody-depleting treatments, and (c) immunotherapeutic treatment strategies.

Activity of secukinumab, an anti-IL-17A antibody, on brain lesions in RRMS: results from a randomized, proof-of-concept study.

Abstract: The objective of this study was to assess the effect of secukinumab, a monoclonal antibody that inhibits interleukin (IL)-17A, on number of new active brain magnetic resonance imaging (MRI) lesions in subjects with relapsing-remitting multiple sclerosis (MS). Subjects (N = 73) were randomized 1:1 to secukinumab 10 mg/kg or placebo by intravenous infusion at weeks 0, 2, 4, 8, 12, 16, and 20. MRI scans were obtained within 30 days prior to randomization, on a monthly basis during the treatment period, and at study completion. The primary endpoint was the cumulative number of combined unique active lesions (CUAL) observed on brain MRI scans from week 4 to week 24. Compared with placebo, secukinumab non-significantly reduced the number of CUAL observed on 4-weekly MRI from week 4 to 24 (primary endpoint) by 49 % (95 % CI −10 to 77 %; P = 0.087) and significantly reduced the number of cumulative new gadolinium-enhancing T1 lesions by 67 % (31–84 %, P = 0.003). CUAL reductions were progressively greater from week 4 (1 %) to week 16 (49 %) and persisted until end-study (50 %). There were no serious adverse events; the adverse event rate was comparable to placebo (53 versus 49 %), although mild-to-moderate infection was somewhat more frequent (37 versus 23 %). This proof-of-concept study provides the first evidence that blocking IL-17A with an antibody may reduce MRI lesion activity in MS. Further studies are needed to confirm this finding and determine the magnitude of effect.

Optimizing treatment success in multiple sclerosis

Abstract: Despite important advances in the treatment of multiple sclerosis (MS) over recent years, the introduction of several disease-modifying therapies (DMTs), the burden of progressive disability and premature mortality associated with the condition remains substantial. This burden, together with the high healthcare and societal costs associated with MS, creates a compelling case for early treatment optimization with highly efficacious therapies. Often, patients receive several first-line therapies, while more recent and in part more effective treatments are still being introduced only after these have failed. However, with the availability of highly efficacious therapies, a novel treatment strategy has emerged, where the aim is to achieve no evidence of disease activity (NEDA). Achieving NEDA necessitates regular monitoring of relapses, disability and functionality. However, there is only a poor correlation between conventional magnetic resonance imaging measures like T2 hyperintense lesion burden and the level of clinical disability. Hence, MRI-based measures of brain atrophy have emerged in recent years potentially reflecting the magnitude of MS-related neuroaxonal damage. Currently available DMTs differ markedly in their effects on brain atrophy: some, such as fingolimod, have been shown to significantly slow brain volume loss, compared to placebo, whereas others have shown either no, inconsistent, or delayed effects. In addition to regular monitoring, treatment optimization also requires early intervention with efficacious therapies, because accumulating evidence shows that effective intervention during a limited period early in the course of MS is critical for maintaining neurological function and preventing subsequent disability. Together, the advent of new MS therapies and evolving management strategies offer exciting new opportunities to optimize treatment outcomes.

Clinical spectrum associated with MOG autoimmunity in adults: significance of sharing rodent MOG epitopes.

Abstract: The aim of this study was to report the clinical spectrum associated with antibodies to myelin oligodendrocyte glycoprotein (MOG) in adult patients, and to assess whether phenotypic variants are dependent on recognition of rodent MOG epitopes. We retrospectively analyzed the features, course and outcome of 56 patients whose samples were investigated by brain tissue immunohistochemistry and cell-based assays using human and rodent MOG. The median age at symptom onset was 37 years (range 18–70); 35 patients (63 %) were female. After a median follow-up of 43 months (range 4–554), only 14 patients (25 %) developed a neuromyelitis optica spectrum disorder (NMOSD), 27 patients (47 %) retained the initial diagnosis of isolated optic neuritis, 7 (12 %) of longitudinally extensive transverse myelitis, and 2 (4 %) of acute disseminated encephalomyelitis; 6 patients (11 %) developed atypical demyelinating syndromes (4 had relapsing episodes of short myelitis lesions which in one occurred with optic neuritis; 1 had relapsing brainstem symptoms, and 1 relapsing demyelinating encephalomyelitis). The course was frequently associated with relapses (71 %) and good outcome. Twenty-seven patients (49 %) had antibodies that recognized rodent MOG epitopes, and 9 of them (16 %) showed a myelin staining pattern in rodent tissue. Only the myelin staining pattern was linked to NMOSD (p = 0.005). In conclusion, MOG autoimmunity in adult patients associates with a clinical spectrum wider than the one expected for patients with suspected NMOSD and overall good outcome. Antibodies to rodent MOG epitopes do not associate with any phenotypic variant.

Timing of retinal neuronal and axonal loss in MS: a longitudinal OCT study

Abstract: The objective of the study was to investigate the timing of central nervous system tissue atrophy in MS by evaluating longitudinal retinal volume changes in a broadly representative cohort with disease duration across the entire arc of disease. In this longitudinal study, 135 patients with MS and 16 healthy reference subjects underwent spectral-domain optical coherence tomography (OCT) at baseline and 2 years later. Following OCT quality control, automated segmentation of the peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell–inner plexiform layer (mGCIPL) and macular inner nuclear layer (mINL) was performed. Generalized estimation equations were used to analyze longitudinal changes and associations with disease duration and clinical measures. Participants had a median disease duration at baseline of 16.4 years (range 0.1–45.4). Nearly half (44 %) of the MS patients had previously experienced MS-related optic neuritis (MSON) more than 6 months prior. The MS patients demonstrated a significant decrease over 2 years of the pRNFL (−1.1 µm, 95 % CI 1.4–0.7, p < 0.001) and mGCIPL (−1.1 µm, 95 % CI −1.4 to −0.8, p < 0.001). This thinning was most pronounced early in the course of disease. These findings were irrespective of previous episodes of MSON. No consistent pattern of change was observed for the mINL (−0.03 µm, 95 % CI −0.2 to 0.2, p = 0.795). This longitudinal study demonstrated that injury of the innermost retinal layers is found in MS and that this damage occurs most rapidly during the early stages of disease. The attenuation of atrophy with longer disease duration is suggestive of a plateau effect. These findings emphasize the importance of early intervention to prevent such injury.

Alterations of functional and structural connectivity of freezing of gait in Parkinson's disease.

Abstract: This study assessed the patterns of functional and structural connectivity abnormalities in patients with Parkinson's disease with freezing of gait (PD FOG+) compared with those without freezing (PD FOG-) and healthy controls (HCs). Resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI) scans were obtained from 14 PD FOG+, 16 PD FOG- and 16HCs. Between-group difference in pedunculopontine nucleus (PPN) functional connectivity (FC) was performed to assess FC dysfunction. Tract-based spatial statistics (TBSS) was applied to compare white matter (WM) impairment across the whole brain between groups. PD FOG+ patients exhibited abnormal PPN FC, compared with HCs and with PD FOG-, mainly in the corticopontine-cerebellar pathways (in the bilateral cerebellum and in the pons), as well as the visual temporal areas (in the right middle temporal gyrus and in the right inferior temporal gyrus). Moreover, PD FOG+ patients, showed more pronounced WM abnormalities, relative to controls, including the interhemispheric connections of corpus callosum, the cortico-cortical WM tracts of the cingulum, the superior longitudinal fasciculus and inferior fronto-occipital fasciculus, the corticofugal tract (cerebral peduncles, internal capsule, corona radiata), as well as tracts connecting the thalamus (thalamic radiation). This study suggests that FOG in PD is associated with abnormal PPN FC network, mainly affecting the corticopontine-cerebellar pathways as well as visual temporal areas involved in visual processing, and with diffuse WM deficits extending to motor, sensory and cognitive regions. Combining rs-fMRI and DTI method, our study should advance the understanding of neural mechanisms underlying FOG in PD.

Myasthenia gravis: a clinical-immunological update

Abstract: Myasthenia gravis (MG) is the archetypic disorder of both the neuromuscular junction and autoantibody-mediated disease. In most patients, IgG1-dominant antibodies to acetylcholine receptors cause fatigable weakness of skeletal muscles. In the rest, a variable proportion possesses antibodies to muscle-specific tyrosine kinase while the remainder of seronegative MG is being explained through cell-based assays using a receptor-clustering technique and, to a lesser extent, proposed new antigenic targets. The incidence and prevalence of MG are increasing, particularly in the elderly. New treatments are being developed, and results from the randomised controlled trial of thymectomy in non-thymomatous MG, due for release in early 2016, will be of particular clinical value. To help navigate an evidence base of varying quality, practising clinicians may consult new MG guidelines in the fields of pregnancy, ocular and generalised MG (GMG). This review focuses on updates in epidemiology, immunology, therapeutic and clinical aspects of GMG in adults.

Hearing and dementia.

Abstract: Hearing deficits associated with cognitive impairment have attracted much recent interest, motivated by emerging evidence that impaired hearing is a risk factor for cognitive decline. However, dementia and hearing impairment present immense challenges in their own right, and their intersection in the auditory brain remains poorly understood and difficult to assess. Here, we outline a clinically oriented, symptom-based approach to the assessment of hearing in dementias, informed by recent progress in the clinical auditory neuroscience of these diseases. We consider the significance and interpretation of hearing loss and symptoms that point to a disorder of auditory cognition in patients with dementia. We identify key auditory characteristics of some important dementias and conclude with a bedside approach to assessing and managing auditory dysfunction in dementia.

Clinical prediction of large vessel occlusion in anterior circulation stroke: mission impossible?

Abstract: Simple clinical scores to predict large vessel occlusion (LVO) in acute ischemic stroke would be helpful to triage patients in the prehospital phase. We assessed the ability of various combinations of National Institutes of Health Stroke Scale (NIHSS) subitems and published stroke scales (i.e., RACE scale, 3I-SS, sNIHSS-8, sNIHSS-5, sNIHSS-1, mNIHSS, a-NIHSS items profiles A-E, CPSS1, CPSS2, and CPSSS) to predict LVO on CT or MR arteriography in 1085 consecutive patients (39.4 % women, mean age 67.7 years) with anterior circulation strokes within 6 h of symptom onset. 657 patients (61 %) had an occlusion of the internal carotid artery or the M1/M2 segment of the middle cerebral artery. Best cut-off value of the total NIHSS score to predict LVO was 7 (PPV 84.2 %, sensitivity 81.0 %, specificity 76.6 %, NPV 72.4 %, ACC 79.3 %). Receiver operating characteristic curves of various combinations of NIHSS subitems and published scores were equally or less predictive to show LVO than the total NIHSS score. At intersection of sensitivity and specificity curves in all scores, at least 1/5 of patients with LVO were missed. Best odds ratios for LVO among NIHSS subitems were best gaze (9.6, 95 %-CI 6.765-13.632), visual fields (7.0, 95 %-CI 3.981-12.370), motor arms (7.6, 95 %-CI 5.589-10.204), and aphasia/neglect (7.1, 95 %-CI 5.352-9.492). There is a significant correlation between clinical scores based on the NIHSS score and LVO on arteriography. However, if clinically relevant thresholds are applied to the scores, a sizable number of LVOs are missed. Therefore, clinical scores cannot replace vessel imaging.

A double-blind, randomized, cross-over, placebo-controlled, pilot trial with Sativex in Huntington’s disease

Abstract: Huntington’s disease (HD) is a neurodegenerative disease for which there is no curative treatment available. Given that the endocannabinoid system is involved in the pathogenesis of HD mouse models, stimulation of specific targets within this signaling system has been investigated as a promising therapeutic agent in HD. We conducted a double-blind, randomized, placebo-controlled, cross-over pilot clinical trial with Sativex®, a botanical extract with an equimolecular combination of delta-9-tetrahydrocannabinol and cannabidiol. Both Sativex® and placebo were dispensed as an oral spray, to be administered up to 12 sprays/day for 12 weeks. The primary objective was safety, assessed by the absence of more severe adverse events (SAE) and no greater deterioration of motor, cognitive, behavioral and functional scales during the phase of active treatment. Secondary objectives were clinical improvement of Unified Huntington Disease Rating Scale scores. Twenty-six patients were randomized and 24 completed the trial. After ruling-out period and sequence effects, safety and tolerability were confirmed. No differences on motor (p = 0.286), cognitive (p = 0.824), behavioral (p = 1.0) and functional (p = 0.581) scores were detected during treatment with Sativex® as compared to placebo. No significant molecular effects were detected on the biomarker analysis. Sativex® is safe and well tolerated in patients with HD, with no SAE or clinical worsening. No significant symptomatic effects were detected at the prescribed dosage and for a 12-week period. Also, no significant molecular changes were observed on the biomarkers. Future study designs should consider higher doses, longer treatment periods and/or alternative cannabinoid combinations. Clincaltrals.gov identifier: NCT01502046

Role of the left frontal aslant tract in stuttering: a brain stimulation and tractographic study

Abstract: The neural correlates of stuttering are to date incompletely understood. Although the possible involvement of the basal ganglia, the cerebellum and certain parts of the cerebral cortex in this speech disorder has previously been reported, there are still not many studies investigating the role of white matter fibers in stuttering. Axonal stimulation during awake surgery provides a unique opportunity to study the functional role of structural connectivity. Here, our goal was to investigate the white matter tracts implicated in stuttering, by combining direct electrostimulation mapping and postoperative tractography imaging, with a special focus on the left frontal aslant tract. Eight patients with no preoperative stuttering underwent awake surgery for a left frontal low-grade glioma. Intraoperative cortical and axonal electrical mapping was used to interfere in speech processing and subsequently provoke stuttering. We further assessed the relationship between the subcortical sites leading to stuttering and the spatial course of the frontal aslant tract. All patients experienced intraoperative stuttering during axonal electrostimulation. On postsurgical tractographies, the subcortical distribution of stimulated sites matched the topographical position of the left frontal aslant tract. This white matter pathway was preserved during surgery, and no patients had postoperative stuttering. For the first time to our knowledge, by using direct axonal stimulation combined with postoperative tractography, we provide original data supporting a pivotal role of the left frontal aslant tract in stuttering. We propose that this speech disorder could be the result of a disconnection within a large-scale cortico-subcortical circuit subserving speech motor control.

Mitochondrial disease: genetics and management

Abstract: Mitochondrial disease is one of the most common groups of genetic diseases with a minimum prevalence of greater than 1 in 5000 in adults. Whilst multi-system involvement is often evident, neurological manifestation is the principal presentation in most cases. The multiple clinical phenotypes and the involvement of both the mitochondrial and nuclear genome make mitochondrial disease particularly challenging for the clinician. In this review article we cover mitochondrial genetics and common neurological presentations associated with adult mitochondrial disease. In addition, specific and supportive treatments are discussed.

Predictors of outcome in HSV encephalitis.

Abstract: This study aims to explore the clinical features, radiological findings, management and the factors influencing prognosis in PCR-confirmed herpes simplex virus encephalitis (HSE). This is a retrospective review of consecutive patients diagnosed with HSE at Mayo Clinic, Rochester, MN, between January 1995 and December 2013. Only HSE cases confirmed by PCR were included. Univariate and multivariate analysis was used to identify factors associated with good (modified Rankin Scale of 0-2) or poor outcome (mRS of 3-6) at hospital discharge and 1-year follow-up. We identified 45 patients with HSE. Median age was 66 (IQR 53.5-78) years. HSE was caused by HSV-1 in 33 cases and by HSV-2 in 9. Nearly half had seizures upon admission or during hospitalization. The most common regions involved on MRI were the temporal lobe in 35 (87.5%), insula in 28 (70.0%), frontal lobe in 27 (67.5%) and thalamus in 11 (27.5%) patients. MRI pattern was quite homogeneous with HSV-1 infection, but much more heterogeneous with HSV-2. Good outcome at discharge and at 6-12 months was seen in 16 (35.6%) and 27 (65.9%) patients, respectively. On multivariate analyses, older age (p = 0.001), coma (p = 0.008), restricted diffusion on MRI (p = 0.005) and acyclovir started after the first day of admission (p = 0.050) were associated with poor outcome at discharge. Older age, development of coma, presence of restricted diffusion on brain MRI and delay in the administration of acyclovir portend poor outcome in HSE. Conversely, presence of seizures, focal neurological deficits, EEG abnormalities and location or extension of FLAIR/T2 abnormalities did not influence functional outcome.

Domain-specific versus generalized cognitive screening in acute stroke

Abstract: Cognitive assessments after stroke are typically short form tests developed for dementia that generates pass/fail classifications (e.g. the MoCA). The Oxford Cognitive Screen (OCS) provides a domain-specific cognitive profile designed for stroke survivors. This study compared the use of the MoCA and the OCS in acute stroke with respect to symptom specificity and aspects of clinical utility. A cross-sectional study with a consecutive sample of 200 stroke patients within 3 weeks of stroke completing MoCA and OCS. Demographic data, lesion side and Barthel scores were recorded. Inclusivity was assessed in terms of completion rates and reasons for non-completion were evaluated. The incidence of cognitive impairments on both the MoCA and OCS sub-domains was calculated and differences in stroke specificity, cognitive profiles and independence of the measures were addressed. The incidence of acute cognitive impairment was high: 76 % of patients were impaired on MoCA, and 86 % demonstrated at least one impairment on the cognitive domains assessed in the OCS. OCS was more sensitive than MoCA overall (87 vs 78 % sensitivity) and OCS alone provided domain-specific information on prevalent post-stroke cognitive impairments (neglect, apraxia and reading/writing ability). Unlike the MOCA, the OCS was not dominated by left hemisphere impairments but gave differentiated profiles across the contrasting domains. The OCS detects important cognitive deficits after stroke not assessed in the MoCA, it is inclusive for patients with aphasia and neglect and it is less confounded by co-occurring difficulties in these domains.

Poor short-term outcome in patients with ischaemic stroke and active cancer

Abstract: Stroke risk is increased in cancer patients and cancer activity has been claimed to play a role in the development of ischaemic stroke (IS). We wanted to further test these assumptions and to explore the impact of such relation on short-term prognosis. We identified all IS patients that were admitted to the neurological department of our primary and tertiary care university hospital between 2008 and 2014 (n = 4918) and reviewed their medical records for an additional diagnosis of cancer. Cancer patients were categorized into those with "active cancer" (AC: recurrent malignant tumour, metastases, ongoing chemo-/radiotherapy) and "non-active cancer" (NAC). We compared demographic, clinical and neuroimaging features of both patient groups and assessed their association with in-hospital mortality. 300 IS patients with known cancer were identified (AC: n = 73; NAC: n = 227). IS patients with AC were significantly younger (70.3 ± 10.6 vs. 74.9 ± 9.9 years), had more severe strokes at admission (NIHSS: median 5 vs. 3), more frequently cryptogenic strokes (50.7 vs. 32.5 %) and more often infarcts in multiple vascular territories of the brain (26 vs. 5.2 %) compared to IS patients with NAC. In-hospital mortality was significantly higher in AC patients (21.9 vs. 6.2 %). Multivariate analysis identified AC (odds ratio [OR] 3.70, 95 % confidence interval [CI] 1.50-9.30), NIHSS at admission (OR 1.10, CI 1.10-1.20) and C-reactive protein level (OR 1.01, CI 1.00-1.02) as factors significantly and independently associated with in-hospital death. Our findings support a direct role of AC in the pathogenesis and prognosis of acute IS. This needs to be considered in the management and counselling of such patients.

Recent advances in amyotrophic lateral sclerosis

Abstract: ALS is a relentlessly progressive and fatal disease, with no curative therapies available to date. Symptomatic and palliative care, provided in a multidisciplinary context, still remains the cornerstone of ALS management. However, our understanding of the molecular mechanisms underlying the disease has advanced greatly over the past years, giving new hope for the development of novel diagnostic and therapeutic approaches. Here, we have reviewed the most recent studies that have contributed to improving both clinical management and our understanding of ALS pathogenesis.

Quantifying the burden of caregiving in Duchenne muscular dystrophy

Abstract: Duchenne muscular dystrophy (DMD) is a rare pediatric neuromuscular disease associated with progressive muscle degeneration and extensive care needs. Our objective was to estimate the caregiver burden associated with DMD. We made cross-sectional assessments of caregiver health-related quality of life (HRQL) and burden using the EuroQol EQ-5D, a Visual Analogue Scale (VAS), the SF-12 Health Survey, and the Zarit Caregiver Burden Interview (ZBI) administered online. Results were stratified by disease stage (early/late ambulatory/non-ambulatory) and caregivers' rating of patients' health and mental status. In total, caregivers to 770 patients participated. Mean EQ-5D utility ranged between 0.85 (95 % CI 0.82-0.88) and 0.77 (0.74-0.80) across ambulatory classes and 0.88 (0.85-0.90) and 0.57 (0.39-0.74) across caregivers' rating of patients' health and mental status. Mean VAS score was 0.74 (0.73-0.75), mean SF-12 Mental Health Component Summary score 44 (43-45), and mean ZBI score 29 (28-30). Anxiety and depression, recorded in up to 70 % of caregivers depending on patients' health and mental status, was significantly associated with annual household cost burden (>$5000 vs. 50 vs. <25 h 3.35, 2.32-4.83) (p < 0.007). We show that caring for a person with DMD can be associated with a substantial burden and impaired HRQL. Our findings suggest that caregivers to patients with DMD should be screened for depression and emphasize the need for a holistic approach to family mental health in the context of chronic childhood disease.

Mutations in the sodium channel gene SCN2A cause neonatal epilepsy with late-onset episodic ataxia

Abstract: Mutations in SCN2A cause epilepsy syndromes of variable severity including neonatal-infantile seizures. In one case, we previously described additional childhood-onset episodic ataxia. Here, we corroborate and detail the latter phenotype in three further cases. We describe the clinical characteristics, identify the causative SCN2A mutations and determine their functional consequences using whole-cell patch-clamping in mammalian cells. In total, four probands presented with neonatal-onset seizures remitting after five to 13 months. In early childhood, they started to experience repeated episodes of ataxia, accompanied in part by headache or back pain lasting minutes to several hours. In two of the new cases, we detected the novel mutation p.Arg1882Gly. While this mutation occurred de novo in both patients, one of them carries an additional known variant on the same SCN2A allele, inherited from the unaffected father (p.Gly1522Ala). Whereas p.Arg1882Gly alone shifted the activation curve by -4 mV, the combination of both variants did not affect activation, but caused a depolarizing shift of voltage-dependent inactivation, and a significant increase in Na(+) current density and protein production. p.Gly1522Ala alone did not change channel gating. The third new proband carries the same de novo SCN2A gain-of-function mutation as our first published case (p.Ala263Val). Our findings broaden the clinical spectrum observed with SCN2A gain-of-function mutations, showing that fairly different biophysical mechanisms can cause a convergent clinical phenotype of neonatal seizures and later onset episodic ataxia.

EEG ultradian rhythmicity differences in disorders of consciousness during wakefulness

Abstract: Temporal fluctuations of cognitively-mediated behaviors in minimally conscious state (MCS) have been linked to changes of awareness, but the time-pattern of these variations remains ill-described. We analyzed 4-h EEG recordings from 12 patients with disorders of consciousness (6 MCS and 6 vegetative state/unresponsive wakefulness syndrome, VS/UWS). Relative powers (delta, theta, alpha, beta1 and beta2 bands) and spectral entropy were estimated (Fz, Cz and Pz derivations). Spectral entropy time-courses were then analyzed. MCS patients had higher theta and alpha and lower delta power when compared to VS/UWS. They showed higher spectral entropy mean value and higher time variability. MCS patients were characterized by spectral entropy fluctuations with periodicities of 70 min (range 57-80 min). Notably, these periodicities closely resemble those described in awake healthy subjects, which were hypothesized to be related to fluctuation in vigilance/attention. No significant periodicity was observed for VS/UWS. The spectral entropy periodicity found in MCS patients could reflect the fluctuation of awareness responsible for the inconsistency of MCS manifestation of cognitively-mediated behaviors. The presence of a 70 min periodicity in spectral entropy could permit clinicians to better choose their time-window when performing a clinical assessment of consciousness. It could also permit to monitor fluctuations in cognitive performance (i.e., response to command) during complementary testing by passive or active electrophysiological or functional neuroimaging paradigms or in resting state conditions.

Long-term outcome after cerebral venous thrombosis: analysis of functional and vocational outcome, residual symptoms, and adverse events in 161 patients

Abstract: Cerebral venous thrombosis (CVT) affects mainly working-aged individuals. Functional recovery after CVT is generally considered good with about 3/4 of patients achieving short-term independence. However, vascular events, long-term functional outcome, and employment after CVT remain poorly investigated. We identified consecutive adult CVT patients treated at the Helsinki University Hospital (1987-2013) and invited them to a follow-up visit. Each clinical examination was combined with interview. We also recorded recurrent venous thromboembolism (VTE) and hemorrhagic events during follow-up and antithrombotic medication use. A modified Rankin Scale (mRS) served to assess functional outcome. Logistic regression served to identify independent factors associated with unemployment and functional recovery. Of the 195 patients identified, 21 died, 9 declined to participate, and 4 were excluded from the study. Thus, 161 patients (106 women) underwent an examination after a median of 39 months (interquartile range 14-95). VTE (one of which was CVT) occurred in 9 (6%) patients, and severe hemorrhagic events in 10 (6%). Functional outcome was good, with 84% scoring 0-1 on the mRS; 42% reported residual symptoms. Altogether, 91 (57%) patients were employed. After adjusting for age and sex, a National Institutes of Health Stroke Scale score>2 at admission and low education level, associated with both unfavorable functional outcome and unemployment. Long-term functional outcome after CVT may appear good if measured with mRS, but patients often have residual symptoms and are frequently unable to return to their previous work.

Functional neurological disorders: mechanisms and treatment

Abstract: Functional neurological disorders are common problems in neurologic practice. In the past decade there has been an increasing interest in this group of disorders both from a clinical as well as research point of view. In this review, we highlight some of the most salient and exciting publications from recent years focusing especially on new findings illuminating mechanism and studies examining treatment.

Quantification of normal-appearing white matter tract integrity in multiple sclerosis: a diffusion kurtosis imaging study.

Abstract: Our aim was to characterize the nature and extent of pathological changes in the normal-appearing white matter (NAWM) of patients with multiple sclerosis (MS) using novel diffusion kurtosis imaging-derived white matter tract integrity (WMTI) metrics and to investigate the association between these WMTI metrics and clinical parameters. Thirty-two patients with relapsing–remitting MS and 19 age- and gender-matched healthy controls underwent MRI and neurological examination. Maps of mean diffusivity, fractional anisotropy and WMTI metrics (intra-axonal diffusivity, axonal water fraction, tortuosity and axial and radial extra-axonal diffusivity) were created. Tract-based spatial statistics analysis was performed to assess for differences in the NAWM between patients and controls. A region of interest analysis of the corpus callosum was also performed to assess for group differences and to evaluate correlations between WMTI metrics and measures of disease severity. Mean diffusivity and radial extra-axonal diffusivity were significantly increased while fractional anisotropy, axonal water fraction, intra-axonal diffusivity and tortuosity were decreased in MS patients compared with controls (p values ranging from <0.001 to <0.05). Axonal water fraction in the corpus callosum was significantly associated with the expanded disability status scale score (ρ = −0.39, p = 0.035). With the exception of the axial extra-axonal diffusivity, all metrics were correlated with the symbol digits modality test score (p values ranging from 0.001 to <0.05). WMTI metrics are thus sensitive to changes in the NAWM of MS patients and might provide a more pathologically specific, clinically meaningful and practical complement to standard diffusion tensor imaging-derived metrics.

Monitoring effectiveness and safety of Tafamidis in transthyretin amyloidosis in Italy: a longitudinal multicenter study in a non-endemic area

Abstract: Tafamidis is a transthyretin (TTR) stabilizer able to prevent TTR tetramer dissociation. There have been a few encouraging studies on Tafamidis efficacy in early-onset inherited transthyretin amyloidosis (ATTR) due to Val30Met mutation. However, less is known about its efficacy in later disease stages and in non-Val30Met mutations. We performed a multi-center observational study on symptomatic ATTR patients prescribed to receive Tafamidis. We followed up patients according to a standardized protocol including general medical, cardiological and neurological assessments at baseline and every 6 months up to 3 years. Sixty-one (42 males) patients were recruited. Only 28 % of enrolled subjects had the common Val30Met mutation, mean age of onset was remarkably late (59 years) and 18 % was in advanced disease stage at study entry. Tafamidis proved safe and well-tolerated. One-third of patients did not show significant progression along 36 months, independently from mutation type and disease stage. Neurological function worsened particularly in the first 6 months but progression slowed significantly thereafter. Autonomic function remained stable in 33 %, worsened in 56 % and improved in 10 %. Fifteen percent of patients showed cardiac disease progression and 30 % new onset of cardiomyopathy. Overall, Tafamidis was not able to prevent functional progression of the disease in 23 (43 %) subjects, including 16 patients who worsened in their walking ability and 12 patients who reached a higher NYHA score during the follow-up period. A higher mBMI at baseline was associated with better preservation of neurological function. In conclusion, neuropathy and cardiomyopathy progressed in a significant proportion of patients despite treatment. However, worsening of neurological function slowed after the first 6 months and also subjects with more advanced neuropathy, as well as patients with non-Val30Met mutation, benefited from treatment. Body weight preservation is an important favorable prognostic factor.

Chronic idiopathic axonal polyneuropathy: a systematic review

Abstract: Chronic idiopathic axonal polyneuropathy (CIAP) is a term describing neuropathies with both sensory and motor involvement in a length dependant distribution where neurophysiology reveals axonal damage, neuropathy onset is insidious and shows slow or no progression of the disease over at least 6 months with no aetiology being identified despite appropriate investigations. This entity merits further consideration given how common it is, the absence of clarity regarding aetiopathogenesis, natural history and therapies. A systematic computer-based literature search was conducted on PubMed database. We used two Medical Subject Headings terms in title. Term A was "axonal", "cryptogenic", "idiopathic" or "unknown" and Term B was "neuropathy" or "polyneuropathy". This search strategy resulted in the identification of 658 articles. After eligibility assessment, 48 papers were used for this review. CIAP is usually diagnosed in the sixth decade of life and it is more prevalent in males (ratio 3:2). It is usually slowly progressive. Some data support a potential role of autoimmunity in CIAP and further larger prospective studies are required to address such potential link and any treatment implications. CIAP is a common type of polyneuropathy but the least studied. Increasing awareness and research into this entity may result in better understanding and in the development of treatment strategies.

Vestibular paroxysmia: a treatable neurovascular cross-compression syndrome.

Abstract: The leading symptoms of vestibular paroxysmia (VP) are recurrent, spontaneous, short attacks of spinning or non-spinning vertigo that generally last less than one minute and occur in a series of up to 30 or more per day. VP may manifest when arteries in the cerebellar pontine angle cause a segmental, pressure-induced dysfunction of the eighth nerve. The symptoms are usually triggered by direct pulsatile compression with ephaptic discharges, less often by conduction blocks. MR imaging reveals the neurovascular compression of the eighth nerve (3D constructive interference in steady state and 3D time-of-flight sequences) in more than 95% of cases. A loop of the anterior inferior cerebellar artery seems to be most often involved, less so the posterior inferior cerebellar artery, the vertebral artery, or a vein. The frequent attacks of vertigo respond to carbamazepine or oxcarbazepine, even in low dosages (200-600 mg/d or 300-900 mg/d, respectively), which have been shown to also be effective in children. Alternative drugs to try are lamotrigine, phenytoin, gabapentin, topiramate or baclofen or other non-antiepileptic drugs used in trigeminal neuralgia. The results of ongoing randomized placebo-controlled treatment studies, however, are not yet available. Surgical microvascular decompression of the eighth nerve is the "ultima ratio" for medically intractable cases or in exceptional cases of non-vascular compression of the eighth nerve by a tumor or cyst. The International Barany Society for Neuro-Otology is currently working on a consensus document on the clinical criteria for establishing a diagnosis of VP as a clinical entity.

Expanded phenotypic spectrum of the m.8344A>G “MERRF” mutation: data from the German mitoNET registry

Abstract: The m.8344A>G mutation in the MTTK gene, which encodes the mitochondrial transfer RNA for lysine, is traditionally associated with myoclonic epilepsy and ragged-red fibres (MERRF), a multisystemic mitochondrial disease that is characterised by myoclonus, seizures, cerebellar ataxia, and mitochondrial myopathy with ragged-red fibres. We studied the clinical and paraclinical phenotype of 34 patients with the m.8344A>G mutation, mainly derived from the nationwide mitoREGISTER, the multicentric registry of the German network for mitochondrial disorders (mitoNET). Mean age at symptom onset was 24.5 years ±10.9 (6–48 years) with adult onset in 75 % of the patients. In our cohort, the canonical features seizures, myoclonus, cerebellar ataxia and ragged-red fibres that are traditionally associated with MERRF, occurred in only 61, 59, 70, and 63 % of the patients, respectively. In contrast, other features such as hearing impairment were even more frequently present (72 %). Other common features in our cohort were migraine (52 %), psychiatric disorders (54 %), respiratory dysfunction (45 %), gastrointestinal symptoms (38 %), dysarthria (36 %), and dysphagia (35 %). Brain MRI revealed cerebral and/or cerebellar atrophy in 43 % of our patients. There was no correlation between the heteroplasmy level in blood and age at onset or clinical phenotype. Our findings further broaden the clinical spectrum of the m.8344A>G mutation, document the large clinical variability between carriers of the same mutation, even within families and indicate an overlap of the phenotype with other mitochondrial DNA-associated syndromes.

Strictly monitored exercise programs reduce motor deterioration in ALS: preliminary results of a randomized controlled trial

Abstract: The objective of our study was to perform a randomized controlled trial (RCT) aimed to evaluate the effects of three strictly monitored exercise programs(SMEP) compared to "usual care" (UCP) in a cohort of ALS patients. We included patients with definite and probable ALS and disease duration ≤24 months. Patients were randomized to receive a SMEPs or a UCP. SMEPs included three subgroups of treatment: active exercises associated with cycloergometer activity (1A), only active (1B) and passive (1C) exercises, respectively. Moreover, SMEP patients and their caregivers were trained to a daily home-based passive exercise program. The UCP group was treated with passive and stretching exercises twice weekly. The treatment period for both groups was 6 months (T180), and patients were assessed by revised ALS Functional Rating Scale (ALSFRS-R), % Forced Vital Capacity (FVC %), and McGill Quality of Life (MGQoL) questionnaire. ALSFRS-R score was also evaluated at 6 months after the treatment period (T360). Sixty ALS patients were randomly assigned to one of two arms: SMEP Group included 30 patients, ten subjects for each subgroup (1A, 1B, and 1C); 30 patients were included in the UCP Group.At T180 and T360, SMEPs group had significantly higher ALSFRS-R score compared to the UCP group (32.8 ± 6.5 vs 28.7 ± 7.5, p = 0.0298; 27.5 ± 7.6 vs 23.3 ± 7.6, p = 0.0338, respectively). No effects of SMEPs on survival, respiratory decline and MGQol were found. In conclusion, although no effect on survival was demonstrated,our data suggest that a strictly monitored exercise program may significantly reduce motor deterioration in ALS patients.