Somatosensory evoked potentials recorded from DBS electrodes: the origin of subcortical N18.

The different peaks of somatosensory-evoked potentials (SEP) originate from a variety of anatomical sites in the central nervous system. The origin of the median nerve subcortical N18 SEP has been studied under various conditions, but the exact site of its generation is still unclear. While it has been claimed to be located in the thalamic region, other studies indicated its possible origin below the pontomedullary junction. Here, we scrutinized and compared SEP recordings from median nerve stimulation through deep brain stimulation (DBS) electrodes implanted in various subcortical targets. We studied 24 patients with dystonia, Parkinson's disease, and chronic pain who underwent quadripolar electrode implantation for chronic DBS and recorded median nerve SEPs from globus pallidus internus (GPi), subthalamic nucleus (STN), thalamic ventral intermediate nucleus (Vim), and ventral posterolateral nucleus (VPL) and the centromedian-parafascicular complex (CM-Pf). The largest amplitude of the triphasic potential of the N18 complex was recorded in Vim. Bipolar recordings confirmed the origin to be close to Vim electrodes (and VPL/CM-Pf) and less close to STN electrodes. GPi recorded only far-field potentials in unipolar derivation. Recordings from DBS electrodes located in different subcortical areas allow determining the origin of certain subcortical SEP waves more precisely. The subcortical N18 of the median nerve SEP-to its largest extent-is generated ventral to the Vim in the region of the prelemniscal radiation/ zona incerta.

Large-Scale Screening: Phenotypic and Mutational Spectrum in Isolated and Combined Dystonia Genes.

BACKGROUND: Pathogenic variants in several genes have been linked to genetic forms of isolated or combined dystonia. The phenotypic and genetic spectrum and the frequency of pathogenic variants in these genes have not yet been fully elucidated, neither in patients with dystonia nor with other, sometimes co-occurring movement disorders such as Parkinson's disease (PD). OBJECTIVES: To screen >2000 patients with dystonia or PD for rare variants in known dystonia-causing genes. METHODS: We screened 1207 dystonia patients from Germany (DysTract consortium), Spain, and South Korea, and 1036 PD patients from Germany for pathogenic variants using a next-generation sequencing gene panel. The impact on DNA methylation of KMT2B variants was evaluated by analyzing the gene's characteristic episignature. RESULTS: We identified 171 carriers (109 with dystonia [9.0%]; 62 with PD [6.0%]) of 131 rare variants (minor allele frequency <0.005). A total of 52 patients (48 dystonia [4.0%]; four PD [0.4%, all with GCH1 variants]) carried 33 different (likely) pathogenic variants, of which 17 were not previously reported. Pathogenic biallelic variants in PRKRA were not found. Episignature analysis of 48 KMT2B variants revealed that only two of these should be considered (likely) pathogenic. CONCLUSION: This study confirms pathogenic variants in GCH1, GNAL, KMT2B, SGCE, THAP1, and TOR1A as relevant causes in dystonia and expands the mutational spectrum. Of note, likely pathogenic variants only in GCH1 were also found among PD patients. For DYT-KMT2B, the recently described episignature served as a reliable readout to determine the functional effect of newly identified variants. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinical characterisation of women with persistent genital arousal disorder: the iPGAD-study.

Persistent Genital Arousal Disorder (PGAD) is a rare condition-mostly in women-where patients perceive prolonged genital arousal without any sexual desire or stimulation. Etiopathological considerations reach from peripheral to central issues over local disturbance of the pudendal nerve to neuropathy, psychosocial, and pharmacological theories. Since well controlled clinical studies about PGAD in conjunction with a mental and somatic health status are missing, this study is a detailed clinical investigation of PGAD patients compared to healthy controls. 26 women who fulfilled diagnostic criteria for PGAD were compared to 26 age matched healthy controls. Investigations included comparison of vegetative, gynaecological and sexual history, psychiatric features as well as a (neuro-)radiological, neurophysiological and gynaecological examination. Moreover, a detailed clinical characterisation of PGAD symptoms was performed. PGAD symptoms were mostly characterised as tingling or prickling and were permanently present. In over 80%, PGAD symptoms were located in the clitoris. Almost 70% reported radiations to other regions of the body. Most frequent trigger factors were tight clothes, mental stress, driving a car/bus/bicycle and sexual intercourse. Relieving factors were mainly distraction, relaxation, physical exercise, masturbation and swimming. In group comparisons, PGAD presented with significant higher rates of sexual dysfunctions, spontaneous orgasms, swelling of the genitals, extraordinary lubrication as well as higher rates in depression, agoraphobia, generalized anxiety disorder and lifetime panic disorder. Significantly more PGAD patients were diagnosed with restless legs symptoms. In contrast childhood traumatization, somatization disorder, suicidality, gynaecological as well as neurophysiological examination of the pudendal nerve were not different between the groups. MRI of the brain, pelvis and spinal cord was unsuspicious and incidental findings - including Tarlov cysts or pelvic venous congestion - were equally distributed among the groups. In summary, our study provides a careful characterization of women with PGAD highlighting a serious mental burden, most probably as a consequence of PGAD. With the current set of clinical investigations there was no evidence of a clear causal relationship to a specific clinical finding as it has been previously discussed. Future studies and additional techniques will have to further explore where and how in the peripheral or central nervous systems PGAD develops.

Tremor is associated with familial clustering of dystonia.

INTRODUCTION: Dystonia is a movement disorder of variable etiology and clinical presentation and is accompanied by tremor in about 50% of cases. Monogenic causes in dystonia are rare, but also in the group of non-monogenic dystonias 10-30% of patients report a family history of dystonia. This points to a number of patients currently classified as idiopathic that have at least in part an underlying genetic contribution. The present study aims to identify clinical and demographic features associated with heritability of yet idiopathic dystonia. METHODS: Seven hundred thirty-three datasets were obtained from the DysTract dystonia registry, patients with acquired dystonia or monogenic causes were excluded. Affected individuals were assigned to a familial and sporadic group, and clinical features were compared across these groups. Additionally, the history of movement disorders was also counted in family members. RESULTS: 18.2% of patients reported a family history of dystonia. Groups differed in age at onset, disease duration and presence of tremor on a descriptive level. Logistic regression analysis revealed that tremor was the only predictor for a positive family history of dystonia (OR 2.49, CI = 1.54-4.11, p < 0.001). Tremor turned out to be the most common movement disorder in available relatives of patients, and presence of tremor in relatives was associated with tremor in index patients (X2(1) = 16.2, p < 0.001). CONCLUSIONS: Tremor is associated with an increased risk of familial clustering of dystonia and with a family history of tremor itself. This indicates a hereditable dystonia-tremor syndrome with a clinical spectrum ranging from tremor-predominant diseases to dystonia.

Real-life use of onabotulinumtoxinA reduces healthcare resource utilization in individuals with chronic migraine: the REPOSE study.

BACKGROUND: Chronic migraine (CM) is associated with substantial economic burden. Real-world data suggests that onabotulinumtoxinA treatment for CM reduces healthcare resource utilisation (HRU) and related costs. METHODS: REPOSE was a 2-year prospective, multicentre, non-interventional, observational study to describe the real-world use of onabotulinumtoxinA in adult patients with CM. This analysis examined the impact of onabotulinumtoxinA on HRU. Patients received onabotulinumtoxinA treatment approximately every 12 weeks according to their physicians' discretion, guided by the summary of product characteristics (SPC) and PREEMPT injection paradigm. HRU outcome measures were collected at baseline and all administration visits and included headache-related hospitalizations and healthcare professional (HCP) visits. Health economic data, including family doctor and specialist visits, inpatient treatment for headache, acupuncture, technical diagnostics, use of nonpharmacologic remedies, and work productivity were also collected for patients enrolled at German study centres. RESULTS: Overall, 641 patients were enrolled at 78 study centres across 7 countries (Germany, UK, Italy, Spain, Norway, Sweden, and Russia), 633 received ≥1 onabotulinumtoxinA dose, and 128 completed the 2-year study. Patients were, on average, aged 45 years, 85% were female, and 60% (n = 377) were from Germany. At the end of the 2-year observation period, significantly fewer patients reported headache-related hospitalizations (p < 0.02) and HCP visits (p < 0.001) within the past 3 months than in the 3 months before baseline. In the German population, reductions were observed across all health services at all follow-up visits compared with baseline. The percentage of patients who saw a family doctor decreased from 41.7% at baseline to 13.5% at administration visit 8 and visits to a medical specialist decreased from 61.7% to 5.2% of patients. Inpatient acute treatment and technical diagnostics declined from 6.4% and 19.7% of patients at baseline to 0.0% and 1.0% at administration 8, respectively. The use of nonpharmacologic remedies and medication for the acute treatment of migraine also decreased with continued onabotulinumtoxinA treatment. Work incapacity, disability, absenteeism, and impaired performance at school/work improved with onabotulinumtoxinA treatment for CM over the 2-year observation period. CONCLUSIONS: Real-world evidence from REPOSE demonstrates that onabotulinumtoxinA treatment is associated with decreased HRU and supports the long-term benefits associated with the use of onabotulinumtoxinA for CM in clinical practice. TRIAL REGISTRATION: NCT01686581 . Name of registry: ClinicalTrials.gov. URL of registry: Date of retrospective registration: September 18, 2012. Date of enrolment of first patient: July 23, 2012.

Challenges and opportunities for Multi-National Investigator-Initiated clinical trials for ALS: European and United States collaborations.

An inherent challenge to clinical trials that aim to test the efficacy of experimental therapeutics for patients with amyotrophic lateral sclerosis (ALS) is the relative rarity of the disease. A promising solution to this problem is a multi-center approach that ideally includes sites distributed across a broad geographic area. In support of such an approach, the European E-RARE program and the United States National Institutes of Health (NIH) partnered to support the investigator-initiated ROCK-ALS trial (Eudra-CT-Nr.: 2017-003676-31, NCT03792490) as a multi-national collaboration between centers in Europe and North America that is led by European investigators. During the set-up of this international trial, however, a number of unanticipated legal, administrative, and financial complexities emerged that required significant adaptation of the proposed trial scheme. Here, we report our experience navigating these obstacles and describe the potential solutions that we explored. Our experience may inform future efforts to implement multi-national investigator-initiated trials that involve both European and United States centers.

Dysphagia in cervical dystonia patients receiving optimised botulinum toxin therapy: a single-center retrospective cohort study.

To explore the correlations of botulinum toxin (BT) therapy with dysphagia, we wanted to study a group of cervical dystonia (CD) patients with optimised BT therapy during a prolonged period of time to record their dysphagia frequency, severity and duration, to study potential risk factors and try to avoid it by BT application with ultrasound guidance. BT therapy of 75 CD patients (23 males, 52 females, age 60 ± 12 years, BT total dose 303.5 ± 101.5 uMU) was retrospectively analysed for 1 year. BT therapy was optimised prior to the observation period. Dysphagia was noticed by one fifth of the patients. In those patients, it only occurred in about one third of the injection series. It was never associated with a functional deficit and lasted several days to 2 weeks. It was not related to patient age or gender, BT total dose, BT dose in the sternocleidomastoid muscle, BT dose in the sternocleidomastoid and scalenii muscles, by BT therapy with bilateral sternocleidomastoid muscle injections or BT therapy with abobotulinumtoxinA. Ultrasound guidance was not able to prevent it. Further prospective studies will be necessary to study underlying dystonia associated swallowing abnormalities as a potentially predisposing factor.

Treatment expectations and patient-reported outcomes of nusinersen therapy in adult spinal muscular atrophy.

BACKGROUND: The antisense-oligonucleotide (ASO) nusinersen has recently been approved as the first genetically modifying therapy for 5q-associated spinal muscular atrophy (SMA) based on randomized sham-controlled trials in infants and children. The efficacy in adults with long disease history and advanced disease status is still widely unknown; the same applies to specific expectations of adult SMA patients and to what extent they are met and may impact outcome measures. METHODS: In a longitudinal monocentric study in adult patients with SMA types 2-4, the Stanford Expectations of Treatment Scale (SETS) was assessed prior to and during nusinersen treatment. Treatment outcome was evaluated using patient-reported outcomes (PROs) as well as objectively quantifiable motor outcome measures. RESULTS: Adult SMA patients had high expectations of nusinersen treatment effectiveness regarding increase in muscle strength and disease stabilization. Via PROs, 75% stated improvements in muscle strength, endurance and independence under therapy which was in line with slight improvements in quantifiable motor scores during a  ten month observation period. In contrast, patients only expressed few negative expectations which further decreased during therapy. CONCLUSIONS: This study showed mainly positive treatment expectations and PROs in patients undergoing nusinersen treatment along with measurable functional improvement in adult SMA patients. Moreover, treatment expectations did not significantly influence outcome measures.

Dyspnea as a Fatigue-Promoting Factor in ALS and the Role of Objective Indicators of Respiratory Impairment.

CONTEXT: There is no evidence-based treatment for fatigue in amyotrophic lateral sclerosis (ALS), and identification of treatable causes determines management strategies. Although dyspnea is a key symptom of ALS and effectively treatable, it has not been sufficiently investigated whether dyspnea may be a fatigue-promoting factor. OBJECTIVES: To determine the level of fatigue in dyspneic ALS patients and whether fatigue is promoted by dyspnea. We further evaluated the correlation of fatigue with respiratory function tests. METHODS: About 101 dyspneic patients and 20 matched controls completed the ALS Functional Rating Scale-Extension and the Fatigue Severity Scale. Dyspneic patients additionally completed the Dyspnea-ALS Scale and the ALS Assessment Questionnaire and underwent respiratory function tests (forced vital capacity, sniff nasal inspiratory pressure, mean inspiratory and expiratory pressure with respective relaxation rates, and blood gases). Multiple regression and correlation analyses were conducted. RESULTS: Dyspneic patients had significantly higher fatigue scores than nondyspneic patients, and their fatigue significantly affected quality of life. Dyspnea alone explained up to 24% of the variance in fatigue. No associations were observed between fatigue and respiratory function tests. Patients with noninvasive ventilation reported significantly more dyspnea and fatigue. CONCLUSION: Fatigue is a frequent and bothersome symptom in dyspneic ALS patients. Dyspnea-related distress is, in contrast to objective indicators of respiratory impairment, a determining factor of experienced fatigue. There is an urgent need for further symptom relief beyond noninvasive ventilation. Adequate treatment of dyspnea has the potential for synergies in symptom management arising from the association between fatigue and dyspnea.

IncobotulinumtoxinA for hypersalivation in patients with amyotrophic lateral sclerosis: an open-label single-centre study.

The objective of this study is to discover whether incobotulinumtoxinA (inco) can reduce relative hypersalivation in patients with amyotrophic lateral sclerosis (ALS). 14 patients with ALS (8 males and 6 females, age 55.4 ± 16.3 years) received ultrasound-guided injection of inco 100 MU in both parotid glands and inco 50 MU in both submandibular glands. Saliva production was gravimetrically measured with three cotton rolls placed in the mouth. Weight increase after 5 min was measured on an electronic scale. Subjective saliva production was registered with drooling frequency scale (DFS) and drooling severity scale (DSS). Saliva production was gravimetrically reduced at week 4 (p = 0.04), week 8 (p = 0.01) but not after week 12 after BT application. DFS was reduced at week 4 (p = 0.04), week 8 (p = 0.02), but not after week 12. DSS was reduced at week 4 (p = 0.03), week 8 (p = 0.04) and week 12 (p = 0.04). Patients in our study did not experience changes in their swallowing patterns or any other safety-relevant events. Inco is effective and well tolerated for saliva reduction in patients with ALS for 8-12 weeks.

Botulinum toxin type D blocks autonomic cholinergic synapses in humans: discussion of a potential therapeutic use.

Based on epidemiological data it was believed that botulinumtoxin type D (BT-D) may not block human cholinergic synapses. We wanted to investigate BT-D's effect on the autonomic cholinergic synapse in humans. For this, we compared in four volunteers intraindividually the hypohidrotic effect of intradermal BT-D and BT-A in Minor's iodine starch sweat test. Altogether, we studied BT-D in doses of 4, 8, 16 and 32MU and BT-A in doses of 2, 4, 8 and 16MU at weekly intervals throughout a period of 13 weeks. All BT doses were diluted in 0.2 ml 0.9% NaCl/H2O. Overall 704 data points were collected. Combined over all four subjects and all four doses BT-D's hypohidrotic effect intensity was half of BT-A's. BT-D's effect peaked around 5 weeks, BT-A's around 7 weeks. BT-D's effect duration was around 12 weeks, of BT-A's was around 14 weeks. For both BT types the hypohidrotic effect was dose dependent. BT-D, when injected intradermally, can block autonomic cholinergic synapses in humans. Compared to BT-A, BT-D's effect intensity was half and its effect duration was some 2 weeks shorter. With its weaker and shorter effect BT-D does not seem to promise therapeutic effects superior to BT-A.

Botulinum neurotoxin serotype D - A potential treatment alternative for BoNT/A and B non-responding patients.

OBJECTIVES: Botulinum neurotoxin serotypes A and B (BoNT/A & B) are highly effective medicines to treat hyperactive cholinergic neurons. Due to neutralizing antibody formation, some patients may become non-responders. In these cases, the serotypes BoNT/C-G might become treatment alternatives. BoNT/D is genetically least related to BoNT/A & B and thereby circumventing neutralisation in A/B non-responders. We produced BoNT/D and compared its pharmacology with BoNT/A ex vivo in mice tissue and in vivo in human volunteers. METHODS: BoNT/D was expressed recombinantly in E. coli, isolated by chromatography and its ex vivo potency was determined at mouse phrenic nerve hemidiaphragm preparations. Different doses of BoNT/D or incobotulinumtoxinA were injected into the extensor digitorum brevis (EDB) muscles (n = 30) of human volunteers. Their compound muscle action potentials were measured 11 times by electroneurography within 220 days. RESULTS: Despite a 3.7-fold lower ex vivo potency in mice, a 110-fold higher dosage of BoNT/D achieved the same clinical effect as incobotulinumtoxinA while showing a 50% shortened duration of action. CONCLUSIONS: BoNT/D blocks dose-dependently acetylcholine release in human motoneurons upon intramuscular administration, but its potency and duration of action is inferior to approved BoNT/A based drugs. SIGNIFICANCE: BoNT/D constitutes a potential treatment alternative for BoNT/A & B non-responders.

Global Hippocampal Volume Reductions and Local CA1 Shape Deformations in Amyotrophic Lateral Sclerosis.

There is increasing evidence for hippocampal involvement in Amyotrophic Lateral Sclerosis (ALS). Recent neuroimaging studies have been focused on disease-related hippocampal volume alterations while changes in hippocampal shape have been investigated less frequently. Here, we aimed to characterize the patterns of hippocampal degeneration using both an automatic and manual volumetric and surface-based approach in a group of 31 patients with ALS and 29 healthy controls. Irrespective of the segmentation type, left, and right hippocampal volumes were significantly reduced in ALS compared to controls. Local shape alterations were identified in the hippocampal head region of patients with ALS that corresponds to the cornu ammonis field 1 (CA1), a region known to be involved in novelty detection, memory processing, and integration of hippocampal input and output information. The results suggest a global hippocampal volume loss in ALS that is complemented by local shape deformations in a highly interconnected region within the hippocampus.

Quantitative Susceptibility MRI to Detect Brain Iron in Amyotrophic Lateral Sclerosis.

Purpose To investigate the whole-brain landscape of iron-related abnormalities in amyotrophic lateral sclerosis (ALS) by using the in vivo MRI technique of quantitative susceptibility mapping (QSM). Materials and Methods For this prospective study, 28 patients with ALS (mean age, 61 years; age range, 43-77 years; 18 men [mean age, 61 years; range, 43-77 years] and 10 women [mean age, 61 years; range, 47-74 years]) recruited between January 17, 2014, and September 4, 2015, and 39 matched control subjects (mean age, 61 years; age range, 39-77 years; 24 men [mean age, 62 years; range, 39-77 years] and 15 women [mean age, 59 years; range, 39-73 years]) were examined by using structural and susceptibility 3.0-T MRI techniques. Group data were cross sectionally compared with family-wise error (FWE) corrections by using voxel-based morphometry (random-field theory), cortical thickness analysis (Monte Carlo simulated), subcortical volumetry (Bonferroni-corrected Wilcoxon rank-sum testing), and QSM analysis (cluster-enhanced whole-brain permutation testing and Bonferroni-corrected rank-sum testing in regions of interest). In patients with ALS, a potential relationship between diffusion and susceptibility measurements in the corticospinal tracts (CSTs) was also examined by using Spearman rank-correlation tests. Results Conventional structural measures failed to identify atrophy in the present cohort (FWE P > .05). However, QSM identified several whole-brain abnormalities (FWE P < .05) in ALS. Regionally, higher susceptibility (expressed as means in parts per million ± standard errors of the mean) was confirmed in the motor cortex (ALS = 0.0188 ± 0.0003, control = 0.0173 ± 0.0003; P < .001), the left substantia nigra (ALS = 0.127 ± 0.004, control = 0.113 ± 0.003; P = .008), the right substantia nigra (ALS = 0.141 ± 0.005, control = 0.120 ± 0.003; P < .001), the globus pallidus (ALS = 0.086 ± 0.003, control = 0.075 ± 0.002; P = .003), and the red nucleus (ALS = 0.115 ± 0.004, control = 0.098 ± 0.003; P < .001). Lower susceptibility was found in CST white matter (ALS = -0.047 ± 0.001, control = -0.043 ± 0.001; P = .01). Nigral and pallidal QSM values were cross correlated in ALS (ρ2 = 0.42, P < .001), a phenomenon visually traceable in many individual patients. QSM in the CST in ALS also correlated with diffusion-tensor metrics in this tract (ρ2 = 0.25, P = .007). Conclusion Whole-brain MRI quantitative susceptibility mapping analysis is sensitive to tissue alterations in amyotrophic lateral sclerosis that may be relevant to pathologic changes. © RSNA, 2018.

The metabolic and endocrine characteristics in spinal and bulbar muscular atrophy.

OBJECTIVE: Spinal and bulbar muscular atrophy (SBMA) is caused by an abnormal expansion of the CAG repeat in the androgen receptor gene. This study aimed to systematically phenotype a German SBMA cohort (n = 80) based on laboratory markers for neuromuscular, metabolic, and endocrine status, and thus provide a basis for the selection of biomarkers for future therapeutic trials. METHODS: We assessed a panel of 28 laboratory parameters. The clinical course and blood biomarkers were correlated with disease duration and CAG repeat length. A subset of 11 patients was evaluated with body fat MRI. RESULTS: Almost all patients reported muscle weakness (99%), followed by dysphagia (77%), tremor (76%), and gynecomastia (75%) as major complaints. Creatine kinase was the most consistently elevated (94%) serum marker, which, however, did not relate with either the disease duration or the CAG repeat length. Paresis duration and CAG repeat length correlated with dehydroepiandrosterone sulfate after correction for body mass index and age. The androgen insensitivity index was elevated in nearly half of the participants (48%). CONCLUSIONS: Metabolic alterations in glucose homeostasis (diabetes) and fat metabolism (combined hyperlipidemia), and sex hormone abnormalities (androgen insensitivity) could be observed among SBMA patients without association with the neuromuscular phenotype. Dehydroepiandrosterone sulfate was the only biomarker that correlated strongly with both weakness duration and the CAG repeat length after adjusting for age and BMI, indicating its potential as a biomarker for both disease severity and duration and, therefore, its possible use as a reliable outcome measure in future therapeutic studies.

Peripheral nerve atrophy together with higher cerebrospinal fluid progranulin indicate axonal damage in amyotrophic lateral sclerosis.

INTRODUCTION: We aimed to investigate whether sonographic peripheral cross-sectional nerve area (CSA) and progranulin (PGRN), a neuritic growth factor, are related to each other and whether they interact to predict clinical and paraclinical measures in amyotrophic lateral sclerosis (ALS). METHODS: We included 55 ALS patients who had forearm median and ulnar nerve CSA, cerebrospinal fluid (CSF) PGRN, and serum PGRN measures available. CSF PGRN was normalized against the CSF / serum albumin ratio (Qalb ). Using age, sex, height, and weight adjusted general linear models, we examined CSA × CSF PGRN interaction effects on various measures. RESULTS: There was a medium-effect size inverse relationship between CSA and CSF PGRN, but not between CSA and serum PGRN. Lower CSA values together with higher CSF PGRN levels were linked to smaller motor amplitudes. DISCUSSION: In ALS, the constellation of peripheral nerve atrophy together with higher CSF PGRN levels indicates pronounced axonal damage. Muscle Nerve 57: 273-278, 2018.

Strategies to decrease injection site pain in botulinum toxin therapy.

Botulinum toxin is now used for numerous indications including dystonias, spasticity, cerebral palsy, hyperhidrosis, cosmetics and chronic migraine. It has to be injected into its target tissues thus causing injection site pain. We wanted to compare the efficacy of various analgesic interventions suggested for reduction of injection site pain. In 13 healthy controls, pain thresholds in the fingertips II and III bilaterally were determined by the Mechanical Pain Threshold Test and the Repetitive Pain Stimulation Test at baseline and under nitrous oxide/oxygen, ice spray, local anaesthetic cream and forearm ischaemia. All interventions studied produce statistically significant and robust elevations of the pain threshold in both tests. Nitrous oxide/oxygen had stronger effects than the other interventions, although this superiority was statistically significant only in the Repetitive Pain Stimulation Test and not against ice spray. Also considering duration, localisation and penetration depth of analgesic effects, hyperhidrosis treatment may benefit from nitrous oxide/oxygen, ice spray and local anaesthetic cream. In palmar hyperhidrosis, forearm ischaemia is possible and also reduces botulinum toxin washout. Cosmetic indications may also benefit from nitrous oxide/oxygen and local anaesthetic cream. For botulinum toxin therapy of spasticity, dystonia and tremor, only nitrous oxide/oxygen may offer intramuscular analgesic effect. Its systemic and prolonged effect is also an advantage in injections in several body parts. Future studies are necessary to test the influence of penetration depth and combinations of analgesic interventions.

Botulinum toxin in the management of chronic migraine: clinical evidence and experience.

Chronic migraine (CM) is a severely disabling neurological condition characterized by episodes of pulsating unilateral or bilateral headache. The United States Food and Drug Administration (FDA) approved onabotulinumtoxinA (Botox®) for the prophylactic treatment of CM in 2010. It has been shown that onabotulinumtoxinA is effective in the reduction of headache frequency and severity in patients with CM. Treatment is well tolerated by the patients. This review reports on the history of botulinum neurotoxin (BoNT) in CM and presents the current clinical evidence for the use of onabotulinumtoxinA in the treatment of CM.

The concept and diagnostic criteria of primary lateral sclerosis.

OBJECTIVES: Primary lateral sclerosis (PLS) is commonly considered as a motor neuron disease (MND) variant which almost exclusively affects upper motor neurons (UMN). There is still no consensus whether PLS should be regarded as an independent disease entity separate from amyotrophic lateral sclerosis (ALS) or as a comparatively slowly progressive variant of ALS. Given these different views, clinical diagnosis of PLS is a challenge. In this multicenter study, we analyzed clinical features of patients diagnosed with PLS in four specialized MND centers. MATERIAL AND METHODS: We retrospectively analyzed clinical, laboratory, imaging, and electrophysiological data of 76 patients with PLS diagnosed in four specialized ALS centers. We analyzed the concept of the disease based on our findings and an extensive review of the literature. RESULTS: We found that 79% of patients showed asymmetrical symptoms, 60% showed clinical or electrophysiological signs of lower motor neuron (LMN) involvement after a mean of 8.4 ± 5.0 years, and extrapyramidal and/or non-motoric symptoms were frequently observed. Interestingly, none of the patients diagnosed with PLS fulfilled the diagnostic criteria proposed by Pringle et al. in 1992. CONCLUSIONS: Our data show that PLS as a disease entity is still not well enough defined and that there are different concepts about its clinical presentation. We believe that further prospective longitudinal studies are needed in order to refine diagnostic criteria to reflect current clinical practice. Furthermore, neuropathological and neuroimaging approaches might help to arrange PLS in the MND spectrum and its classification.

Interhemispheric connectivity in amyotrophic lateral sclerosis: A near-infrared spectroscopy and diffusion tensor imaging study.

PURPOSE: Aim of the present study was to investigate potential impairment of non-motor areas in amyotrophic lateral sclerosis (ALS) using near-infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI). In particular, we evaluated whether homotopic resting-state functional connectivity (rs-FC) of non-motor associated cortical areas correlates with clinical parameters and disease-specific degeneration of the corpus callosum (CC) in ALS. MATERIAL AND METHODS: Interhemispheric homotopic rs-FC was assessed in 31 patients and 30 healthy controls (HCs) for 8 cortical sites, from prefrontal to occipital cortex, using NIRS. DTI was performed in a subgroup of 21 patients. All patients were evaluated for cognitive dysfunction in the executive, memory, and visuospatial domains. RESULTS: ALS patients displayed an altered spatial pattern of correlation between homotopic rs-FC values when compared to HCs (p = 0.000013). In patients without executive dysfunction a strong correlation existed between the rate of motor decline and homotopic rs-FC of the anterior temporal lobes (ATLs) (ρ = - 0.85, p = 0.0004). Furthermore, antero-temporal homotopic rs-FC correlated with fractional anisotropy in the central corpus callosum (CC), corticospinal tracts (CSTs), and forceps minor as determined by DTI (p < 0.05). CONCLUSIONS: The present study further supports involvement of non-motor areas in ALS. Our results render homotopic rs-FC as assessed by NIRS a potential clinical marker for disease progression rate in ALS patients without executive dysfunction and a potential anatomical marker for ALS-specific degeneration of the CC and CSTs.