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.

Characteristics in Non-Vitamin K Antagonist Oral Anticoagulant-Related Intracerebral Hemorrhage.

Background and Purpose- Given inconclusive studies, it is debated whether clinical and imaging characteristics, as well as functional outcome, differ among patients with intracerebral hemorrhage (ICH) related to vitamin K antagonists (VKA) versus non-vitamin K antagonist (NOAC)-related ICH. Notably, clinical characteristics according to different NOAC agents and dosages are not established. Methods- Multicenter observational cohort study integrating individual patient data of 1328 patients with oral anticoagulation-associated ICH, including 190 NOAC-related ICH patients, recruited from 2011 to 2015 at 19 tertiary centers across Germany. Imaging, clinical characteristics, and 3-months modified Rankin Scale (mRS) outcomes were compared in NOAC- versus VKA-related ICH patients. Propensity score matching was conducted to adjust for clinically relevant differences in baseline parameters. Subgroup analyses were performed regarding NOAC agent, dosing and present clinically relevant anticoagulatory activity (last intake <12h/24h or NOAC level >30 ng/mL). Results- Despite older age in NOAC patients, there were no relevant differences in clinical and hematoma characteristics between NOAC- and VKA-related ICH regarding baseline hematoma volume (median [interquartile range]: NOAC, 14.7 [5.1-42.3] mL versus VKA, 16.4 [5.8-40.6] mL; P=0.33), rate of hematoma expansion (NOAC, 49/146 [33.6%] versus VKA, 235/688 [34.2%]; P=0.89), and the proportion of patients with unfavorable outcome at 3 months (mRS, 4-6: NOAC 126/179 [70.4%] versus VKA 473/682 [69.4%]; P=0.79). Subgroup analyses revealed that NOAC patients with clinically relevant anticoagulatory effect had higher rates of intraventricular hemorrhage (n/N [%]: present 52/109 [47.7%] versus absent 9/35 [25.7%]; P=0.022) and hematoma expansion (present 35/90 [38.9%] versus absent 5/30 [16.7%]; P=0.040), whereas type of NOAC agent or different NOAC-dosing regimens did not result in relevant differences in imaging characteristics or outcome. Conclusions- If effectively anticoagulated, there are no differences in hematoma characteristics and functional outcome among patients with NOAC- or VKA-related ICH. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT03093233.

Heparin for prophylaxis of venous thromboembolism in intracerebral haemorrhage.

OBJECTIVE: To determine the occurrence of intracranial haemorrhagic complications (IHC) on heparin prophylaxis (low-dose subcutaneous heparin, LDSH) in primary spontaneous intracerebral haemorrhage (ICH) (not oral anticoagulation-associated ICH, non-OAC-ICH), vitamin K antagonist (VKA)-associated ICH and non-vitamin K antagonist oral anticoagulant (NOAC)-associated ICH. METHODS: Retrospective cohort study (RETRACE) of 22 participating centres and prospective single-centre study with 1702 patients with VKA-associated or NOAC-associated ICH and 1022 patients with non-OAC-ICH with heparin prophylaxis between 2006 and 2015. Outcomes were defined as rates of IHC during hospital stay among patients with non-OAC-ICH, VKA-ICH and NOAC-ICH, mortality and functional outcome at 3 months between patients with ICH with and without IHC. RESULTS: IHC occurred in 1.7% (42/2416) of patients with ICH. There were no differences in crude incidence rates among patients with VKA-ICH, NOAC-ICH and non-OAC-ICH (log-rank p=0.645; VKA-ICH: 27/1406 (1.9%), NOAC-ICH 1/130 (0.8%), non-OAC-ICH 14/880 (1.6%); p=0.577). Detailed analysis according to treatment exposure (days with and without LDSH) revealed no differences in incidence rates of IHC per 1000 patient-days (LDSH: 1.43 (1.04-1.93) vs non-LDSH: 1.32 (0.33-3.58), conditional maximum likelihood incidence rate ratio: 1.09 (0.38-4.43); p=0.953). Secondary outcomes showed differences in functional outcome (modified Rankin Scale=4-6: IHC: 29/37 (78.4%) vs non-IHC: 1213/2048 (59.2%); p=0.019) and mortality (IHC: 14/37 (37.8%) vs non-IHC: 485/2048 (23.7%); p=0.045) in disfavour of patients with IHC. Small ICH volume (OR: volume <4.4 mL: 0.18 (0.04-0.78); p=0.022) and low National Institutes of Health Stroke Scale (NIHSS) score on admission (OR: NIHSS <4: 0.29 (0.11-0.78); p=0.014) were significantly associated with fewer IHC. CONCLUSIONS: Heparin administration for venous thromboembolism (VTE) prophylaxis in patients with ICH appears to be safe regarding IHC among non-OAC-ICH, VKA-ICH and NOAC-ICH in this observational cohort analysis. Randomised controlled trials are needed to verify the safety and efficacy of heparin compared with other methods for VTE prevention.

Management of therapeutic anticoagulation in patients with intracerebral haemorrhage and mechanical heart valves.

Aims: Evidence is lacking regarding acute anticoagulation management in patients after intracerebral haemorrhage (ICH) with implanted mechanical heart valves (MHVs). Our objective was to investigate anticoagulation reversal and resumption strategies by evaluating incidences of haemorrhagic and thromboembolic complications, thereby defining an optimal time-window when to restart therapeutic anticoagulation (TA) in patients with MHV and ICH. Methods and results: We pooled individual patient-data (n = 2504) from a nationwide multicentre cohort-study (RETRACE, conducted at 22 German centres) and eventually identified MHV-patients (n = 137) with anticoagulation-associated ICH for outcome analyses. The primary outcome consisted of major haemorrhagic complications analysed during hospital stay according to treatment exposure (restarted TA vs. no-TA). Secondary outcomes comprised thromboembolic complications, the composite outcome (haemorrhagic and thromboembolic complications), timing of TA, and mortality. Adjusted analyses involved propensity-score matching and multivariable cox-regressions to identify optimal timing of TA. In 66/137 (48%) of patients TA was restarted, being associated with increased haemorrhagic (TA = 17/66 (26%) vs. no-TA = 4/71 (6%); P < 0.01) and a trend to decreased thromboembolic complications (TA = 1/66 (2%) vs. no-TA = 7/71 (10%); P = 0.06). Controlling treatment crossovers provided an incidence rate-ratio [hazard ratio (HR) 10.31, 95% confidence interval (CI) 3.67-35.70; P < 0.01] in disadvantage of TA for haemorrhagic complications. Analyses of TA-timing displayed significant harm until Day 13 after ICH (HR 7.06, 95% CI 2.33-21.37; P < 0.01). The hazard for the composite-balancing both complications, was increased for restarted TA until Day 6 (HR 2.51, 95% CI 1.10-5.70; P = 0.03). Conclusion: Restarting TA within less than 2 weeks after ICH in patients with MHV was associated with increased haemorrhagic complications. Optimal weighing-between least risks for thromboembolic and haemorrhagic complications-provided an earliest starting point of TA at Day 6, reserved only for patients at high thromboembolic risk.

Factors Predicting Survival in ALS Patients--Data from a Population-Based Registry in Rhineland-Palatinate, Germany.

BACKGROUND: The possibility to survive with amyotrophic lateral sclerosis (ALS) varies considerably and survival extends from a few months to several years. A number of demographic and clinical factors predicting survival have been described; however, existing data are conflicting. We intended to predict patient survival in a population-based prospective cohort of ALS patients from variables known up to the time of diagnosis. METHODS: Incident ALS patients diagnosed within three consecutive years were enrolled and regularly followed up. Candidate demographic and disease variables were analysed for survival probability using the Kaplan-Meier method. The Cox proportional hazard regression model was used to assess the influence of selected predictor variables on survival prognosis. RESULTS: In the cohort of 193 patients (mean age 65.8, standard deviation 10.2 years), worse prognosis was independently predicted by older age, male gender, bulbar onset, probable or definite ALS according to El Escorial criteria, shorter interval between symptom onset and diagnosis, lower Functional Rating Scale, diagnosis of frontotemporal dementia, and living without a partner. CONCLUSIONS: Taking into account these predictor variables, an approximate survival prognosis of individual ALS patients at diagnosis seems feasible.

Factors predicting one-year mortality in amyotrophic lateral sclerosis patients--data from a population-based registry.

BACKGROUND: Survival in amyotrophic lateral sclerosis varies considerably. About one third of the patients die within 12 months after first diagnosis. The early recognition of fast progression is essential for patients and neurologists to weigh up invasive therapeutic interventions. In a prospective, population-based cohort of ALS patients in Rhineland-Palatinate, Germany, we identified significant prognostic factors at time of diagnosis that allow prediction of early death within first 12 months. METHODS: Incident cases, diagnosed between October 2009 and September 2012 were enrolled and followed up at regular intervals of 3 to 6 months. Univariate analysis utilized the Log-Rank Test to identify association between candidate demographic and disease variables and one-year mortality. In a second step we investigated a multiple logistic regression model for the optimal prediction of one-year mortality rate. RESULTS: In the cohort of 176 ALS patients (mean age 66.2 years; follow-up 100%) one-year mortality rate from diagnosis was 34.1%. Multivariate analysis revealed that age over 75 years, interval between symptom onset and diagnosis below 7 months, decline of body weight before diagnosis exceeding 2 BMI units and Functional Rating Score below 31 points were independent factors predicting early death. CONCLUSIONS: Probability of early death within 12 months from diagnosis is predicted by advanced age, short interval between symptom onset and first diagnosis, rapid decline of body weight before diagnosis and advanced functional impairment. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01955369, registered September 28, 2013).

Vertebral artery hypoplasia and hemodynamic impairment in transient global amnesia: a case control study.

Introduction: The aetiology of transient global amnesia (TGA) is still a matter of debate. Besides ischemia of the mesial temporal lobe including the hippocampus, migraine-like mechanisms, epileptic seizures affecting mnestic structures, or venous congestion in the (para) hippocampal area due to jugular vein insufficiency have been discussed. We assessed the diameters of the intracranial arteries of TGA patients compared to controls to identify differences that support the hypothesis of reduced hippocampal perfusion as a pivotal factor in the pathophysiology of TGA. Methods: We reviewed magnetic resonance imaging time of flight angiographies (TOF-MRA) that were acquired during in-patient treatment of 206 patients with acute TGA. Results: The diameters of the vertebral artery (VA) in the V4 segment, the proximal basilar artery, and the internal carotid arteries were measured manually. We compared the findings with TOF-MRA images of an age and sex matched control group of neurological patients without known cerebrovascular pathology. In TGA patients the diameter of the right VA was significantly (p < 0.01) smaller compared to controls (2.09 mm vs. 2.35 mm). There were no significant differences in the diameters of the other vessels. Only the fetal variant of the posterior cerebral artery was slightly more common in TGA. Discussion: The smaller diameter (hypoplasia) of the right VA supports the hypothesis of a contribution of hemodynamic factors to the pathophysiology of TGA. The fact that hypoplasia represents a congenital condition might be the explanation why previous studies failed to find an increased rate of the classical (acquired) vascular risk factors.

Rapid response of parkinsonian tremor to STN-DBS changes: direct modulation of oscillatory basal ganglia activity?

Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) has proved to be effective for tremor and other cardinal symptoms in Parkinson's disease (PD), the precise mechanisms of action of DBS are still unclear. We analyzed the time course of resting tremor amplitude and frequency during discontinuation and subsequent reinitiation of STN-DBS in nine PD patients, using a computerized three-dimensional motion analysis combined with surface electromyography. Following discontinuation of STN-DBS, resting tremor amplitude rapidly increased, reaching maximum amplitude after 2 min (mean +/- 95%CI: 34.3 +/- 13.8 mm; P < 0.01), subsequently stabilizing at a medium level. Reinitiation of stimulation after 30 min resulted in rapid, nearly complete suppression of tremor activity within 1 min (1.4 +/- 1.3 mm; P < 0.01) and, furthermore, increased tremor frequency within a few seconds in seven of nine patients. These findings support the hypothesis that STN-DBS acts by direct interference with the neurotransmission of basal ganglia networks involved in tremor.

Visual Evoked Potentials in Acute Retinal Migraine.

This case report describes monocular blurred vision and photopsia with headache.

Tremor reduction by subthalamic nucleus stimulation and medication in advanced Parkinson's disease.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has proved to be effective for tremor in Parkinson's disease (PD). Most of the recent studies used only clinical data to analyse tremor reduction. The objective of our study was to quantify tremor reduction by STN DBS and antiparkinsonian medication in elderly PD patients using an objective measuring system. Amplitude and frequency of resting tremor and re-emergent resting tremor during postural tasks were analysed using an ultrasound-based measuring system and surface electromyography. In a prospective study design nine patients with advanced PD were examined preoperatively off and on medication, and twice postoperatively during four treatment conditions: off treatment, on STN DBS, on medication, and on STN DBS plus medication. While both STN DBS and medication reduced tremor amplitude, STN DBS alone and the combination of medication and STN DBS were significantly superior to pre- and postoperative medication. STN DBS but not medication increased tremor frequency, and off treatment tremor frequency was significantly reduced postoperatively compared to baseline. These findings demonstrate that STN DBS is highly effective in elderly patients with advanced PD and moderate preoperative tremor reduction by medication. Thus, with regard to the advanced impact on the other parkinsonian symptoms, STN DBS can replace thalamic stimulation in this cohort of patients. Nevertheless, medication was still effective postoperatively and may act synergistically. The significantly superior efficacy of STN DBS on tremor amplitude and its impact on tremor frequency in contrast to medication might be explained by the influence of STN DBS on additional neural circuits independent from dopaminergic neurotransmission.

Propriospinal myoclonus due to cervical disc herniation. Case report.

Propriospinal myoclonus is a rare form of spinal myoclonus. In most cases the cause has remained unclear. Secondary propriospinal myoclonus has been described secondary to various disorders including trauma, tumor, and infection. Thus far, propriospinal myoclonus caused by cervical disc herniation has not been reported. In the present report, the authors describe the case of a 53-year-old man who presented with radicular symptoms of the right C-6 nerve root and myoclonic twitches predominantly affecting the abdominal muscles but spreading to adjacent muscles. The spread was triggered and enforced by certain movements. Magnetic resonance imaging studies revealed a C-6 nerve root compression at the C5-6 level on the right side but no cervical myelopathy. Electromyography studies confirmed the diagnosis of propriospinal myoclonus. After discectomy and cage-augmented fusion via an anterior approach, the myoclonic movement disorder gradually subsided. To the authors' knowledge, this is the first report on successful treatment of propriospinal myoclonus by spinal disc surgery.

Variability and prognostic relevance of different phenotypes in amyotrophic lateral sclerosis - data from a population-based registry.

OBJECTIVES: The clinical spectrum of amyotrophic lateral sclerosis (ALS) is characterized by a considerable variation. Different phenotypes have been described by previous studies. We assessed clinical variability and prognostic relevance of these phenotypes in a prospective, population-based cohort of ALS patients in Rhineland-Palatinate, Germany. METHODS: Incident ALS cases, diagnosed between October 2009 and September 2012, were prospectively enrolled and classified according to established ALS phenotype classification (bulbar, classic, flail arm, flail leg, pyramidal, respiratory). Survival probability was described using Kaplan-Meier method. Moreover, the influence of an additional frontotemporal dementia (FTD) was analysed. RESULTS: Phenotypes of all 200 patients were determined. Bulbar and classic phenotypes accounted for 75% of all cases. Deterioration of functional impairment during disease progression was lowest in flail leg and pyramidal variants, and most pronounced in bulbar and classic phenotypes. A poor survival prognosis was observed for bulbar, classic or respiratory phenotypes. Patients with an additional FTD showed an even worse outcome. CONCLUSIONS: Results suggest that ALS is a heterogeneous disease, as ALS phenotypes differ in disease progression and survival time. Patients classified as suffering from bulbar, classic and respiratory ALS, as well as those with an additional FTD, show a marked reduction of survival time.

Incidence of amyotrophic lateral sclerosis in Rhineland-Palatinate, Germany.

There is a lack of prospective and population based epidemiological data on amyotrophic lateral sclerosis in Germany to date. The ALS registry Rhineland-Palatinate was established to investigate the incidence, course and phenotypic variety of ALS in this south-west German state of about 4 million inhabitants. During the period 2010-2011, consecutive incident patients with amyotrophic lateral sclerosis according to the revised El Escorial criteria were included and followed up using multiple overlapping sources of case ascertainment. One hundred and forty-six patients were enrolled. The annual crude incidence for amyotrophic lateral sclerosis in Rhineland-Palatinate was 1.8/100,000 person-years (95% CI 1.6-2.2). Male to female ratio was 1.1:1. Incidence increased with age reaching a peak in the 70-74 years age group and declined thereafter. Late-onset ALS (≥ 75 years) was found in 14.4% of patients. About 32% of patients presented with bulbar onset. In conclusion, incidence rate of amyotrophic lateral sclerosis in Rhineland-Palatinate is within the range of other prospective population based registers in Europe and North America. Gender ratio is nearly balanced.

Combined pallidal and subthalamic nucleus stimulation in sporadic dystonia-parkinsonism.

Multifocal deep brain stimulation (DBS) is a new technique that has been introduced recently. A 39-year-old man with dystonia-parkinsonism underwent the simultaneous implantation of subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS electrodes. While bilateral STN DBS controlled the parkinsonian symptoms well and allowed for a reduction in levodopa, the improvement of dystonia was only temporary. Additional GPi DBS also alleviated dystonic symptoms. Formal assessment at the 1-year follow-up showed that both the parkinsonian symptoms and the dystonia were markedly improved via continuous bilateral combined STN and GPi stimulation. Sustained benefit was achieved at 3 years postoperatively.

Hans von Bülow: creativity and neurological disease in a famous pianist and conductor.

Hans von Bülow (1830-1894) was a conductor and pianist of worldwide reputation and founder of many stylistic interpretations of classic and romantic symphonies. The close friendship with Richard Wagner, but not the enthusiastic admiration of his dramatic musical opus, ended abruptly when Hans von Bülow became aware of the betrayal of his wife Cosima and Richard Wagner. Hans von Bülow reported symptoms and signs of neurological disease in many letters that were kept and edited by his second wife Marie. For decades he suffered from chronic neuralgiforme headaches, which were caused by a tumor of the cervical radicular nerves. At the age of 45 years, he suddenly developed a motorsensory deficit in the right arm and hand and a contralateral facial deficit, suggestive of brainstem infarction. He recovered and celebrated even greater successes as a musician, although phases of major depression also interfered with his professional life. In the last, phase of his life, he experienced the consequences of generalized atherosclerosis and cerebral microangiopathy. It was a second cerebrovascular accident of the brainstem that caused his death, only 10 months after his last concert performance. Although his death occurred in Egypt, an autopsy was performed by Professor Ludwig Edinger and the results will be presented.

Posttraumatic peripherally-induced dystonia and multifocal deep brain stimulation: case report.

OBJECTIVE: We report on the effect of multifocal deep brain stimulation for the treatment of posttraumatic peripherally-induced dystonia. CLINICAL PRESENTATION: A 34-year-old woman presented with an 8-year history of painful tonic dystonia starting in her left leg after injury of the third metatarsal bone. She did not benefit from right-sided pallidal stimulation by an electrode misplaced in the globus pallidus externus in another hospital. INTERVENTION: Quadripolar deep brain stimulation electrodes were placed in the globus pallidus internus and the ventrolateral thalamus by computed tomographic-guided stereotactic surgery and microelectrode recording contralateral to the side of dystonia. The Burke-Fahn-Marsden motor score of 34 did not improve with chronic pallidal or thalamic stimulation. CONCLUSION: Although deep brain stimulation is received with great enthusiasm, it is important to identify its limitations in certain subtypes of dystonia.