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.

Microelectrode recording and hemorrhage in functional neurosurgery: a comparative analysis in a consecutive series of 645 procedures.

Objective: Functional stereotactic neurosurgery including deep brain stimulation (DBS) and radiofrequency lesioning is well established and widely used for treatment of movement disorders and various other neurological and psychiatric diseases. Although functional stereotactic neurosurgery procedures are considered relatively safe, intracranial hemorrhage resulting in permanent neurological deficits may occur in 1%-3% of patients. Microelectrode recording (MER) has been recognized as a valuable tool for refining the final target in functional stereotactic neurosurgery.

Does Temporary Externalization of Electrodes After Deep Brain Stimulation Surgery Result in a Higher Risk of Infection?

Objectives: Deep brain stimulation (DBS) is a well-established surgical therapy for movement disorders that comprises implantation of stimulation electrodes and a pacemaker. These procedures can be performed separately, leaving the possibility of externalizing the electrodes for local field potential recording or testing multiple targets for therapeutic efficacy. It is still debated whether the temporary externalization of DBS electrodes leads to an increased risk of infection.

Heterozygous UCHL1 loss-of-function variants cause a neurodegenerative disorder with spasticity, ataxia, neuropathy, and optic atrophy.

Purpose: Biallelic variants in UCHL1 have been associated with a progressive early-onset neurodegenerative disorder, autosomal recessive spastic paraplegia type 79. In this study, we investigated heterozygous UCHL1 variants on the basis of results from cohort-based burden analyses.

Methods: Gene-burden analyses were performed on exome and genome data of independent cohorts of patients with hereditary ataxia and spastic paraplegia from Germany and the United Kingdom in a total of 3169 patients and 33,141 controls.

Are Transventricular Approaches Associated With Increased Hemorrhage? A Comparative Study in a Series of 624 Deep Brain Stimulation Surgeries.

Background: Deep brain stimulation (DBS) surgery has advanced tremendously, for both clinical applications and technology. Although DBS surgery is an overall safe procedure, rare side effects, in particular, hemorrhage, may result in devastating consequences. Although there are certain advantages with transventricular trajectories, it has been reasoned that avoidance of such trajectories would likely reduce hemorrhage.

Longterm Improvement After Cessation of Chronic Deep Brain Stimulation in Acquired Dystonia.

Introduction: Deep brain stimulation (DBS) has become an accepted treatment for inherited and idiopathic dystonia but less so for acquired dystonia. Patients benefit from long-term improvement with chronic DBS. Prolonged benefit over months has even been reported after cessation of stimulation on long-term follow-up.

Deep brain stimulation in patients on chronic antiplatelet or anticoagulation treatment.

Background: In the aging society, many patients with movement disorders, pain syndromes, or psychiatric disorders who are candidates for deep brain stimulation (DBS) surgery suffer also from cardiovascular co-morbidities that require chronic antiplatelet or anticoagulation treatment. Because of a presumed increased risk of intracranial hemorrhage during or after surgery and limited knowledge about perioperative management, chronic antiplatelet or anticoagulation treatment often has been considered a relative contraindication for DBS. Here, we evaluate whether or not there is an increased risk for intracranial hemorrhage or thromboembolic complications in patients on chronic treatment (paused for surgery or bridged with subcutaneous heparin) as compared to those without.

Improvement of head and neck range of motion induced by chronic pallidal deep brain stimulation for cervical dystonia.

Background: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an accepted treatment for severe cervical dystonia (CD). Assessment of therapeutic efficacy of DBS mostly focused on head position at rest but hardly on limitations of head and neck mobility, which represent a functionally important impairment in CD.

Objective: We aimed to determine prospectively head and neck range of motion (ROM) preoperatively and during chronic bilateral GPi DBS in a series of 11 patients with idiopathic CD or segmental dystonia with prominent CD using a computerized motion analysis.

Centromedian-Parafascicular and Somatosensory Thalamic Deep Brain Stimulation for Treatment of Chronic Neuropathic Pain: A Contemporary Series of 40 Patients.

The treatment of neuropathic and central pain still remains a major challenge. Thalamic deep brain stimulation (DBS) involving various target structures is a therapeutic option which has received increased re-interest. Beneficial results have been reported in several more recent smaller studies, however, there is a lack of prospective studies on larger series providing long term outcomes.

Implementation of New Technology in Patients with Chronic Deep Brain Stimulation: Switching from Non-Rechargeable Constant Voltage to Rechargeable Constant Current Stimulation.

Introduction: Deep brain stimulation (DBS) for movement disorders has been mainly performed with constant voltage (CV) technology. More recently also constant current (CC) systems have been developed which theoretically might have additional advantages. Furthermore, rechargeable (RC) system implantable pulse generators (IPG) are increasingly being used rather than the former solely available non-rechargeable (NRC) IPGs.

Position-Dependent Dysfunction of Deep Brain Stimulation in Tourette Syndrome: Diagnostic Clues.

Background: Detection of defective deep brain stimulation (DBS) contacts/electrodes is sometimes challenging.

Case Report: We report a patient with Tourette syndrome (TS), who presented with abrupt tic increase and mild generalized headache 9 years after DBS implantation. On the suspicion of a hardware defect, a fracture of the DBS electrode and extension lead was ruled out by radiography and standard implantable pulse generator readouts.

Deep brain stimulation for dystonia-choreoathetosis in cerebral palsy: Pallidal versus thalamic stimulation.

Introduction: Dystonia-choreoathetosis is common in patients with cerebral palsy, and medical treatment is mostly unsatisfactory. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has shown some effect, but there is still a need to optimize treatment strategies. We aimed to assess whether the thalamic ventral intermediate nucleus (Vim) might be an alternative DBS target in dystonia-choreoathetosis.

Does being physically active prevent future disability in older people? Attenuated effects when taking time-dependent confounders into account.

Background: Causal experimental evidence that physical activity prevents disability in older people is sparse. Being physically active has nonetheless been shown to be associated with disability-free survival in observational studies. Observational studies are, however, prone to bias introduced by time-dependent confounding.

Sensory Alterations in Patients with Isolated Idiopathic Dystonia: An Exploratory Quantitative Sensory Testing Analysis.

Abnormalities in the somatosensory system are increasingly being recognized in patients with dystonia. The aim of this study was to investigate whether sensory abnormalities are confined to the dystonic body segments or whether there is a wider involvement in patients with idiopathic dystonia. For this purpose, we recruited 20 patients, 8 had generalized, 5 had segmental dystonia with upper extremity involvement, and 7 had cervical dystonia.

Development of Hyperkinesias after Long-term Pallidal Stimulation for Idiopathic Segmental Dystonia.

Background: Chronic deep brain stimulation (DBS) of the globus pallidus internus (GPi) has become an established treatment for dystonia. While bradykinetic symptoms may occur on chronic stimulation, the appearance of hyperkinetic movements has not been well characterized.

Case Report: We report on the development of hyperkinesias after more than 10 years of GPi DBS.

Pedunculopontine nucleus deep brain stimulation in Parkinson's disease: A clinical review.

Pedunculopontine nucleus region deep brain stimulation (DBS) is a promising but experimental therapy for axial motor deficits in Parkinson's disease (PD), particularly gait freezing and falls. Here, we summarise the clinical application and outcomes reported during the past 10 years. The published dataset is limited, comprising fewer than 100 cases.

Pathological crying induced by deep brain stimulation of the subthalamic nucleus in Parkinson's disease.

We report on a patient with deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's disease (PD) who developed pathologic crying (PC) immediately postoperatively. A spread of DBS current to adjacent cortico-ponto-cerebellar pathways might be responsible. In contrast to the few cases published previously, there was no pre-existing additional lesion that would have favoured occurrence of PC.

Causes of failure of pallidal deep brain stimulation in cases with pre-operative diagnosis of isolated dystonia.

Introduction: Pallidal deep brain stimulation (GPi-DBS) is an effective therapy for isolated dystonia, but 10-20% of patients show improvement below 25-30%. We here investigated causes of insufficient response to GPi-DBS in isolated dystonia in a cross-sectional study.

Methods: Patients with isolated dystonia at time of surgery, and <30% improvement on the Burke-Fahn-Marsden dystonia-rating-scale (BFMDRS) after ≥6 months of continuous GPi-DBS were videotaped ON and OFF stimulation, and history, preoperative videos, brain MRI, medical records, stimulation settings, stimulation system integrity, lead location, and genetic information were obtained and reviewed by an expert panel.

Diagnostic and Prognostic Relevance of Magnetic Resonance Imaging and Electrophysiological Findings in Acute Spinal Ischemia.

Objective: Our purpose was to classify the rare entity of spontaneous spinal ischemia with clinical, magnetic resonance-tomographic, and electrophysiological parameters to determine criteria for outcome prediction.

Methods: We analyzed the stroke registry database of the University Hospital Mannheim, Germany, from 2004 to 2010 for patients with a diagnosis of vascular spinal cord ischemia.

Results: Ten patients were identified (mean age 65 years [range 50-83], 5 women).

Long-term follow-up of chronic spinal cord stimulation for medically intractable orthostatic tremor.

Orthostatic tremor (OT) is a rare form of tremor occurring in the legs when standing upright. Medical treatment frequently is unsatisfactory, thus in selected cases, surgical treatment, such as spinal cord stimulation (SCS) or thalamic deep brain stimulation has been proposed. We report the long-term results (follow-up (FU) 34-133 months) of SCS in four patients with medically intractable OT.

Hypokinetic gait changes induced by bilateral pallidal deep brain stimulation for segmental dystonia.

Background: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) has been established as an effective and safe treatment for dystonia. In general, side effects are rare, but there is increasing evidence that GPi DBS in dystonia can induce hypokinetic symptoms like micrographia or freezing of gait. We aimed to evaluate and quantify possible changes of gait following bilateral chronic GPi DBS for dystonia by computerized gait analyses.