Development and Characterization of Novel Conductive Sensing Fibers for In Vivo Nerve Stimulation

Advancements in electrode technologies to both stimulate and record the central nervous system’s electrical activities are enabling significant improvements in both the understanding and treatment of different neurological diseases. However, the current neural recording and stimulating electrodes are metallic, requiring invasive and damaging methods to interface with neural tissue. These electrodes may also degrade, resulting in additional invasive procedures. Furthermore, metal electrodes may cause nerve damage due to their inherent rigidity. This paper demonstrates that novel electrically conductive organic fibers (ECFs) can be used for direct nerve stimulation. The ECFs were prepared using a standard polyester material as the structural base, with a carbon nanotube ink applied to the surface as the electrical conductor. We report on three experiments: the first one to characterize the conductive properties of the ECFs; the second one to investigate the fiber cytotoxic properties in vitro; and the third one to demonstrate the utility of the ECF for direct nerve stimulation in an in vivo rodent model.

Subthalamic nucleus deep brain stimulation with a multiple independent constant current-controlled device in Parkinson's disease (INTREPID): a multicentre, double-blind, randomised, sham-controlled study

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus is an established therapeutic option for managing motor symptoms of Parkinson's disease. We conducted a double-blind, sham-controlled, randomised controlled trial to assess subthalamic nucleus DBS, with a novel multiple independent contact current-controlled (MICC) device, in patients with Parkinson's disease.

METHODS

This trial took place at 23 implanting centres in the USA. Key inclusion criteria were age between 22 and 75 years, a diagnosis of idiopathic Parkinson's disease with over 5 years of motor symptoms, and stable use of anti-parkinsonian medications for 28 days before consent. Patients who passed screening criteria were implanted with the DBS device bilaterally in the subthalamic nucleus. Patients were randomly assigned in a 3:1 ratio to receive either active therapeutic stimulation settings (active group) or subtherapeutic stimulation settings (control group) for the 3-month blinded period. Randomisation took place with a computer-generated data capture system using a pre-generated randomisation table, stratified by site with random permuted blocks. During the 3-month blinded period, both patients and the assessors were masked to the treatment group while the unmasked programmer was responsible for programming and optimisation of device settings. The primary outcome was the difference in mean change from baseline visit to 3 months post-randomisation between the active and control groups in the mean number of waking hours per day with good symptom control and no troublesome dyskinesias, with no increase in anti-parkinsonian medications. Upon completion of the blinded phase, all patients received active treatment in the open-label period for up to 5 years. Primary and secondary outcomes were analysed by intention to treat. All patients who provided informed consent were included in the safety analysis. The open-label phase is ongoing with no new enrolment, and current findings are based on the prespecified interim analysis of the first 160 randomly assigned patients. The study is registered with ClinicalTrials.gov, NCT01839396.

FINDINGS

Between May 17, 2013, and Nov 30, 2017, 313 patients were enrolled across 23 sites. Of these 313 patients, 196 (63%) received the DBS implant and 191 (61%) were randomly assigned. Of the 160 patients included in the interim analysis, 121 (76%) were randomly assigned to the active group and 39 (24%) to the control group. The difference in mean change from the baseline visit (post-implant) to 3 months post-randomisation in increased ON time without troublesome dyskinesias between the active and control groups was 3·03 h (SD 4·52, 95% CI 1·3-4·7; p<0·0001). 26 serious adverse events in 20 (13%) patients occurred during the 3-month blinded period. Of these, 18 events were reported in the active group and 8 in the control group. One death was reported among the 196 patients before randomisation, which was unrelated to the procedure, device, or stimulation.

INTERPRETATION

This double-blind, sham-controlled, randomised controlled trial provides class I evidence of the safety and clinical efficacy of subthalamic nucleus DBS with a novel MICC device for the treatment of motor symptoms of Parkinson's disease. Future trials are needed to investigate potential benefits of producing a more defined current field using MICC technology, and its effect on clinical outcomes.

FUNDING

Boston Scientific.

Deep brain stimulation for appetite disorders: a review

The mechanisms of appetite disorders, such as refractory obesity and anorexia nervosa, have been vigorously studied over the last century, and these studies have shown that the central nervous system has significant involvement with, and responsibility for, the pathology associated with these diseases. Because deep brain stimulation has been shown to be a safe, efficacious, and adjustable treatment modality for a variety of other neurological disorders, it has also been studied as a possible treatment for appetite disorders. In studies of refractory obesity in animal models, the ventromedial hypothalamus, the lateral hypothalamus, and the nucleus accumbens have all demonstrated elements of success as deep brain stimulation targets. Multiple targets for deep brain stimulation have been proposed for anorexia nervosa, with research predominantly focusing on the subcallosal cingulate, the nucleus accumbens, and the stria terminalis and medial forebrain bundle. Human deep brain stimulation studies that focus specifically on refractory obesity and anorexia nervosa have been performed but with limited numbers of patients. In these studies, the target for refractory obesity has been the lateral hypothalamus, ventromedial hypothalamus, and nucleus accumbens, and the target for anorexia nervosa has been the subcallosal cingulate. These studies have shown promising findings, but further research is needed to elucidate the long-term efficacy of deep brain stimulation for the treatment of appetite disorders.

Covalent Poly(lactic acid) Nanoparticles for the Sustained Delivery of Naloxone

The opioid epidemic currently plaguing the United States has been exacerbated by an alarming rise in fatal overdoses as a result of the proliferated abuse of synthetic mu opioid receptor (MOR) agonists, such as fentanyl and its related analogues. Attempts to manage this crisis have focused primarily on widespread distribution of the clinically approved opioid reversal agent naloxone (Narcan); however, due to the intrinsic metabolic lability of naloxone, these measures have demonstrated limited effectiveness against synthetic opioid toxicity. This work reports a novel polymer-based strategy to create a long-acting formulation of naloxone with the potential to address this critical issue by utilizing covalent nanoparticle (cNP) drug delivery technology. Covalently loaded naloxone nanoparticles (Nal-cNPs) were prepared via the naloxone-initiated, ring-opening polymerization (ROP) of l-lactide in the presence of a bifunctional thiourea organocatalyst with subsequent precipitation of the resulting naloxone-poly(l-lactic acid) polymer. This protocol afforded well-defined nanoparticles possessing a drug loading of approximately 7% w/w. The resulting Nal-cNPs demonstrated excellent biocompatibility, while exhibiting sustained linear release kinetics in vitro and blocking the effects of high dose (10 mg/kg) acute morphine for up to 98 h in an in vivo rodent model of neuropathic pain.

Deep Brain Stimulation of the Hypothalamus Leads to Increased Metabolic Rate in Refractory Obesity

OBJECTIVE

Obesity has become a worldwide epidemic, with very few long-term successful treatment options for refractory disease. Deep brain stimulation (DBS) of the bilateral lateral hypothalamus (LH) in refractory obesity has been performed safely. However, questions remain regarding the optimal settings and its effects on metabolic rate. The goals of our experiment were to determine the optimal DBS settings and the actual effect of optimal stimulation on energy expenditure.

METHODS

After bilateral LH DBS implantation, 2 subjects with treatment refractory obesity underwent 4 days of metabolic testing. The subjects slept overnight in a respiratory chamber to measure their baseline sleep energy expenditure, followed by 4 consecutive days of resting metabolic rate (RMR) testing at different stimulation settings. On day 4, the optimized DBS settings were used, and sleep energy expenditure was measured again overnight in the room calorimeter.

RESULTS

During daily testing, the RMR fluctuated acutely with changes in stimulation settings and returned to baseline immediately after turning off the stimulation. Optimal stimulation settings selected for participants showed a 20% and 16% increase in RMR for the 2 participants. Overnight sleep energy expenditure measurements at these optimized settings on day 4 yielded a 10.4% and 4.8% increase over the baseline measurements for the 2 participants.

CONCLUSIONS

These findings have demonstrated the efficacy of optimized DBS of the LH on increasing the RMR acutely and maintaining this increase during overnight sleep. These promising preliminary findings have laid the groundwork for the possible treatment of refractory obesity with DBS.

Thalamic Deep Brain Stimulation

The use of deep brain stimulation (DBS) of the thalamus has been proven to be a safe and efficacious treatment for the management of many diseases. The most common indication for thalamic DBS remains essential tremor (ET), one of the most common movement disorders in the world. ET patients should be considered for surgical intervention when their tremor has demonstrated to be refractory to medication, a characteristic estimated to be present in roughly 50% of ET cases. Advantages of DBS over thalamotomy include its reversibility, the ability to adjust stimulation settings to optimize efficacy and minimize side effects, the ability to perform bilateral procedures safely, and an association with a lower risk of postoperative cognitive problems. The most common target of DBS for ET is the ventralis intermedius (VIM) of the thalamus, and the optimal electrode location corresponds to the anterior margin of the VIM. Other indications for thalamic DBS include non-ET tremor, obsessive-compulsive disorder, neuropathic pain, traumatic brain injury, Tourette's syndrome, and drug-resistant epilepsy among others.

Scoliosis Secondary to Dystonia: A Case Report and Review of the Literature

CASE

An adolescent girl presented with an atypical scoliotic curve, pelvic obliquity, back pain, and lower-extremity paresthesias. A workup revealed generalized primary torsion dystonia. The condition was refractory to medical treatment and necessitated implantation of a deep brain stimulator. The scoliosis required operative correction, and the patient underwent posterior spinal arthrodesis with hook-rod instrumentation, which resulted in successful correction through 7 years of follow-up.

CONCLUSION

The differential diagnosis for adolescent scoliosis should include dystonia as a potential cause, especially when a patient presents with muscular contractures, an atypical scoliotic curve, pelvic obliquity, or changing curve characteristics.

Effect of TLIF Cage Placement on In Vivo Kinematics

BACKGROUND

The influence of interbody cage positioning on clinical outcomes following lumbar interbody fusion is not well understood, though it has been hypothesized to play a significant role in stability of the treated level. The purpose of this study was to evaluate any correlations between cage placement in TLIF procedures and post-operative kinematics.

METHODS

Thirteen patients who had previously undergone a TLIF procedure were evaluated using the Vertebral Motion Analysis (VMA) system, an automated fluoroscopic method of tracking kinematics in vivo. Upright and recumbent bending platforms were used to guide patients through a set range of motion (ROM) standing up and lying down, respectively, in both flexion-extension (FE) and lateral bending (LB). Intervertebral ROM was measured via fluoroscopic images captured sequentially throughout the movement. DICOM images acquired by the VMA system were used to calculate cage positioning. Intra-rater and inter-rater reliability of TLIF cage position were also assessed.

RESULTS

Statistically significant correlations were noted between sagittal cage position and lying LB (r = -0.583, p = 0.047), and coronal cage positioning with both standing (r = 0.672, p = 0.012) and lying LB (r = 0.632, p = 0.027). Additionally, the correlation between sagittal cage position and standing FE was trending towards significance (r = -0.542, p = 0.055).

CONCLUSIONS

The intuitive correlation between coronal cage position and both standing and lying lateral bending ROM is supported by the data from this study, suggesting placement closer to midline is optimal for stability. Additionally, the VMA system appears to be a sensitive and repeatable means to obtain information on postoperative kinematic outcomes. Further work to establish the relationship between cage placement, these kinematic outcomes and, potentially, functional pain outcomes seems to be warranted based on the results obtained here.

Stability and Load Sharing Characteristics of a Posterior Dynamic Stabilization Device

Background

Lumbar interbody fusion is a common treatment for a variety of spinal pathologies. It has been hypothesized that insufficient mechanical loading of the interbody graft can prevent proper fusion of the joint. The purpose of this study was to evaluate the mechanical stability and anterior column loading sharing characteristics of a posterior dynamic system compared to titanium rods in an anterior lumbar interbody fusion (ALIF) model.

Methods

Range of motion, interpedicular kinematics and interbody graft loading were measured in human cadaveric lumbar segments tested under a pure moment flexibility testing protocol.

Results

Both systems provided significant fixation compared to the intact condition and to an interbody spacer alone in flexion extension and lateral bending. No significant differences in fixation were detected between the devices. A significant decrease in graft loading was detected in flexion for the titanium rod treatment compared to spacer alone. No significant differences in graft loading were detected between the spacer alone and posterior dynamic system or between the posterior dynamic system and the titanium rod.

Conclusions

The results of this study indicate that the posterior dynamic system provides similar fixation compared to that of a titanium rod, however, studies designed to evaluate the efficacy of fixation in a cadaver model may not be sufficiently powered to establish differences in load sharing using the techniques described here.

The history of external ventricular drainage

External ventricular drainage (EVD) is one of the most commonly performed neurosurgical procedures. It was first performed as early as 1744 by Claude-Nicholas Le Cat. Since then, there have been numerous changes in technique, materials used, indications for the procedure, and safety. The history of EVD is best appreciated in 4 eras of progress: development of the technique (1850-1908), technological advancements (1927-1950), expansion of indications (1960-1995), and accuracy, training, and infection control (1995-present). While EVD was first attempted in the 18th century, it was not until 1890 that the first thorough report of EVD technique and outcomes was published by William Williams Keen. He was followed by H. Tillmanns, who described the technique that would be used for many years. Following this, many improvements were made to the EVD apparatus itself, including the addition of manometry by Adson and Lillie in 1927, and continued experimentation in cannulation/drainage materials. Technological advancements allowed a great expansion of indications for EVD, sparked by Nils Lundberg, who published a thorough analysis of the use of intracranial pressure (ICP) monitoring in patients with brain tumors in 1960. This led to the application of EVD and ICP monitoring in subarachnoid hemorrhage, Reye syndrome, and traumatic brain injury. Recent research in EVD has focused on improving the overall safety of the procedure, which has included the development of guidance-based systems, virtual reality simulators for trainees, and antibiotic-impregnated catheters.

Ethical Considerations in Deep Brain Stimulation for the Treatment of Addiction and Overeating Associated With Obesity

The success of deep brain stimulation (DBS) for movement disorders and the improved understanding of the neurobiologic and neuroanatomic bases of psychiatric diseases have led to proposals to expand current DBS applications. Recent preclinical and clinical work with Alzheimer's disease and obsessive-compulsive disorder, for example, supports the safety of stimulating regions in the hypothalamus and nucleus accumbens in humans. These regions are known to be involved in addiction and overeating associated with obesity. However, the use of DBS targeting these areas as a treatment modality raises common ethical considerations, which include informed consent, coercion, enhancement, threat to personhood, and manipulation of the reward center. Pilot studies for both of these conditions are currently investigational. If these studies show promise, then there is a need to address the ethical concerns related to the initiation of clinical trials including the reliability of preclinical evidence, patient selection, study design, compensation for participation and injury, cost-effectiveness, and the need for long-term follow-up. Multidisciplinary teams are necessary for the ethical execution of such studies. In addition to establishing safety and efficacy, the consideration of these ethical issues is vital to the adoption of DBS as a treatment for these conditions. We offer suggestions about the pursuit of future clinical trials of DBS for the treatment of addiction and overeating associated with obesity and provide a framework for addressing ethical concerns related to treatment.

Lateral hypothalamic area deep brain stimulation for refractory obesity: a pilot study with preliminary data on safety, body weight, and energy metabolism

OBJECT

Deep brain stimulation (DBS) of the lateral hypothalamic area (LHA) has been suggested as a potential treatment for intractable obesity. The authors present the 2-year safety results as well as early efficacy and metabolic effects in 3 patients undergoing bilateral LHA DBS in the first study of this approach in humans.

METHODS

Three patients meeting strict criteria for intractable obesity, including failed bariatric surgery, underwent bilateral implantation of LHA DBS electrodes as part of an institutional review board- and FDA-approved pilot study. The primary focus of the study was safety; however, the authors also received approval to collect data on early efficacy including weight change and energy metabolism.

RESULTS

No serious adverse effects, including detrimental psychological consequences, were observed with continuous LHA DBS after a mean follow-up of 35 months (range 30-39 months). Three-dimensional nonlinear transformation of postoperative imaging superimposed onto brain atlas anatomy was used to confirm and study DBS contact proximity to the LHA. No significant weight loss trends were seen when DBS was programmed using standard settings derived from movement disorder DBS surgery. However, promising weight loss trends have been observed when monopolar DBS stimulation has been applied via specific contacts found to increase the resting metabolic rate measured in a respiratory chamber.

CONCLUSIONS

Deep brain stimulation of the LHA may be applied safely to humans with intractable obesity. Early evidence for some weight loss under metabolically optimized settings provides the first "proof of principle" for this novel antiobesity strategy. A larger follow-up study focused on efficacy along with a more rigorous metabolic analysis is planned to further explore the benefits and therapeutic mechanism behind this investigational therapy.

Cranial plate anchoring of spinal cord stimulation paddle leads: technical note

BACKGROUND

Lead migration is a frequent complication of spinal cord stimulation (SCS) and requires revision surgery. The evolution of wider paddle leads has necessitated more extensive laminotomy and epidural adhesiolysis, which may increase the risk of lead migration.

OBJECTIVE

We describe a novel anchoring technique for SCS paddle leads with use of a cranial "dogbone" plate.

METHODS

We retrospectively reviewed a consecutive series of 11 patients who underwent placement of paddle lead spinal cord stimulators with titanium plate anchoring. Patients were followed for a mean of 29.5 months from SCS implantation (range, 5-65 months). A 4-hole linear titanium cranial plate and two 4-mm screws were used to tightly affix the proximal paddle lead wiring to the lamina below the laminotomy defect.

RESULTS

All patients continue to have satisfactory spinal cord stimulation with no loss of efficacy or need for revision. No complications have been attributed to titanium plate anchoring, and there have been no cases of lead migration with this technique. Titanium plate anchoring added minimal time (approximately 3-5 minutes) to the operative case.

CONCLUSION

We report a safe and effective anchoring technique for paddle lead SCS with the use of a cranial plate. Our experience has been that this technique, which anchors the proximal lead wiring to the remaining lamina at the inferior laminotomy defect, is superior to anchoring methods that rely on suturing of lead wiring.

Expanding applications of deep brain stimulation: a potential therapeutic role in obesity and addiction management

BACKGROUND

The indications for deep brain stimulation (DBS) are expanding, and the feasibility and efficacy of this surgical procedure in various neurologic and neuropsychiatric disorders continue to be tested. This review attempts to provide background and rationale for applying this therapeutic option to obesity and addiction. We review neural targets currently under clinical investigation for DBS—the hypothalamus and nucleus accumbens—in conditions such as cluster headache and obsessive-compulsive disorder. These brain regions have also been strongly implicated in obesity and addiction. These disorders are frequently refractory, with very high rates of weight regain or relapse, respectively, despite the best available treatments.

METHODS

We performed a structured literature review of the animal studies of DBS, which revealed attenuation of food intake, increased metabolism, or decreased drug seeking. We also review the available radiologic evidence in humans, implicating the hypothalamus and nucleus in obesity and addiction.

RESULTS

The available evidence of the promise of DBS in these conditions combined with significant medical need, support pursuing pilot studies and clinical trials of DBS in order to decrease the risk of dietary and drug relapse.

CONCLUSIONS

Well-designed pilot studies and clinical trials enrolling carefully selected patients with obesity or addiction should be initiated.

Parkinson's disease: an inquiry into the etiology and treatment

Parkinson’s disease affects over one million people in the United States. Although there have been remarkable advances in uncovering the pathogenesis of this disabling disorder, the etiology is speculative. Medical treatment and operative procedures provide symptomatic relief only. Compression of the cerebral peduncle of the midbrain by the posterior cerebral artery in a patient with Parkinson’s Disease (Parkinson’s Disease) was noted on magnetic resonance imaging (MRI) scan and at operation in a patient with trigeminal neuralgia. Following the vascular decompression of the trigeminal nerve, the midbrain was decompressed by mobilizing and repositioning the posterior cerebral artery The patient's Parkinson's signs disappeared over a 48-hour period. They returned 18 months later with contralateral peduncle compression. A blinded evaluation of MRI scans of Parkinson's patients and controls was performed. MRI scans in 20 Parkinson's patients and 20 age and sex matched controls were evaluated in blinded fashion looking for the presence and degree of arterial compression of the cerebral peduncle. The MRI study showed that 73.7 percent of Parkinson's Disease patients had visible arterial compression of the cerebral peduncle. This was seen in only 10 percent of control patients (two patients, one of whom subsequently developed Parkinson’s Disease); thus 5 percent. Vascular compression of the cerebral peduncle by the posterior cerebral artery may be associated with Parkinson’s Disease in some patients. Microva-scular decompression of that artery away from the peduncle may be considered for treatment of Parkinson’s Disease in some patients.

Mapping of microstimulation evoked responses and unit activity patterns in the lateral hypothalamic area recorded in awake humans. Technical note

Major contributions to the understanding of human brain function have come from detailed clinical reports of responses evoked by electrical stimulation and specific brain regions during neurosurgical procedures in awake humans. In this study, microstimulation evoked responses and extracellular unit recordings were obtained intraoperatively in 3 awake patients undergoing bilateral implantation of deep brain stimulation electrodes in the lateral hypothalamus. The microstimulation evoked responses exhibited a clear anatomical distribution. Anxiety was most reliably evoked by stimulation directed ventromedially within or adjacent to the ventromedial nucleus of the hypothalamus, nausea was most reliably evoked by stimulation directed at the center of the lateral hypothalamus, and paresthesias were most reliably evoked by stimulation at the border of the lateral hypothalamus and basal nuclei. Regarding the unit recordings, the firing rates of individual neurons did not have an anatomical distribution, but a small subpopulation of neurons located at the border of the lateral hypothalamus and basal nuclei exhibited a fast rhythmically bursting behavior with an intraburst frequency of 200-400 Hz and an interburst frequency of 10-20 Hz. Based on animal studies, the lateral hypothalamic area and surrounding hypothalamic nuclei are putatively involved with a variety of physiological, behavioral, and sensory functions. The lateral hypothalamus is situated to play a dynamic and complex role in human behavior and this report further shows that to be true. In addition, this report should serve as a valuable resource for future intracranial work in which accurate targeting within this region is required.

Measurement of occlusion of the spinal canal and intervertebral foramen by intervertebral disc bulge

Background

Disc protrusion has been proposed to be a possible cause of both pain and stenosis in the lower spine. No previous study has described the amount of disc occlusion of the spinal canal and intervertebral foramen that occurs under different loading conditions. The objective of this study was to quantitatively assess the percent occlusion of the spinal canal and intervertebral foramen by disc bulge under different loading conditions.

Methods

Spinal canal depth and foraminal width were measured on computed tomography–scanned images of 7 human lumbar spine specimens. In vitro disc bulge measurements were completed by use of a previously described method in which single functional spinal units were subjected to 3 separate load protocols in a spine test machine and disc bulge was recorded with an optoelectric motion system that tracked active light-emitting diodes placed on the posterior and posterolateral aspects of the intervertebral disc. Occlusion was defined as percentage of encroachment into area of interest by maximum measured disc bulge at corresponding point of interest (the spinal canal is at the posterior point; the intervertebral foramen is at the posterolateral point).

Results

The mean spinal canal depth and mean foraminal width were 19 4 ± mm and 5 ± 2 mm, respectively. Mean spinal canal occlusion under a 250-N axial load, ± 2.5 Nm of flexion/extension, and ± 2.5 Nm of lateral bend was 2.5% ± 1.9%, 2.5% ± 1.6%, and 1.5% ± 0.8%, respectively. Mean intervertebral foramen occlusion under a 250-N axial load, ± 2.5 Nm of flexion/extension, and ± 2.5 Nm of lateral bend was 7.8% ± 4.7%, 9.5% ± 5.7%, and 11.3% ± 6.2%, respectively.

Conclusion

Percent occlusion of the spinal canal and intervertebral foramen is dependent on magnitude and direction of load. Exiting neural elements at the location of the intervertebral foramen are the most vulnerable to impingement and generation of pain.

Induction of panic attack by stimulation of the ventromedial hypothalamus

Panic attacks are sudden debilitating attacks of intense distress often accompanied by physical symptoms such as shortness of breath and heart palpitations. Numerous brain regions, hormones, and neurotransmitter systems are putatively involved, but the etiology and neurocircuitry of panic attacks is far from established. One particular brain region of interest is the ventromedial hypothalamus (VMH). In cats and rats, electrical stimulation delivered to the VMH has been shown to evoke an emotional “panic attack–like” escape behavior, and in humans, stimulation targeting nuclei just posterior or anterior to the VMH has reportedly induced panic attacks. The authors report findings obtained in an awake patient undergoing bilateral implantation of deep brain stimulation electrodes into the hypothalamus that strongly implicates the VMH as being critically involved in the genesis of panic attacks. First, as the stimulating electrode progressed deeper into the VMH, the intensity of stimulation required to evoke an attack systematically decreased; second, while stimulation of the VMH in either hemisphere evoked panic, stimulation that appeared to be in the center of the VMH was more potent. Thus, this evidence supports the role of the VMH in the induction of panic attacks purported by animal studies.

Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion

BACKGROUND CONTEXT

Multilevel fusions, the use of allograft bone, and smoking have been associated with an increased risk of nonunion after anterior cervical discectomy and fusion (ACDF) procedures. Pulsed electromagnetic field (PEMF) stimulation has been shown to increase arthrodesis rates after lumbar spine fusion surgery, but there are minimal data concerning the effect of PEMF stimulation on cervical spine fusion.

PURPOSE

To determine the efficacy and safety of PEMF stimulation as an adjunct to arthrodesis after ACDF in patients with potential risk factors for nonunion.

STUDY DESIGN

A randomized, controlled, prospective multicenter clinical trial.

PATIENT SAMPLE

Three hundred and twenty-three patients with radiographic evidence (computed tomography-myelogram [CT-myelo] or magnetic resonance imaging [MRI]) of a compressed cervical nerve root and symptomatic radiculopathy appropriate to the compressed root that had failed to respond to nonoperative management were enrolled in the study. The patients were either smokers (more than one pack per day) and/or were undergoing multilevel fusions. All patients underwent ACDF using the Smith-Robinson technique. Allograft bone and an anterior cervical plate were used in all cases.

OUTCOME MEASURES

Measurements were obtained preoperatively and at each postoperative interval and included neurologic assessment, visual analog scale (VAS) scores for shoulder/arm pain at rest and with activity, SF-12 scores, the neck disability index (NDI), and radiographs (anteroposterior, lateral, and flexion-extension views). Two orthopedic surgeons not otherwise affiliated with the study and blinded to treatment group evaluated the radiographs, as did a blinded radiologist. Adverse events were reported by all patients throughout the study to determine device safety.

METHODS

Patients were randomly assigned to one of two groups: those receiving PEMF stimulation after surgery (PEMF group, 163 patients) and those not receiving PEMF stimulation (control group, 160 patients). Postoperative care was otherwise identical. Follow-up was carried out at 1, 2, 3, 6, and 12 months postoperatively.

RESULTS

The PEMF and control groups were comparable with regard to age, gender, race, past medical history, smoking status, and litigation status. Both groups were also comparable in terms of baseline diagnosis (herniated disc, spondylosis, or both) and number of levels operated (one, two, three, or four). At 6 months postoperatively, the PEMF group had a significantly higher fusion rate than the control group (83.6% vs. 68.6%, p=.0065). At 12 months after surgery, the stimulated group had a fusion rate of 92.8% compared with 86.7% for the control group (p=.1129). There were no significant differences between the PEMF and control groups with regard to VAS pain scores, NDI, or SF-12 scores at 6 or 12 months. No significant differences were found in the incidence of adverse events in the groups.

CONCLUSIONS

This is the first randomized, controlled trial that analyzes the effects of PEMF stimulation on cervical spine fusion. PEMF stimulation significantly improved the fusion rate at 6 months postoperatively in patients undergoing ACDF with an allograft and an anterior cervical plate, the eligibility criteria being patients who were smokers or had undergone multilevel cervical fusion. At 12 months postoperatively, however, the fusion rate for PEMF patients was not significantly different from that of the control group. There were no differences in the incidence of adverse events in the two groups, indicating that the use of PEMF stimulation is safe in this clinical setting.

Fast-track programming and rehabilitation model: a novel approach to postoperative deep brain stimulation patient care

OBJECTIVE

To propose a new model of integrated, multidisciplinary postoperative care of the patients with deep brain stimulation (DBS).

DESIGN

Observational cohort study with follow-up at 3 months and 1 year.

SETTING

Academic medical center movement disorder clinic.

PARTICIPANTS

Seventy-three consecutive patients with medically refractory Parkinson's disease underwent bilateral DBS. Patients were then transferred directly to an inpatient rehabilitation facility.

INTERVENTION

DBS and inpatient programming and rehabilitation. Simultaneous programming and rehabilitation was carried out by a multidisciplinary team.

MAIN OUTCOME MEASURES

The FIM instrument, Unified Parkinson Disease Rating Scale (UPDRS), and levodopa dosage.

RESULTS

The average rehabilitation stay was 17.3 days, with a mean of 6.2 stimulator adjustments during that time. FIM scores improved from 62.1 (admission) to 98.5 (discharge), an average improvement of 36.4 (58.6%). Average UPDRS scores improved from 52.5 (preoperative off) and 30.1 (preoperative on) to 20.4 (3mo postoperative on-medication, on-stimulation), a 32.2% improvement from the preoperative on score. Levodopa dosages decreased by an average of 48.3% (all P<.001).

CONCLUSIONS

We describe our fast-track protocol, which allows for rapid DBS programming and tapering of Parkinson's medications. It also provides for treatment of concomitant medical and psychologic problems and optimized physical performance.

January 2001: A 37 year old man with a history of Hodgkin's disease

The January Cases of the Month (COM): A case of intracranial metastatic nodular sclerosing Hodgkin's disease without dural attachment in a 37-year-old previously stage III male is presented with a brief review of the literature. Both the primary tumor in the lymph node biopsy and the metastatic brain tumor showed similar histopathology and a immunohistochemical profile typical for Hodgkin's Disease. After chemotherapy, there are no signs of recurrence or systemic disease on follow-up for five months.

Prolonged survival in a patient with sinonasal teratocarcinosarcoma with cranial extension. Case report

Sinonasal teratocarcinosarcoma is a rare malignant neoplasm characterized by the combined histological features of carcinosarcoma and teratoma. The primary symptoms of this tumor are usually nasal obstruction and epistaxis, and a nasal cavity mass is the most common clinical finding. The authors describe an exceptionally rare case in which the patient presented with massive intracranial extension and exhibited confusion as an initial symptom. He subsequently underwent combined radical surgery and radiation therapy and has remained free of disease for 31 months. The surgical approach to the lesion, histological features, and clinical course are detailed.

Stereotactic biopsy of non-neoplastic lesions in adults

Stereotactic biopsy of intracranial lesions has been used primarily for the diagnosis of neoplastic lesions. A series of 158 consecutive stereotactic biopsies performed at The Cleveland Clinic Foundation resulted in 28 diagnoses of non-neoplastic disorders (18%). The majority of these were infectious, inflammatory, or demyelinating disorders. Stereotactic biopsy alone was diagnostic in 17 cases (61%), and biopsy in conjunction with clinical and laboratory data established definitive diagnoses in six cases (22%). All 23 definitive diagnoses led to modifications in patient management. Permanent neurologic morbidity occurred in only two patients (7%). We maintain that this procedure is underused. Stereotactic biopsy is safe, accurate, and useful for diagnosis of non-neoplastic neurologic disorders when the diagnosis is unclear by conventional means. In such cases, its use can lead to early diagnosis and treatment.

Cervical neurenteric cyst associated with Klippel-Feil syndrome: a case report and review of the literature

A neurenteric cyst of the spine is a rare congenital disorder secondary to alimentary duplication and vertebral malformation. It should, however, be included in the differential diagnosis of an intradural, extramedullary spinal lesion. We present a case of a cervical neurenteric cyst associated with Klippel-Feil syndrome and discuss the clinical, radiologic, histopathologic, immunohistochemical and embryologic characteristics of this disorder.

Intractable complex partial seizures associated with occult temporal lobe encephalocele and meningoangiomatosis: a case report

Occult congenital temporal lobe encephalocele has rarely been reported in association with medically intractable complex partial seizures. The four previously reported cases were unsuspected preoperatively. We present the case of an 18-year-old woman with intractable complex partial seizures since age 13. Seizure onset was electrically localized to the right temporal lobe. Preoperative neuroimaging studies revealed a middle fossa defect and inferior herniation of the right temporal lobe. Pathologic examination of the resected encephalocele revealed prominent features of meningoangiomatosis. We believe this to be the first case of temporal lobe encephalocele and epilepsy to be diagnosed preoperatively, and the first case also to be associated with meningoangiomatosis. The relevant literature on meningoangiomatosis and on temporal lobe encephalocele as a cause of epilepsy is reviewed.

Intra-arterial chemotherapy for brain tumors

Direct comparisons of theoretical modeling with actual drug delivery can lead to improved brain tumor therapy. In this study, normal and brain tumor-bearing rabbits received infusions of BCNU, or carmustine (1,3-bis [2-chlorethyl]-1-nitrosourea), with ethanol or hyperoxygenated perfluorocarbons as BCNU diluent. When ethanol was used as a diluent, right (infused) hemisphere:left (noninfused) hemisphere ratios of BCNU concentrations in both rabbit groups were markedly lower than had been predicted with theoretical pharmacokinetic modeling. When perfluorocarbons were used as a diluent, ratios of BCNU were significantly improved. These laboratory studies were directly translated into a two-phase protocol for human brain tumor patients. This combined research program demonstrates the successful integration of laboratory and clinical programs.

Management of subarachnoid hemorrhage in the critical care unit

Subarachnoid hemorrhage from a ruptured intracranial saccular aneurysm is associated with a high rate of morbidity and mortality. Most complications occur two to three weeks after the initial hemorrhage. The key to minimizing morbidity and mortality is early and aggressive intensive-care management. The Cleveland Clinic Neurosurgical Intensive Care Unit approach is reviewed.