Double-crescent sign as a predictor of chronic subdural hematoma recurrence following burr-hole surgery

OBJECTIVE

Subdural hygroma has been reported as a causative factor in the development of a chronic subdural hematoma (CSDH) following a head trauma and/or neurosurgical procedure. In some CSDH cases, the presence of a 2-layered space delineated by the same or similar density of CSF surrounded by a superficial, residual hematoma is seen on CT imaging after evacuation of the hematoma. The aims of the present study were to test the hypothesis that the double-crescent sign (DCS), a unique imaging finding described here, is associated with the postoperative recurrence of CSDH, and to investigate other factors that are related to CSDH recurrence.

METHODS

The authors retrospectively analyzed data from 278 consecutive patients who underwent single burr-hole surgery for CSDH between April 2012 and March 2017. The DCS was defined as a postoperative CT finding, characterized by the following 2 layers: a superficial layer demonstrating residual hematoma after evacuation of the CSDH, and a deep layer between the brain's surface and the residual hematoma, depicted as a low-density space. Correlation of the recurrence of CSDH with the DCS was evaluated by multivariate logistic regression modeling. The authors also investigated other classic predictive factors including age, sex, past history of head injury, hematoma laterality, anticoagulant and antiplatelet therapy administration, preoperative hematoma volume, postoperative residual hematoma volume, and postoperative brain reexpansion rate.

RESULTS

A total of 277 patients (320 hemispheres) were reviewed. Fifty (18.1%) of the 277 patients experienced recurrence of CSDH within 3 months of surgery. CSDH recurred within 3 months of surgery in 32 of the 104 hemispheres with a positive DCS. Multivariate logistic analyses revealed that the presence of the DCS (OR 3.36, 95% CI 1.72-6.57, p < 0.001), large postoperative residual hematoma volume (OR 2.88, 95% CI 1.24-6.71, p = 0.014), anticoagulant therapy (OR 3.03, 95% CI 1.02-9.01, p = 0.046), and bilateral hematoma (OR 3.57, 95% CI 1.79-7.13, p < 0.001) were significant, independent predictors of CSDH recurrence.

CONCLUSIONS

In this study, the authors report that detection of the DCS within 7 days of surgery is an independent predictive factor for CSDH recurrence. They therefore advocate that clinicians should carefully monitor patients for postoperative DCS and subsequent CSDH recurrence.

Analysis of Endoscopic Findings in the Chronic Subdural Hematoma Cavity: Bleeding Factors in Chronic Subdural Hematoma Natural History and as Predictors of Recurrence

OBJECTIVE

Possible factors associated with bleeding from endoscopy-detected chronic subdural hematomas (CSDHs) have rarely been analyzed. We therefore evaluated intraoperative endoscopic findings to elucidate the clinical course and assess predictors of CSDH recurrence.

METHODS

Altogether, 540 CSDHs were reviewed in this retrospective study. Six possible signs of bleeding were detected in the cavity: spotty bleeding on the outer membrane, hematoma clots, cerebral parenchymal suspension, stretched cortical vessels, intraluminal trabecular structures, and septa separating the cavity. We evaluated the association of each with the radiologic findings, endoscopic features, and interval from trauma to surgery and then assessed the correlation between each endoscopic feature and CSDH recurrence.

RESULTS

Spotty bleeding, cerebral parenchymal suspension, and stretched cortical vessels occurred during every period. Hematoma clots exhibited a 2-peak pattern with significant resurgence during the chronic phase. Trabecular structures significantly increased 61 days after the trauma, reaching 71.2% of patients on day 91. Septa were found in the cavity in only 12.5% during the initial 30 days but subsequently increased significantly to 37.3%. At 2 months, an exacerbation stage was inferred. The multivariable analysis revealed that trabecular structures and residual septa were significant independent risk factors for recurrence. We opened most septa intraoperatively. Their recurrence rate was 7.5%, which is lower than has been previously reported.

CONCLUSIONS

Evaluation of the changes in the endoscopic findings and their association with recurrence was useful for clarifying the mechanism of CSDH enlargement, the risk of recurrence, and the potential for endoscopic surgery.

Clinicopathological and genetic characteristics associated with brain metastases from lung adenocarcinoma and utility as prognostic factors

Brain metastases (BM) are common in patients with lung adenocarcinoma, and represent a significant cause of morbidity in the disease. A more comprehensive understanding of the clinicopathological characteristics that serve as prognostic factors for survival in patients with BM from lung adenocarcinoma may aid in informing treatment strategies for this patient population. In the present study, clinicopathological factors, including EGFR mutation status, were evaluated in 59 patients who were diagnosed with BM from lung adenocarcinoma, and underwent BM resection between January 1985 and December 2014 at Fukuoka University Hospital. The most frequent subtype of BM from lung adenocarcinoma was solid adenocarcinoma (57.6%), followed by papillary adenocarcinoma (22.0%) and acinar adenocarcinoma (18.6%). A total of 14 patients (23.7%) exhibited EGFR mutations, which were significantly associated with female sex (9/14, 64.3%), non-smoker status (8/14, 57.1%), BM in the frontal lobes (9/14, 64.3%) and papillary adenocarcinoma (5/14, 35.7%). Statistical analysis revealed a significant association between non-smoker status and BM in the frontal lobes, and more favorable disease prognosis. The results of the present study suggest that histological and genetic analysis of tissue from BM provides information useful for managing treatment of patients with resectable BM arising from lung adenocarcinoma.

An Infratemporal Dermoid Cyst That Expanded the Foramen Ovale: A Case Report

BACKGROUND

Dermoid cysts are rare tumors usually seen in the midline structure of the brain but rarely arise in the petrous apex and cavernous sinus. There have been very few reports of dermoid cysts arising in the infratemporal fossa, with scarce anatomic descriptions. Here we report the case of a patient with a dermoid cyst in the left infratemporal fossa.

CASE DESCRIPTION

The patient was a 43-year-old female with complaints of nonspecific headaches. A computed tomography (CT) scan revealed a cystic lesion measuring 25 × 18 × 15 mm in the left infratemporal fossa that had expanded the foramen ovale. The same lesion was observed as a high-intensity area on T1-weighted magnetic resonance imaging (MRI) with fat saturation. Diffusion-weighted MRI showed no restriction, unlike in cases of epidermoid cysts. A left fronto-temporo-sphenoidal craniotomy with a detachment of the zygoma was performed to approach the lesion. The tumor wall was continuously attached to the dura, although the tumor itself was entirely extradural in location. The V3 branch of the trigeminal nerve was firmly attached around the tumor. The tumor was cystic, and it shrunk after the fatty yellowish contents were suctioned. Complete resection was achieved without complications. A pathological analysis enabled the diagnosis of a dermoid cyst. No tumor recurrences or associated complications were observed at the 1-year follow-up.

CONCLUSIONS

Dermoid cysts in the infratemporal fossa are extremely rare. However, tumor resections can be performed safely and efficaciously using anatomically detailed preoperative planning.

Spot sign as a predictor of rebleeding after endoscopic surgery for intracerebral hemorrhage

OBJECTIVE

In patients with spontaneous intracerebral hemorrhage (sICH), postoperative recurrent hemorrhage (PRH) is one of the most severe complications after endoscopic evacuation of hematoma (EEH). However, no predictors of this complication have been identified. In the present study, the authors retrospectively investigated whether PRH can be preoperatively predicted by the presence of the spot sign on CT scans.

METHODS

In total, 143 patients with sICH were treated by EEH between June 2009 and March 2017, and 127 patients who underwent preoperative CT angiography were included in this study. Significant correlations of PRH with the patients' baseline, clinical, and radiographic characteristics, including the spot sign, were evaluated using multivariable logistic regression models.

RESULTS

The incidence of and risk factors for PRH were assessed in 127 patients with available data. PRH occurred in 9 (7.1%) patients. Five (21.7%) cases of PRH were observed among 23 patients with the spot sign, whereas only 4 (3.8%) cases of PRH occurred among 104 patients without the spot sign. The spot sign was the only independent predictor of PRH (OR 5.81, 95% CI 1.26-26.88; p = 0.02). The following factors were not independently associated with PRH: age, hypertension, poor consciousness, antihemostatic factors (thrombocytopenia, coagulopathy, and use of antithrombotic drugs), the location and size of the sICH, other radiographic findings (black hole sign and blend sign), surgical duration and procedures, and early surgery.

CONCLUSIONS

The spot sign is likely to be a strong predictor of PRH after EEH among patients with sICH. Complete and careful control of bleeding in the operative field should be ensured when surgically treating such patients. New surgical strategies and procedures might be needed to improve these patients' outcomes.

Endoscopic surgery via a combined frontal and suboccipital approach for cerebellar hemorrhage

Background

Spontaneous cerebellar hemorrhages (CHs), which frequently require surgical intervention, are life-threatening and can be complicated by intraventricular hemorrhages (IVHs) and obstructive hydrocephalus. Commonly, endoscopic surgery is performed to remove CHs via a suboccipital approach (SA) alone. At our institution, when patients exhibited supratentorial IVH-associated hydrocephalus, we used a combined frontal and suboccipital approach (CA) to evacuate both CHs and supratentorial IVHs. The present study retrospectively evaluated the effectiveness and safety of this CA, as no prior studies examining this approach currently exist.

Methods

Twenty-six patients with spontaneous CH were surgically treated at our hospital from April 2009 to March 2016. Twenty-two patients who could independently perform activities of daily living before the onset underwent endoscopic surgery to evacuate the CHs; among these, 13 patients underwent the SA alone, while nine underwent the CA. We assessed and compared the patients' baseline characteristics, surgical results, and prognosis at 1 month after the intervention between the SA and CA groups.

Results

Patients who underwent the CA had significantly poorer consciousness before the surgery owing to IVH extension and obstructive hydrocephalus. However, the surgical results and prognosis at 1 month were not significantly different between the two approaches. The CH-associated IVHs were successfully removed with the CA and resulted in shorter external ventricular drainage (EVD) placement durations.

Conclusion

Endoscopic surgery performed via the CA appeared to neutralize the deteriorating effects of CH-associated IVHs. Surgical strategies employing the CA may have the potential to improve the prognosis of patients with CH.

Cerebral and spinal cavernomas associated with Klippel-Trenaunay syndrome: case report and literature review

Klippel-Trenaunay-Weber syndrome (KTWS) involves a triad of conditions, including cutaneous hemangiomas, venous varicosities, and osseous and soft-tissue hypertrophy of the affected limb. We describe a rare case of multiple cavernomas in the central nervous system in a patient with KTWS. A-64-year-old man with KTWS and a previous brain hemorrhage presented with sudden onset of gait and vesicorectal disturbance. The magnetic resonance imaging scan showed a cavernoma associated with hemorrhage in his lumbosacral spinal cord. Moreover, numerous cavernomas were identified in his brain. He was treated conservatively with no adverse events. Gait disturbance improved, but vesicorectal disturbance did not improve.

Biofeedback effect of hybrid assistive limb in stroke rehabilitation: A proof of concept study using functional near infrared spectroscopy

Introduction

Robot-assisted rehabilitation has been increasingly drawing attention in the field of neurorehabilitation. The hybrid assistive limb (HAL) is an exoskeleton robot developed based on the “interactive biofeedback” theory, and several studies have shown its efficacy for patients with stroke. We aimed to investigate the mechanisms of the facilitative effect of neurorehabilitation using a single-joint HAL (HAL-SJ) and functional near-infrared spectroscopy (fNIRS).

Materials and methods

Subacute stroke patients admitted to our hospital were assessed in this study for HAL eligibility. We evaluated motor-related cortical activity using an fNIRS system at baseline and immediately after HAL-SJ treatment on the same day. Cortical activity was determined through the relative changes in the hemoglobin concentrations. For statistical analysis, we compared the number of flexion/extension movements before and immediately after HAL-SJ treatment using paired t-test. fNIRS used both the methods of statistical parametric mapping and random effect analysis.

Results

We finally included 10 patients (eight men, two women; mean age: 66.8 ± 12.0 years). The mean number of flexion/extension movements within 15 s increased significantly from 4.2 ± 3.1 to 5.3 ± 4.1 immediately after training. fNIRS showed increased cortical activation in the primary motor cortex of the ipsilesional hemisphere immediately after HAL-SJ treatment compared to the baseline condition.

Conclusions

This study is the first to support the concept of the biofeedback effect from the perspective of changes in cortical activity measured with an fNIRS system. The biofeedback effect of HAL immediately increased the task-related cortical activity, and this may address the functional recovery. Further studies are warranted to support our findings.

Tailor-made rehabilitation approach using multiple types of hybrid assistive limb robots for acute stroke patients: A pilot study

This article investigated the feasibility of a tailor-made neurorehabilitation approach using multiple types of hybrid assistive limb (HAL) robots for acute stroke patients. We investigated the clinical outcomes of patients who underwent rehabilitation using the HAL robots. The Brunnstrom stage, Barthel index (BI), and functional independence measure (FIM) were evaluated at baseline and when patients were transferred to a rehabilitation facility. Scores were compared between the multiple-robot rehabilitation and single-robot rehabilitation groups. Nine hemiplegic acute stroke patients (five men and four women; mean age 59.4 ± 12.5 years; four hemorrhagic stroke and five ischemic stroke) underwent rehabilitation using multiple types of HAL robots for 19.4 ± 12.5 days, and 14 patients (six men and eight women; mean age 63.2 ± 13.9 years; nine hemorrhagic stroke and five ischemic stroke) underwent rehabilitation using a single type of HAL robot for 14.9 ± 8.9 days. The multiple-robot rehabilitation group showed significantly better outcomes in the Brunnstrom stage of the upper extremity, BI, and FIM scores. To the best of the authors' knowledge, this is the first pilot study demonstrating the feasibility of rehabilitation using multiple exoskeleton robots. The tailor-made rehabilitation approach may be useful for the treatment of acute stroke.

Postoperative lead migration in deep brain stimulation surgery: Incidence, risk factors, and clinical impact

Introduction

Deep brain stimulation (DBS) is an effective treatment for multiple movement disorders and shows substantial promise for the treatment of some neuropsychiatric and other disorders of brain neurocircuitry. Optimal neuroanatomical lead position is a critical determinant of clinical outcomes in DBS surgery. Lead migration, defined as an unintended post-operative displacement of the DBS lead, has been previously reported. Despite several reports, however, there have been no systematic investigations of this issue. This study aimed to: 1) quantify the incidence of lead migration in a large series of DBS patients, 2) identify potential risk factors contributing to DBS lead migration, and 3) investigate the practical importance of this complication by correlating its occurrence with clinical outcomes.

Methods

A database of all DBS procedures performed at UF was queried for patients who had undergone multiple post-operative DBS lead localization imaging studies separated by at least two months. Bilateral DBS implantation has commonly been performed as a staged procedure at UF, with an interval of six or more months between sides. To localize the position of each DBS lead, a head CT is acquired ~4 weeks after lead implantation and fused to the pre-operative targeting MRI. The fused targeting images (MR + stereotactic CT) acquired in preparation for the delayed second side lead implantation provide an opportunity to repeat the localization of the first implanted lead. This paradigm offers an ideal patient population for the study of delayed DBS lead migration because it provides a large cohort of patients with localization of the same implanted DBS lead at two time points. The position of the tip of each implanted DBS lead was measured on both the initial post-operative lead localization CT and the delayed CT. Lead tip displacement, intracranial lead length, and ventricular indices were collected and analyzed. Clinical outcomes were characterized with validated rating scales for all cases, and a comparison was made between outcomes of cases with lead migration versus those where migration of the lead did not occur.

Results

Data from 138 leads in 132 patients with initial and delayed lead localization CT scans were analyzed. The mean distance between initial and delayed DBS lead tip position was 2.2 mm and the mean change in intracranial lead length was 0.45 mm. Significant delayed migration (>3 mm) was observed in 17 leads in 16 patients (12.3% of leads, 12.1% of patients). Factors associated with lead migration were: technical error, repetitive dystonic head movement, and twiddler’s syndrome. Outcomes were worse in dystonia patients with lead migration (p = 0.035). In the PD group, worse clinical outcomes trended in cases with lead migration.

Conclusions

Over 10% of DBS leads in this large single center cohort were displaced by greater than 3 mm on delayed measurement, adversely affecting outcomes. Multiple risk factors emerged, including technical error during implantation of the DBS pulse generator and failure of lead fixation at the burr hole site. We hypothesize that a change in surgical technique and a more effective lead fixation device might mitigate this problem.

Analysis of Evolving Clinicopathological Features of Metastatic Brain Tumors Over 30 Years of Surgical Management

We reviewed 232 cases, in which patients underwent surgical resection and histopathological diagnosis of metastatic brain tumor between 1985 and 2014. We analyzed trends in clinicopathological changes present over three decades in a single institution. The most frequent site of metastatic tumors was the frontal lobe. The average patient age and the percentage of female patients increased over the 30-year study period. The most frequent primary cancer was lung cancer, followed by breast cancer; these were the top two primary cancer types over the three decades. However, use of chemotherapy and radiotherapy as standard treatments for postoperative treatment of metastatic brain tumors has increased over the past 20 years. Development of novel, targeted treatments for these cancer types have created new tools for use in the clinical care of patients with metastatic brain tumors. Incorporation of these tools in a multimodal approach is critical in contemporary management of metastatic brain tumors.

Contralateral Cerebral Hypometabolism After Cerebellar Stroke: A Functional Near-Infrared Spectroscopy Study

INTRODUCTION

We report the changes in cortical activity evaluated using functional near-infrared spectroscopy (fNIRS) in 2 cases with cerebellar stroke.

METHODS

Using an fNIRS imaging system, changes in the oxygenated hemoglobin concentration (ΔOxy-Hb) from baseline were estimated. Design and verbal fluency tasks were conducted for evaluation of visuospatial and language functions, respectively.

RESULTS

The contralateral prefrontal area showed limited activation compared with the ipsilateral one in the case with either cerebellar stroke.

CONCLUSIONS

A negative impact of cerebellar stroke on the multimodal association of cortex, regardless of the type of stroke (infarct or hemorrhage).

Combined therapy using botulinum toxin A and single-joint hybrid assistive limb for upper-limb disability due to spastic hemiplegia

We investigated the combination of robot-assisted rehabilitation (RT) using a single-joint hybrid assistive limb (HAL-SJ) and botulinum toxin A (BTX-A) as therapy for paretic arm with spasticity in post-stroke patients. Participants were seven patients (4 females, 3 males; mean (±SD) age: 60.6±8.4years) who had spastic hemiplegia following chronic stroke. On the day following BTX-A injection, we started RT, which was performed for 20 sessions of 60min each over a two-week period. Clinical outcome measures, including Fugl-Meyer Assessment (FMA), Motor Activity Log (MAL), and Disability Assessment Scale (DAS), and cortical activity were evaluated at baseline, and two weeks, and four months following BTX-A injection. Cortical activity associated with elbow joint movement of the affected arm was assessed via functional near infrared spectroscopy (fNIRS). FMA, MAL, and DAS scores significantly improved at two weeks and four months (p<0.05), except DAS scores at four months (p=0.068). The fNIRS study showed that cortical activation increased in the ipsilesional primary sensorimotor area at two weeks and at the four months follow-up. Our pilot study showed that the combination of RT and BTX-A therapy was an effective approach for treating spastic hemiplegia due to stroke, and functional imaging study showed neuroplasticity induced by the treatment.

Changes in Motor-Related Cortical Activity Following Deep Brain Stimulation for Parkinson's Disease Detected by Functional Near Infrared Spectroscopy: A Pilot Study

It remains unclear how deep brain stimulation (DBS) modulates the global neuronal network involving cortical activity. We aimed to evaluate changes in cortical activity in six (two men; four women) patients with Parkinson’s disease (PD) who underwent unilateral globus pallidus interna (GPI) DBS surgery using a multi-channel near infrared spectroscopy (NIRS) system. As five of the patients were right-handed, DBS was performed on the left in these five cases. The mean age was 66.8 ± 4.0 years. The unified Parkinson’s disease rating scale (UPDRS) motor scores were evaluated at baseline and 1- and 6-month follow-up. Task-related NIRS experiments applying the block design were performed at baseline and 1-month follow-up. The mean of the total UPDRS motor score was 48.5 ± 11.1 in the off-medication state preoperatively. Postoperatively, total UPDRS motor scores improved to 26.8 ± 16.6 (p < 0.05) and 22.2 ± 8.6 (p < 0.05) at 1- and 6-month follow-up, respectively. A task-related NIRS experiment showed a postoperative increase in the cortical activity of the prefrontal cortex comparable to the preoperative state. To our knowledge, this is the first study to use a multi-channel NIRS system for PD patients treated with DBS. In this pilot study, we showed changes in motor-associated cortical activities following DBS surgery. Therapeutic DBS was concluded to have promoted the underlying neuronal network remodeling.

Synthesis and Characterization of Poly(Propylene Imine)-Based Liquid Crystalline Dendrimers

Poly(propylene imine)-based liquid crystalline dendrimers (PPILCDs) with a relatively flexible dendritic scaffold were successfully synthesized by reaction of poly(propylene imine) dendrimers with 4′-cyanobiphenyl hydrogen glutarate in the presence of condensing agent, diphenyl(2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate. The structures of PPILCDs were characterized by IR, 1H NMR and MALDI-TOF mass spectroscopies and elemental analysis. These LCDs did not show a thermotropic liquid crystalline nature, but exhibited the liquid crystalline textures in the samples sheared at 70 °C. Furthermore, they showed a lyotropic liquid crystalline property in the 80 wt% DMF solutions.

Delayed Onset Eye Opening Apraxia due to Progression of Brain Atrophy following Subthalamic Nucleus Deep Brain Stimulation: A Case Report

Eye opening apraxia (EOA) has been described in literature as a complication of deep brain stimulation (DBS), especially after electrode implantation in the subthalamic nucleus (STN). EOA can be either worsened or alleviated by DBS depending on the etiology. Herein, we report a rare case where the progression of brain atrophy may have contributed to the delayed onset of EOA. The patient, a 73-year-old woman, had previously undergone bilateral STN-DBS for advanced Parkinson’s disease (PD), which was performed by another DBS team, at the age of 68 years. She initially experienced a dramatic improvement in her motor symptoms, with no adverse events. However, she had difficulty in opening her right eye 3 years after the DBS surgery. Imaging studies showed that the brain atrophy had progressed over the past 5 years, and that the DBS electrodes were implanted through the far anterior entry points. We considered that the relative movement of the DBS might have been caused by the progression of the brain atrophy to the posterior limb of the internal capsule (IC) where the corticobulbar tract exists, and this was enhanced by the lower implantation angle. The present case illustrates the importance of the DBS insertion angle considering the a+ trophic effect and the follow-up imaging studies after DBS.

Interactive Bio-feedback Therapy Using Hybrid Assistive Limbs for Motor Recovery after Stroke: Current Practice and Future Perspectives

Interactive bio-feedback (iBF) was initially developed for the rehabilitation of motor function in patients with neurological disorders, and subsequently yielded the development of the hybrid assistive limb (HAL). Here, we provide a review of the theory underlying HAL treatment as well as our clinical experience and recommendations for future clinical studies using HAL in acute stroke patients. We performed a PubMed-based literature search, a retrospective data review of our acute stroke case series, and included a sample case report of our findings. Given past animal studies and functional imaging results, iBF therapy using the HAL in the acute phase of stroke seems an appropriate approach for preventing learned non-use and interhemispheric excitation imbalances. iBF therapy may furthermore promote appropriate neuronal network reorganization. Based on experiences in our stroke center, HAL rehabilitation is a safe and effective treatment modality for recovering motor impairments after acute stroke, and allows the design of tailored rehabilitation programs for individual patients. iBF therapy through the HAL system seems to be an effective and promising approach to stroke rehabilitation; however, the superiority of this treatment to conventional rehabilitation remains unclear. Further clinical studies are warranted. Additionally, the formation of a patient registry will permit a meta-analysis of HAL cases and address the problems associated with a controlled trial (e.g., the heterogeneity of an acute stroke cohort). The development of robotic engineering will improve the efficacy of HAL rehabilitation and has the potential to standardize patient rehabilitation practice.

Feasibility of rehabilitation using the single-joint hybrid assistive limb to facilitate early recovery following total knee arthroplasty: A pilot study

We aimed to evaluate the feasibility of robot-assisted rehabilitation in an early postoperative setting to improve knee mobility following total knee arthroplasty (TKA). A total of 20 patients were alternatively assigned to robotassisted rehabilitation (n = 10; all women) or a control group (n = 10; 2 men and 8 women). The use of a single-joint hybrid assistive limb (HAL-SJ) in active assistive knee exercise was performed for the robot-assisted rehabilitation group while the control patients underwent conventional active assistive knee exercise. We measured the extension lag (defined as the difference between active and passive range of knee extension). We also evaluated the visual analog scale score (VAS) during active movements and active assistive movement. Concerning the extension lag, the robot-assisted rehabilitation group showed 89.4% ± 15.7% improvement (p < 0.01) while the control group showed 34.8% ± 32.1% improvement (p = 0.016). As to the VAS, the robot-assisted rehabilitation group showed 40.7% ± 23.5% improvement while the control group showed 20.4% ± 25.8% improvement (p < 0.01). The use of HAL-SJ may facilitate early recovery from knee surgery and prevent long-term complications such as quadriceps arthrogenic muscle inhibition.

Brain Stimulation Therapy for Central Post-Stroke Pain from a Perspective of Interhemispheric Neural Network Remodeling

Central post-stroke pain (CPSP) is a debilitating, severe disorder affecting patient quality of life. Since CPSP is refractory to medication, various treatment modalities have been tried with marginal results. Following the first report of epidural motor cortex (M1) stimulation (MCS) for CPSP, many researchers have investigated the mechanisms of electrical stimulation of the M1. CPSP is currently considered to be a maladapted network reorganization problem following stroke, and recent studies have revealed that the activities of the impaired hemisphere after stroke may be inhibited by the contralesional hemisphere. Even though this interhemispheric inhibition (IHI) theory was originally proposed to explain the motor recovery process in stroke patients, we considered that IHI may also contribute to the CPSP mechanism. Based on the IHI theory and the fact that electrical stimulation of the M1 suppresses CPSP, we hypothesized that the inhibitory signals from the contralesional hemisphere may suppress the activities of the M1 in the ipsilesional hemisphere, and therefore pain suppression mechanisms may be malfunctioning in CPSP patients. In this context, transcranial direct current stimulation (tDCS) was considered to be a reasonable procedure to address the interhemispheric imbalance, as the bilateral M1 can be simultaneously stimulated using an anode (excitatory) and cathode (inhibitory). In this article, we review the potential mechanisms and propose a new model of CPSP. We also report two cases where CPSP was addressed with tDCS, discuss the potential roles of tDCS in the treatment of CPSP, and make recommendations for future studies.

Observation of laser-induced electronic structure in oriented polyatomic molecules

All attosecond time-resolved measurements have so far relied on the use of intense near-infrared laser pulses. In particular, attosecond streaking, laser-induced electron diffraction and high-harmonic generation all make use of non-perturbative light-matter interactions. Remarkably, the effect of the strong laser field on the studied sample has often been neglected in previous studies. Here we use high-harmonic spectroscopy to measure laser-induced modifications of the electronic structure of molecules. We study high-harmonic spectra of spatially oriented CH3F and CH3Br as generic examples of polar polyatomic molecules. We accurately measure intensity ratios of even and odd-harmonic orders, and of the emission from aligned and unaligned molecules. We show that these robust observables reveal a substantial modification of the molecular electronic structure by the external laser field. Our insights offer new challenges and opportunities for a range of emerging strong-field attosecond spectroscopies.

Microsurgical anatomy of subtotal temporal bone resection en bloc with the parotid gland and temporomandibular joint

BACKGROUND

Subtotal temporal bone resection (STBR) has been used for half a century to remove temporal bone malignancies. However, there are few reports on the detailed anatomy involved in the resection.

OBJECTIVE

To describe the microsurgical anatomy of STBR combined en bloc with the resection of the parotid gland and temporomandibular joint (TMJ).

METHODS

Cadaveric specimens were dissected in a stepwise manner using 3× to 40× magnification.

RESULTS

STBR can be combined with the total parotidectomy and the resection of the TMJ if the tumor extends into the parotid gland, TMJ, or facial nerve. In this study, we describe the step-by-step microsurgical anatomy of STBR en bloc with the parotid gland and TMJ. The surgical technique described combines 3 approaches: the high cervical, subtemporal-infratemporal fossa, and retromastoid-paracondylar approaches. Combining these 3 approaches aided in efficiently completing this modified approach.

CONCLUSION

STBR is a complicated and technically challenging procedure. This study highlights the importance of understanding the surgical anatomy of STBR and will serve as a catalyst for improvement of the surgical technique for temporal bone resection.

Smile without euphoria induced by deep brain stimulation: a case report

Poststroke central pain (PSCP) can be a debilitating medication-refractory disorder. We report a single case where right unilateral ventral capsule/ventral striatum (VC/VS) deep brain stimulation was used to treat PSCP and inadvertently induced a smile without euphoria. The patient was a 69 year-old woman who had a stroke with resultant dysesthesia and allodynia in her left hemibody and also a painful left hemibody dystonia. In her case, VC/VS stimulation induced a smile phenomenon, but without a euphoric sensation. This phenomenon was different from the typical smile responses we have observed in obsessive-compulsive disorder cases. This difference was considered to be possibly attributable to impairment in the emotional smile pathway.

Atrophy and other potential factors affecting long term deep brain stimulation response: a case series

OBJECTIVE

To describe three DBS cases which presented with new side effects or loss of benefit from stimulation after long-term follow-up and to discuss the potential contributing factors.

METHODS

A University of Florida (UF) database (INFORM) search was performed, identifying three patients, two Parkinson's disease (PD) and one Essential Tremor (ET), with an unexpected change in long-term programming thresholds as compared to initial evaluation. Clinical follow-up, programming, imaging studies, and lead measurements were reviewed. The UF Institutional Review Board (IRB) approved this study.

RESULTS

A substantial increase in the 3rd ventricular width (120%), Evans index (6%), ventricular index (5%), and cella media index (17%) was uncovered. A change in thresholds across lead contacts with a decrease in current densities as well as a relative lateral change of lead location was also observed. Hardware-related complications, lead migration, and impedance variability were not identified.

CONCLUSIONS

Potential factors contributing to long-term side effects should be examined during a DBS troubleshooting assessment. Clinicians should be aware that in DBS therapy there is delivery of electricity to a changing brain, and atrophy may possibly affect DBS programming settings as part of long-term follow-up.

Surgical anatomy of endoscope-assisted approaches to common aneurysm sites

BACKGROUND

The endoscope is being introduced as an adjuvant to improve visualization of certain areas in open cranial surgery.

OBJECTIVE

To describe the endoscopic anatomy of common aneurysm sites and to compare it with the microsurgical anatomy.

METHODS

Pterional, anterior interhemispheric, and subtemporal approaches to the most common aneurysm sites were examined in cadaveric heads under the surgical microscope and with the endoscope.

RESULTS

The endoscopic view, particularly with the angled endoscopes, provides a significant improvement compared with the microscopic view, especially for poorly visualized sites such as the medial aspect of the supraclinoid carotid artery and its branches, the area below the anterior perforated substance and optic tract, and the carotid and basilar bifurcations. The endoscope aided in the early visualization of perforating branches at each aneurysm site except the middle cerebral artery. Small-diameter optics (2.7 mm) provided greater space for dissection and less potential for tissue damage in narrow places, whereas the larger 4-mm diameter optics provided better visualization and less panoramic distortion. The positioning of the endoscope for each aneurysm site is reviewed.

CONCLUSION

The endoscope provides views that complement or improve the microscopic view at each aneurysm site except the middle cerebral artery. Endoscopy training and a thorough knowledge of endoscopic vascular anatomy are essential to safely introduce endoscopic assistance in vascular surgery.

Deep brain stimulation for treatment-resistant depression: systematic review of clinical outcomes

Major depressive disorder (MDD) is a widespread, severe, debilitating disorder that markedly diminishes quality of life. Medication is commonly effective, but 20-30 % of patients are refractory to medical therapy. The surgical treatment of psychiatric disorders has a negative stigma associated with it owing to historical abuses. Various ablative surgeries for MDD have been attempted with marginal success, but these studies lacked standardized outcome measures. The recent development of neuromodulation therapy, especially deep brain stimulation (DBS), has enabled controlled studies with sham stimulation and presents a potential therapeutic option that is both reversible and adjustable. We performed a systematic review of the literature pertaining to DBS for treatment-resistant depression to evaluate the safety and efficacy of this procedure. We included only studies using validated outcome measures. Our review identified 22 clinical research papers with 5 unique DBS approaches using different targets, including nucleus accumbens, ventral striatum/ventral capsule, subgenual cingulate cortex, lateral habenula, inferior thalamic nucleus, and medial forebrain bundle. Among the 22 published studies, only 3 were controlled trials, and 2, as yet unpublished, multicenter, randomized, controlled trials evaluating the efficacy of subgenual cingulate cortex and ventral striatum/ventral capsule DBS were recently discontinued owing to inefficacy based on futility analyses. Overall, the published response rate to DBS therapy, defined as the percentage of patients with > 50 % improvement on the Hamilton Depression Rating Scale, is reported to be 40-70 %, and outcomes were comparable across studies. We conclude that DBS for MDD shows promise, but remains experimental and further accumulation of data is warranted.

Coordinate-based lead location does not predict Parkinson's disease deep brain stimulation outcome

Background

Effective target regions for deep brain stimulation (DBS) in Parkinson's disease (PD) have been well characterized. We sought to study whether the measured Cartesian coordinates of an implanted DBS lead are predictive of motor outcome(s). We tested the hypothesis that the position and trajectory of the DBS lead relative to the mid-commissural point (MCP) are significant predictors of clinical outcomes. We expected that due to neuroanatomical variation among individuals, a simple measure of the position of the DBS lead relative to MCP (commonly used in clinical practice) may not be a reliable predictor of clinical outcomes when utilized alone.

Methods

55 PD subjects implanted with subthalamic nucleus (STN) DBS and 41 subjects implanted with globus pallidus internus (GPi) DBS were included. Lead locations in AC-PC space (x, y, z coordinates of the active contact and sagittal and coronal entry angles) measured on high-resolution CT-MRI fused images, and motor outcomes (Unified Parkinson's Disease Rating Scale) were analyzed to confirm or refute a correlation between coordinate-based lead locations and DBS motor outcomes.

Results

Coordinate-based lead locations were not a significant predictor of change in UPDRS III motor scores when comparing pre- versus post-operative values. The only potentially significant individual predictor of change in UPDRS motor scores was the antero-posterior coordinate of the GPi lead (more anterior lead locations resulted in a worse outcome), but this was only a statistical trend (p<.082).

Conclusion

The results of the study showed that a simple measure of the position of the DBS lead relative to the MCP is not significantly correlated with PD motor outcomes, presumably because this method fails to account for individual neuroanatomical variability. However, there is broad agreement that motor outcomes depend strongly on lead location. The results suggest the need for more detailed identification of stimulation location relative to anatomical targets.

Swallowing outcomes following unilateral STN vs. GPi surgery: a retrospective analysis

The adverse effects of deep brain stimulation (DBS) surgery on swallowing could potentially exacerbate the natural deterioration of airway protection associated with Parkinson's disease (PD) degeneration and increase the incidence of aspiration pneumonia and associated death. There are no studies that compare swallowing outcomes associated with subthalamic nucleus (STN) versus globus pallidus interna (GPi) DBS surgery; therefore, we completed a retrospective study comparing swallowing outcomes in a cohort of patients with PD who underwent unilateral DBS surgery in either the STN or GPi. A chart review was completed to identify all patients with a diagnosis of PD who received videofluoroscopic swallowing evaluations before DBS and after unilateral DBS in the STN or GPi. The retrospective search yielded 33 patients (STN = 14, GPi = 19) with idiopathic PD who met the inclusion criteria. Mean penetration-aspiration (PA) scores did not change significantly for participants who underwent GPi surgery (z = -.181, p = .857), but mean PA scores significantly worsened for participants who underwent STN DBS (z = -2.682, p = .007). There was a significant improvement in Unified PD Rating Scale (UPDRS) scores off medication before surgery, to off medication and on stimulation after surgery for both groups (F = 23.667, p < .001). Despite the limitations of a retrospective analysis, this preliminary study suggests that unilateral STN DBS may have an adverse effect on swallowing function, while unilateral GPi DBS does not appear to have a similar deleterious effect. This study and other future studies should help to elucidate the mechanisms underpinning the effects of DBS on swallowing function.

Surgical neuroanatomy and programming in deep brain stimulation for obsessive compulsive disorder

OBJECTIVES

Deep brain stimulation (DBS) has been established as a safe, effective therapy for movement disorders (Parkinson's disease, essential tremor, etc.), and its application is expanding to the treatment of other intractable neuropsychiatric disorders including depression and obsessive-compulsive disorder (OCD). Several published studies have supported the efficacy of DBS for severely debilitating OCD. However, questions remain regarding the optimal anatomic target and the lack of a bedside programming paradigm for OCD DBS. Management of OCD DBS can be highly variable and is typically guided by each center's individual expertise. In this paper, we review the various approaches to targeting and programming for OCD DBS. We also review the clinical experience for each proposed target and discuss the relevant neuroanatomy.

MATERIALS AND METHODS

A PubMed review was performed searching for literature on OCD DBS and included all articles published before March 2012. We included all available studies with a clear description of the anatomic targets, programming details, and the outcomes.

RESULTS

Six different DBS approaches were identified. High-frequency stimulation with high voltage was applied in most cases, and predictive factors for favorable outcomes were discussed in the literature.

CONCLUSION

DBS remains an experimental treatment for medication refractory OCD. Target selection and programming paradigms are not yet standardized, though an improved understanding of the relationship between the DBS lead and the surrounding neuroanatomic structures will aid in the selection of targets and the approach to programming. We propose to form a registry to track OCD DBS cases for future clinical study design.

Unilateral thalamic deep brain stimulation in essential tremor demonstrates long-term ipsilateral effects

INTRODUCTION

Deep Brain Stimulation (DBS) of thalamus in essential tremor (ET) is effective for the treatment of contralateral tremors. Bilateral DBS controls tremors on both sides but is associated with increased morbidity and risks. We evaluated if unilateral surgery had ipsilateral benefits on tremors and thus could be a potentially safer alternative to bilateral DBS.

METHODS

Medication refractory ET patients undergoing unilateral thalamic DBS were included and longitudinally followed. Tremor rating scale was used to record total motor, arm tremor and activities of daily living (ADL) scores at baseline, six months and at last visit (three or more years after surgery). Postoperative scores were recorded with DBS turned OFF and ON.

RESULTS

Twenty-two patients with a mean follow-up 3.4 ± 0.14 years were enrolled. When baseline scores were compared to scores with the DBS turned ON, significant improvements were noted in total tremor (40%), ADL (67%) and arm tremor scores both on the ipsilateral and the contralateral side at six months and at the last visit of follow-up (all p < 0.05). Ipsilateral arm tremor (∼56%) improvements were milder compared to the contralateral side (∼73%) tremors.

CONCLUSION

Unilateral thalamic DBS in ET demonstrates significant long-term benefits for ipsilateral arm tremors and can be offered to higher risk and to select patients.

Chronological changes in astrocytes induced by chronic electrical sensorimotor cortex stimulation in rats

Motor cortex stimulation (MCS) is a treatment option for various disorders such as medically refractory pain, poststroke hemiplegia, and movement disorders. However, the exact mechanisms underlying its effects remain unknown. In this study, the effects of long-term chronic MCS were investigated by observing changes in astrocytes. A quadripolar stimulation electrode was implanted on the dura over the sensorimotor cortex of adult rats, and the cortex was continuously stimulated for 3 hours, 1 week, 4 weeks, and 8 weeks. Immunohistochemical staining of microglia (ionized calcium-binding adaptor molecule 1 [Iba1] staining) and astrocytes (glial fibrillary acidic protein [GFAP] staining), and neuronal degeneration histochemistry (Fluoro-Jade B staining) were carried out to investigate the morphological changes following long-term chronic MCS. Iba1 staining and Fluoro-Jade B staining showed no evidence of Iba1-positive microglial changes or neurodegeneration. Following continuous MCS, GFAP-positive astrocytes were enlarged and their number increased in the cortex and the thalamus of the stimulated hemisphere. These findings indicate that chronic electrical stimulation can continuously activate astrocytes and result in morphological and quantitative changes. These changes may be involved in the mechanisms underlying the neuroplasticity effect induced by MCS.