Fornix deep brain stimulation circuit effect is dependent on major excitatory transmission via the nucleus accumbens.

INTRODUCTION: Deep brain stimulation (DBS) is a circuit-based treatment shown to relieve symptoms from multiple neurologic and neuropsychiatric disorders. In order to treat the memory deficit associated with Alzheimer's disease (AD), several clinical trials have tested the efficacy of DBS near the fornix. Early results from these studies indicated that patients who received fornix DBS experienced an improvement in memory and quality of life, yet the mechanisms behind this effect remain controversial. It is known that transmission between the medial limbic and corticolimbic circuits plays an integral role in declarative memory, and dysfunction at the circuit level results in various forms of dementia, including AD. Here, we aimed to determine the potential underlying mechanism of fornix DBS by examining the functional circuitry and brain structures engaged by fornix DBS. METHODS: A multimodal approach was employed to examine global and local temporal changes that occur in an anesthetized swine model of fornix DBS. Changes in global functional activity were measured by functional MRI (fMRI), and local neurochemical changes were monitored by fast scan cyclic voltammetry (FSCV) during electrical stimulation of the fornix. Additionally, intracranial microinfusions into the nucleus accumbens (NAc) were performed to investigate the global activity changes that occur with dopamine and glutamate receptor-specific antagonism. RESULTS: Hemodynamic responses in both medial limbic and corticolimbic circuits measured by fMRI were induced by fornix DBS. Additionally, fornix DBS resulted in increases in dopamine oxidation current (corresponding to dopamine efflux) monitored by FSCV in the NAc. Finally, fornix DBS-evoked hemodynamic responses in the amygdala and hippocampus decreased following dopamine and glutamate receptor antagonism in the NAc. CONCLUSIONS: The present findings suggest that fornix DBS modulates dopamine release on presynaptic dopaminergic terminals in the NAc, involving excitatory glutamatergic input, and that the medial limbic and corticolimbic circuits interact in a functional loop.

Fractionated stereotactic radiotherapy using Novalis for confined intra-orbital optic nerve glioma in pediatric patient.

INTRODUCTION: Optic gliomas are the most common tumors in the optic pathways during childhood. Among them, about 10 % are located within intra-orbital cavity. However, the optimal management for intra-orbital optic nerve gliomas remains controversial. An 11-year-old male complained about progressive decline of vision in his right eye. Brain MRI revealed a fusiform enlargement of right optic nerve within intra-orbital cavity. MATERIALS AND METHODS: A presumptive diagnosis of optic nerve glioma was made. Therefore, we performed fractionated stereotactic radiotherapy (FSRT) using Novalis. DISCUSSION: Five years after FSRT treatment, follow-up MRI revealed size reduction of tumor and visual acuity improvement without radiation-related complications.

An intracranial malignant solitary fibrous tumor.

Intracranial malignant solitary fibrous tumor (SFT) is very rare. It was identified in a 39-year-old female patient who underwent malignant transformation over 6 months. MRI revealed an 8 × 5 × 6 cm mass with heterogenous strong enhancement in the left occipital lobe. Histologic findings and immunophenotype (positive for CD34, bcl-2 and vimentin, and negative for epithelial membrane antigen or S100 protein) of the primary tumor were typical of SFT. However, there was a focal area (<10% of tumor volume) showing hypercellularity, nuclear pleomorphism and increased Ki-67 labeling index (LI) of 10% (average, 1%). At the second operation, the recurrent tumor revealed full-blown histologic features of malignant SFT, such as infiltrative brain invasion, marked nuclear pleomorphism, frequent mitotic figures (15/10 high power fields), and high Ki-67 LI (25%). The presence of atypical histologic finding or increased Ki-67 LI in the typical SFT, although it is focal, needs to be mentioned in the diagnosis and also may require more aggressive surgical management.

Colonic mucosal necrosis following administration of calcium polystryrene sulfonate (Kalimate) in a uremic patient.

Colonic necrosis is known as a rare complication following the administration of Kayexalate (sodium polystryrene sulfonate) in sorbitol. We report a rare case of colonic mucosal necrosis following Kalimate (calcium polystryrene sulfonate), an analogue of Kayexalate without sorbitol in a 34-yr-old man. He had a history of hypertension and uremia. During the management of intracranial hemorrhage, hyperkalemia developed. Kalimate was administered orally and as an enema suspended in 20% dextrose water to treat hyperkalemia. Two days after administration of Kalimate enema, he had profuse hematochezia, and a sigmoidoscopy showed diffuse colonic mucosal necrosis in the rectum and sigmoid colon. Microscopic examination of random colonic biopsies by two consecutive sigmoidoscopies revealed angulated crystals with a characteristic crystalline mosaic pattern on the ulcerated mucosa, which were consistent with Kayexalate crystals. Hematochezia subsided with conservative treatment after a discontinuance of Kalimate administration.

Phenytoin versus levetiracetam as prophylaxis for postcraniotomy seizure in patients with no history of seizures: systematic review and meta-analysis.

OBJECTIVEDe novo seizure following craniotomy (DSC) for nontraumatic pathology may adversely affect medical and neurological outcomes in patients with no history of seizures who have undergone craniotomies. Antiepileptic drugs (AEDs) are commonly used prophylactically in patients undergoing craniotomy; however, evidence supporting this practice is limited and mixed. The authors aimed to collate the available evidence on the efficacy and tolerability of levetiracetam monotherapy and compare it with that of the classic AED, phenytoin, for DSC.METHODSPubMed, Embase, Web of Science, and the Cochrane Library were searched for studies that compared levetiracetam with phenytoin for DSC prevention. Inclusion criteria were adult patients with no history of epilepsy who underwent craniotomy with prophylactic usage of phenytoin, a comparator group with levetiracetam treatment as the main treatment difference between the two groups, and availability of data on the numbers of patients and seizures for each group. Patients with brain injury and previous seizure history were excluded. DSC occurrence and adverse drug reaction (ADR) were evaluated. Seizure occurrence was calculated using the Peto odds ratio (POR), which is the relative effect estimation method of choice for binary data with rare events.RESULTSData from 7 studies involving 803 patients were included. The DSC occurrence rate was 1.26% (4/318) in the levetiracetam cohort and 6.60% (32/485) in the phenytoin cohort. Meta-analysis showed that levetiracetam is significantly superior to phenytoin for DSC prevention (POR 0.233, 95% confidence interval [CI] 0.117-0.462, p < 0.001). Subgroup analysis demonstrated that levetiracetam is superior to phenytoin for DSC due to all brain diseases (POR 0.129, 95% CI 0.039-0.423, p = 0.001) and tumor (POR 0.282, 95% CI 0.117-0.678, p = 0.005). ADRs in the levetiracetam group were cognitive disturbance, thrombophlebitis, irritability, lethargy, tiredness, and asthenia, whereas rash, anaphylaxis, arrhythmia, and hyponatremia were more common in the phenytoin group. The overall occurrence of ADR in the phenytoin (34/466) and levetiracetam (26/432) groups (p = 0.44) demonstrated no statistically significant difference in ADR occurrence. However, the discontinuation rate of AEDs due to ADR was 53/297 in the phenytoin group and 6/196 in the levetiracetam group (POR 0.266, 95% CI 0.137-0.518, p < 0.001).CONCLUSIONSLevetiracetam is superior to phenytoin for DSC prevention for nontraumatic pathology and has fewer serious ADRs that lead to discontinuation. Further high-quality studies that compare levetiracetam with placebo are necessary to provide evidence for establishing AED guidelines.

High-degree centrum semiovale-perivascular spaces are associated with development of subdural fluid in mild traumatic brain injury.

BACKGROUND: Severe centrum semiovale perivascular spaces (CSO-PVSs) are associated with the onset of brain atrophy and dementia. This study explored the relationship between severity of CSO-PVS and development of subdural fluid (SDF) in patients with mild traumatic brain injury (TBI), with the aim of investigating independent radiological risk factors for development of SDF. METHODS: The study cohort comprised 222 patients with a mean age of 51 years (64.0% men) who presented with mild TBI from January 2013 to November 2016. In this study, mild TBI was defined as a Glasgow Coma Scale (GCS) of ≥ 13, Post-Traumatic Amnesia (PTA) of <1 day, and Loss of Consciousness (LOC) of <30 minutes. The severity of CSO-PVS was categorized as low or high-degree. RESULTS: Among the 222 enrolled patients, 38 (17.1%) and 90 (40.5%) had high-degree PVS in the basal ganglia (BG) and centrum semiovale, respectively. Compared with patients who did not develop SDF, the mean age of patients who developed SDF was significantly higher (47.41 years versus 60.33 years, P < 0.0001). The incidence of de novo SDF was significantly higher in men than in women (77.8% versus 59.5%, P = 0.0151). Patients who showed SDF on brain computed tomography at admission more frequently developed de novo SDF (68.5% versus 38.1%, P < 0.0001). In multivariate logistic regression analysis of risk factors, high-degree CSO-PVS, male sex, initial SDF on admission, and old age were independently associated with development of de novo SDF after mild TBI. In Cox proportional hazards models of risk factors for SDF-development free survival rate, high-degree CSO-PVS, old age, and initial subdural hemorrhage showed statistically significant differences. CONCLUSIONS: Our study might help neurosurgeons determine the frequency of brain CT or the duration of follow-up for patients who present with mild TBI with high-degree CSO-PVS.

Extraneural metastases of anaplastic oligodendroglioma.

Extraneural metastases from primary central nervous system (CNS) tumors are unusual, and glioblastomas and medulloblastomas constitute the majority of these. That oligodendroglioma frequently seeds within the CNS is well known. However, extraneural metastases of anaplastic oligodendroglioma are rare. We report a 50-year-old woman who developed multiple lung and liver metastases 28 months after resection of a temporal lobe anaplastic oligodendroglioma.

The Prevalence and Characterization of Cerebral Microbleeds in Young People Having Intracerebral Hemorrhage.

OBJECTIVE: Cerebral microbleeds (CMBs) are known as the neuroimaging markers of risk in stroke and dementia. Many studies on CMBs in elderly patients with hemorrhagic or ischemic stroke have been reported; however, reports on CMBs in young populations with intracerebral hemorrhage (ICH) are lacking. MATERIALS AND METHODS: A total of 272 patients aged 18-54 years presented to our hospital with ICH between December 2009 and August 2017. Among these, CMB presence, count, and topography with respect to ICH were evaluated on magnetic resonance imaging (MRI) gradient echo images (GREs). We also evaluated the prevalence and risk factors of CMBs. RESULTS: Among 272 patients, only 66 underwent GRE T2-weighted MRI. CMBs were detected in 40 patients (61%), with 29 (73%) being of the multifocal type. Among the 219 CMBs, 150 (68.5%) were of the deep type and 69 (31.5%) of the lobar type. CMB prevalence was higher in men. In multivariate logistic regression analysis, history of hypertension (adjusted odds ratio [aOR], 4.048; 95% confidence interval [CI], 1.14-14.32; p = 0.030), and male sex (aOR, 4.233; 95% CI, 1.09-16.48; p = 0.037) were independently associated with CMBs. CONCLUSION: In young patients who presented with spontaneous ICH, CMBs were highly prevalent in 61% of patients and strongly associated with history of hypertension and male sex.

Extracranial metastases of a supratentorial primitive neuroectodermal tumour.

Extracranial metastases from primary central nervous system (CNS) tumours have rarely been reported in the literature, and glioblastomas and medulloblastomas constitute the majority of these. The tendency of supratentorial primitive neuroectodermal tumours (PNET) to spread within the CNS is well-known, but few cases of extracranial metastases of supratentorial PNET have been reported. We report a 29-year-old man with a supratentorial PNET, which metastasized to his vertebral bodies and lung.

Delayed Burr Hole Surgery in Patients with Acute Subdural Hematoma: Clinical Analysis.

OBJECTIVE: To evaluate the effectiveness and efficacy of delayed burr hole surgery in relation to the reduction of postoperative subdural hematoma (SDH) volume in patients with acute SDH. METHODS: We retrospectively analyzed patients with acute SDH who received delayed burr hole surgery at our institute. Age, sex, Glasgow coma scale, maximal SDH thickness, volume of SDH, midline shifts, hounsfield unit (HU), and medical history of anticoagulant agent usage were recorded. Outcome measures were delayed operation day, reduction of SDH volume after operation, and the Glasgow outcome scale (GOS) score at discharge. The patients were divided two groups according to the post-operative reduction of volume of SDH (≥50%, group A; <50%, group B). We also analyzed variables and differences between two groups. RESULTS: Eighteen patients were available for this analysis. The mean delayed of surgery was 13.9±7.5 days. Maximal thickness of SDH was changed from 10.0±3.5 mm to 12.2±3.7 mm. Volume of SDH was changed from 38.7±28.0 mL to 42.6±29.6 mL. Midline shifts were changed from 5.8±3.3 mm to 6.6±3.3 mm. HU were changed from 66.4±11.2 to 53.2±20.6. Post-operative reduction of SDH volume was 52.1±21.1%. Eleven patients (61%) had a discharge GOS score of 1 (good recovery). Ten patients (56%) were enrolled in group A. Midline shifting was greater in group A than in group B (7.4±3.3 vs. 3.0±2.4 mm; p<0.02). The delay of surgery was shorter for group A than group B (9.2±2.3 vs. 19.8±7.7 days; p<0.0008). CONCLUSION: Among well selected patients, delayed burr hole surgery in patients with acute SDH may be effective for reduction of SDH volume. Further studies will be necessary to establish the effectiveness and safety of delayed burr hole surgery in patients with acute SDH.

Are There Differences in the Progression of Ossification of the Posterior Longitudinal Ligament Following Laminoplasty Versus Fusion?: A Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis of studies for the treatment of cervical myelopathy with ossification of the posterior longitudinal ligament (OPLL) treated with laminoplasty or fusion. OBJECTIVE: To delineate whether OPLL continues to progress after laminoplasty compared with fusion and to clarify the relationship between radiological progression of OPLL and neurological decline. SUMMARY OF BACKGROUND DATA: Laminoplasty is usually performed in patients with multilevel OPLL due to the surgical morbidity of anterior surgery. However, the disadvantage of laminoplasty is that the remaining OPLL can progress after the surgery. METHODS: A literature search of PubMed, Embase, Web of Science, and the Cochrane library was performed to identify investigations concerning the progression of OPLL after laminoplasty or fusion. The pooled results were analyzed by calculating the effect size based on the event rate and the logit event rate. RESULTS: We included data from 11 studies involving 530 patients, of whom 429 underwent laminoplasty and 101 underwent fusion surgery. The prevalence of radiological OPLL progression was 62.5% (95% confidence interval [CI] 55.3%-69.3%) for the laminoplasty group and 7.6% (95% CI 3.4%-15.9%) for the fusion group. The laminoplasty displayed substantially high prevalence of the progression of OPLL compared with the fusion group. In the laminoplasty group, the prevalence of OPLL progression increased with time and reached 60% at about 10-year follow-up. The prevalence for neurological decline was similar for about 2 years, 8.3% (95% CI 3.7%-17.9%) for the laminoplasty group and 3.8% (95% CI 1.3%-10.2%) for the fusion group. CONCLUSION: Laminoplasty frequently induces progression of OPLL compared with fusion surgery, but does not make significant clinical deterioration. However, laminoplasty may not be recommended for OPLL patient because it can be getting worse with time. LEVEL OF EVIDENCE: 1.

Scoliosis associated with idiopathic lumbosacral epidural lipomatosis.

There are very few reports of spinal epidural lipomatosis (SEL) in association with scoliosis. A 49-year-old man presented with persistent back pain and right hip lump. The lumbar spine X-rays showed scoliosis (Lenke classification 5BN). Lumbar MRI demonstrated circumferential epidural fat deposit from L1 to lower S2 level. There was no obvious etiology of SEL except mild increased body mass index (BMI). The patient was managed with conservative treatment. After 6 months medication (limaprost and ginkgo), his symptoms were relieved.

Prevotella brain abscess in a healthy young patient with a patent foramen ovale.

Brain abscesses are frequently caused by poly-microbial conditions. Comparatively, brain abscesses caused by Prevotella species are very rare. Right-to-left cardiac shunting due to a patent foramen ovale may predispose patients to infection. We report an isolated Prevotella brain abscess that occurred in a healthy, young, male patient with a patent foramen ovale. The patient did not have a clinically obvious odontogenic source of infection, and no other distant extracranial infectious sources were observed. The patient was successfully treated with stereotactic aspiration and antibiotics.

Efficacy of pulsed radiofrequency medial branch treatment in low back pain patients.

BACKGROUND: It was thought that the efficacy of pulsed radiofrequency (PRF) treatment of the medial branch in patients with lower back pain was not as long lasting as that of continuous radiofrequency (CRF) thermo-coagulation techniques. OBJECTIVE: The goal of this study was to determine the efficacy and the long-term effects of PRF treatment of the medial branch in selected low back pain patients. METHODS: We retrospectively reviewed and analyzed patients with lower back pain who underwent PRF treatment on the medial branch at our institute. Pain relief was evaluated by visual analog scale (VAS) score at pretreatment, 2 weeks, 6 months, 1 year and 2 years post-treatment. Oswestry disability index (ODI) score was evaluated pretreatment and at 2 years post-treatment. We also recorded the satisfaction period after PRF treatment. RESULTS: Twenty-three patients were available for the 2-year follow-up analysis. None of the patients had any side effects or procedure-related complications during the follow up period. The average VAS score declined from 7.1 ± 2.4 pre-treatment to 2.9 ± 2.1 2 weeks post-treatment, 2.6 ± 1.8 at 6 months, 2.8 ± 2.1 at 1 year and 3.0 ± 2.5 at 2 years. The average ODI score decreased from 33.6 ± 13.6 pre-treatment to 15.3 ± 5.7 at 2 years post-treatment. Mean satisfaction period after PRF treatment was 16.6 ± 9.43 months. CONCLUSION: PRF treatment on the medial branch is an effective and safe treatment option for patients with lower back pain.

Anterior Thalamic Deep Brain Stimulation: Functional Activation Patterns in a Large Animal Model.

BACKGROUND: Deep brain stimulation (DBS) of the anterior thalamic nucleus (ATN) exerts its effects by modulating neural circuits involved in seizures. However, these networks remain incompletely characterized. OBJECTIVE: Investigate the effects of ATN DBS on network activity in a large animal model using 3-T fMRI. METHODS: Anesthetized swine underwent ATN DBS using stimulation parameters applied in the Stimulation of the Anterior Thalamus for the Treatment of Epilepsy (SANTE) trial. Stimulation amplitude, frequency, and temporal paradigm were varied and the resulting blood oxygen level-dependent signal was measured. RESULTS: ATN DBS resulted in activation within temporal, prefrontal, and sensorimotor cortex. An amplitude-dependent increase in cluster volume was observed at 60 Hz and 145 Hz stimulation. CONCLUSION: ATN DBS in swine induced parameter-dependent activation in cortical regions including but not limited to the Papez circuit. These findings may hold clinical implications for treatment of epilepsy in patients with temporal or extratemporal seizure foci.

Low Grade Myofibroblastic Sarcoma Occurred in the Scalp.

Low-grade myofibroblastic sarcoma (LGMS) is a rare sarcoma with myofibroblastic differentiation. LGMS has a propensity for local recurrence and is associated with a low risk of metastatic spread. A 26-year-old man presented with a 12-month history of a slow growing palpable hard mass in the right parietal scalp. Enhanced CT scan of head showed a 3×4 cm sized well-defined and heterogeneously enhancing scalp mass. The patient underwent excision of the tumor. The histological and immunohistochemical features were consistent with a LGMS. We performed re-operation for remnant tumor removal after diagnosis. After 14 months of surgery, the patient was well-being state.

Twelve contiguous spinous process fracture of cervico-thoracic spine.

The clay-shoveler's fracture is an isolated avulsion fracture of the lower cervical or upper thoracic spinous process. Among them, multiple spinous process fractures are very rare. We present 34-year-old male patient who have multiple spinous process fractures with twelve contiguous levels of cervico-thoracic spine (from C4 to T8) after motorcycle accident. This case is multiple isolated spinous process fractures with good clinical outcome.

Spontaneous regression of cervical disc herniation: a case report.

Spontaneous regression of cervical disc herniation is a rare, and such reports are few. A 39 year-old woman complained of severe neck pain associated with tingling and numbness of right upper extremity. The MRI of the cervical spine revealed a posterior disc extrusion at the C4-C5 level in the right para-central location. The patient was treated with conservative management without any surgical treatment. The patient's symptoms were significant improvement. After two years later, we performed follow-up cervical MRI that revealed significant spontaneous regression of the C4-C5 intervertebral disc extrusion.

Microanatomy and histological features of central myelin in the root exit zone of facial nerve.

OBJECTIVE: The aim of this study was to evaluate the microanatomy and histological features of the central myelin in the root exit zone of facial nerve. METHODS: Forty facial nerves with brain stem were obtained from 20 formalin fixed cadavers. Among them 17 facial nerves were ruined during preparation and 23 root entry zone (REZ) of facial nerves could be examined. The length of medial REZ, from detach point of facial nerve at the brain stem to transitional area, and the thickness of glial membrane of central myelin was measured. We cut brain stem along the facial nerve and made a tissue block of facial nerve REZ. Each tissue block was embedded with paraffin and serially sectioned. Slices were stained with hematoxylin and eosin (H&E), periodic acid-Schiff, and glial fibrillary acid protein. Microscopy was used to measure the extent of central myelin and thickness of outer glial membrane of central myelin. Thickness of glial membrane was examined at two different points, the thickest area of proximal and distal REZ. RESULTS: Special stain with PAS and GFAP could be differentiated the central and peripheral myelin of facial nerve. The length of medial REZ was mean 2.6 mm (1.6-3.5 mm). The glial limiting membrane of brain stem is continued to the end of central myelin. We called it glial sheath of REZ. The thickness of glial sheath was mean 66.5 µm (40-110 µm) at proximal REZ and 7.4 µm (5-10 µm) at distal REZ. CONCLUSION: Medial REZ of facial nerve is mean 2.6 mm in length and covered by glial sheath continued from glial limiting membrane of brain stem. Glial sheath of central myelin tends to become thin toward transitional zone.

The efficacy of pulsed radiofrequency treatment of cervical radicular pain patients.

OBJECTIVE: Cervical radicular pain is defined as pain arising in the arm caused by irritation of a cervical spinal nerve or its roots. Although many treatment modalities are described in the literature, the available evidence for efficacy is not sufficient to allow definitive conclusions. The goal of this study was to establish the benefits and prognostic factors of pulsed radiofrequency (PRF) on the adjacent cervical dorsal root ganglia (DRG) of cervical radicular pain patients. METHODS: A retrospective study of PRF treatment of patients with cervical radicular pain was carried out. Two times diagnostic block of cervical DRG were performed before PRF. PRF was applied for 2 minutes at a setting of 2 Hz and 45 V by two times on the same targets, with the end point being an electrode tip temperature 42℃. Numerical rating scale (NRS) score was evaluated post-treatment 2 week, 1 month, 3 months and 6 months, which were compared with pretreatment value. A successful outcome was defined that NRS change was improved more than 50% at 6 months. RESULTS: The mean age was 54 years. The success rate was 68%(15/22) after six months of follow-up. PRF induced complications were not observed. Between success and failure group, we do not find any positive outcome prognostic factor. Interestingly, PRF treatment on foraminal stenosis is better outcome than herniated cervical disc. CONCLUSION: PRF on adjacent cervical DRG is effective and safe treatment option for cervical radicular pain patients. However, more long-term follow up and larger patients are needed to establish effectiveness PRF treatment on cervical radicular pain patients.