Custom shaping of distal access catheter for navigation of microcatheter into inferolateral and meningohypophyseal trunk feeders.

OBJECTIVE: Navigating a microcatheter to tiny feeding arteries such as the inferolateral trunk (ILT) and meningohypophyseal trunk (MHT) of the internal carotid artery (ICA) is technically challenging because of the anatomical features of steep angulation, small diameter, and significant caliber difference from the ICA. To guide the microcatheter to these ICA side branch feeders, the authors thought that a custom shaping of the intermediate catheter would be helpful to determine the direction of the microcatheter and strongly back it up. The aim of this study was to report the detailed methodology and clinical outcomes of patients who had undergone the embolization of ILT and MHT feeders using this method. METHODS: This was a retrospective study of consecutive patients with intracranial tumors and dural arteriovenous fistulas (DAVFs) who had undergone endovascular embolization. The details of the embolization procedures were examined, especially the technique of guiding a low-profile microcatheter supported by the thermoformed intermediate catheter. The authors assessed the patient background, procedural outcomes, and postoperative complications. RESULTS: Between October 2013 and June 2022, 43 patients with intracranial tumors and 45 with DAVFs underwent embolization at the authors' institutions. Among these cases, embolization of the ICA side branch feeder was attempted in 10 intracranial tumors and 2 DAVFs. Of these 12 patients, the microcatheter was guided deep enough for successful embolization in 11 cases (92%). Two asymptomatic arteriovenous fistulas were complicated during guidewire manipulation deep in the feeder. Yet, both disappeared completely after glue injection into the feeding artery. No spasm or dissection of the parent artery occurred during the procedure. Postoperative radiological evaluation showed no intracranial hematoma or symptomatic cerebral infarction. One patient (9%) developed permanent postoperative cranial neuropathy that gradually improved after embolization. CONCLUSIONS: This study revealed that custom shaping of distal access catheters is an effective technique that enabled the embolization of ILT and MHT feeders with a success rate of more than 90%.

Efficacy of a Novel Augmented Reality Navigation System Using 3D Computer Graphic Modeling in Endoscopic Transsphenoidal Surgery for Sellar and Parasellar Tumors.

In endoscopic transsphenoidal skull base surgery, knowledge of tumor location on imaging and the anatomic structures is required simultaneously. However, it is often difficult to accurately reconstruct the endoscopic vision of the surgical field from the pre-surgical radiographic images because the lesion remarkably displaces the geography of normal anatomic structures. We created a precise three-dimensional computer graphic model from preoperative radiographic data that was then superimposed on a visual image of the actual surgical field and displayed on a video monitor during endoscopic transsphenoidal surgery. We evaluated the efficacy of this augmented reality (AR) navigation system in 15 consecutive patients with sellar and parasellar tumors. The average score overall was 4.7 [95% confidence interval: 4.58-4.82], which indicates that the AR navigation system was as useful as or more useful than conventional navigation in certain patients. In two patients, AR navigation was assessed as less useful than conventional navigation because perception of the depth of the lesion was more difficult. The developed system was more useful than conventional navigation for facilitating an immediate three-dimensional understanding of the lesion and surrounding structures.

Anatomical Factors That Impede Using the Radial Artery Approach for Carotid Artery Revascularization.

OBJECTIVES: We investigated the anatomical characteristics that complicate utilizing the radial artery approach (RAA) for craniocervical intravascular intervention. METHODS: The data of 73 lesions in 65 consecutive patients who underwent transradial cervical carotid artery intervention was evaluated. We assessed the success rate of RAA in right-sided and left-sided lesions. The diameters and angles of the left and right common carotid arteries and the aortic, brachiocephalic, and right subclavian arteries, which constitute the paths of the guiding sheath, were assessed for each of the left- and right-sided lesions. RESULTS: It was difficult to apply RAA in 10 cases (13.7%), of which 2 (5.0%) involved right-sided and 8 (24.2%) left-sided lesions. The approach was significantly more difficult to perform in left-sided than in right-sided lesions (P = 0.02). Although the treatments were successfully completed, crossover to the femoral artery approach was required in 4 cases (5.5%, 2 cases for left-sided lesions). Placement of the guiding sheath in the common carotid artery was successful for all right-sided lesions; however, the guiding sheath slipped off to the aorta during stent advancement in 2 cases. When the angle between the brachiocephalic artery and aortic arch was small, the introduction of the guiding sheath to left-sided lesions was difficult in eight cases (P = 0.0001). CONCLUSIONS: RAA was difficult to perform in cases involving left-sided lesions and a small angle between the brachiocephalic artery and aortic arch. This study could help delineate the factors associated with difficulty of catheter introduction and instability of RAA.

Retrograde endovascular revascularization for chronic total occlusion of the internal carotid artery: a case report.

Endovascular revascularization of a chronically occluded internal carotid artery (ICA) is challenging because the occlusive segment can be long and tortuous. A case is presented of a successful recanalization of a chronically occluded ICA by retrograde passing of a guidewire from the intracranial ICA to the cervical ICA via the posterior communicating artery. This case suggests that a retrograde approach for reopening an occluded artery may be useful during neurovascular interventions, similar to percutaneous coronary interventions. In this patient, daily transient ischemic attacks disappeared after successful recanalization of the ICA.

A Case of Nervus Intermedius Neuralgia.

BACKGROUND: Nervus intermedius neuralgia is an extremely rare craniofacial neuralgia characterized by paroxysmal episodes of pain located deep in the ear, typically triggered by sensory or mechanical stimuli at the wall of the auditory canal without underlying pathology. Pain is sometimes associated with disorders of lacrimation, salivation, and taste. CASE DESCRIPTION: We present a case of a surgically treated 68-year-old man with left paroxysmal deep ear pain for 20 years before presentation. Preoperative 3-dimensional magnetic resonance cisternography/magnetic resonance angiography (3D-MRC/MRA) fusion imaging showed severe compression of the facial nerve by the anterior inferior cerebellar artery in the cisternal portion with associated nerve deformity. We suspected nervus intermedius neuralgia and decided to perform microvascular decompression of the facial nerve. Transposition of the artery led to sufficient decompression of the nerve. The pain disappeared immediately after surgery. CONCLUSIONS: It is important to keep in mind the possibility of nervus intermedius neuralgia in patients who present with intermittent episodes of pain located deep in the ear. Furthermore, 3D-MRC/MRA fusion imaging is useful for decision-making in surgery. Microvascular decompression was highly effective in our case. Based on radiological findings, microvascular decompression should be considered a viable treatment option.

A Case of Intravascular Treatment for Acute Ischemic Stroke with Internal Carotid Artery Stenosis That Developed While Driving.

Objective: We report a case of acute cerebral infarction that may have been associated with high-energy trauma due to onset while driving. Case Presentation: A 67-year-old man had a traffic accident. His neurological symptoms were left hemiplegia and contrast CT revealed right middle cerebral artery occlusion. Intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) and intravascular treatment were performed. Right carotid artery angiography demonstrated internal carotid artery stenosis. Middle cerebral artery (MCA) revascularization was performed only by percutaneous transluminal angioplasty (PTA) of the internal carotid artery. Thoracic hemorrhage was observed a few hours after surgery, and hemostasis was performed by thoracotomy. Carotid artery stenting (CAS) was performed 8 days after onset. The patient was transferred to a convalescent rehabilitation hospital. Conclusion: Rt-PA and acute CAS were not recommended for cerebral infarction due to traffic accident.

Spontaneous Temporal Pole Encephalocele Presenting with Epilepsy: Report of Two Cases.

BACKGROUND: Refractory temporal lobe epilepsy due to spontaneous temporal pole encephalocele is a rare but increasingly recognized condition. Optimal surgical management is complicated by the lack of knowledge regarding both the extent of the epileptogenic area and the need for repair of the encephalocele. CASE DESCRIPTION: We report two cases that add significant information to these issues. In Case 1, with a 5-year history of refractory seizures, implantation of diagnostic subdural electrodes into the anterior temporal base happened to abolish the seizures completely. No structural changes were evident on postoperative magnetic resonance imaging. In Case 2, with a large encephalocele and a 5-year history of refractory seizures, surgical disconnection of the temporal pole successfully abolished seizures without any need for encephalocele repair. CONCLUSIONS: These two cases support the view that the epileptogenic area is confined to within the temporal pole for spontaneous temporal pole encephalocele. Temporopolar disconnection represents one surgical option for this entity that achieves seizure cessation without requiring extra repair procedures.

Dissociated roles of the inferior frontal gyrus and superior temporal sulcus in audiovisual processing: top-down and bottom-up mismatch detection.

Visual inputs can distort auditory perception, and accurate auditory processing requires the ability to detect and ignore visual input that is simultaneous and incongruent with auditory information. However, the neural basis of this auditory selection from audiovisual information is unknown, whereas integration process of audiovisual inputs is intensively researched. Here, we tested the hypothesis that the inferior frontal gyrus (IFG) and superior temporal sulcus (STS) are involved in top-down and bottom-up processing, respectively, of target auditory information from audiovisual inputs. We recorded high gamma activity (HGA), which is associated with neuronal firing in local brain regions, using electrocorticography while patients with epilepsy judged the syllable spoken by a voice while looking at a voice-congruent or -incongruent lip movement from the speaker. The STS exhibited stronger HGA if the patient was presented with information of large audiovisual incongruence than of small incongruence, especially if the auditory information was correctly identified. On the other hand, the IFG exhibited stronger HGA in trials with small audiovisual incongruence when patients correctly perceived the auditory information than when patients incorrectly perceived the auditory information due to the mismatched visual information. These results indicate that the IFG and STS have dissociated roles in selective auditory processing, and suggest that the neural basis of selective auditory processing changes dynamically in accordance with the degree of incongruity between auditory and visual information.

Simultaneous recording of single-neuron activities and broad-area intracranial electroencephalography: electrode design and implantation procedure.

BACKGROUND: There has been growing interest in clinical single-neuron recording to better understand epileptogenicity and brain function. It is crucial to compare this new information, single-neuronal activity, with that obtained from conventional intracranial electroencephalography during simultaneous recording. However, it is difficult to implant microwires and subdural electrodes during a single surgical operation because the stereotactic frame hampers flexible craniotomy. OBJECTIVE: To describe newly designed electrodes and surgical techniques for implanting them with subdural electrodes that enable simultaneous recording from hippocampal neurons and broad areas of the cortical surface. METHODS: We designed a depth electrode that does not protrude into the dura and pulsates naturally with the brain. The length and tract of the depth electrode were determined preoperatively between the lateral subiculum and the lateral surface of the temporal lobe. A frameless navigation system was used to insert the depth electrode. Surface grids and ventral strips were placed before and after the insertion of the depth electrodes, respectively. Finally, a microwire bundle was inserted into the lumen of the depth electrode. We evaluated the precision of implantation, the recording stability, and the recording rate with microwire electrodes. RESULTS: Depth-microwire electrodes were placed with a precision of 3.6 mm. The mean successful recording rate of single- or multiple-unit activity was 14.8%, which was maintained throughout the entire recording period. CONCLUSION: We achieved simultaneous implantation of microwires, depth electrodes, and broad-area subdural electrodes. Our method enabled simultaneous and stable recording of hippocampal single-neuron activities and multichannel intracranial electroencephalography.

[A case of a penetrating brain injury due to an explosion of a construction machine].

Penetrating brain injury caused by a high speed projectile is rather rare in Japan, known for its strict gun-control laws. We report a case of a 55-year-old male, who was transferred to our hospital with a foreign body in the brain due to penetrating head injury, which was caused by an explosion of a construction machine. Neurological examination demonstrated severe motor aphagia with no apparent motor paresis. The patient had a scalp laceration on his left forehead with exposed cerebral tissue and CSF leakage. Head CT scan and plain skull X-ray revealed a 20 mm×25 mm bolt which had penetrated due to the explosion of the machine. The anterior wall of the left frontal sinus was fractured resulting in dural laceration, and scattered bone fragments were seen along the trajectory of the bolt. Digital subtraction angiography showed no significant vascular injuries including superior sagittal sinus. We performed open surgery, and successfully removed the bolt along with the damaged frontal lobe. The patient had no infection or seizure after the surgery, and was transferred for further rehabilitation therapy. We performed a cosmetic cranioplasty six months later. Surgical debridement of the damaged cerebral tissue along the trajectory led to successful removal of the bolt with no further neurological deficit.

A prospective, open-label, multicenter study to assess the efficacy of spinal cord stimulation and identify patients who would benefit.

OBJECTIVE: To identify patients likely to benefit from spinal cord stimulation (SCS). MATERIALS AND METHODS: This multicenter, prospective, open-label study included medical centers experienced in SCS therapy, carried out in 13 physicians in seven centers. We recruited 55 patients with complex regional pain syndrome, failed back surgery syndrome, or peripheral vascular disease. Neurostimulators were implanted in 34 patients found to respond to SCS in a preliminary test, who were then followed for six months. Thirty-four patients scored their pain on a visual analog scale (VAS) and completed the EuroQol-5D questionnaire before and after test stimulation and after one and six months. RESULTS: During test stimulation, the mean VAS and quality of life (QOL) scores improved from 74.0 to 23.4 and from 0.430 to 0.664, respectively, in the 34 patients. At six months, the mean VAS score was 29.7 in 29 patients and the mean QOL score was 0.661 in 31 patients. CONCLUSION: SCS may improve pain management and QOL.

Isolated recurrence of intracranial and temporal bone myeloid sarcoma--case report.

A 52-year-old man presented with a rare case of isolated recurrence of myeloid sarcoma (MS) manifesting as rapidly growing intracranial and temporal bone masses 5 years after complete remission (CR) of acute myeloid leukemia (AML) (M2 in the French-American-British classification). Magnetic resonance imaging and computed tomography of the head revealed enhanced mass lesions on the superior aspect of the right petrous bone and within the right mastoid air cells, extending into the right middle ear cavity without bone destruction. Peripheral blood testing found no evidence of relapse. As the right temporal bone mass showed significant growth into the right temporal lobe over one month and diagnostic tissue was not available, he was admitted to our department for biopsy. On admission, blood testing showed relapse of AML and tumoral hemorrhage in the right temporal lobe. Emergent evacuation of the hematoma and biopsy of the right temporal lobe tumor was performed, resulting in a diagnosis of MS. Chromosomal analysis of the peripheral blood identified t(8;21)(q22;q22) abnormality. Before initiation of anti-AML chemotherapy, tumoral bleeding occurred again and he died 12 days after the operation of brain herniation. Autopsy revealed leukemia cell infiltrations in the perivascular region of the peritumoral brain parenchyma associated with hemorrhage, indicating vascular damage caused by leukemic cell infiltration from MS induced cerebral hemorrhage. Although relapse after 5 years of CR is uncommon in patients with AML, the possibility of MS recurrence must be considered.

Osteomalacia caused by skull base tumors: report of 2 cases.

BACKGROUND AND IMPORTANCE: Tumor-induced osteomalacia (TIO) is an uncommon paraneoplastic syndrome rarely encountered in neurosurgical practice. We report on 2 cases of TIO caused by skull base tumors. Although the diagnosis of TIO is difficult to make and often is delayed because of the insidious nature of the symptoms, mostly systemic pain and weakness, it is curable once it is diagnosed and properly treated. CLINICAL PRESENTATION: Both patients presented with severe pain developing in the lower extremities and moving out to the entire body, as well as difficulty moving. They were diagnosed with TIO several years after onset. A high level of serum FGF23 was confirmed, and whole-body imaging studies demonstrated tumors in the middle and anterior cranial base, respectively. The patient with the anterior cranial base tumor had a history of hemorrhage into the frontal lobe and partial resection. En bloc resection of tumor with surrounding skull bone was performed. The histological diagnosis for both cases was phosphaturic mesenchymal tumor, mixed connective tissue variant. CONCLUSION: The level of FGF23 normalized immediately after surgery. Both patients experienced a dramatic relief of pain and recovery of muscle power. Although reports of osteomalacia caused by tumors in the neurosurgical field are extremely rare in the literature, its true incidence is unknown. We emphasize the importance of recognition of this syndrome and recommend total resection of tumors when possible.

The effect of pulsed radiofrequency current on mechanical allodynia induced with resiniferatoxin in rats.

BACKGROUND: Pulsed radiofrequency (PRF) is a popular pain treatment modality. The effect of PRF current on neuropathic pain has not been examined in detail. We investigated the effect of PRF current on mechanical allodynia induced with resiniferatoxin (RTX) in rats, especially regarding the influence of the duration of allodynia before PRF procedures and that of exposure time to PRF. METHODS: Adult male Sprague-Dawley rats (weighing 250-400 g) received a single intraperitoneal injection of RTX (200 microg/kg) under 2 to 3% sevoflurane anesthesia. Rats in group S(2) (n = 5) were assigned to receive PRF current to the right sciatic nerve for 2 minutes 1 week after RTX treatment; rats in group M(2) (n = 6), PRF current for 2 minutes 3 weeks after RTX treatment; rats in group L(2) (n = 7), PRF current for 2 minutes 5 weeks after RTX treatment; rats in group S(4) (n = 5), PRF current for 4 minutes 1 week after RTX treatment; rats in group S(6) (n = 5), PRF current for 6 minutes 1 week after RTX treatment; and rats in group S(0) (n = 3), no PRF current was delivered. Instead, the needle and electrode were inserted at proper points for 6 minutes 1 week after RTX treatment. All rats were evaluated for sensitivity to mechanical stimulation with von Frey filaments and to thermal stimulation with a thermal testing apparatus and for motor function using placing and grasping reflexes before injection of RTX, every week after injection of RTX, and 1, 2, 3, 4, and 5 weeks after PRF treatment. RESULTS: The paw withdrawal thresholds of both hindpaws 1 week after RTX treatment were significantly lower than the pre-RTX baseline in all groups. In groups S(2), S(4), S(6), and M(2), after PRF procedures, the ipsilateral paw withdrawal thresholds significantly increased. A statistically significant difference was detected between the PRF-treated and PRF-untreated hindpaws. The ipsilateral-contralateral paw withdrawal thresholds after PRF procedures in group S(2) were significantly higher than those in groups M(2) and L(2). Between groups M(2) and L(2), significant differences were found 1, 2, 4, and 5 weeks after PRF procedures. The ipsilateral-contralateral paw withdrawal thresholds in group S(6) were significantly higher than those in groups S(2) and S(4) 5 weeks after PRF procedures. No significant difference was found between groups S(2) and S(4) at any time. After PRF procedures, no difference in the withdrawal latency after heat stimulation and no motor disturbance were observed at any time in all groups. CONCLUSIONS: PRF treatment was more effective when applied in the early stages of mechanical allodynia (1 week) in rats. Increased exposure time to PRF current from 2 to 6 minutes showed a significant antiallodynic effect without motor impairment. We propose the application of PRF current for 6 minutes adjacent to the nerve as soon as possible when allodynia appears.

Co-transfection of EYFP-GH and ECFP-rab3B in an experimental pituitary GH3 cell: a role of rab3B in secretion of GH through porosome.

Recently, in order to elucidate the role of rab3B in porosome, we have observed the incorporation of rab3B in the secretion of GH through porosome under confocal laser scanning microscopy (CLSM). Transfected cells with GH-EYFP fusion protein and rab3B-ECFP fusion protein were observed under CLSM, which showed the colocalization of EYFP-GH and ECFP-rab3B in the budding configuration of secretory process. These structural and functional images of rab3B imply the incorporation of rab3B in the secretion of GH through porosome.

Disappearance of gadolinium enhancement in a chemoresistant astrocytoma of the tectum after high-dose interferon beta.

Interferon beta 6 million units per week was administered to a patient with an aggressive astrocytoma in the tectum that was resistant to cisplatin, etoposide, vinblastine, and the oral alkylating agent temozolomide. The tumor was immunopositive for O6-methylguanine-DNA methyltransferase (MGMT). Interferon beta caused the disappearance of the gadolinium-enhanced lesion in the tectum. Interferons have apoptotic and antiangiogenic effects on tumor cells, and the lesion's disappearance may have been induced by complexes of these effects. Administration of interferon beta might have a favorable effect on tectal gliomas that are immunopositive for MGMT and resistant to chemoradiotherapy including temozolomide.

Peptide-nucleic acid-modified ion-sensitive field-effect transistor-based biosensor for direct detection of DNA hybridization.

Here, we report the development of a peptide-nucleic acid (PNA)-modified ion-sensitive field-effect transistor (IS-FET)-based biosensor that takes advantage of the change in the surface potential upon hybridization of a negatively charged DNA. PNA was immobilized on a silicon nitride gate insulator by an addition reaction between a maleimide group introduced on the gate surface, the succinimide group of N-(6-maleimidocaproyloxy) succinimide, and the thiol group of the terminal cysteine in PNA. The surface was characterized after each step of the reaction by X-ray photoelectron spectroscopy analysis, and the kinetic analysis of the hybridization events was assessed by surface plasmon resonance. In addition, we measured the -potential before and after PNA-DNA hybridization in the presence of counterions to investigate the change in surface charge density at the surface-solution interface within the order of the Debye length. On the basis of the zeta-potential, the surface charge density, DeltaQ, calculated using the Grahame equation was approximately 4.0 x 10(-3) C/m2 and the estimated number of hybridized molecules was at least 1.7 x 10(11)/cm2. The I-V characteristics revealed that the PNA-DNA duplexes induce a positive shift in the threshold voltage, VT, and a decrease in the saturated drain current, ID. These results demonstrate that direct detection of DNA hybridization should be possible using a PNA-modified IS-FET-based biosensor. PNA is particularly advantageous for this system because it enables highly specific and selective binding at low ionic strength.

Alteration of regional cerebral blood flow in patients with chronic pain--evaluation before and after epidural spinal cord stimulation.

BACKGROUND: Chronic pain is defined as intractable pain caused by abnormal pain transmission or impairment of the pain control system per se. Alteration of regional cerebral blood flow (rCBF) is known to occur under the presence of pain stimulation. Epidural spinal cord stimulation (SCS) is occasionally effective in relieving the symptom. OBJECTIVE: The aim of the current study is to investigate the alteration of rCBF in baseline condition and to find the association between the rCBF change and the efficacy of SCS in chronic pain. METHODS: A total of 18 patients underwent Tc-99m-HMPAO SPECT before and after SCS. Analysis with three-dimensional stereo-tactic surface projections (3D-SSP) with stereo-tactic extraction estimation (SEE) software was adopted to evaluate the rCBF. We assessed the extent score of the abnormal region in each segment (rate of the coordinates with a Z-value that exceeds three kinds of threshold value 2.0, 2.5 and 3.0 in all coordinates within a segment). According to the therapeutic response defined by visual analogue scale, we categorized patients into two groups, the good responder (GR) group (n=12) and poor responder (PR) group (n=6). In the analysis, we compared the extent score in the following two conditions. (1) Comparison between the PR group and normal control group under both baseline condition and after SCS. (2) Comparison between the GR group and normal control group under both baseline condition and after SCS. RESULTS: (1) In the PR group, increased rCBF was observed in left thalamus, bilateral precuneus and bilateral cerebellum under the baseline condition. After SCS, the range of these increased rCBF areas localized but remained. Decrease of rCBF was noted in bilateral subcallosal gyrus, superior temporal gyrus (STG) and bilateral anterior cingulate gyrus (ACG). They localized after SCS, but remained. (2) In the GR group, increased rCBF areas were noted in bilateral precuneus and bilateral cerebellum under the baseline condition. After SCS, they localized in bilateral precuneus but those of bilateral cerebellum remained. Decreased rCBF area was noted in bilateral subcallosal gyrus, STG and bilateral ACG under the baseline. After SCS, they localized in bilateral subcallosal gyrus and bilateral STG. In contrast, they enlarged in bilateral ACG. CONCLUSION: Chronic pain patients demonstrated abnormal rCBF distribution on both baseline and post SCS conditions. Increased rCBF of thalamus and precuneus under both conditions in the PR group and decreased rCBF of ACG under post SCS conditions in the GR group were characteristic patterns. Tc-99m-HMPAO SPECT with 3D-SSP and SEE analysis is likely objective and effective in monitoring and evaluating therapeutic outcome by SCS in chronic pain. In addition, it provides information that is useful in the selection of SCS candidates.