Excessive Heat Generation by Power-driven Craniotomy Tools: A Possible Cause of Autologous Bone Flap Resorption Observed in an Ex Vivo Simulation

BACKGROUND

Bone flap resorption is an issue after autologous cranioplasty. Critical temperatures above 50°C generated by power-driven craniotomy tools may lead to thermal osteonecrosis, a possible factor in resorption. This ex vivo study examined whether the tools produced excessive heat resulting in bone flap resorption.

METHODS

Using swine scapulae maintained at body temperature, burr holes, straight and curved cuts, and wire-pass holes were made with power-driven craniotomy tools. Drilling was at the conventional feed rate (FR) plus irrigation (FR-I+), at a high FR plus irrigation (hFR-I+), and at high FR without irrigation (hFR-I-). The temperature in each trial was recorded by an infrared thermographic camera.

RESULTS

With FR-I+, the maximum temperature at the burr holes, the cuts, and the wire-pass holes was 69.0°C, 56.7°C, and 46.2°C, respectively. With hFR-I+, these temperatures were 53.1°C, 52.1°C, and 46.0°C, with hFR-I- they were 56.0°C, 66.5°C, and 50.0°C; hFR-I- burr hole- and cutting procedures resulted in the highest incidence of bone temperatures above 50°C followed by FR-I+, and hFR-I+. At the site of wire-pass holes, only hFR-I- drilling produced this temperature.

CONCLUSIONS

Except during prolonged procedures in thick bones, most drilling with irrigation did not reach the critical temperature. Drilling without irrigation risked generating the critical temperature. Knowing those characteristics may be a help to perform craniotomy with less thermal bone damage.

Combination of neuroendoscopic hematoma evacuation and endovascular coil embolization for a ruptured anterior choroidal artery aneurysm in patients with moyamoya disease: illustrative cases

BACKGROUND

The treatment strategy for hemorrhagic moyamoya disease (MMD) due to a ruptured aneurysm at the distal portion of the anterior choroidal artery remains controversial. The authors successfully treated the ruptured aneurysm with neuroendoscopic hematoma evacuation, followed by endovascular coil embolization.

OBSERVATIONS

The authors encountered two patients with massive hemorrhagic MMD whose MMD had already been diagnosed and who had a periventricular anastomosis due to a ruptured aneurysm of the distal portion of the anterior choroidal artery involving the periventricular anastomosis. In both cases, neuroendoscopic hematoma evacuation was performed for hemorrhagic MMD in the acute phase, followed by endovascular coil embolization of the ruptured aneurysm in the chronic phase. In both endovascular treatments, the patient's condition was stabilized by hematoma evacuation, allowing a detailed preoperative evaluation of the anatomical findings of the vessel and functional findings of intraoperative neurophysiological monitoring using continuous monitoring of motor evoked potentials to preserve motor function.

LESSONS

Combination therapy can be useful for hemorrhagic MMD in patients with diagnosed MMD with a periventricular anastomosis. Additionally, a preoperative understanding of the vascular construction and intraoperative neurophysiological monitoring will aid in the successful coil embolization of aneurysms at the distal portion of the anterior choroidal artery with hemorrhagic MMD.

Angiographic evaluation of the distance from the top of the jugular bulb to the inferior petrosal sinus-internal jugular vein junction: simple classification and identification method for the orifice of the non-visualized inferior petrosal sinus during neuroendovascular surgery

BACKGROUND

The inferior petrosal sinus (IPS) is the transvenous access route for neurointerventional surgery that is occasionally undetectable on digital subtraction angiography (DSA) because of blockage by a clot or collapse. This study was aimed at analyzing the distance from the jugular bulb (JB) to the IPS-internal jugular vein (IJV) junction and proposing a new anatomical classification system for the IPS-IJV junction to identify the non-visualized IPS orifice.

METHODS

DSA of 708 IPSs of 375 consecutive patients were retrospectively investigated to calculate the distance from the top of the JB to the IPS-IJV junction, and a simple classification system based on this distance was proposed.

RESULTS

The median distance from the top of the JB to the IPS-IJV junction was 20.8 ± 14.7 mm. Based on the lower (10.9 mm) and upper (31.1 mm) quartiles, IPS-IJV junction variants were: type I, 0-10 mm (22.3%); type II, 11-30 mm (45.8%); type III, > 31 mm (23.9%); and type IV, no connection to the IJV (8.0%). Bilateral distances showed a positive interrelationship, with a correlation coefficient of 0.86. The bilateral symmetry type (visualized IPSs bilaterally) according to our classification occurred in 267 of 300 (89.0%) patients.

CONCLUSIONS

In this study, the IPS-IJV junction was located far from the JB (types II and III), with a higher probability (69.6%). This distance and the four-type classification demonstrated high degrees of homology with the contralateral side. These results would be useful for identifying the non-visualized IPS orifice.

Multiple trauma complicated by traumatic vertebral artery injury without cervical vertebral injury: A case report

Background

Blunt traumatic vertebral artery injury is commonly associated with head and cervical spinal trauma. However, those associated with chest or upper extremity injuries without cervical spine-related trauma are rare.

Case presentation

A 94-year-old woman was injured in a motor vehicle crash. She was diagnosed with traumatic subarachnoid hemorrhage, bilateral subdural hematomas, right vertebral artery injury, and right clavicle fracture. No cervical spine injuries were observed. It was possible that the fracture fragment of the right clavicle may have directly injured the right vertebral artery. Coil embolization was performed for the vertebral artery injury. The patient had a good postoperative course and was transferred to the hospital for rehabilitation on day 65.

Conclusion

Regarding the high-risk injury mechanism, blunt traumatic vertebral artery injuries in the V1-2 segment may occur in cases with clavicle fractures.

RAB35 is required for murine hippocampal development and functions by regulating neuronal cell distribution

RAB35 is a multifunctional small GTPase that regulates endocytic recycling, cytoskeletal rearrangement, and cytokinesis. However, its physiological functions in mammalian development remain unclear. Here, we generated Rab35-knockout mice and found that RAB35 is essential for early embryogenesis. Interestingly, brain-specific Rab35-knockout mice displayed severe defects in hippocampal lamination owing to impaired distribution of pyramidal neurons, although defects in cerebral cortex formation were not evident. In addition, Rab35-knockout mice exhibited defects in spatial memory and anxiety-related behaviors. Quantitative proteomics indicated that the loss of RAB35 significantly affected the levels of other RAB proteins associated with endocytic trafficking, as well as some neural cell adhesion molecules, such as contactin-2. Collectively, our findings revealed that RAB35 is required for precise neuronal distribution in the developing hippocampus by regulating the expression of cell adhesion molecules, thereby influencing spatial memory.

Frontotemporal Craniotomy for Clipping of Unruptured Aneurysm Using a Diamond-Coated Thread Wire Saw and Reconstruction Using Calcium Phosphate Cement without Metal Fixation

Metal fixation systems for cranial bone flaps cut by a drill are convenient devices for cranioplasty, but cause several complications. We use modified craniotomy using a fine diamond-coated threadwire saw (diamond T-saw) to reduce the bone defect, and osteoplasty calcium phosphate cement without metal fixation. We report our outcomes and tips of this method. A total of 78 consecutive patients underwent elective frontotemporal craniotomy for clipping of unruptured intracranial aneurysms between 2015 and 2019. The follow-up periods ranged from 13 to 66 months. The bone fixation state was evaluated by bone computed tomography (CT) and three-dimensional CT (3D-CT). The diamond T-saw could minimize the bone defect. Only one wound infection occurred within 1 week postoperatively, and no late infection. No pain, palpable/cosmetically noticeable displacement of the bone flap, fluid accumulations, or other complications were observed. The condition of bone fixation and the cosmetic efficacy were thoroughly satisfactory for all patients, and bone CT and 3D-CT demonstrated that good bone fusion. No complication typical of metal fixation occurred. Our method is technically easy and safety, and achieved good mid-term bone flap fixation in the mid-term course, so has potential for bone fixation without the use of metal plates.

Scratching and Stretching the Shrunken Cranial Dura for Primary Closure

BACKGROUND

At craniotomy, the dura shrinks due to the drying effect of illumination and air exposure, rendering its primary closure difficult. When the opening is narrow, it can be patched with autologous grafts. However, tissue harvesting and meticulous suturing take time. As the cost-effectiveness of using dural substitutes is poor, we developed a new technique that involves dural scratching for the primary closure of dural openings.

METHODS

We applied our technique because in 53 adults who underwent supratentorial craniotomy we encountered difficulties with the primary closure of a dural opening 5 mm or less in width. With a scalpel, we placed several fine scratches parallel to the edge of the opening on the surface of the dura, taking care not to perforate the deep layer. This relieved dural tension and the tissue was stretched enough to permit closing with sutures.

RESULTS

Our technique achieved primary dural closure in 46 of 53 patients (87%) who primarily had undergone narrow supratentorial craniotomies. The other 7 additionally required small autologous grafts to patch narrow residual openings at the intersection of the durotomy. There were no procedure-related complications such as cerebrospinal fluid leakage and persistent headache due to tension of the closed dura.

CONCLUSIONS

Dural scratching is simple, safe, requires no special instrumentation, facilitates primary closure of the shrunken dura by stretching, and reduces the need for patch grafting.

Endoscope-integrated indocyanine green video angiography and the detection of the fragile periventricular collaterals associated with moyamoya disease: illustrative cases

BACKGROUND

Hemorrhagic moyamoya disease (MMD) and the fragile periventricular collaterals are known to have a causal relationship. Digital subtraction angiography and magnetic resonance angiography have shown the presence of fragile periventricular moyamoya vessels. However, dynamic fragile periventricular moyamoya vessels have never been observed under direct vision.

OBSERVATIONS

The authors treated two patients with hemorrhagic MMD: a 42-year-old man with intraventricular hemorrhage and a 47-year-old woman with intracerebral hemorrhage. Endoscope-integrated indocyanine green video angiography (EICG angiography) could visualize the dynamic fragile periventricular collaterals. In particular, EICG angiography enabled visualization of invisible moyamoya vessels buried in the subependyma and characterization of the blood flow in the moyamoya vessels located inside the lateral ventricles and hematoma cavity.

LESSONS

EICG angiography can confirm the fragile periventricular collaterals associated with MMD by direct visualization. The high spatial resolution and real-time imaging can help to avoid accidental hemorrhage in and after evacuation of hemorrhage in patients with MMD.

Relationship between subarachnoid hemorrhage and nonocclusive mesenteric ischemia as a fatal complication: patient series

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI) causes intestinal necrosis due to irreversible ischemia of the intestinal tract. The authors evaluated the incidence of NOMI in patients with subarachnoid hemorrhage (SAH) due to ruptured aneurysms, and they present the clinical characteristics and describe the outcomes to emphasize the importance of recognizing NOMI.

OBSERVATIONS

Overall, 7 of 276 consecutive patients with SAH developed NOMI. Their average age was 71 years, and 5 patients were men. Hunt and Kosnik grades were as follows: grade II, 2 patients; grade III, 3 patients; grade IV, 1 patient; and grade V, 1 patient. Fisher grades were as follows: grade 1, 1 patient; grade 2, 1 patient; and grade 3, 5 patients. Three patients were treated with endovascular coiling, 3 with microsurgical clipping, and 1 with conservative management. Five patients had abdominal symptoms prior to the confirmed diagnosis of NOMI. Four patients fell into shock. Two patients required emergent laparotomy followed by second-look surgery. Four patients could be managed conservatively. The overall mortality of patients with NOMI complication was 29% (2 of 7 cases).

LESSONS

NOMI had a high mortality rate. Neurosurgeons should recognize that NOMI can occur as a fatal complication after SAH.

Coexistence of anterior cranial fossa dural arteriovenous fistula and arteriovenous malformation with the same drainage system: illustrative case

BACKGROUND

The authors report a rare case of coexistence of dural arteriovenous fistula (DAVF) and arteriovenous malformation (AVM), with a common trunk drainer from both DAVF and AVM in the left anterior cranial fossa (ACF) with simple DAVF in the right ACF.

OBSERVATIONS

A 63-year-old female presented with seizure. Cerebral angiography showed bilateral DAVFs in the ACF and AVM in the left frontal lobe. A dilated frontal vein acted as a simple drainer of the right DAVF. In contrast, a dilated vein with large varix was the common drainer of both the left DAVF and the AVM. During surgery, indocyanine green videoangiography was performed with direct observation. In the left ACF, the drainer occlusion of the DAVF resulted in partial shrinkage of the varix and decreased distal blood flow. Additional main feeder occlusion of the AVM could decrease the blood flow further, but not completely because of the residual pial supplies for the AVM. Finally, the nidus of the AVM with varix was removed by en bloc resection.

LESSONS

Neurosurgeons should be aware of the coexistence of DAVF and AVM with a common trunk drainer. Only simple occlusion of the drainer from DAVF is not sufficient, so removal of the AVM is essential.

A Case of Synchronous Occurrence of Intracranial Germinoma and Systemic Sarcoidosis

Although the synchronous occurrence of testicular seminoma and systemic sarcoidosis has been reported, that of intracranial germinoma and systemic sarcoidosis is unknown. A 26-year-old man presented with symptoms of panhypopituitarism and consciousness disturbance. Imaging demonstrated a large nodule in the upper right lung field and swelling of multiple bilateral pulmonary and mediastinal lymph nodes in addition to the bifocal pineal and suprasellar tumors with obstructive hydrocephalus. The pathological diagnosis of the intracranial bifocal tumors was pure germinoma, whereas that of the mediastinal lymph nodes was epithelioid granuloma. Three courses of chemotherapy using carboplatin and etoposide were administered, followed by whole ventricle irradiation. The intracranial tumors completely disappeared, but the lung nodule and mediastinal lymph nodes progressed. Whole-body fluorine-18-fluorodeoxyglucose positron emission tomography demonstrated accumulation in the mediastinal lymphadenopathy, lung masses, and multiple lymph nodes of the whole body. Transbronchial lung biopsy revealed epithelioid granuloma with multinucleated giant cells. In conjunction with the high blood concentration of angiotensin-converting enzyme and soluble interleukin-2 receptor, these findings established a diagnosis of sarcoidosis. This is the first report of synchronous occurrence of intracranial germinoma and sarcoidosis. Such coexistence is extremely rare, but we should mind that sarcoidosis can occur with intracranial germinoma.

Cortical Neural Damage Associated with Cerebral Hyperperfusion after Reperfusion Therapy for Acute Ischemic Stroke: 123I-iomazenil Single-photon Emission Computed Tomography Findings

We present an 88-year-old man with cerebral hyperperfusion (CH) after acute reperfusion therapy. He developed acute cerebral ischemia as a result of occluded middle cerebral artery that was subsequently recanalized with endovascular thrombectomy. I-123 N-isopropyl-p-iodoamphetamine single-photon emission computed tomography (SPECT) after reperfusion therapy showed increased cerebral blood flow (CBF) in brain areas that exhibited no abnormal findings on magnetic resonance imaging (MRI). Follow-up MRI did not demonstrate structural brain damage associated with CH. However, later I-123 iomazenil SPECT imaging showed a reduction in benzodiazepine receptor binding potential (BRBP) in these areas, a finding that correlates with cortical neural damage. CH is being increasingly observed after endovascular treatment for acute stroke. However, little is known about CH when not associated with cerebral hemorrhage or infarction. The role of CH after reperfusion therapy in causing brain damage remains unclear. BRBP on I-123 iomazenil SPECT images is useful to evaluate brain neural density: a reduction in cortical BRBP indicates cortical neural damage or loss. Our findings suggest that post-reperfusion hyperperfusion induces cortical neural damage even in the absence of associated brain infarction or hemorrhage on MRI. Early postoperative SPECT is recommended to detect CH after acute reperfusion therapy. CH should be considered when the recovery from stroke is unexpectedly poor for a patient.

Strategic neuronavigation-guided emergent endoscopic evacuation of the hematoma caused by ruptured brain arteriovenous malformation: Technical note and retrospective case series

The treatment strategy for ruptured brain arteriovenous malformations (bAVMs) in the acute phase is still controversial. We describe five consecutive cases of successful emergent endoscopic evacuation (EEE) of intracerebral hematoma (ICH) caused by ruptured bAVMs with the electromagnetic (EM)-neuronavigation system to avoid damage to the bAVMs intended to save valuable time in the emergent phase. A single-institution retrospective analysis was performed in patients with ruptured bAVMs treated by the EM-navigated EEE as part of the strategic multimodality therapy. EM-navigated EEE was performed as follows: 1) obtaining three-dimensional computed tomography to identify the location of the nidus, large draining vein, feeding artery, and hematoma; 2) using a supine position without rigid head fixation for both supra- and infratentorial hematoma; 3) planning the entry point and trajectory of the endoscope as far as possible from the location of the nidus using the EM-navigation system; 4) designing a linear skin incision line suitable for the endoscopic surgery as well as possible decompressive craniectomy; and 5) performing EM-navigated endoscopic partial evacuation of ICH. EM-navigated EEE of ICH was successfully performed for all 5 patients, resulting in partial removal of the ICH without rebleeding from bAVMs. The mean surgical time was 37 min. Subsequent strategic endovascular embolization and curative resection of bAVMs could be performed for all patients, achieving Glasgow Coma Scale score of 15. EM-navigated EEE of partial ICH may be valuable in the emergent phase of ruptured bAVMs with massive life-threatening ICH to reduce the intracranial pressure and to obtain better prognosis.

Life-threatening traumatic epistaxis due to massive bleeding into the maxillary sinus

A 77-year-old woman with no medical history fell, and her face was strongly impacted on the ground. On arrival at our hospital, her initial vital signs were stable. She underwent an endoscopy to stop the bleeding. However, identification of the origin of the bleeding failed, and her injury resulted in hemorrhagic shock during the procedure. Head to face contrast computed tomography showed extravasation of contrast media into the maxillary sinus. Transcatheter arterial embolization was performed for the ruptured infraorbital artery branching from the maxillary artery. She recovered from the "shock" state after transcatheter arterial embolization and was admitted to the intensive care unit. There were no complications associated with transcatheter arterial embolization during hospitalization. For this case, early recognition of an active hemorrhage was challenging because the hemorrhage was pooled in the sinuses. Although epistaxis is sometimes fatal, transcatheter arterial embolization can be the first choice for the treatment of life-threatening epistaxis, owing to its safety and effectiveness.

Spatial and temporal diversity of DCLK1 isoforms in developing mouse brain

Doublecortin-like kinase 1 (DCLK1) is a Doublecortin family kinase involved in a range of brain development processes including cell migration, axon/dendrite growth, and synapse development. The Dclk1 gene potentially generates multiple splicing isoforms, but the detailed expression patterns in the brain as well as in vivo functions of each isoform are still incompletely understood. Here we assessed expression patterns of DCLK1 isoforms using multiple platforms including in silico, in situ, and in vitro datasets in the developing mouse brain, and show quantitative evidence that among the four DCLK1 isoforms, DCLK1-L and DCL are mainly expressed in the embryonic cortex whereas DCLK1-L and CPG16 become dominant compared to DCL and CARP in the postnatal cortex. We also provide compelling evidence that DCLK1 isoforms are distributed in the partially distinct brain regions in the embryonic and the postnatal stages. We further show that overexpression of DCLK1-L, but not the other isoforms, in neural progenitors causes severe migration defects in the cortex, and that the migration defects are dependent on the kinase activity of DCLK1-L. Our data thus uncover partially segregated localization of DCLK1 isoforms in the developing mouse brain and suggest different roles for distinct DCLK1 isoforms in the brain development and function.

Adeno-Associated Virus-Mediated Single-Cell Labeling of Mitral Cells in the Mouse Olfactory Bulb: Insights into the Developmental Dynamics of Dendrite Remodeling

Neurons typically remodel axons/dendrites for functional refinement of neural circuits in the developing brain. Mitral cells in the mammalian olfactory system remodel their dendritic arbors in the perinatal development, but the underlying molecular and cellular mechanisms remain elusive in part due to a lack of convenient methods to label mitral cells with single-cell resolution. Here we report a novel method for single-cell labeling of mouse mitral cells using adeno-associated virus (AAV)-mediated gene delivery. We first demonstrated that AAV injection into the olfactory ventricle of embryonic day 14.5 (E14.5) mice preferentially labels mitral cells in the olfactory bulb (OB). Birthdate labeling indicated that AAV can transduce mitral cells independently of their birthdates. Furthermore, in combination with the Cre-mediated gene expression system, AAV injection allows visualization of mitral cells at single-cell resolution. Using this AAV-mediated single-cell labeling method, we investigated dendrite development of mitral cells and found that ~50% of mitral cells exhibited mature apical dendrites with a single thick and tufted branch before birth, suggesting that a certain population of mitral cells completes dendrite remodeling during embryonic stages. We also found an atypical subtype of mitral cells that have multiple dendritic shafts innervating the same glomeruli. Our data thus demonstrate that the AAV-mediated labeling method that we reported here provides an efficient way to visualize mitral cells with single-cell resolution and could be utilized to study dynamic aspects as well as functions of mitral cells in the olfactory circuits.

Intravascular treatment for ruptured facial artery aneurysm via percutaneous cardiopulmonary support device: A case report

Even in cases of cardiac arrest caused by hemorrhagic shock, when reliable control of the bleeding source is possible, ECPR may be an effective treatment option if anticoagulant therapy is well-managed and is withdrawn early.

[Cerebral Amyloid Angiopathy-related Inflammation Demonstrating Early Venous Filling on Digital Subtraction Angiography:A Case Report]

Cerebral amyloid angiopathy-related inflammation(CAA-RI)is a rare condition thought to be caused by an inflammatory response to amyloid beta(Aβ)protein in the walls of the small arteries and capillaries of the cerebral cortex. A 73-year-old female presented with left hemiparesis and dysarthria. Fluid-attenuated inversion recovery(FLAIR)imaging disclosed progressive enlargement of infiltrative white matter abnormalities in the right temporo-occipito-parietal lobes. Interestingly, digital subtraction angiography(DSA)demonstrated early venous filling. Pathological examination of the biopsy specimen demonstrated lymphocytes infiltration surrounding the blood vessels and in the thickened walls with amyloid-beta deposition. The diagnosis given was CAA-RI. The patient was successfully treated with high dose corticosteroids and clinical improvement was associated with shrinkage of the high intensity lesion on FLAIR imaging. Early venous filling resolved on the follow-up DSA. Most patients with CAA-RI can be treated with corticosteroids. However, the clinical condition will worsen without appropriate treatment. Early diagnosis is the key. If an expanding disease of the white matter appears in an elderly patient, we should exclude other cerebrovascular diseases by DSA, followed by biopsy without delay. The present case demonstrated that early venous filling on DSA may appear until inflammation is resolved by the treatment of CAA-RI.

Direct measurement of 1-mN-class thrust and 100-s-class specific impulse for a CubeSat propulsion system

This paper presents the development of a thrust stand to enable direct measurement of thrust and specific impulse for a CubeSat propulsion system during firing. The thrust stand is an inverted pendulum and incorporates a mass balance for direct in situ mass measurement. The proposed calibration procedure allows precise performance characterization and achieves a resolution of 80 μN thrust and 0.01 g mass loss, by taking into account the drift of the thrust-stand zero caused by propellant consumption. The performance of a water micro-resistojet propulsion system for CubeSats was directly characterized as a proof of concept of the thrust stand. Continuous profiles of thrust, specific impulse, and mass consumption were acquired under various conditions in a single firing test. A thrust from 1 mN to 10 mN and a specific impulse from 45 s to 100 s with a maximum measurement uncertainty of ±15.3% were measured for the throat Reynolds number in the range 100-400.

Adjustment of Subthalamic Deep Brain Stimulation Parameters Improves Wheeze and Dyspnea in Parkinson's Disease

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for motor features in Parkinson's disease (PD). We present the case of a 56-year-old man with a 17-year history of PD. He underwent bilateral STN-DBS at the age of 51 years because of troublesome dyskinesia and wearing off. His motor features dramatically improved after the operation; however, he developed dysarthria and a refractory wheeze associated with dyspnea due to abnormal hyperadduction of the false vocal fold. By adjusting the stimulation site of STN, his severe wheeze, which was considered to be the result of the unfavorable spread of current to the corticobulbar tract, was significantly improved. This report provides concrete evidence that wheezing is caused by hyperadduction of the false vocal fold as an adverse effect of STN-DBS and can be reversed by adjusting the stimulation site for STN-DBS.

Half-tied Stay Suture Technique for Cerebrovascular End-to-side Anastomosis: A Technique to Expand the View of the Hidden Ostium

In cerebrovascular end-to-side anastomosis, thick, hard donor arteries overlying thin recipient arteries impair the view of the ostium, and may result in occlusion of the anastomosis. To improve the intraoperative view, we modified the stay sutures. After performing standard recipient arteriotomy and placing the first stay suture, we half-tied the second stay suture to leave a loop: half-tied stay suture (HSS). The thread of the HSS was secured with a clip to avoid slippage. For suturing side A, the clip pulling on the HSS was gently moved to the opposite side of side A, i.e. to side B, and the donor artery was revolved by several degrees to side B; the first stay suture was used as the fulcrum. Under the expanded view of the ostium, untied interrupted sutures were placed on side A. Then the donor vessel was revolved to the opposite side and side B was sutured in the same manner. At last, the HSS and all other sutures were tied fully. Our HSS method was used in three adults who underwent superficial temporal- to middle cerebral artery anastomosis despite anticipated poor visibility of the ostium. Compared with the conventional method, the view of the ostium was expanded with less manipulation of the vessel walls. There were no complications, and the anastomosis remained patent in all three patients. This simple modification of the stay sutures reduces the risk of anastomotic occlusion due to iatrogenic vascular damage by excessive manipulation under a restricted view.

Visual disorders caused by cranial arteriovenous fistula with venous drainage into the superior ophthalmic vein

BACKGROUND

Although the abnormal venous drainage into the superior ophthalmic vein (SOV) is a well-known entity responsible for ocular symptoms, it remains unclear to what degree it affects the visual function. The purpose of this study was to evaluate the incidence, characteristics and outcomes of the visual disorders in patients with intracranial arteriovenous fistula (AVF) with venous drainage into the SOV.

METHODS

This retrospective study involved eight patients diagnosed with intracranial AVFs with abnormal venous drainage into the SOV between January 2014 and December 2016.

RESULTS

The most common location of AVF was the cavernous sinus (CS) in five patients, followed by the intraorbit in two patients and superior sagittal sinus (SSS) in one patient. Visual disorders were detected in three patients (two intraorbit and one CS). The visual field contraction was observed in a patient with intraorbital AVF, and the reduction of visual acuity was confirmed in another patient with intraorbital AVF and a patient with CS dural AVF. All patients underwent an interventional treatment consisting of endovascular embolisation, stereotactic radiosurgery or both, which was selected based on their angioarchitecture. Although angiographic cure of AVF was confirmed in all patients, visual function did not fully recover in two patients with intraorbital AVF.

CONCLUSIONS

In cases of intraorbital AVF, visual disorders are more frequent and can result in poorer outcomes compared with other dural AVFs with drainage into the SOV. Early diagnosis and treatment are crucial to preserve the visual function of patients with intraorbital AVF.

Abstract WP328: Suppression of Tachycardia and Cost Effectiveness of Bisoprolol Transdermal Patch Addition to Intravenous Nicardipine in Antihypertensive Treatment for Acute Intracerebral Hemorrhage

Introduction: In patients with hypertensive intracerebral hemorrhage (ICH), intravenous (i.v.) Nicardipine is often used to lower the blood pressure. However, reflex tachycardia is a well-known side effect. Bisoprolol transdermal patch, a beta-blocker to be percutaneously absorbed, recently became commercially available in Japan. It can be used for patients with acute ICH with vomiting or dysphagia. The aim of this study is to evaluate suppressing effect of tachycardia and cost effectiveness of adding Bisoprolol transdermal patch to i.v. Nicardipine in patients with hypertensive ICH.

Methods: We randomly assigned patients who were admitted to our department from January 2015 through April 2017 because of acute ICH to single antihypertensive treatment group (i.v. Nicardipine only) or combination treatment group (Bisoprolol transdermal patch and i.v. Nicardipine). The primary outcome was heart rate during 24 hours after admission. Key secondary outcomes were dose of Nicardipine (drug costs), neurological prognosis as defined by modified Rankin scale 0 to 2, and adverse drug reactions.

Results: A total of 59 patients were randomized into two groups; 35 patients were assigned to single antihypertensive treatment group and 24 patients were assigned to combination treatment group. There were no significant differences between two groups in baseline characteristics on admission (age, body weight, hematoma volume, NIHSS, systolic blood pressure, heart rate). Mean heart rate during 24 hours after admission were significantly lower in combination treatment group (78.10±11.43 vs. 86.13±12.46, P=0.021). Hourly heart rate of combination treatment group was significantly lower in 5 to 24 hours later from start of treatment. Dose of Nicardipine was tended to be lower in combination treatment group (80.54±65.93 vs. 119.7±96.80mg, P=0.10), and costs of antihypertensive drug was tended to be lower in combination treatment group (5708±4569 vs. 8292±6708 yen, P=0.13). Neurological prognosis showed no difference (P=0.72), and bradycardia occurred in three patients of combination treatment group.

Conclusions: Adding Bisoprolol transdermal patch to Nicardipine can decrease heart rate and may reduce drug costs in antihypertensive treatment for acute ICH.

Relationship between Stroke Events during Pachinko Play and Prognosis

BACKGROUND

This study investigated whether pachinko play influences the outcome of stroke events, and identified the significant variables affecting outcomes.

METHODS

We reviewed the medical and imaging records of 2075 consecutive patients with stroke from January 2003 through June 2012. The remaining patients were divided into 2 groups, the pachinko players group (PP) and the non-pachinko players group (NPP). Background factors were recorded on admission. Multivariate logistic regression analysis was used to identify the factors significantly correlated with Glasgow Outcome Scale (GOS) score and risk of death at the time of discharge.

RESULTS

The PP group exhibited higher prevalence of hypertension and current smoking compared with the NPP group. However, no difference was found in outcomes between the PP and NPP groups. Multivariate analysis identified the dependent predictive variables for GOS as age (adjusted β = -.18, 95% confidence interval [CI]: -.22 to -.14, P <.001), Glasgow Coma Scale (GCS) score on admission (adjusted β = .64, 95% CI: .60 to .68, P <.001), and history of hypertension (adjusted β = -.06, 95% CI: -.10 to -.02, P = .007). Logistic regression analysis showed that age (odds ratio = 1.02, 95% CI: 1.01 to 1.04, P <.001) and GCS score on admission (odds ratio = .72, 95% CI: .69 to .75, P <.001) were significantly associated with death at the time of discharge.

CONCLUSIONS

Patients with stroke during playing pachinko have higher prevalence of hypertension and higher smoking rate, but pachinko play itself was not a critical factor determining the outcome of patients with stroke in our emergency center.

DCLK1 phosphorylates the microtubule-associated protein MAP7D1 to promote axon elongation in cortical neurons

Doublecortin-like kinase 1 (DCLK1) is a member of the neuronal microtubule-associated doublecortin (DCX) family and functions in multiple stages of neural development including radial migration and axon growth of cortical neurons. DCLK1 is suggested to play the roles in part through its protein kinase activity, yet the kinase substrates of DCLK1 remain largely unknown. Here we have identified MAP7D1 (microtubule-associated protein 7 domain containing 1) as a novel substrate of DCLK1 by using proteomic analysis. MAP7D1 is expressed in developing cortical neurons, and knockdown of MAP7D1 in layer 2/3 cortical neurons results in a significant impairment of callosal axon elongation, but not of radial migration, in corticogenesis. We have further defined the serine 315 (Ser 315) of MAP7D1 as a DCLK1-induced phosphorylation site and shown that overexpression of a phosphomimetic MAP7D1 mutant in which Ser 315 is substituted with glutamic acid (MAP7D1 S315E), but not wild-type MAP7D1, fully rescues the axon elongation defects in Dclk1 knockdown neurons. These data demonstrate that DCLK1 phosphorylates MAP7D1 on Ser 315 to facilitate axon elongation of cortical neurons. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 419-437, 2017.

Inhibition of Trigeminal Respiratory Activity by Suckling

The trigeminal motor system is involved in many rhythmic oral-motor behaviors, such as suckling, mastication, swallowing, and breathing. Despite the obvious importance of functional coordination among these rhythmic activities, the system is not well-understood. In the present study, we examined the hypothesis that an interaction between suckling and breathing exists in the brainstem, by studying the respiratory activity in trigeminal motoneurons (TMNs) during fictive suckling using a neonatal rat in vitro brainstem preparation. The results showed that fictive suckling, which was neurochemically induced by bath application of N-methyl-D,L-aspartate and bicuculline-methiodide, or by local micro-injection of the same drugs to the trigeminal motor nucleus, inhibited the inspiratory activities in both respiration TMNs and respiratory rhythm-generating neurons. Under patch-clamp recording, fictive suckling caused membrane potential hyperpolarization of respiration TMNs. We conclude that the brainstem preparation contains an inhibitory circuit for respiratory activity in the trigeminal motor system via the rhythm-generating network for suckling. Abbreviations: BIC, bicuculline methiodide; GABA, gamma aminobutyric acid; NMA, N-methyl-D,L-aspartate; NMDA, N-methyl-D-aspartate; and TMN, trigeminal motoneuron.

Expressions of isopeptide bonds and corneodesmosin in middle ear cholesteatoma

OBJECTIVE

Isopeptide bonds form cross-links between constituent proteins in the horny layer of the epidermis. Corneodesmosin (CDSN) is a major component of corneodesmosomes, which bind corneocytes together. Both play important roles in maintaining epidermal barrier functions. In the present study, we investigated the expressions of isopeptide bonds, CDSN, and related enzymes in middle ear cholesteatoma in comparison with the skin.

DESIGN

Prospective case series of patients with middle ear cholesteatoma.

SETTING

Tertiary medical institute.

PARTICIPANTS

Cholesteatoma and normal postauricular skin were collected from patients with acquired middle ear cholesteatoma during tympanomastoidectomy.

MAIN OUTCOME MEASURES

Expression of e-(g-glutamyl)lysine isopeptide bonds was examined by immunohistochemistry; Expressions of transglutaminase (TGase)1, TGase2, TGase3, and TGase5 by immunohistochemistry and quantitative RT-PCR (qRT-PCR); expression of CDSN by immunohistochemistry, qRT-PCR, and Western blot; and expressions of tissue kallikrein-related peptidase (KLK)5, KLK7, KLK14, and serine peptidase inhibitor Kazal type 5 (SPINK5) by qRT-PCR.

RESULTS

TGase2 was higher (P=0.0046) and TGase5 was lower (P=0.0008) in cholesteatoma than in the postauricular skin. Immunoreactivity for isopeptide bonds was localized in the granular and horny layers, and was not different between the two tissues. Immunoreactivity for CDSN was localized in the granular layer, and was lower in cholesteatoma than in the skin (P=0.0090). Western blot and qRT-PCR confirmed that the expression of CDSN was lower in cholesteatoma than in the skin. Expressions of KLK5, KLK7, KLK14, or SPINK5 were not different between the two tissues.

CONCLUSIONS

These results indicate that the production of CDSN is likely to be suppressed in cholesteatoma, which would account, at least in part, for the mechanical fragility and increased permeability of the cholesteatoma epithelium.

Studies on the validity of urinary enzyme assay in the diagnosis of drug-induced renal lesions in rats

The validity of urinary enzyme assays in the diagnosis of renal lesions was studied in rats for evaluation in comparison with other tests such as urinalysis and serum biochemical assay. Tubular damages of slight or severe degree were induced by daily intramuscular administration of 500 mg/kg or 1,000 mg/kg of kanamycin (KM) for 7 and 6 days respectively. Glomerular lesions were induced subcutaneous injection of 30 mg/kg of puromycin (PM) for 6 days. The enzymes, assayed daily before and after the onset of administration, were lactic dehydrogenase (LDH), aspartate aminotransferase (GOT), alkaline phosphatase (AI-P), acid phosphatase (Ac-P), leucin aminopeptidase (LAP) and γ-glutamyl transpeptidase (γ-GT). The distribution of these enzymic activities in the kidneys was histochemically examined. Assays of LDH and GOT on the kidney tissue homogenate were also conducted. Histological alterations of the kidneys were examined in the rats sacrificed after termination of administration.

Significant elevation of the LDH and GOT urine levels were observed within 24 hours in rats treated with 500 mg/kg of KM with the high enzyme levels being maintained throughout the administration period, while the other enzymes remained within pretreatment levels or were only slightly elevated. Serum urea nitrogen (BUN) and creatinine levels remained unchanged with no abnormality being found in the urinalysis of this group. In the group treated with 1,000 mg/ kg of KM, concomitant rising of all urine enzyme levels was observed, with elevation of the LDH and GOT levels being extreme while the BUN and serum creatinine levels rose only at the termination of the administration period. The BUN level rose earlier than did most of the urinary enzymes in puromycin-treated rats.

Depletion of LDH activity was histochemically demonstrated in the kidneys where no histological alteration was observable, while the activities of AI-P, γ-GT, and LAP showed no distinct changes until the tabular destruction became severe. Upon termination of both KM and PM administration, the depletion of LDH and GOT activities was noted in a kidney homogenate assay for the enzymes.

These results clearly showed that among the enzymes studied, the LDH and GOT urine levels are the most sensitive indicators for detecting proximal tubular lesions induced by KM. It was further demonstrated that the urinary enzyme assay in combination with serum BUN measurement is an effective examination for distinguishing tubular from glomerular lesions.

[Extendable Cords to Prevent Tumbling of a Suction Device during Craniotomy]

OBJECTIVE

Suction is necessary during craniotomy, and intraoperative tumbling of the suction device interrupts operative procedures. To avoid this, we developed a technique that would fasten the device to an extendable cord as is used to secure cell phones.

SURGICAL TECHNIQUE

We used this technique in more than 300 craniotomies at the specific point of time when the suction device tends to tumble, i. e., during the opening and closure of a wound, which requires frequent instrument exchanges. Extendable cords fastened to the tip of the suction hose using a gift tie were attached to the drapes to secure the suction device next to the operative field. During the operation, the extendable cord followed the suction device manipulations. Consequently, although there was some tension in the cord during its extension, the maneuverability of the suction device was maintained. As the hanging suction device was closer to the operative field than devices stored in conventional pockets, its manipulation was easier and quicker. Upon release, the suction device automatically returned to its original position without distracting the surgeon. Tumbling of the device was prevented, and there were no procedure-related complications.

CONCLUSIONS

Our simple modification using extendable cords prevented tumbling, avoided unnecessary replacements, and eased the manipulation of a suction device.

Increased permeability of the epithelium of middle ear cholesteatoma

OBJECTIVE

We investigated the electrical impedance of and the expressions of tight junction molecules in the cholesteatoma epithelium to provide supporting evidence for the acid lysis theory of bone resorption in middle ear cholesteatoma.

METHODS

Study subjects were patients with primary acquired middle ear cholesteatoma and those with non-cholesteatomatous chronic otitis media who underwent tympanomastoidectomy. The electrical impedance of the cholesteatoma epithelium was measured during tympanomastoidectomy by loading alternating currents of 320 Hz and 30.7 kHz. The expressions of tricellulin (MARVELD2), claudin-1 (CLDN1) and claudin-3 (CLDN3) were examined by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction.

RESULTS

The electrical impedance of the cholesteatoma epithelium was significantly lower than that of the post-auricular skin and external auditory canal skin at both 320 Hz and 30.7 kHz. Immunoreactivity for MARVELD2, CLDN1 and CLDN3 was localised mainly in the granular layer, and to lesser degree, in the horny and spinous layers in both the cholesteatoma tissue and post-auricular skin. Fluorescence intensity was moderate for MARVELD2, weak for CLDN1 and strong for CLDN3. The expressions of MARVELD2, CLDN1 and CLDN3 mRNA were significantly lower in the cholesteatoma tissue than in the post-auricular skin.

CONCLUSIONS

These results indicate the increased permeability of the cholesteatoma epithelium and suggest that this change is, at least partially, dependent on the decrease in the expressions of the tight junction molecules. This evidence supports the acid lysis hypothesis of bone resorption in cholesteatoma.

Adult Drosophila sensory neurons specify dendritic territories independently of dendritic contacts through the Wnt5-Drl signaling pathway

Here, Yasunaga et al. use Drosophila class IV dendrite arborization (C4da) sensory neurons as a system to investigate how neurons specify dendritic territories during neuronal development. They show that, unlike the larval dendrites, adult C4da dendrites define the dendritic boundary independently of dendritic contacts and that Wnt5 derived from sternites is required for specification of the ventral boundaries of C4da dendrites. These findings provide novel insights into how dendritic territories of neurons develop and the role of the Wnt5–Drl signaling pathway in the contact-independent dendritic boundary specification.

Sensory neurons with common functions are often nonrandomly arranged and form dendritic territories in stereotypic spatial patterns throughout the nervous system, yet molecular mechanisms of how neurons specify dendritic territories remain largely unknown. In Drosophila larvae, dendrites of class IV sensory (C4da) neurons completely but nonredundantly cover the whole epidermis, and the boundaries of these tiled dendritic fields are specified through repulsive interactions between homotypic dendrites. Here we report that, unlike the larval C4da neurons, adult C4da neurons rely on both dendritic repulsive interactions and external positional cues to delimit the boundaries of their dendritic fields. We identify Wnt5 derived from sternites, the ventral-most part of the adult abdominal epidermis, as the critical determinant for the ventral boundaries. Further genetic data indicate that Wnt5 promotes dendrite termination on the periphery of sternites through the Ryk receptor family kinase Derailed (Drl) and the Rho GTPase guanine nucleotide exchange factor Trio in C4da neurons. Our findings thus uncover the dendritic contact-independent mechanism that is required for dendritic boundary specification and suggest that combinatory actions of the dendritic contact-dependent and -independent mechanisms may ensure appropriate dendritic territories of a given neuron.

Crystallization of high-quality protein crystals using an external electric field

The effect of a 20 kHz external electric field on the quality of tetragonal hen egg white (HEW) lysozyme crystals was investigated using X-ray diffraction rocking-curve measurements. The full width at half-maximum was found to be larger for high-order reflections but smaller for low-order reflections. In particular, it was revealed that a large amount of local strain is accumulated in tetragonal HEW lysozyme crystals grown under an applied field at 20 kHz. Comparison with previous results obtained for crystals grown with an applied field at 1 MHz [Koizumi, Uda, Fujiwara, Tachibana, Kojima & Nozawa (2013).J. Appl. Cryst.46, 25–29] indicated that improvement of the protein crystal quality could be achieved by selection of an appropriate frequency for the applied electric field, which has a significant effect on the growth of the solid.

Wearable blood flowmeter appcessory with low-power laser Doppler signal processing for daily-life healthcare monitoring

A new appcessory for monitoring peripheral blood flow in daily life consists of a wearable laser Doppler sensor device and a cooperating smart phone application. Bluetooth Low Energy connects them wirelessly. The sensor device features ultralight weight of 15 g and an intermittent signal processing technique that reduces power consumption to only 7 mW at measurement intervals of 0.1 s. These features enable more than 24-h continuous monitoring of peripheral blood flow in daily life, which can provide valuable vital-sign information for healthcare services.

Elastic constants in orthorhombic hen egg-white lysozyme crystals

The ultrasonic sound velocities of cross-linked orthorhombic hen egg-white lysozyme (HEWL) crystals, including a large amount of water in the crystal, were measured using an ultrasonic pulse-echo method. As a result, seven elastic constants of orthorhombic crystals were observed to be C11 = 5.24 GPa, C22 = 4.87 GPa, C12 = 4.02 GPa, C33 = 5.23 GPa, C44 = 0.30 GPa, C55 = 0.40 GPa, and C66 = 0.43 GPa, respectively. However, C13 and C23 could not be observed because the suitable crystal planes could not be cut from bulk crystals. We conclude that the observed elastic constants of the cross-linked crystals are coincident with those of the intrinsic crystals without cross-linking. Moreover, the characteristics of the elastic constants in orthorhombic HEWL crystals are due to the fact that the shear elastic constants, C44, C55, and C66, are softer than in tetragonal crystals. That is, the shear components, C44, C55, and C66, are one half of those of the tetragonal crystals.

Doublecortin-like kinase enhances dendritic remodelling and negatively regulates synapse maturation

Dendritic morphogenesis and formation of synapses at appropriate dendritic locations are essential for the establishment of proper neuronal connectivity. Recent imaging studies provide evidence for stabilization of dynamic distal branches of dendrites by the addition of new synapses. However, molecules involved in both dendritic growth and suppression of synapse maturation remain to be identified. Here we report two distinct functions of doublecortin-like kinases, chimeric proteins containing both a microtubule-binding domain and a kinase domain in postmitotic neurons. First, doublecortin-like kinases localize to the distal dendrites and promote their growth by enhancing microtubule bundling. Second, doublecortin-like kinases suppress maturation of synapses through multiple pathways, including reduction of PSD-95 by the kinase domain and suppression of spine structural maturation by the microtubule-binding domain. Thus, doublecortin-like kinases are critical regulators of dendritic development by means of their specific targeting to the distal dendrites, and their local control of dendritic growth and synapse maturation.

Hanging foot switch for bipolar forceps: a device for surgeons operating in the standing position: technical note

For surgeons operating in the standing position, the manipulation of foot switches involves shifting of the weight to the pivoting leg and the possible loss of contact between the switch and the foot. We solved this problem by changing the position of the switch that operates bipolar forceps. Our novel device is made of aluminum plates. The base plate features a foot strap and a height-adjustable overhang over the switch-operating foot. A commercially-available disc type foot switch is attached to the underside of the overhang in upside-down position, so the switch is operable with the toe. To turn on the switch, the toe is flexed dorsally to push the switch pedal, so the action is limited to the part distal to the metatarsophalangeal joints. Our switch was used in more than 100 consecutive microsurgeries performed by surgeons operating in the standing position. The switch manipulation required no shifting of the weight and was easier and quicker than manipulation of conventionally-placed switches. The surgeons were able to change the foot position freely with the modified switch, thereby avoiding loss of contact with the switch. The modified switch placement reduced physical fatigue in the lower extremities, annoyance related to the manipulation of conventionally-placed switches, and increased the comfort of surgeons operating in the standing position.

Improvement of crystal quality for tetragonal hen egg white lysozyme crystals under application of an external alternating current electric field

X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white lysozyme (HEWL) crystals grown with and without application of an external alternating current (AC) electric field, and then the crystal quality was assessed by the FWHMs of each rocking-curve profile. The FWHMs for HEWL crystals grown with an external electric field were smaller than those for crystals grown without. In particular, the average FWHM for the 12 12 0 reflection with an external electric field (0.0034°) was significantly smaller than that without (0.0061°). This indicates that the crystal quality of HEWL crystals was improved by application of the external AC electric field. This crystallization technique can be expected to enhance the resolution of protein molecule structure analysis by X-ray diffraction.

Electric field measurement in microwave discharge ion thruster with electro-optic probe

In order to understand the internal phenomena in a microwave discharge ion thruster, it is important to measure the distribution of the microwave electric field inside the discharge chamber, which is directly related to the plasma production. In this study, we proposed a novel method of measuring a microwave electric field with an electro-optic (EO) probe based on the Pockels effect. The probe, including a cooling system, contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. This method enables measurement of the electric field profile under ion beam acceleration. We first verified the measurement with the EO probe by a comparison with a finite-difference time domain numerical simulation of the microwave electric field in atmosphere. Second, we showed that the deviations of the reflected microwave power and the beam current were less than 8% due to inserting the EO probe into the ion thruster under ion beam acceleration. Finally, we successfully demonstrated the measurement of the electric-field profile in the ion thruster under ion beam acceleration. These measurements show that the electric field distribution in the thruster dramatically changes in the ion thruster under ion beam acceleration as the propellant mass flow rate increases. These results indicate that this new method using an EO probe can provide a useful guide for improving the propulsion of microwave discharge ion thrusters.

Control of Gibbs free energy relationship between hen egg white lysozyme polymorphs under application of an external alternating current electric field

The distribution of phases between bulk (tetragonal structure) and spherulitic crystals for hen egg white lysozyme was controlled under application of an external alternating current electric field. The distribution of phases differed depending on differences in the magnitude of the electrostatic energy contribution to the respective chemical potentials of the two solid phases. Therefore, the Gibbs free energy relationship between the two solid phases could be controlled by changing the frequency of the applied external electric field. Such a method of controlling the Gibbs free energy relationship among polymorphs would be adaptable to many kinds of protein.

Cell type-specific localization of optineurin in the striatal neurons of mice: implications for neuronal vulnerability in Huntington's disease

Striatal neuropathology of Huntington's disease (HD) involves primary and progressive degeneration of the medium-sized projection neurons, with relative sparing of the local circuit interneurons. The mechanism for such a patterned cell loss in the HD striatum continues to remain unclear. Optineurin (OPTN) is one of the proteins interacting with huntingtin and plays a protective role in several neurodegenerative disorders. To determine the cellular localization pattern of OPTN in the mouse striatum, we employed a highly sensitive immunohistochemistry with the tyramide signal amplification system. In this study, we show that OPTN appeared as a cytoplasmic protein within the subsets of the striatal neurons. Of particular interest was that OPTN was abundantly expressed in the interneurons, whereas low levels of OPTN were observed in the medium projection neurons. This cell type-specific distribution of OPTN in the striatum is strikingly complementary to the pattern of neuronal loss typically observed in the striatum of patients with HD. We suggest that OPTN abundance is an important cellular factor in considering the cell type-specific vulnerability of striatal neurons in HD.