Paralumbar Spine Disease as a Cause of Low Back Pain in Older Adults.

Introduction Low back pain (LBP) is a major contributor to decreases in the ability to perform activities of daily living (ADL) in older adults. Paralumbar spine disease (PLSD) is a common cause of LBP. We aimed to investigate the causes of LBP, including PLSD, among older adults. Methods Among 744 consecutive patients with LBP, 75 patients (10.1%) aged >80 years (25 males and 50 females) were included. The average patient age was 83.9 years. All patients were evaluated using lumbar magnetic resonance imaging (MRI) and radiography to diagnose the causes of LBP. PLSD was diagnosed based on clinical symptoms, palpation, and the effects of the block. Results Eleven patients (11/75, 14.7%) had acute osteoporotic vertebral fractures. Twenty-eight of the remaining 64 patients exhibited decreased LBP with oral medication, and six (6/75, 8.0%) exhibited lumbar spinal canal stenosis on MRI. PLSD was suspected in 19 of the remaining 30 cases based on clinical symptoms and palpation. Blocks were effective in 16 patients with PLSD, which involved superior cluneal nerve entrapment (SCN-E) in eight patients (10.7%), middle cluneal nerve entrapment (MCN-E) in nine patients (12.0%), sacroiliac joint (SIJ) pain in five patients (6.7%), and gluteus medius muscle (GMeM) pain in three patients (4.0%). The average numerical rating scale (NRS) scores for pain changed from 7.5 ± 1.5 before treatment to 1.3 ± 0.9 at discharge (p < 0.05). Conclusion Osteoporotic acute vertebral fracture (14.7%) was identified as the cause of LBP in older adults. Block therapy for PLSD may aid in the diagnosis and treatment of non-specific LBP.

Manual superficial temporal artery compression using a circular plastic material for embolization of meningioma: illustrative case.

BACKGROUND: In meningiomas that occur in the high-convexity region, the superficial temporal artery (STA) frequently feeds the tumor, and when embolizing from the middle meningeal artery (MMA), the embolic material may not reach the tumor vessels because of the pressure gradient resulting from the STA blood flow, resulting in inadequate embolization. In this case, a circular plastic material was used to apply circumferential pressure around the parietal foramen to control blood flow to the tumor. OBSERVATIONS: A 45-year-old male underwent head magnetic resonance imaging that revealed a 2.2-cm meningioma in the right high-convexity region. Preoperative embolization was performed. When N-butyl-2-cyanoacrylate was injected from the right MMA while using a circular plastic material to compress the skin around the parietal foramen through which the bilateral STAs (the tumor feeders) flow, it was able to fully penetrate the tumor vessel and occlude the other feeders in a retrograde manner. The patient underwent tumor removal after embolization uneventfully. LESSONS: Manual compression of the STA using a circular plastic material is useful when the tumor is fed by the STA through the parietal foramen and is also applicable to transarterial embolization of dural arteriovenous fistulas fed by the STA or occipital artery.

Pain Relief Following Selective Tibial Neurotomy for Spastic Equinus Foot Secondary to Stroke and Traumatic Brain Injury.

OBJECTIVE: Selective tibial neurotomy (STN) has been indicated for spastic equinus foot (SEF); however, the impact of this procedure on quality of life and activities of daily living has not been evaluated in detail. This study aimed to evaluate the surgical outcomes of STN and its effect on SEF accompanied by pain. METHODS: We evaluated 26 patients (mean age: 59.6 ± 15.2 years; 14 men and 12 women) who underwent STN for SEF, 10 of whom complained of spontaneous pain preoperatively. We used the following scales for clinical evaluation: the Modified Ashworth Scale, Medical Research Council (MRC), 10-m walking test, Functional Independence Measure, and numeric rating scale for pain. These scales were evaluated preoperatively and postoperatively. Differences in clinical characteristics were compared between the 10 patients with pain and the 16 patients without pain. RESULTS: Significant differences were observed in all evaluation scale scores except for the Functional Independence Measure, and no serious adverse events were reported. Pain intensity was significantly improved from 6.4 ± 2.0 to 2.7 ± 2.3 (P < 0.05). An analysis showed that the preoperative mean Medical Research Council score of ankle movement was significantly lower in patients with pain but recovered to the same level postoperatively at the 6-month follow-up. CONCLUSIONS: Our study showed significant improvements in spasticity and its associated symptoms, and STN effectively addressed spastic pain and motor weakness. Among various treatment modalities, STN may be positively indicated for patients with spastic pain in the lower leg.

Target Embolization of Complex Vertebral Artery Dissecting Aneurysm with Endovascular Reconstructive Technique Using Cone-Beam Computed Tomography Angiography: Technical Note.

OBJECTIVE: Detailed vasculature of vertebral artery dissecting aneurysms (VADAs) is often complicated owing to the irregular structure with the intimal flap/double lumen. Our aim was to present an endovascular reconstructive technique with assessment of detailed vasculature and the relationship between dissection and surrounding vessels using cone-beam computed tomography angiography (CBCT-A). METHODS: The study included 6 cases with complex vertebral artery dissecting aneurysm. Selective digital subtraction angiography initially identified the location and shape of dissection. CBCT-A was then performed with selective injection into the affected vertebral artery. Luminal morphology of the dissection and surrounding arterial anatomy were assessed using CBCT-A. RESULTS: CBCT-A clearly demonstrated luminal morphology of the intimal flap/double lumen, the entrance into the pseudolumen, and the entire dissecting segment. Tiny perforator arteries were also identified. In all 6 cases, target coil embolization for the pseudolumen and stent placement using an LVIS stent for the entire dissecting segment were successfully performed with the aid of information obtained from CBCT-A. No complications occurred in the perioperative period, and improvement of dissection was identified in the follow-up period. CONCLUSIONS: Target embolization of complex vertebral artery dissecting aneurysm with endovascular reconstructive technique with special reference to the detailed anatomy of dissection using CBCT-A would be useful for safe and effective treatment results.

Variations of en Bloc Resection for Advanced External Auditory Canal Squamous Cell Carcinoma: Detailed Anatomical Considerations.

Currently, only lateral temporal bone resection (LTBR) and subtotal temporal bone resection (STBR) are widely utilized for the surgical treatment of advanced squamous cell carcinoma of the external auditory canal (EAC-SCC). However, there are few descriptions of variations on these surgical approaches. This study aimed to elucidate the variations of en bloc resection for advanced EAC-SCC. We dissected the four sides of cadaveric heads to reveal the anatomical structures related to temporal bone resection. From the viewpoint of surgical anatomy, surgical patterns of temporal bone cutting can be divided into four categories: conventional LTBR, extended LTBR, conventional STBR, and modified STBR. Extended LTBR is divided into four types: superior, inferior, anterior, and posterior extensions. Several extension procedures can be combined based on the extension of the tumor. Furthermore, en bloc resection with the temporomandibular joint or glenoid fossa increases the technical difficulty of a surgical procedure because the exposure and manipulation of the petrous segment of the internal carotid artery are limited from the middle cranial fossa. Surgical approaches for advanced SCC of the temporal bone are diverse. They require accurate preoperative evaluation of the tumor extension and preoperative consideration of the exact line of resection to achieve marginal negative resection.

Middle cluneal nerve entrapment neuropathy attributable to lumbar disc herniation.

BACKGROUND: Middle cluneal nerve entrapment neuropathy (MCN-EN) is a known cause of low back pain (LBP). Here, we succeeded in treating a patient with a lumbar disc herniation who actually had MCN-EN with a nerve block and neurolysis. CASE DESCRIPTION: A 52-year-old female presented with severe left lower back and lateral thigh pain making it difficult to walk. The lumbar MRI revealed a disc herniation on the left at the L5/S1 level. On palpation, we identified a trigger point on the buttock where the MCN penetrates the long posterior sacroiliac ligament between the posterior superior and inferior iliac spine. Two left-sided MCN blocks, followed by the left MCN neurolysis procedure, were performed under local anesthesia. At the last follow-up, 10 months after surgery, the LBP has not recurred, and she requires no medications for pain control. CONCLUSION: Here, a patient with a left-sided L5S1 disc herniation and low back/leg pain was successfully treated for MCN-EN with nerve block followed by neurolysis.

Clinical features of middle cluneal nerve entrapment neuropathy.

BACKGROUND: Entrapment of the middle cluneal nerve (MCN), a peripheral nerve in the buttock, can elicit low back pain (LBP). We examined the epidemiology, clinical course, and treatment of MCN entrapment (MCN-EN). METHODS: Among 383 LBP patients who visited our institute, 105 were admitted for intractable LBP. They were 42 men and 63 women; their average age was 64 years. Based on clinical symptoms, palpation, and the effects of MCN block, we suspected MCN-EN in these 105 patients, 50 of whom are our study subjects. Their treatment outcomes were assessed at the time of discharge and at follow-up visits. RESULTS: MCN-EN was diagnosed in 50 of the 383 patients (13.1%) and they were hospitalized. In 43 (11.2%), MCN-EN was associated with other diseases (superior cluneal nerve entrapment, n = 21, sacroiliac joint pain, n = 9, other, n = 13). At the time of discharge, the symptoms of patients with LBP due to MCN-EN were significantly improved by repeat MCN blocks. In 7 of the 383 patients (1.8%), LBP was improved by only MCN blocks; 5 of them had reported leg symptoms in the dorsal part of the thigh. After discharge, 22 of the 50 hospitalized patients required no additional treatments after 2-5 blocks; 19 required only conservative treatment, and 9 underwent microsurgical release of the MCN. CONCLUSIONS: We confirmed MCN-EN in 50 of 105 patients admitted for intractable LBP. Repeat MCN blocks were effective in 22 patients; 19 required additional conservative treatment, and 9 underwent surgery. Buttock pain radiating to the posterior thigh was an MCN-EN symptom that has been diagnosed as pseudo-sciatica. Before subjecting patients with intractable LBP to surgery, the presence of MCN-EN must be ruled out.

Endoscopic-assisted Duraplasty with Collagen Matrix for Growing Skull Fracture: A Case Report.

Growing skull fracture (GSF) is a rare complication of pediatric head injury. Early diagnosis and immediate surgical intervention are required for the prevention of irreversible brain damage. Surgical management involves water-tight closure of the dural defect and commonly uses autologous materials because of tissue compatibility; however, a large skin flap and craniotomy are necessary to harvest the autologous materials and repair the dural defect. We describe a successful case of endoscopic-assisted duraplasty using collagen matrix in a female infant suffering from early phase GSF. A 4-month-old female infant presented with a GSF. We surgically treated her because the fracture width progressively expanded 6 days post-injury. A zigzag skin incision was made, and the extent of the skull fracture and dural laceration was observed using an endoscope. Utilizing the collagen matrix, duraplasty was performed to completely seal the dural defect. Subsequently, cranioplasty was performed and the opposite sides of the fracture margins were drawn and bonded by nylon suture. Postoperatively, the patient did not develop any complication or experience recurrence. This is the first report of duraplasty using collagen matrix in GSF, and the collagen matrix can be used as a dural substitute. This novel technique was safe and a less invasive surgical approach for treating patients with GSF.

Optimal surgical indications of endoscopic surgery for traumatic acute subdural hematoma in elderly patients based on a single-institution experience.

Recently, treatment of acute subdural hematoma (ASDH) by minimally invasive surgery with endoscopy has been successfully demonstrated. However, few case series are available on this procedure for ASDH, and the surgical indication has not been established. We retrospectively analyzed the data of patients (n = 26) aged 65 years or older who underwent endoscopic surgery (ES) for ASDH at our institution between January 2011 and March 2019. We then evaluated the surgical outcomes and procedure-related complications in patients who underwent ES. The mean hematoma reduction rate was over 90%. Percentage of favorable outcomes at discharge was 69.2% in ES-treated patients. The presence of a skull fracture, subarachnoid hemorrhage, midline shift/subdural hematoma thickness ratio > 1.0, and early surgery were associated with postoperative IPHs in patients who underwent ES or conventional surgery for ASDH. The present study revealed that ES for elderly patients with ASDH is likely to be an efficient and safe procedure when patients are selected appropriately. However, ES is not recommended in patients with significant IPHs on initial CT scan. Additionally, ES should be carefully considered in cases with the factors, where IPHs may progress following surgery.

High-frequency thermal coagulation to treat middle cluneal nerve entrapment neuropathy.

OBJECTIVE: Middle cluneal nerve entrapment (MCN-E) around the sacroiliac joint can elicit low back pain (LBP). Pain control can be obtained with anesthetic nerve blocks; however, when their effectiveness is transient, surgical release may be necessary. We investigated the efficacy of radiofrequency thermocoagulation (RFTC) in patients with MCN-E. METHODS: Between December 2018 and August 2019, 11 consecutive patients (4 men, 7 women; mean age 76.4 years) with intractable medial buttock pain due to MCN-E underwent MCN RFTC. The mean symptom duration was 49.5 months; pre-RFTC local MCN blocks provided pain relief for a mean of 7.7 days. The severity of pain in the medial buttock due to MCN-E was recorded before and 2, 6, 12, and 24 weeks after RFTC on the numerical rating scale (NRS) and the Roland-Morris Disability Questionnaire (RDQ). RESULTS: All patients reported pain alleviation; there were no complications. While there was a significant difference in the pre- and post-RFTC treatment NRS (p < 0.05), the RDQ scores were significantly lower only after 12 weeks. The duration of pain relief was significantly prolonged by RFTC (p < 0.05). Two patients suffered pain relapse 10 weeks post-RFTC; pain alleviation was obtained by re-RFTC performed 2 weeks after pain recurrence. Two other patients relapsed 20 and 21 weeks post-RFTC; their symptoms also disappeared by MCN block administered 24 weeks after they had undergone RFTC. CONCLUSION: RFTC may safely control intractable LBP due to MCN-E.

Dynamic assessment of internal carotid artery and elongated styloid process in a case of bilateral carotid artery dissection.

BACKGROUND: Vascular Eagle syndrome is that an elongated styloid process causes ischemic stroke due to internal carotid artery (ICA) dissection. Dynamic assessment using radiological imaging has not been well investigated. We assessed the change in the relative positional relationship between the elongated styloid process and the ICA using a cone-beam computed tomography (CBCT). CASE DESCRIPTION: A 46-year-old female presenting with disturbance of consciousness, right hemiparesis, and aphasia was admitted to our hospital. Initial CT analysis showed a bilateral elongated styloid process. Magnetic resonance angiography (MRA) showed occlusion of the left ICA and a near occlusion of the right ICA. MRA also revealed the intimal flap and intramural hematoma in the bilateral ICA. Digital subtraction angiography showed bilateral ICA occlusion and carotid artery stenting was performed subsequently. After that, we visualized the movement of carotid stent with CBCT fusion methods. The stent moved forward and backward at the attachment point of the styloid process during head rotation, and there was a possibility that mechanical stress was emphasized at this point. Styloidectomy was performed after her rehabilitation. The patient did not experience a recurrence of stroke. CONCLUSION: We showed that repeated attachment of the styloid process and ICA may trigger an ICA dissection during head rotation. This finding would be helpful for understanding the causes of vascular Eagle syndrome.

Treatment of Coexisting Paralumbar Spine Diseases in Patients with Lumbar Disc Herniation.

Lumbar disc herniation (LDH) elicits low back pain (LBP) and lower-limb symptoms. Paralumbar spine disease (PLSD), for example, superior cluneal nerve/middle cluneal nerve entrapment (SCN-EN, MCN-EN) and sacroiliac joint pain (SIJ), may be attributable to LDH whose treatment may not ameliorate their symptoms. We treated LDH patients and addressed their coexisting PLSDs. We retrospectively analyzed the effects of targeted block therapy for PLSD in 47 patients with LDH. They were 23 men and 24 women ranging in age from 21 to 79 years. They were seen between August 2014 and October 2018, within 3 weeks of LDH onset. PLSD was diagnosed based on the symptoms of patients whose pain was not controlled by oral medications. The treatment outcome was assessed by comparing the numerical rating scale (NRS) and the Roland-Morris Disability Questionnaire (RDQ) score recorded before and 2 weeks after last block treatment. Of the 47 patients with LDH, 2 suffered no LBP and 30 reported tenderness in the low back. We performed block therapy in 13 patients; 9 (19.1%) had concurrent PLSD and experienced pain relief. Their NRS improved from 8.1 ± 1.8 before- to 1.3 ± 0.9 after treatment; their RDQ score fell from 11.2 ± 6.0 to 0.9 ± 1.2 (both, p < 0.01). In an LDH patient with MCN-EN alone, MCN neurolysis was performed 2 weeks after a single MCN block proved to be only transiently effective. Paralumbar diseases may coexist in patients with LDH; treatment of the former may alleviate their LBP.

Artery Transposition Using Indocyanine Green for Tarsal Tunnel Decompression.

BACKGROUND: Surgery for idiopathic tarsal tunnel syndrome (TTS) is of limited effectiveness or ineffective. Using indocyanine green video angiography (ICG-VA), we treated idiopathic TTS by posterior tibial artery (PTA) decompression from the posterior tibial nerve (PTN) and evaluated postoperative patency of the PTA. METHODS: We treated 12 patients (12 feet) with idiopathic TTS by PTA decompression from the PTN and transposed its location. Age range of patients was 70-87 years (mean 77.9 years); all patients were operated on under local anesthesia. After a 2-cm skin incision, the flexor retinaculum was resected, and the PTA was decompressed from the PTN. It was then sutured to the flexor retinaculum for decompression and to prevent compression recurrence. ICG-VA was used to confirm the absence of PTA flow disturbance and to inspect the vasa nervorum of the PTN. RESULTS: We encountered no intraoperative or postoperative complications. Postoperatively, ICG-VA confirmed blood flow in the PTA and intactness of the vasa nervorum in all cases. One patient required adjustment of PTA position. All patients reported symptom improvement. CONCLUSIONS: Our surgical method of treating idiopathic TTS under ICG-VA monitoring is simple, safe, and effective.

Toward global standardization of conducting fair investigations of allegations of research misconduct.

In the United States, through nation-wide discussions, the procedures for handling allegations of research misconduct are now well established. Procedures are geared toward carefully treating both complainants and respondents fairly in accordance with the US framework. Other countries, which have their own cultural and legal framework, also need fair and legally compatible procedures for conducting investigations of allegations of research misconduct. Given the rapid growth of international collaboration in research, it is desirable to have a global standard, or common ground, for misconduct investigations. Institutions need clear guidance on important subjects such as what information should be included in the investigation reports, how the investigation committee should be organized once research misconduct allegation has been received, how to conduct the investigation, how the data and information obtained should be taken as evidence for vs. against misconduct, and what policies the investigation committee should follow. We explore these issues from the viewpoint of members of committees investigating accusations of research misconduct (hereafter referred to as "investigation committees") as well as persons overseeing the committees in Japan. We hope to engender productive discussions among experts in misconduct investigations, leading to a formulation of international standards for such investigation.

Impact of Spot Sign Etiology in Supratentorial Intracerebral Hemorrhage on Outcomes of Endoscopic Surgery.

BACKGROUND: The spot sign (SS) in spontaneous intracerebral hemorrhage has been reported to be a predictive factor of poor outcome; however, how SS is related with the clinical outcome remains unclear. We aimed to investigate how etiology associated with SS affects the clinical outcome of endoscopic surgery. METHODS: We retrospectively analyzed data from 104 patients (43 women and 61 men, mean age: 64.2 ± 11.0 years) who underwent endoscopic surgery for supratentorial intracerebral hemorrhage. The outcome variables analyzed were in-hospital mortality and modified Rankin scale score at 90 days from onset. RESULTS: The prevalence of intraventricular hemorrhage and the mean initial modified Graeb score were greater in SS-positive than in SS-negative patients (100% vs. 47.7%, P < 0.001, and 14.4 ± 5.4 vs. 10.6 ± 6.0, P = 0.03, respectively). Postoperative rebleeding occurred more frequently in SS-positive than -negative patients (25.0% vs. 6.8%, P = 0.045). The in-hospital mortality rate was 7.7% and was not significantly different between the groups (18.8% vs. 5.7%, P = 0.09). There was a significant unfavorable shift in modified Rankin scale scores at 90 days among SS-positive patients compared with SS-negative patients in an analysis with ordinal logistic regression (adjusted common odds ratio, 4.38; 95% confidence interval 0.06-0.79, P = 0.02). CONCLUSIONS: Intraventricular hemorrhage and postoperative rebleeding were considered to be associated with the poor outcome in patients with SS. The SS on computed tomography angiography may be valuable in predicting rebleeding and clinical outcome after surgery.

A Case of Juvenile Stroke due to Carotid Artery Dissection from an Elongated Styloid Process-Revisiting Conservative Management.

Carotid artery dissection is a significant etiology of juvenile stroke. Blunt trauma from an elongated styloid process can rarely cause carotid artery dissection, which is one of well-known clinical presentations of Eagle's syndrome as known as stylocarotid syndrome. Growing number of publications contributed improved awareness and diagnostic modalities for this clinical entity, thus the carotid artery dissection from an elongated styloid process is often diagnosed appropriately. The management of carotid artery dissection in stylocarotid syndrome tends to be nonconservative (ie, removal of the process or carotid stenting) presumably due to a publication bias prone to surgical intervention. However, the compression of elongated styloid process to carotid artery is usually difficult or even dangerous to directly prove. Furthermore, stent fracture with subsequent stent and carotid artery occlusion has been reported as a complication of the treatment. Here, we report a male presenting with acute embolic stroke due to carotid artery dissection with the ipsilateral elongated styloid process who has been managed conservatively for more than 1.5 years without any sequelae. We will discuss the management strategy and emphasize the importance of patient education of daily life, since the surgical intervention seems not always necessary in this clinical setting.

Characteristics of Low Back Pain due to Superior Cluneal Nerve Entrapment Neuropathy.

Study Design: Retrospective analysis. Purpose: The present study aimed to investigate the features of low back pain (LBP) due to superior cluneal nerve (SCN) entrapment neuropathy (SCN-EN) using the Roland Morris Disability Questionnaire (RMDQ), and to analyze the differences between LBP due to SCN-EN and lumbar spinal canal stenosis (LSS). Overview of Literature: The SCN is derived from the cutaneous branches of the dorsal rami of T11-L5 and passes through the thoracolumbar fascia. LBP due to SCN-EN is exacerbated by various types of lumbar movement, and its features remain to be fully elucidated, often resulting in the misdiagnosis of lumbar spine disorder. Methods: The present study included 35 consecutive patients with SCN-EN treated via nerve blocks or surgical release between April 2016 and August 2017 (SCN-EN group; 16 men, 19 women; mean age, 65.5±17.0 years; age range, 19-89 years). During the same period, 33 patients were surgically treated with LSS (LSS group; 19 men, 14 women; mean age, 65.3±12.0 years; age range, 35-84 years). The characteristics of LBP were then compared between patients with SCN-EN and those with LSS using the RMDQ. Results: The duration of disease was significantly longer in the SCN-EN group than in the LSS group (26.0 vs. 16.0 months, p =0.012). Median RMDQ scores were significantly higher in the SCN-EN group (13 points; interquartile range, 8-15 points) than in the LSS group (7 points; interquartile range, 4-9 points; p <0.001). For seven items (question number 1, 8, 11, and 20-23), the ratio of positive responses was higher in the SCN-EN group than in the LSS group. Conclusions: Patients with SCN-EN exhibit significantly higher RMDQ scores and greater levels of disability due to LBP than patients with LSS. The findings further demonstrate that SCN-EN may affect physical and psychological function.

Gluteus medius muscle decompression for buttock pain: a case-series analysis.

BACKGROUND: The causes of low back and buttock pain are variable. Elsewhere, we presented a surgical technical note addressing the gluteus medius muscle (GMeM) pain that elicited buttock pain treatable by surgical decompression. Here, we report minimum 2-year surgical outcomes of GMeM decompression for intractable buttock pain. METHODS: Between January 2014 and December 2015, we surgically treated 55 consecutive patients with a GMeM pain. Of these, 39 were followed for at least 2 years; they were included in this study. Their average age was 69.2 years; 17 were men and 22 were women. The affected side was unilateral in 24 patients and bilateral in the other 15 (total 54 sites). The mean follow-up period was 40.0 months (range 25-50 months). The severity of pre- and post-treatment pain was recorded on the numerical rating scale (NRS) and the Roland-Morris Disability Questionnaire (RDQ). RESULTS: Of the 39 patients, 35 also presented with leg symptoms. They were exacerbated by walking in all 39 patients and by prolonged sitting in 33 patients; 19 had a past history of lumbar surgery and 4 manifested failed back surgery syndrome. Repeat surgery for wider decompression was performed in 5 patients due to pain recurrence 15.8 months after the first operation. At the last follow-up, the symptoms were significantly improved; the average NRS fell from 7.4 to 2.1 and the RDQ score from 10.5 to 3.3 (p < 0.05). CONCLUSIONS: When diagnostic criteria are met, GMeM decompression under local anesthesia is a useful treatment for intractable buttock pain.

Microsurgical Anatomy of the Jugular Process as an Anatomical Landmark to Access the Jugular Foramen: A Cadaveric and Radiological Study.

BACKGROUND: The jugular process forms the posteroinferior surface of the jugular foramen and is an important structure for surgical approaches to the foramen. However, its morphological features have not been well described in modern texts. OBJECTIVE: To elucidate the microsurgical anatomy of the jugular process and examine its morphological features. METHODS: Five adult cadaveric specimens were dissected in a cadaveric study, and computed tomography data from 31 heads (62 sides) were examined using OsiriX (Pixmeo SARL, Bernex, Switzerland) to elucidate the morphological features of the jugular process. RESULTS: The cadaveric study showed that it has a close relationship with the sigmoid sinus, jugular bulb, rectus capitis lateralis, lateral atlanto-occipital ligament, and lateral and posterior condylar veins. The radiographic study showed that 9/62 sigmoid sinuses protruded inferiorly into the jugular process and that in 5/62 sides, this process was pneumatized. At the entry of the jugular foramen, if the temporal bone has a bulb-type jugular bulb, and if surgery concerns the right side of the head, the superior surface of the jugular process is more likely to be steep. CONCLUSION: The jugular process forms the posteroinferior border of the jugular foramen. Resection of the jugular process is a critical step for opening the jugular foramen from the posterior and lateral aspects. Understanding the morphological features of the jugular process, and preoperative and radiographical examination of this process thus help skull base surgeons to access the jugular foramen.