Middle cluneal nerve entrapment sites in the surgical field.

INTRODUCTION: Middle cluneal nerve (MCN) entrapment around the sacroiliac joint elicits low back pain (LBP). For surgical decompression to be successful, the course of the MCN must be known. We retrospectively studied the MCN course in 15 patients who had undergone MCN neurolysis. METHODS: Enrolled in this retrospective study were 15 patients (18 sides). We inspected their surgical records and videos to determine the course of the entrapped MCN. The area between the posterior superior- and the posterior inferior iliac spine was divided into areas A-D from the rostral side. The MCN transit points were identified at the midline and the lateral edge connecting the posterior superior- and posterior inferior iliac spine. Before and 6 months after surgery, the patients recorded the degree of LBP on the numerical rating scale and the Roland-Morris Disability Questionnaire. RESULTS: We decompressed 24 MCNs. The mean number was 1.3 nerves per patient (range 1-2). The MCN course was oblique in the cranio-caudal direction; the nerve tended to be observed in areas C and D. In six patients (40%), we detected two MCN branches, they were in the same area and adjacent. Postoperatively, LBP was improved significantly in all patients. CONCLUSION: Between the posterior superior- and the posterior inferior iliac spine, the MCN ran obliquely in the cranio-caudal direction; it was prominent in areas on the caudal side. In six (40%) patients, we decompressed two adjacent MCNs. Our findings are useful for MCN decompression surgery.

Long-term outcome after surgery for middle cluneal nerve entrapment neuropathy.

PURPOSE: Entrapment of the middle cluneal nerve (MCN-E) can elicit low back pain (LBP). Patients whose LBP responds only transiently to the analgesic effects of MCN blockage may be candidates for surgery. This study addresses its long-term efficacy. METHODS: We initially subjected 34 MCN-E patients (48 sides) to surgical release. Of these, 4 were excluded from this study because their follow-up was shorter than 24 months. The mean age of the 30 included patients was 71.5 years; the mean postoperative follow-up period was 40.4 months. Clinical outcomes were assessed on the Numerical Rating Scale (NRS) for LBP and the Roland Morris Disability Questionnaire (RDQ) before surgery and at the latest follow-up visit. RESULTS: The 30 patients (44 sides) reported severe LBP, leg symptoms were elicited by 32 sides. A mean of 1.4 MCN branches were surgically released, 32 sides were addressed by neurolysis, 7 by neurectomy, and 5 underwent both procedures due to the presence of 2 nerve branches. There were no complications. In the course of a mean follow-up of 26.3 months, MCN-E elicited recurrent symptoms on 6 sides; all had undergone neurolysis or neurectomy and a second operation improved the symptoms. All patients showed significant improvement at the last follow-up visit. Postoperatively both their NRS for LBP and their RDQ scores were improved (pre- vs. postoperative scores, p < 0.05). CONCLUSIONS: While surgical release of MCN-E is expected to yield long-term symptom relief, on 6 of 32 sides (18.8%) treated by neurolysis the patients reported pain recurrence. Whether neurectomy effectively prevents the recurrence of MCN-E in the long term requires further study.

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.

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.

[Microvascular Decompression to Treat Abducens Nerve Paralysis Caused by Compression of the Anterior Inferior Cerebellar Artery:A Case Report].

Microvascular decompression(MVD)is an effective treatment for hemifacial spasm and trigeminal neuralgia. However, there are few reports regarding its use with abducens nerve palsy. Here, we report the case of a 77-year-old male who presented with diplopia and was admitted to our facility for right abducens nerve palsy. MRI constructive interference in steady-state(CISS)showed that the right anterior inferior cerebellar artery(AICA)was curved in a posterior-superior direction at the beginning of the region of origin, causing compression of the root exit zone of the right abducens nerve. In addition, MRI showed an unruptured fusiform aneurysm(5.3mm×7.1mm)of the vertebral artery(VA)involving the posterior inferior cerebellar artery(PICA). However it was not related to abducens nerve paralysis. The aneurysm was successfully treated with an occipital artery-posterior inferior cerebellar artery(OA-PICA)bypass and clipping of the proximal VA and PICA origin. The position of the offending artery was moved using a Teflon® felt fibrin glue and the retrosigmoid transcondylar fossa approach. The patient recovered from abducens nerve paralysis with no new neurological deficit. We emphasize the importance of choosing an appropriate approach as this increases the possibility of treating abducens nerve paralysis in a timely manner.

Middle cluneal nerve entrapment mimics sacroiliac joint pain.

BACKGROUND: Sacroiliac joint (SIJ)-related pain is associated with low back- and buttock pain and the SIJ score is diagnostically useful because it helps to differentiate between SIJ-related pain and pain due to other factors such as lumbar disc herniation and lumbar spinal canal stenosis. Middle cluneal nerve (MCN) entrapment (MCN-E) can produce pain involving the lower back and buttocks. Therefore, the origin of the pain must be identified. We successfully treated patients with a high SIJ score whose pain was attributable to MCN-E. METHODS: Between August 2016 and June 2017, we treated 40 patients with non-specific low back pain. Among them, 18 (45%) presented with a positive SIJ score. Although SIJ treatment was unsuccessful in 4 of these patients, they responded to MCN-E treatment. RESULTS: All 4 patients reported tenderness at the site of the sacrotuberous ligament (STL); 3 were positive for the one-finger test and experienced pain while sitting in a chair. The effect of SIJ block was inadequate in the 4 patients. As they reported severe pain at the trigger point in the area of the MCN, we performed MCN blockage. It resulted in pain control. However, in 1 patient, the effect of MCN block was transient and required MCN neurolysis. At the last visit, our patients' symptoms were significantly improved; their average numerical rating scale score fell from 8.3 to 1.0, their Roland-Morris Disability Questionnaire score fell from 12.8 to 0.3, and their average Japanese Orthopaedic Association score rose from 12.5 to 19.5. CONCLUSIONS: In patients with suspected SIJ-related pain, the presence of MCN-E must be considered when the effect of SIJ block is unsatisfactory.

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.

[Microneurosurgical Treatment for Refractory Entrapment Neuropathy of Suprascapular Nerve:A Case Report].

Suprascapular nerve entrapment is rarely treated by neurosurgeons in Japan. However, it is often observed in post-stroke patients and in cases of accessory nerve injury as a complication of posterior fossa craniotomy. We report a case of suprascapular nerve entrapment due to superior transverse scapular ligament, which was successfully diagnosed and surgically treated. The patient was a 66-year-old female who used be a janitor. She complained of dysesthesia around the shoulder. The diagnosis was made based on the characteristic neurological findings including pain around the scapula, supraspinatus muscle weakness, and favorable but temporary response to suprascapular nerve block. After undergoing conservative management for one and a half year, she decided to undergo the nerve decompression surgery. The surgical treatment was performed under microscope with neuromonitoring. Following surgery, the painful area was dramatically reduced. We believe that suprascapular nerve disorders can be treated with careful neurological evaluation by neurosurgeons.

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.

Impact of Dynamic Change of Meandering of Parallel Artery to the Idiopathic Tarsal Tunnel Syndrome.

In idiopathic tarsal tunnel syndrome (TTS), walking seems to make symptoms worse. The findings imply that an ankle movement dynamic component may have an impact on the etiology of idiopathic TTS. We describe how the ankle movement affects the nerve compression caused by the surround tissue, particularly the posterior tibial artery. We enrolled 8 cases (15 sides) that had TTS surgery after tarsal tunnel (TT) MRI preoperatively. Dorsiflexion and plantar flexion were the two separate ankle positions used for the T2* fat suppression 3D and MR Angiography of TT. Based on these findings, we looked at how the two different ankle positions affected the posterior tibial artery's ability to compress the nerve. Additionally, we assessed the posterior tibial artery's distorted angle. We divided the region around the TT into four sections: proximal and distal to the TT and proximal half and distal half to the TT. Major compression cause was posterior tibial artery. Most severe compression point was proximal half in the TT in all cases without one case. In each scenario, the nerve compression worsens by the plantar flexion. The angle of the twisted angle of the posterior tibial artery was significantly worsened by the plantar flexion. In idiopathic TTS, deformation of posterior tibial artery was the primary compression component. Nerve compression was exacerbated by the plantar flexion, and it was attributable with the change of the distorted angle of the posterior tibial artery. This could be a contributing factor of the deteriorating etiology by walking in idiopathic TTS.

Perioperative Complications and Adverse Events after Surgery for Peripheral Nerve- and Para-lumbar Spine Diseases.

Peripheral nerve diseases are common. Para-lumbar spine diseases (PLSDs) include peripheral neuropathy around the lumbar spine, e.g., cluneal nerve entrapment and gluteus medius muscle pain. While these diseases can be treated by less invasive surgery, postoperative complications have not been sufficiently investigated. We document complications after surgery for peripheral nerve diseases and PLSDs. Between July 2014 and December 2020, 678 consecutive patients with peripheral nerve diseases and PLSDs underwent 1068 surgical procedures (upper limb 200 sites, lower limb 447 sites, para-lumbar spine 394 sites, and tumor 27 sites). After excluding 27 procedures to address tumors, we examined the remaining 1,041 procedures undergone by 672 patients (average age 68.2 years) and recorded the complication rate observed within 30 days after the procedures. The overall surgical complication rate was 3.9% (41/1041 procedures); 6 procedures required surgical salvage and 35 were treated conservatively. There were no long-term sequelae from complications. The complication rate was high after surgery for lateral femoral cutaneous-, saphenous-, and common peroneal nerve entrapment and tarsal tunnel syndrome; all sites involved the lower limbs. As a result, intergroup comparison showed that the complication rate was significantly higher for the upper limb (3.0%) procedures than the lower limb (6.7%) and PLSD (1.3%) procedures. It was significantly lower for PLSD operations than lower and upper limb operations. The patient age and diabetes mellitus were significant risk factors for postoperative complications. Their rate was low in patients treated for peripheral nerve diseases and PLSDs; 34 of the 41 complications (82.9%) were related to the surgical wound.

Spontaneous Obliteration of a Dissecting Aneurysm of Recurrent Artery of Heubner Monitored by Serial Magnetic Resonance Vessel Wall Imaging.

Aneurysms of the recurrent artery of Heubner (RAH) are known to be one of the uncommon cerebral aneurysms, predominantly presenting with bleeding symptoms. Previously, nine cases of the RAH aneurysms have been reported, all of which were treated surgically or endovascularly and most cases developed postoperative cerebral infarct in the ipsilateral caudate nucleus. Herein, we report a man presenting with transient ischemic attack due to diffuse cerebral vasospasm from a minor non-disabling subarachnoid hemorrhage (SAH) from an RAH aneurysm. He visited our hospital 7 days after the first experience of a thunderclap headache complaining with transient unilateral motor weakness and thin SAH in the right sylvian fissure. Diagnostic catheter angiography revealed a dissecting fusiform aneurysm (8 mm in size) originating from the left RAH contralateral to the thin SAH. Contrast-enhanced magnetic resonance vessel wall imaging (MR-VWI) helped to identify the ruptured nature of the RAH aneurysm. Owing to his delayed ischemic condition after minor SAH, he was conservatively treated with serial MR-VWI monitoring. The aneurysm was spontaneously obliterated with an asymptomatic lacunar infarct in the ipsilateral caudate nucleus in a month. Together, this case was considered as the dissecting aneurysm of RAH with a favorable outcome after the conservative management. Although long-term follow-up is mandatory because the disappearance of the vessel wall enhancement does not necessarily secure the permanent cure of the lesion, serial MR-VWI is helpful to diagnose the ruptured nature and monitor its chronological change in combination with conventional radiological imaging techniques.

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.

Posterior Inferior Cerebellar Artery Originating from the Jugular Branch of the Ascending Pharyngeal Artery.

The variation in which the posterior inferior cerebellar artery arises from the hypoglossal branch of the ascending pharyngeal artery is thought to be related to the remnant of the primitive hypoglossal artery, and is referred to as a primitive hypoglossal artery variant. Cases in which the posterior inferior cerebellar artery arises from the jugular branch of the ascending pharyngeal artery are extremely rare. The authors present a case of a 50-year-old male with vertebral artery dissection who had this extremely rare variation bilaterally. The patient also had several rare variations of the intracranial vessels. This posterior inferior cerebellar artery arising from the jugular branch of the ascending pharyngeal artery may have developed due to the anastomosis between the meningeal and the pial vessels of the posterior fossa. Alternatively, an unknown primitive anastomotic artery may have passed through the jugular foramen. Genetic factors may play an important role in the presence of this anomalous vessel.