Juntaro Matsumoto

Do Characteristics of Dissection Differ between the Posterior Inferior Cerebellar Artery and the Vertebral Artery

OBJECTIVE The purpose of this study was to clarify the features of posterior inferior cerebellar artery (PICA) dissection. MATERIALS AND METHODS We prospectively registered 93 consecutive patients and 108 arteries with confirmed diagnoses of dissection in the vertebral artery (VA) or PICA between February 2007 and January 2014. Patients were diagnosed with arterial dissection when they had both acute symptoms and radiological characteristics in magnetic resonance imaging or digital subtraction angiography. Patients were divided into 2 groups depending on whether the site of dissection was VA (VA group) or PICA (PICA group). We compared the clinical and radiological characteristics and clinical outcomes of PICA versus VA dissection. RESULTS Of the 93 patients included in this study, 83 were in the VA group, and 10 had arterial dissection in the PICA. Patients with PICA dissection more frequently suffered from SAH (P < .001), whereas nonstroke symptom was often the initial symptom in the VA group. Pearl sign was seen most frequently at the dissection site of PICA. Surgical or endovascular treatment was performed in 9 of 10 PICA dissections, whereas more than half of the VA dissections were treated conservatively (P < .001). SAH was significantly more severe in the patients with PICA dissection compared with those in the VA group (P = .049). CONCLUSION Patients with PICA dissection suffered from subarachnoid hemorrhage more frequently than those with VA dissection. PICA dissection was treated with surgical intervention, whereas VA dissection was treated conservatively.

Common diseases mimicking lumbar disc herniation and their treatment

1Department of Neurosurgery, Chiba Hokuso Hospital, Nippon Medical School, Inzai-city, Chiba 270-1694, Japan. 2Department of Neurosurgery, Kushiro Rosai Hospital, Kushiro-city, Hokkaido 085-0088, Japan. 3Department of Neurosurgery, Nippon Medical School, Bunkyo-ku, Tokyo 113-8603, Japan. 4Department of Neurosurgery, Teikyo University, Itabashi-ku, Tokyo 173-8606, Japan. 5Department of Neurosurgery, Iwate Medical University, Morioka-city, Iwate 020-8505, Japan.

Surgical treatment of middle cluneal nerve entrapment neuropathy: technical note

OBJECTIVE The etiology of low-back pain (LBP) is heterogeneous and is unknown in some patients with chronic pain. Superior cluneal nerve entrapment has been proposed as a causative factor, and some patients suffer severe symptoms. The middle cluneal nerve (MCN) is also implicated in the elicitation of LBP, and its clinical course and etiology remain unclear. The authors report the preliminary outcomes of a less invasive microsurgical release procedure to address MCN entrapment (MCN-E). METHODS The authors enrolled 11 patients (13 sites) with intractable LBP judged to be due to MCN-E. The group included 3 men and 8 women ranging in age from 52 to 86 years. Microscopic MCN neurolysis was performed under local anesthesia with the patient in the prone position. Postoperatively, all patients were allowed to walk freely with no restrictions. The mean follow-up period was 10.5 months. LBP severity was evaluated on the numerical rating scale (NRS) and by the Japanese Orthopaedic Association (JOA) and the Roland-Morris Disability Questionnaire (RDQ) scores. RESULTS All patients suffered buttock pain, and 9 also had leg symptoms. The symptoms were aggravated by standing, lumbar flexion, rolling over, prolonged sitting, and especially by walking. The numbers of nerve branches addressed during MCN neurolysis were 1 in 9 patients, 2 in 1 patient, and 3 in 1 patient. One patient required reoperation due to insufficient decompression originally. There were no local or systemic complications during or after surgery. Postoperatively, the symptoms of all patients improved statistically significantly; the mean NRS score fell from 7.0 to 1.4, the mean RDQ from 10.8 to 1.4, and the mean JOA score rose from 13.7 to 23.6. CONCLUSIONS Less invasive MCN neurolysis performed under local anesthesia is useful for LBP caused by MCN-E. In patients with intractable LBP, MCN-E should be considered.

Impact of initial symptom for accurate diagnosis of vertebral artery dissection

Background It has been recognized that spontaneous vertebral artery dissection without neurological symptoms is not rare and easily misdiagnosed. Clinical clue for diagnosis of vertebral artery dissection includes initial symptoms such as headache, neck pain, or dizziness. Aim To assess the role of initial symptoms for diagnosis of spontaneous vertebral artery dissection. Methods Between September 2007 and January 2014, we retrospectively reviewed clinical records of 83 patients with unilateral vertebral artery dissection without consciousness disturbance at admission. Based on the diagnostic criteria of the Spontaneous Cervicocephalic Arterial Dissections Study, the patients were divided into three groups: possible, probable, and definite cases of vertebral artery dissection. Initial symptoms were collected at the time of diagnosis from medical record for the presence or absence of headache, neck pain, tinnitus and vertigo, as well as the area of pain and its characteristics. Results The numbers of definite, probable, and possible vertebral artery dissection were 39, 26, and 18, respectively. Out of 83 cases, unilateral or bilateral headache was the most commonly seen (in 60 cases), followed by neck pain (in 41 cases) and vertigo (in 20 cases). Statistically, unilateral headache and/or neck pain was more common in cases with definite vertebral artery dissection group compared with other classification of the Spontaneous Cervicocephalic Arterial Dissections Study (P = 0.040). Vertigo was also associated with the stratification of Spontaneous Cervicocephalic Arterial Dissections Study criteria (P = 0.012). Conclusions In our study, headache and/or neck pain, especially unilateral presentation, and vertigo were symptoms associated with the stratification of Spontaneous Cervico-cephalic Arterial Dissections Study criteria. Physicians should carefully obtain clinical history for the presence of a unilateral headache and/or neck pain and vertigo when vertebral artery dissection is suspected in patients with or without objective neurological signs.

Treatment of low back pain elicited by superior cluneal nerve entrapment neuropathy after lumbar fusion surgery

Object Low back pain (LBP) attributable to fusion failure, implant failure, infection, malalignment, or adjacent segment disease may persist after lumbar fusion surgery (LFS). Superior cluneal nerve (SCN) entrapment neuropathy (SCNEN) is a clinical entity that can produce LBP. We report that SCNEN treatment improved LBP in patients who had undergone LFS. Methods Between April 2012 and August 2015, we treated 8 patients (4 men and 4 women ranging in age from 38 to 88 years; mean age, 69 years) with SCNEN for their LBP after LFS. Our criteria for the diagnosis of SCNEN included a trigger point over the posterior iliac crest 7 cm from the midline and numbness and radiating pain in the SCN area upon compression of the trigger point. Symptom relief was obtained in more than 75% of patients within 2 h of inducing a local nerve block at the trigger point in the buttocks. The mean postoperative follow-up period was 28 months (range, 9-54 months). Results LBP was unilateral in 3 and bilateral in 5 patients. The senior author (T.I.) operated all patients for SCNEN under local anesthesia because they reported recurrence of pain after the analgesic effect of repeat injections wore off. This led to a significant improvement of their LBP. Conclusions SCNEN should be considered in patients reporting LBP after LFS. Treatment of SCNEN may be a useful option in patients with failed back surgery syndrome after LFS.

Deep Decompression of the Lateral Femoral Cutaneous Nerve Under Local Anesthesia

OBJECTIVE Meralgia paresthetica is a mononeuropathy of the lateral femoral cutaneous nerve (LFCN) caused by compression around the inguinal ligament. We report a surgical alternative for the treatment of meralgia paresthetica under local anesthesia and its outcomes. METHODS We operated on 12 patients with unilateral meralgia paresthetica whose age at surgery ranged from 62 to 75 years. The mean postoperative follow-up period was 19 months. Microsurgical deep decompression of LFCN was performed with the patient under local anesthesia. Clinical outcomes of surgical treatment were assessed based on the patients most recent follow-up visit and were classified into 3 categories: complete, partial, or no relief of symptoms. Symptoms of pain or numbness in the anterolateral part of the thigh were evaluated, using a visual analog scale, before surgery and after surgery, i.e., at the most recent follow-up visit. RESULTS All patients reported symptom improvement: complete relief in 9 patients (75%) and partial relief in 3 patients (25%). In the 3 patients with partial relief, the remaining symptoms did not affect their daily living. Overall, the visual analog scale scores were significantly improved in all patients (P < 0.05), and no patient experienced postoperative recurrence of their symptoms at the time of the last follow-up visit. CONCLUSIONS Symptoms of meralgia paresthetica can resemble those of a lumbosacral disorder. Microsurgical deep decompression under local anesthesia produces good surgical outcomes. The use of local anesthesia contributes not only to reduction of pain during surgery but also eliminates excessive surgical procedures and reduces the duration of hospital stay.

Clinical Features and Surgical Treatment of Superficial Peroneal Nerve Entrapment Neuropathy

Superficial peroneal nerve (S-PN) entrapment neuropathy (S-PNEN) is comparatively rare and may be an elusive clinical entity. There is yet no established surgical procedure to treat idiopathic S-PNEN. We report our surgical treatment and clinical outcomes. We surgically treated 5 patients (6 sites) with S-PNEN. The 2 men and 3 women ranged in age from 67 to 91 years; one patient presented with bilateral leg involvement. Mean post-operative follow-up was 25.3 months. We recorded their symptoms before- and at the latest follow-up visit after surgery using a Numerical Rating Scale and the Japan Orthopedic Association score to evaluate the affected area. We microsurgically decompressed the affected S-PN under local anesthesia without a proximal tourniquet. We made a linear skin incision along the S-PN and performed wide S-PN decompression from its insertion point at the peroneal tunnel to the peroneus longus muscle (PLM) to the point where the S-PN penetrated the deep fascia. One patient who had undergone decompression in the area of a Tinel-like sign at the initial surgery suffered symptom recurrence and required re-operation 4 months later. We performed additional extensive decompression to address several sites with a Tinel-like sign. All 5 operated patients reported symptom improvement. In patients with idiopathic S-PNEN, neurolysis under local anesthesia may be curative. Decompression involving only the Tinel area may not be sufficient and it may be necessary to include the area from the PLM to the peroneal nerve exit point along the S-PN.

Utility of cone-beam computed tomography angiography for the assessment of vertebral artery dissection

Vertebral artery dissection (VAD) has been recognized as a cause of headache and stroke. Accurate evaluation of dissection using several modalities such as catheter-based angiography, CT angiography (CTA), and magnetic resonance imaging (MRI) is essential for subsequent management. The aim of this retrospective study is to compare cone-beam computed tomography angiography (CBCT-A) with other image modalities for the evaluation of the detailed structures of VAD. Twenty-five consecutive cases identified as having VAD were included. They underwent catheter-based angiography (2D-digital subtraction angiography [DSA], 3D-DSA, and CBCT-A), CTA, and MRI for the diagnosis of VAD. CBCT-A was performed following conventional angiography. Dissecting lesions were evaluated for the presence of intimal flap/double lumen, wall thickening, and enhancement of outer wall. This study results showed that CBCT-A was the most superior modality to detect intimal flap/double lumen (found in 56% of the cases) due to its high spatial resolution. MRI was superior for the assessment of wall thickening as an intramural hematoma in 76% of the cases. However, wall thickening was detected in 44% of cases using CBCT-A. In 5 cases, enhancement of outer wall was identified only in CBCT-A. In conclusion, CBCT-A provides detailed luminal and wall morphology of VADs. CBCT-A is useful for the accurate diagnosis of VADs.

Undiagnosed Peripheral Nerve Disease in Patients with Failed Lumbar Disc Surgery

Study Design Retrospective study (level of evidence=3). Purpose We examine the relationship between residual symptoms after discectomy for lumbar disc herniation and peripheral nerve (PN) neuropathy. Overview of Literature Patients may report persistent or recurrent symptoms after lumbar disc herniation surgery; others fail to respond to a variety of treatments. Some PN neuropathies elicit symptoms similar to those of lumbar spine disease. Methods We retrospectively analyzed data for 13 patients treated for persistent (n=2) or recurrent (n=11) low back pain (LBP) and/or leg pain after primary lumbar discectomy. Results Lumbar re-operation was required for four patients (three with recurrent lumbar disc herniation and one with lumbar canal stenosis). Superior cluneal nerve (SCN) entrapment neuropathy (EN) was noted in 12 patients; SCN block improved the symptoms for eight of these patients. In total, nine patients underwent PN surgery (SCN-EN, n=4; peroneal nerve EN, n=3; tarsal tunnel syndrome, n=1). Their symptoms improved significantly. Conclusions Concomitant PN disease should be considered for patients with failed back surgery syndrome manifesting as persistent or recurrent LBP.