Kazuyoshi Yamazaki

Treatment of low back pain in patients with vertebral compression fractures and superior cluneal nerve entrapment neuropathies

Background: Superior cluneal nerve entrapment neuropathy (SCN-EN) may contribute to low back pain (LBP). However, it is often misdiagnosed as lumbar spine disorder and poorly understood. Methods: Between April 2012 and September 2013, we treated 27 patients (3 men, 24 women; mean age 75.0 years) with LBP due to SCN-EN elicited by vertebral compression fractures. Symptoms were unilateral in 4 patients and bilateral in 23 patients. The interval between symptom onset and treatment averaged 10.8 months; the mean postoperative follow-up period was 19.0 months. The clinical outcomes were assessed utilizing the numeric rating scale (NRS) for LBP, the Japanese Orthopedic Association (JOA) score, and the Roland–Morris Disability Questionnaire (RDQ) before and after treatment (e.g., until the latest follow-up). Results: LBP in 17 patients was immediately improved by SCN block only. The remaining 10 patients required surgery (involving 18 sites) as SCN blocks were only transiently effective. Operative intervention resulted in the immediate and continued improvement of their LBP. Notably, their NRS decreased from 7.4 to 1.5, their RDQ scores from 19.6 to 7.0, and their JOA scores increased from 10.7 to 20.3. Conclusions: In this series, 27 patients with LBP due to SCN-EN responded either to SCN blocks (17 patients) or surgical release of SCN entrapment (10 patients at 18 sites).

A novel application of four-dimensional magnetic resonance angiography using an arterial spin labeling technique for noninvasive diagnosis of Moyamoya disease

BACKGROUND Noncontrast-enhanced time-resolved four-dimensional magnetic resonance angiography using an arterial spin labeling technique (ASL-4D MRA) is emerging as a next generation angiography for the management of neurovascular diseases. This study evaluated the feasibility of ASL-4D MRA for the diagnosis of Moyamoya disease (MMD) and MMD staging by using digital subtraction angiography (DSA) and time-of-flight MRA (TOF MRA) as current standards. METHODS Eleven consecutive non-operated patients who underwent DSA for the diagnosis of MMD were recruited. Two independent observers evaluated the three tests. The data were analyzed for inter-observer and inter-modality agreements on MMD stage. Nine of 22 hemispheres underwent surgical revascularization and ASL-4D MRA was repeated postoperatively. RESULTS Time-resolved inflow of blood through the cerebral vessels, including moyamoya vessels, was visualized in all the 22 non-operated hemispheres. MMD stages assessed by DSA and ASL-4D MRA were completely matched in 18 hemispheres, with a significant positive correlation between these modalities (r=0.93, P<0.001). Inter-observer agreement with ASL-4D MRA (κ=0.91±0.04, P<0.001) and inter-modality agreement between ASL-4D MRA and DSA (κ=0.93±0.04, P<0.001) were both excellent. MMD stages assessed by ASL-4D MRA have also a significant positive correlation with those assessed by TOF MRA (r=0.68, P=0.004). Repeated ASL-4D MRA clearly demonstrated the bypassed arteries and changes in the dynamic flow patterns of cerebral arteries in all the nine hemispheres after surgical revascularization. Of these, postoperative focal hyperperfusion was detected by single photon emission tomography in 7 hemispheres. In five of the seven hemispheres (71%) with postoperative hyperperfusion, ASL-4D MRA demonstrated focal hyperintense signals in the bypassed arteries, although TOF MRA did not. CONCLUSIONS Noninvasive ASL-4D MRA is feasible for the diagnosis of MMD staging. This next generation angiography may be useful for monitoring disease evolution and treatment response in cerebral arteries after revascularization surgery in MMD.

Low Back Pain Caused by Superior Cluneal Nerve Entrapment Neuropathy in Patients with Parkinson Disease

n patients with Parkinson disease (PD), postural abnormalities and increased muscle tonus lead to musculoskeletal I problems. The incidence of such problems was significantly higher in patients with PD than in an age-matched control group comprising patients with stroke and brain tumor. Low back pain (LBP) in particular was reported more frequently by patients with PD; in approximately 50%, it negatively affected their quality of life and activities of daily living (ADL). It is difficult to treat LBP in patients with PD, and the results of surgery to address their spinal diseases are unsatisfactory.

Clinical feathers and treatment of peroneal nerve entrapment neuropathy

OBJECTIVE Peroneal nerve entrapment neuropathy (PEN) is generally known as a drop foot with sensory disturbance. However, some patients experience numbness and pain in the affected area without severe paresis due to PEN. We report the clinical features and our surgical results of PEN cases. METHODS We encountered 17 cases of PEN. The patients were 7 females and 10 males and their ages ranged from 30 to 78 years(average 56.1 years). In these cases, conservative therapy was unsuccessful;therefore, we performed surgical treatment for PEN. RESULTS Among the 17 cases, 4 were of bilateral and 13 were of unilateral PEN. There was no severe paresis, as in drop foot;however, mild paresis (4/5, manual muscle test, MMT) was noted in 15 cases. In all cases, intermittent claudication presented, which ranged from 10 to 800 m (average 150 m). In 13 cases, radiological abnormality of the lumbar region was noted and 8 cases had a history of lumbar surgery (they had failed back surgery syndrome). In all the cases, we performed neurolysis of the peroneal nerve under local anesthesia;there was no surgical complication. After the surgery, symptoms improved, and the numerical rating of the lower limb improved from 8.6/10 to 0.8/10. Intermittent claudication also improved in all of the cases. CONCLUSIONS We successfully treated 17 cases of PEN, which had lower limb pain without severe paresis, as in drop foot. Our results indicate that PEN should be recognized as a cause of intermittent claudication. Neurolysis for PEN under local anesthesia is less invasive and is useful for the treatment of lower limb pain.

Treatment Strategy for Bilateral Carotid Stenosis: 2 Cases of Carotid Endarterectomy for the Symptomatic Side Followed by Carotid Stenting

Since the introduction of carotid stenting (CAS), a combined treatment for bilateral lesions using carotid endarterectomy (CEA) and CAS has been developed. However, there has been only 1 report about CEA then CAS. Herein we describe 2 patients with bilateral severe carotid stenosis who were treated by CEA for the symptomatic side and CAS for the contralateral asymptomatic side. A 71-year-old man underwent CEA for the symptomatic side. Although the patient suffered hyperperfusion syndrome after CEA, he recovered fully after 3 weeks of rehabilitation. Two months later, CAS was performed for the asymptomatic side, and he was discharged with no deficit. A 67-year-old man underwent CEA for the symptomatic side. The patient developed no postoperative neurologic deficits except for hoarseness. Four weeks later, CAS was performed for the contralateral asymptomatic side. After the procedure, however, severe hypotension occurred, and treatment by continuous injection of catecholamine was necessary to maintain systematic blood pressure. The patient was ultimately discharged with no deficit. The combined therapy of CAS for the asymptomatic side and then CEA for the symptomatic side has been recommended by several authors. However, one of the problems of this strategy is the higher incidence of postprocedural hemodynamic complications, and hypotension after CAS may be dangerous for the symptomatic hemisphere. We suggest a combined therapy using CEA for the symptomatic side and then CAS for the asymptomatic side can be 1 beneficial treatment option for patients with bilateral carotid stenosis without coronary artery disease.

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.

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.

[Non-Specific Back Pain due to Superior Cluneal Nerve Entrapment Neuropathy Treated with Neurolysis: A Case Report].

A 43-year-old man with a 10-year history of low back pain (LBP) had been conservatively treated elsewhere with medications for non-specific back pain. He presented to our institute with LBP and difficulty in standing up, sitting down, and sitting for prolonged periods. His Numerical Rating Scale score, due to LBP, was 8 out of 10. He had numbness on the lateral aspect of his left thigh. A lumbar radiography and magnetic resonance imaging studies revealed mild degenerative changes and mild canal stenosis in the lumbar spine. Palpation over the left posterior superior iliac crest, 8 cm from the midline over the iliac crest, revealed severe tenderness. A superior cluneal nerve(SCN)block performed at the trigger point in both the buttocks resulted in complete pain abatement and disappearance of the radiating pain. Therefore, we diagnosed SCN entrapment neuropathy(SCNE). However, the pain reappeared a few days later and subsequent treatments failed to relieve it; therefore, we decided to perform surgery. The SCN penetrates the thoracolumbar fascia through an orifice just before crossing over the iliac crest. We opened the orifice with microscissors in a distal to rostral direction along the SCN and released the entrapped nerve. After surgery, the symptoms were relieved and the patient experienced no recurrence in the last 4 years after the treatment. SCNE should be considered as a causative factor of LBP, and its treatment using minimally invasive surgery yields excellent clinical outcome.

The Relationship between Carotid Stump Pressure and Changes in Motor-Evoked Potentials in Carotid Endarterectomy Patients

Background The threshold of ischemic tolerance has not been completely identified in human clinical studies. Distal carotid artery pressure can be easily measured through the internal shunt tube during carotid endarterectomy (CEA). To confirm the critical threshold of intracranial arterial pressure and its maximum duration, we investigated the distal internal carotid artery (ICA) pressure and motor-evoked potential (MEP) changes during ICA clamping. Material and Methods Between September 2012 and March 2014, 9 patients (10 sides) with carotid stenosis (70-99%) were surgically treated at our hospital. All CEAs were performed under general anesthesia, and we routinely used a carotid shunt with the intraoperative MEP monitors. When the MEP amplitude decreased to < 50% of the control during carotid clamping, the MEP amplitude was defined as significantly reduced. Results The MEP amplitude significantly decreased in 2 of the 10 procedures (20%) during ICA clamping. The mean distal ICA pressure varied widely, ranging from 13 to 48 mm Hg. In seven cases with a mean distal ICA pressure > 20 mm Hg, there were no significant changes in the MEP during ICA clamping. However, there were three cases with a mean distal ICA pressure < 20 mm Hg, and the MEP amplitude significantly decreased in two of those three patients from 4 to 5 minutes after clamping. Conclusions The present study provides considerable information about a higher incidence of MEP amplitude deterioration in CEA patients with a mean distal ICA pressure < 20 mm Hg during ICA clamping.

[Successful acute endovascular therapy of cerebral embolism for a patient with ventricular assist device: a case report].

The number of patients with a ventricular assist device(VAD)will increase with the spread of heart transplantation in Japan. On the other hand, it is likely that VADs could cause cerebral embolism. However, there are few reports about endovascular therapy for intracranial embolic infarction from VAD. The authors report successful acute endovascular therapy for cerebral embolism. A 19-year-old woman with a VAD who received anti-coagulant treatment by warfarin sodium presented disturbance of consciousness and right hemiparesis. CT scan showed early CT sign in the left middle cerebral artery (MCA) area. 3D-CTA demonstrated occlusion of the left MCA and basilar artery (BA). We first performed endovascular recanalization in the left MCA, because IV tPA was ineligible. The left MCA was recanalized with TICI 2b perfusion and her symptoms were significantly improved. The treatment of the VAD patient reveals important issues. First, the femoral puncture requires ultrasound due to pulseless femoral artery. Second, the access route is an intact artery because of the anatomy of the VAD. Third, even if the patient has a hemorrhagic complication by intervention, the patient must be kept on anti-coagulant treatment because the VAD requires it. Careful consideration should be given to recanalization of occlusive vessels.