Microvascular decompression of the root emerging zone for hemifacial spasm: evaluation by fusion magnetic resonance imaging and technical considerations

Object

The root exit zone (RExZ) of the facial nerve has been considered to be the target in microvascular decompression (MVD) for hemifacial spasm. However, more proximal segments with oligodendrocyte-derived myelin, where the facial nerve root emerges at the pontomedullary sulcus and adheres to the brainstem surface (root emerging zone [REmZ]), may also be susceptible to neurovascular compression. This study evaluated the predictive value of magnetic resonance (MR) imaging in detecting and assessing the features of vascular compression, especially in the pontomedullary sulcus, and describes the technical considerations of MVD procedures for the more proximal segments of the facial nerve.

Methods

Twenty patients treated with MVD underwent three-dimensional constructive interference in steady-state MR imaging and three-dimensional time-of-flight MR angiography. Their fusion images were used to evaluate the anatomical neurovascular relationships and intraoperative findings were analyzed.

Results

Most offending arteries at the REmZ and the RExZ of the facial nerve were correctly identified by fusion MR imaging. During surgery, neurovascular contacts were identified at one or more segments of the facial nerve in all patients. The REmZ of the facial nerve was affected in 55 % of the patients. The most common offending vessel at the REmZ was the posterior inferior cerebellar artery rather than the anterior inferior cerebellar artery. The key procedure to explore the deep-seated REmZ in the pontomedullary sulcus was full dissection of the lower cranial nerves to the brainstem origin.

Conclusions

Our definition more correctly describes the specific anatomical relationship of the facial nerve origin from the brainstem and the clinically relevant target for MVD surgery. Fusion MR imaging is very useful to identify neurovascular contacts at both the RExZ and the REmZ of the facial nerve.     

Combined intraoperative monitoring of abnormal muscle response and Z-L response for hemifacial spasm with tandem compression type

Background

Multiple neurovascular compression is present in about 38 % cases of hemifacial spasm (HFS). In these cases, the vertebral artery (VA) compresses another vessel, which in turn compresses the nerve. This type was named as “the tandem type”. In the tandem type, the real offending vessel is often concealed by the VA. It is sometimes neglected by the surgeons. In this study, we report our experience in using abnormal muscle response (AMR) and ZL-Response (ZLR) simultaneously as intraoperative monitoring for MVD surgery of HFS with “the tandem type” vascular compression involving VA.

Methods

Fourteen “tandem type” patients treated with microvascular decompression surgery (MVD) surgery were included. ZLR and AMR were recorded simultaneously to identify the offending vessels in operation.

Results

After MVD surgery, 13 patients achieved excellent resolution of spasm. In one case, the patient failed to attain resolution in the first operation, underwent early reoperation and had good resolution. There were no operative deaths or serious operative complications. In all 14 cases, we found that VA compressed the anterior inferior cerebellar artery (AICA) or posterior inferior cerebellar artery (PICA), which in turn compressed the root exit zone (REZ). A typical ZLR was identified from the AICA or PICA but not from the VA. AMR was absent in one case and persisted in one case. After the VA was transposed, the typical AMR was unchanged, unstable or disappeared, and ZLR from the AICA/PICA also existed. AMR and ZLR did not disappear until AICA/PICA was sufficiently decompressed.

Conclusions

The combination of AMR and ZLR provides more useful information than does the AMR alone, and ZLR may be the only useful intraoperative monitoring for MVD surgery in times when AMR is absent or persists. ZLR played a crucial role in finding the real offending vessel, which was often concealed by the VA in tandem type.     

Microvascular decompression for trigeminal neuralgia using the ‘Stitched Sling Retraction’ technique in recurrent cases after previous microvascular decompression

Background

Microvascular decompression is a well-known therapeutic option for trigeminal neuralgia. It is considered safe and effective, and is the surgical treatment of choice for the malady. However, there is no standard technique for it and different authors have proposed different techniques of performing it. In this study, we observe the clinical results of the so-called ‘stitched sling retraction’ technique for recurrent cases of trigeminal neuralgia.

Methods

Twelve consecutive patients with recurrent trigeminal neuralgia after previous microvascular decompression(s) were admitted to our institution form February 2009 to February 2011 and underwent microvascular decompression of the trigeminal nerve using the ‘stitched sling retraction’ technique. In this technique, the offending loop of the superior cerebellar artery is retracted from the nerve and, using a silk thread loop around it, is suspended to the adjacent tentorium.

Results

All patients experienced pain resolution during the immediate post-operative period or within the first 6 months after surgery. They were followed for 24 to 38 months. No recurrence occurred.

Conclusions

The ‘stitched sling retraction’ technique shows promising preliminary results in recurrent cases of trigeminal neuralgia after previous microvascular decompression(s). Since it is a ‘transposing’ technique, it might be associated with less recurrence rates (due to resuming of the neurovascular conflict) than the classic interposing technique, which uses a prosthesis between the offending vessel and the trigeminal nerve.     

Treatment of basilar invagination

Purpose

Basilar invagination is a rare craniocervical malformation which may lead to neurological deficits related to compression of brainstem and upper cervical cord as well as instability of the craniocervical junction. This study presents results of a treatment algorithm developed over a 20-year period focussing on anatomical findings, short-term and long-term outcomes.

Methods

69 patients with basilar invagination (mean age 41 ± 18 years, history 64 ± 85 months) were encountered. The clinical courses were documented with a score system for individual neurological symptoms for short-term results after 3 and 12 months. Long-term outcomes were analyzed with Kaplan–Meier statistics.

Results

Patients with (n = 31) or without (n = 38) ventral compression were distinguished. 25 patients declined an operation, while 44 patients underwent 48 operations. Surgical management depended on the presence of ventral compression and segmentation anomalies between occiput and C3, signs of instability and presence of caudal cranial nerve dysfunctions. 16 patients without ventral compression underwent foramen magnum decompressions without fusion. 19 patients with ventral compression and abnormalities of segmentation or evidence of instability underwent a foramen magnum decompression with craniocervical (n = 18) or C1/2 (n = 1) stabilization. In nine patients with severe ventral compression and caudal cranial nerve deficits, a transoral resection of the odontoid was combined with a posterior decompression and fusion. Within the first postoperative year neurological scores improved for all symptoms in each patient group. In the long-term, postoperative deteriorations were related exclusively to instabilities either becoming manifest after a foramen magnum decompression in three or as a result of hardware failures in two patients.

Conclusions

The great majority of patients with basilar invagination report postoperative improvements with this management algorithm. Most patients without ventral compression can be managed by foramen magnum decompression alone. The majority of patients with ventral compression can be treated by posterior decompression, realignment and stabilization alone, reserving anterior decompressions for patients with profound, symptomatic brainstem compression.     

Emprical factors associated with Brainstem auditory evoked potential monitoring during microvascular decompression for hemifacial spasm and its correlation to hearing loss

Background

Cranial nerve VIII is at risk during microvascular decompression (MVD) for hemifacial spasm (HFS). The primary aim of this study is to evaluate the empirical factors associated with brainstem auditory evoked potential monitoring and its correlation to post operative hearing loss (HL) after MVD for HFS.

Methods

Pre-operative and post-operative audiogram data and BAEP from ninety-four patients who underwent MVD for HFS were analyzed. Pure tone audiometry (PTA) and Speech Discrimination Score (SDS) were performed on all patients before and after surgery. Intraoperative neurophysiological data were reviewed independently. HL was assessed using the AAO-HNS classification system for non-serviceable hearing loss (Class C/D), defined as PTA >50 dB and/or SDS <50 % within the speech range of frequencies.

Results

Patients with HL had higher rates of loss in the amplitude of wave V and prolongation in the interpeak latency of peak I-V latency during MVD. Gender, age, side, and MVD duration did not increase the risk of HL. There was no correlation between successive number of BAEP changes (reflective of the number of surgical attempts) and HL. There was no association between the speed of recovery of BAEPs and HL.

Conclusions

Patients with new post-operative HL have a faster rate of change in the amplitude of wave V and the interpeak I-V latency during intraoperative BAEP monitoring for HFS. Our alarm criteria to inform the surgeon about impending nerve injury might have to be modified and prospectively tested to prevent rapid change in BAEPs.     

Surgical treatment of hemifacial spasm with zone-4 offending vessel

Background

Increasing evidence shows that vascular compression on any of the four zones of facial nerve may cause hemifacial spasms. Vascular compression on zone 4 (the cisternal portion) of the nerve is quite common, but only a very small percentage of such compression will elicit hemifacial spasm, because zone 4 is less susceptible than zone 3 (the root exit zone). Therefore, it seems difficult for the neurosurgeons to distinguish the real culprit vessels in zone 4. Here, our experience in treating vascular compression located in zone 4 of the facial nerve is reported.

Methods

Twelve patients of HFS due to compression of zone 4 were treated with microvascular decompression (MVD) surgery with the aid of combined monitoring of abnormal muscle response (AMR) and Z-L response (ZLR).

Results

All of the 12 patients had a zone 4 compression. In addition, there were vascular compressions on zone 3 (the root exit zone) and/or zone 2 (the attached segment) in six cases. AMR was absent in two cases, unstable in one case, and persisted after vascular decompression in another one case. ZLR was stable before decompression of zone 4 and disappeared after decompression in all cases. After MVD surgery, 11 patients were cured and one patient achieved good resolution of spasm. One patient had postoperative transient tinnitus.

Conclusions

The neurosurgeon should not ignore vascular compression at zone 4, especially when compressions at zones 2 and 3 co-exist. With the aid of AMR and ZLR, we are able to judge whether offending vessels exist at zone 4.     

CT angiography of anterior spinal artery in cervical spondylotic myelopathy

Purpose

To identify anterior spinal artery (ASA) infarct or occlusion by CT angiography (CTA) in patients with cervical spondylotic myelopathy (CSM).

Methods

Fourteen patients with CSM were performed CTA of ASA after admission. T2-weighted hyperintensity of MR image was compared with image of CTA of ASA.

Results

All patients presented spinal canal sagittal diameter compression from 10 to 80 % and different T2-weighted hyperintensity of MR images. No ASA infarct or occlusion was found in CSM patients.

Conclusion

ASA infarct or occlusion is not commonly seen in CSM patients with spinal canal sagittal diameter compression less than 80 %. Pathological changes about T2-weighted hyperintensity of MR image in CSM have no close correlation with ASA infarct.     

Discovery of a new waveform for intraoperative monitoring of hemifacial spasms

Background

Surgeons often rely on intraoperative electrophysiological monitoring to determine whether decompression is sufficient during microvascular decompression surgery for hemifacial spasms. A new monitoring method is needed when an abnormal muscle response is occasionally not available or is unreliable. This study was an observational clinical trial exploring a new waveform recorded from the facial muscles while the offending artery wall was electrically stimulated.

Methods

Thirty-two patients with typical hemifacial spasm and 12 with trigeminal neuralgia as a control were included. The facial muscle response was recorded during microvascular decompression surgery while the offending artery wall was stimulated (2?mA?×?0.2?ms). The latency, amplitude, and effective refractory period were analyzed.

Results

A waveform was recorded from the facial muscles of patients with hemifacial spasm when the offending artery wall was stimulated and was named the “Z-L response.” The latency was 7.3?±?0.8?ms, the amplitude was 0.08?±?0.02?mV, and the effective refractory period was 3.5–4?ms. The Z-L response disappeared immediately after microvascular decompression. No waveform was recorded from the facial muscles of patients with trigeminal neuralgia while the anterior inferior cerebellar artery, which adheres to the facial nerve, was stimulated (2?mA?×?0.2?ms).

Conclusion

We found a new waveform for intraoperative monitoring of hemifacial spasm. The Z-L response was useful when the abnormal muscle response was absent before decompression or persisted after all vascular compressions were properly treated. Particularly, the Z-L response may help neurosurgeons determine the real culprit when multiple offending vessels exist.     

Long-term results of microvascular decompression for trigeminal neuralgia and hemifacial spasms according to preoperative symptomatology

Background

Microvascular decompression (MVD) is currently used in several centres for the treatment of trigeminal neuralgia (TN) and hemifacial spasms (HFS). How long-term results relate to the preoperative symptoms still needs to be documented. The primary aim of this study was to assess long-term results of MVD for TN and HFS, as related to the types of preoperative symptoms.

Methods

We performed a retrospective study including all first-time MVDs for TN and HFS done during the 11-year period (1999–2009) in the Department of Neurosurgery, The National Hospital (Rikshospitalet), Oslo. The patients were categorized depending on the pre-operative symptomatology.

Results

The study population includes 303 first-time procedures performed by the senior author (PKE), 243 TN patients (65 % TN without constant pain and 35 % TN with constant pain) and 60 HFS patients (95 % typical HFS and 5 % atypical HFS). The patients were followed for a mean 71 months (range, 14–147). In both the TN and HFS patients, MVD caused lasting symptom relief in a high proportion of patients, including patients with atypical symptoms.

Conclusion

After MVD for TN and HFS, regardless of preoperative symptoms, lasting relief is observed in a high proportion of patients, with a favorable complication profile.     

Spontaneous cerebrospinal fluid leakage detected by magnetic resonance cisternography--case report.

A 49-year-old male with no history of head trauma suffered cerebrospinal fluid (CSF) discharge from the left nostril for one month. Coronal computed tomography (CT) showed lateral extension of the sphenoid sinus on both sides and CSF collection on the left side. CT cisternography could not identify the site of CSF leakage. Heavily T2-weighted magnetic resonance (MR) imaging (MR cisternography) in the coronal plane clearly delineated a fistulous tract through the sphenoid bone into the sphenoid sinus. Patch graft with muscle fragment completely relieved the CSF rhinorrhea. Postoperative three-dimensional CT showed the two bone defects identified during surgery. Small bony dehiscences in the sphenoid bone and lateral extension of the sphenoid sinus predisposed the present patient to CSF fistula formation. MR cisternography in the coronal and sagittal planes is superior to CT scanning or CT cisternography for detection of the site of active CSF leakage.     

Posterior C1–C2 screw and rod instrument for reduction and fixation of basilar invagination with atlantoaxial dislocation

Purpose

To report the surgical technique and preliminary clinical results for the treatment of basilar invagination (BI) with atlantoaxial dislocation (AAD) by posterior C1–C2 pedicle screw and rod instrument.

Methods

Between July 2012 and August 2013, 33 patients who had BI with AAD underwent surgery at our institution. Pre and postoperative three-dimensional computed tomographic (CT) scans were performed to assess the degree of dislocation. Magnetic resonance (MR) imaging was used to evaluate the compression of the medulla oblongata. For all patients, reduction of the AAD was conducted by two steps: fastening nuts and rods was performed to achieve the horizontal reduction. Distraction between C1 and C2 screws was performed to obtain the vertical reduction.

Results

No neurovascular injury occurred during surgery. Follow-up ranged from 6 to 15 months (mean 10.38 months) in 32 patients. Post-operative three-dimensional CT showed that complete horizontal reduction was obtained in 30/33 (90.9 %), and complete vertical reduction was obtained in 31/33 (93.9 %). The repeated three-dimensional CT and MR image demonstrated that bony fusion and the decompression of the medulla oblongata were obtained in all patients. Clinical symptoms improved significantly 3 months after surgery.

Conclusions

This C1–C2 pedicle screw and rod instrument is a promising technique for the treatment of BI with AAD.     

Intraoperative panoramic image using alignment grid, is it accurate?

Background

Minimally invasive orthopedic trauma surgery relies heavily on intraoperative fluoroscopic images to evaluate the quality of fracture reduction and fixation. However, fluoroscopic images have a narrow field of view and often cannot visualize the entire long bone axis.

Objectives

To compare the coronal femoral alignment between conventional X-rays to that achieved with a new method of acquiring a panoramic intraoperative image.

Materials and methods

Twenty-four cadaveric femurs with simple diaphyseal fractures were fixed with an angulated broad DCP to create coronal plane malalignment. An intraoperative alignment grid was used to help stitch different fluoroscopic images together to produce a panoramic image. A conventional X-ray of the entire femur was then performed. The coronal plane angulation in the panoramic images was then compared to the conventional X-rays using a Wilcoxon signed rank test.

Results

The mean angle measured from the panoramic view was 173.9° (range 169.3°–178.0°) with median of 173.2°. The mean angle measured from the conventional X-ray was 173.4° (range 167.7°–178.7°) with a median angle of 173.5°. There was no significant difference between both methods of measurement (P = 0.48).

Conclusion

Panoramic images produced by stitching fluoroscopic images together with help of an alignment grid demonstrated the same accuracy at evaluating the coronal plane alignment of femur fractures as conventional X-rays.     

A recommendation on the basis of long-term follow-up resultsof our microvascular decompression operation for hemifacial spasm

Background

Microvascular decompression (MVD) for hemifacial spasm (HFS) has been popular, but it may take enough time to master this special operative technique and procedure. This may induce uneven distribution of the number of MVD operations in each institute, possibly resulting in an overall unsatisfactory quality of MVD surgeons. Nakanishi’s approach to MVD operations has the feature of using a, “supine, no retractor” technique, which would achieve various benefits for patients and medical professionals. We would like to recommend this approach for MVD surgeons on the basis of our follow-up outcomes.

Methods

A questionnaire, which was based on the method of evaluation for the long-term results of post-MVD operation as recommended by the Japanese Society of MVD, was sent by mail to the 154 HFS patients who had received Nakanishi’s approach at our hospital.

Results

Except for 42 patients who had changed their residences, 89 patients (79.5 % of 112) fully answered. The mean postoperative follow-up term was 13.0 years. The 76.4 % of the patients was estimated as excellent. Postoperative deafness was not present. The average value of satisfaction degree for the results of the MVD operation was 87.9 %.

Conclusions

This study revealed that Nakanishi’s approach produced good results equivalent of other approaches for HFS patients. This approach is considered to have many advantages comparing to the other approaches. Therefore, we would like to recommend that Nakanishi’s approach would contribute to overall advancement of the level of MVD surgeons.     

Treatment of basilar invagination with atlantoaxial dislocation: atlantoaxial joint distraction and fixation with transoral atlantoaxial reduction plate (TARP) without odontoidectomy

Purpose

Although direct transoral decompression and one-stage posterior instrumentation can obtain satisfactory cord decompression for the treatment of basilar invagination with atlantoaxial dislocation, surgical injuries run high as combinative anterior-posterior approaches were necessary. Furthermore, the complications will rise notably when involvement of dens and/or clivus in the decompression necessitates relatively complicated surgical techniques. First initiated in 2005, transoral atlantoaxial reduction plate (TARP) works as an internal fixation for the treatment of basilar invagination with irreducible atlantoaxial dislocation. Therefore, this article aimed to describe several operative experiences about this approach, which has delivered successful decompression, fixation and fusion.

Methods

21 consecutive patients with basilar invagination underwent the TARP operation. The pre- and postoperative medulla-cervical angles were measured and compared. The JOA scores of spinal cord function were calculated pre- and post-operatively. 20 cases (20/21) were followed up to average 12.5 months.

Results

Symptoms of all the 20 cases were relieved in different degrees. The postoperative imaging showed the odontoid processes obtained ideal reduction and the internal fixators were all in good position. The medulla-cervical angle was correctd from an average (± standard deviation) 128.7° + 11.9° (n = 20) before surgery to 156.5° + 8.1° (n = 20) after surgery (P < 0.01). The average preoperative and postoperative Japaneses Orthopedic Association scores were 11.25 (n = 20) and 15.9 (n = 20), respectively, indicating 76 % improvement. Screw-loosening was observed in one patient due to severe osteoporosis. After a revised operation with a TARP in another size, the neurological symptoms showed no obvious improvements. Then the treatment was terminated.

Conclusions

The TARP operation and intra-operative traction could reduce the odontoid process superiorly migrating into the foramen magnum, directly ease the ventral compression of spinal cord, and fix the reduced atlantoaxial joints through a single transoral approach without the need of a posterior operation. In this stury, 21 patients were evaluated and 20 did well with TARP operation. The preliminary clinical result was satisfactory.     

Transoral anterior revision surgeries for basilar invagination with irreducible atlantoaxial dislocation after posterior decompression: a retrospective study of 30 cases

Purpose

To report the surgical techniques and clinical results of one-stage transoral anterior revision surgeries for basilar invagination (BI) with atlantoaxial dislocation (AAD) after posterior decompression.

Methods

From September 2008 to June 2012, 30 patients (16 men and 14 women) who had BI with irreducible atlantoaxial dislocation (IAAD) after posterior decompression underwent anterior revision surgeries in our department. Dynamic cervical radiographs, computed tomographic scans and magnetic resonance imaging were obtained pre- and postoperatively to assess the degree of AAD and ventral compression on the cervical cord. The JOA scoring system was used to evaluate the neurological status. The revision surgeries were conducted by anterior approach, using the transoral atlantoaxial reduction plate (TARP) system.

Results

The revision surgeries were successfully performed in all of the cases. The average follow-up duration was 16 months (range 6–39 months). For all of the cases, complete or more than 50 % reduction and decompression of C1–C2 were achieved. The cervicomedullary angle was improved by an average of 32.9°. Bone fusion was achieved within 3–6 months in all of the cases. Clinical symptoms were alleviated in 29 patients (96.7 %) and stabilised in 1 patient (3.3 %). No patients have developed recurrent or progressive atlantoaxial instability so far.

Conclusion

Anterior revision surgeries using the TARP system achieved reduction, decompression and fixation of C1–C2 in one stage for BI with IAAD. This technique offers an effective, simple and safe method for the revision of such cases after posterior decompression.     

Endoscopic transnasal odontoidectomy to treat basilar invagination with congenital osseous malformations

Purpose

Transoral resection of the odontoid has been accepted as a standard procedure to decompress the cervicomedullary junction during the past several decades. The endoscopic transnasal odontoidectomy is emerging as a feasible surgical alternative to conventional microscopic transoral approach. In this article, we describe several operative nuances and pearls from our experience about this approach, which provided successful decompression.

Methods

From September 2009 to April 2010, three consecutive patients with basilar invagination, of which the etiology was congenital osseous malformations, underwent endoscopic transnasal odontoidectomy. All patients presented with myelopathy. The last two cases also received occipitocervical fixation and bone fusion during the same surgical episode to ensure stability.

Results

All the patients were extubated after recovery from anesthesia and allowed oral food intake the next day. Cerebrospinal fluid rhinorrhea was found in the second case and cured by continuous lumber drainage of cerebrospinal fluid. No infection was noted. The average follow-up time was more than 24 months. Remarkable neurological recovery was observed postoperative in all patients.

Conclusion

The endoscopic transnasal odontoidectomy is a feasible approach for anterior decompression of pathology at the cervicomedullary junction. The advantages over the standard transoral odontoidectomy include elimination of risk of tongue swelling and teeth damaging, improvement of visualization, alleviation of prolonged intubation, reduction of need for enteral tube feeding and less risk of affecting phonation. The minimally invasive access and faster recovery associated with this technique make it a valid alternative for decompression of the ventral side of the cervicomedullary junction.     

Clinical characteristics and surgical outcomes of spinal intramedullary ependymal cysts

Object

Intramedullary ependymal cysts are exceedingly rare lesions, and have been previously reported in the literature as case reports. The aim of this study was to discuss the clinical presentation and the outcomes of microsurgery for these benign lesions.

Methods

The authors retrospectively reviewed the records of ten patients who underwent microsurgery for intramedullary ependymal cysts. All patients had preoperative and postoperative magnetic resonance imaging. The surgical treatment included gross total resection and biopsy plus a cyst-subarachnoid shunt. The diagnosis of intramedullary ependymal cysts was based on radiological and pathological criteria. All patients were followed up, with a mean duration of 47.6 months.

Results

Intramedullary ependymal cysts were hypointense on T1-weighted images and hyperintense on T2-weighted images. Contrast-enhanced T1-weighted images showed no enhancement. Gross total resection was achieved in one case. Biopsy of the cyst wall plus cyst-subarachnoid shunt placement was achieved in nine cases. Long-term neurological function was improved in eight patients. No recurrence was observed on magnetic resonance imaging.

Conclusions

Ependymal cysts should be considered in the differential diagnosis of intramedullary cysts. For symptomatic patients, early surgery should be performed before neurological deficits deteriorate. Complete decompression and cyst-subarachnoid shunt placement is the optimal treatment and the outcome may be favorable.     

Microvascular decompression for neurovascular conflicts in the cerebello-pontine angle: which role for endoscopy?

Background

Microvascular decompression (MVD) is the surgical intervention designed to resolve neurovascular conflicts (NCs) in the cerebellopontine angle (CPA). Today, endoscopy is commonly used in many neurosurgical procedures. This study aims to retrospectively assess the usefulness of endoscopy during MVD, focusing on microscopic endoscopic-assisted (MEA) MVD.

Methods

Between January 2010 and December 2012, 141 patients underwent MVD procedures: 119 (84.5 %) were affected by idiopathic trigeminal neuralgia (TN), 20 (14 %) by hemifacial spasm (HFS), 1 by glossopharyngeal neuralgia (GN) and 1 by TN and GN simultaneously; 128 (91 %) MVD were first time procedures, while 13 (9 %) were recurrences (10 TN, 3 HFS). Visualization techniques used were: pure microscopic in 89 (63 %) cases, fully endoscopic in 12 (8.5 %) and MEA in 40 (28.5 %). The MEA technique was used when the conflict was not clearly identified under microscopic view or it was not certainly resolved.

Results

Overall, a NC was found in 130 (92 %) cases, while 11 patients had no intraoperative evidence of NC. Considering specifically the 40 MEA cases, 12 (8.5 % overall) conflicts not clearly visible with the microscope were revealed and solved, a complete conflict resolution was confirmed in 13 (9 % overall) cases, while an incomplete conflict resolution was shown in four cases (3 % overall).

Conclusion

Pure microscopic MVD remains the technique of choice. The endoscope is a useful adjunctive imaging tool in confirming NCs identified by the microscope, revealing conflicts missed by the microscopic survey alone and verifying adequate nerve decompression.     

Coronal plane fractures of the distal humerus involving the capitellum and trochlea treated with open reduction internal fixation

Introduction

Coronal plane fractures of the distal humerus involving the capitellum and trochlea are rare. Treatments have evolved from closed reduction to open reduction and internal fixation (ORIF) to achieve a stable joint that allows early mobilization.

Background

We determined the functional outcomes of treating coronal plane fractures of the distal humerus with ORIF.

Methods

We reviewed the records of all patients with coronal plane fractures of the distal humerus treated by ORIF. Fractures were classified according to Bryan and Morrey. Cannulated screws were used for fixation. All patients were evaluated using the Mayo Elbow Score Performance Index (MEPI) and disabilities of the arm, shoulder, and hand (DASH) scores at least 1 year later.

Results

Of the 18 patients evaluated (12 women), the mean (SD) age was 45.3(16.5) years (range 16–70). There were seven Type-I, five Type-III, and six Type-IV fractures. Mean follow-up was 43.6 (38.1) months (range 12–120). The mean elbow range of motion in sagittal plane at last follow-up ranged from 8.9° to 132.8°. The mean MEPI score was 86.7 (15.2) points (range 60–100), corresponding to 12 excellent, 2 good, and 4 fair outcomes. The mean DASH score was 15.3 (13.5) points (range 17–35.8). Heterotrophic ossification developed in one patient with delayed fixation; 14 patients with excellent or good results returned to their previous activity levels. Functional scores did not differ by age, sex, or fracture types (P > 0.05 for all comparisons).

Conclusion

ORIF with cannulated screws, which maintain a stable anatomic articular position, provides satisfactory results in coronal plane fractures of the distal humerus.

Level of evidence

Level IV case series.     

Trigeminal Neuralgia in a Patient with Marfan Syndrome: Case Report

Marfan syndrome can demonstrate tortuous and elongated intracranial arteries. However, these arteries rarely cause neurovascular compression resulting in hemifacial spasm or trigeminal neuralgia. The authors report a 33-year-old woman who was diagnosed as Marfan syndrome, suffered from trigeminal neuralgia. Magnetic resonance (MR) angiography showed tortuous and elongated left vertebral artery (VA). The coronal section of three dimensional (3D) MR cisternography with contrast enhancement showed that the left trigeminal nerve was compressed from underneath by the tortuous and elongated left VA. After successful surgery of microvascular decompression, the patient’s symptom resolved and no recurrence was encountered. Neurosurgeons should not only be aware of hemifacial spasm but also of trigeminal neuralgia caused by elongated vessels in a patient with Marfan syndrome, although it is an extremely rare condition. In addition, offending vessel is not atherosclerotic in younger patients unlike usual cases of trigeminal neuralgia. Thus, microvascular decompression can be easier than usual cases. Care should be taken to prevent arterial dissection during transposition by using some technical tips.