Is Common Trunk Anomaly Frequent in Hemifacial Spasm? Comparison with Normal Subjects Using Magnetic Resonance Imaging.

OBJECTIVE: Hemifacial spasm (HFS) results from vascular compression at the root exit of the facial nerve. Although the underlying etiology has yet to be identified, it has been suggested that congenital vascular anomalies are involved. We have hypothesized common trunk anomaly of the anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) which may play a role in HFS. However, no previous studies have directly compared the incidence of this anomaly between HFS patients and normal subjects. The present study was designed to address this gap in the literature. METHODS: This case-control study compared magnetic resonance angiography data from 65 HFS patients and 65 normal subjects. Dominant AICA/PICA is defined as the absence of PICA/AICA, with the remaining AICA/PICA supplying both vascular territories. The term "common trunk" encompasses both dominant AICA and dominant PICA. The frequency of common trunk and dominant AICA/PICA was compared between the 2 groups. RESULTS: There were no significant differences in the incidence of a common trunk (68.5% and 64.6%), dominant AICA (30.8% and 32.3%) and dominant PICA (37.7% and 32.3%) between the 2 groups. Additionally, no differences were found in the frequency of atherosclerosis risk factors. CONCLUSIONS: There was no apparent association between common trunk anomaly and HFS. It is suspected that some vascular anomalies other than a common trunk are involved in HFS.

[Trigeminal Neuralgia and Hemifacial Spasm: What to Do If It Does Not Cure?]

Although microvascular decompression(MVD)is a highly effective treatment, there is little pathological evidence and some aspects of its mechanism remain unclear. Therefore, when symptoms appear after surgery, it is difficult to determine the pathological condition and select the treatment method. Therefore, we recommend dividing these factors into three categories. The first is "prolonged cure." Compressed nerves may take time to regenerate; therefore, it is necessary to wait at least one year to see if they recover naturally, especially in facial spasms. The second is "uncured." Intraoperative video and postoperative imaging findings should be reviewed. If a compressed blood vessel is overlooked or inappropriately decompressed, additional surgery should be performed. The third is "true recurrence," which is the loss of fixation of compressed blood vessels and granulomatization of the Teflon. Nerve bending that occurs again due to the retraction of the trigeminal nerve is corrected by reoperation. The therapeutic effects of reoperation are particularly strong in trigeminal neuralgia. Owing to the risk of nerve damage due to adhesion dissection, it is important to carefully consider and establish good communication with patients before surgery.

Asymptomatic subarachnoid hemorrhage following carotid endarterectomy: illustrative case.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting are common surgical interventions for internal carotid artery stenosis. Cerebral hyperperfusion syndrome (CHS) is a well-known complication of both procedures that can lead to intracranial hemorrhage and worsen clinical outcomes. Here, the authors report a rare case of non-aneurysmal subarachnoid hemorrhage (SAH) following CEA and review the relevant literature. OBSERVATIONS: A 70-year-old woman with hypertension and diabetes presented with progressive visual loss in the right eye and was diagnosed with ocular ischemic syndrome. Imaging revealed severe right cervical carotid artery stenosis. CEA was performed with no complications. Postoperatively, the patient's blood pressure was tightly controlled, with no evidence of CHS. However, an asymptomatic SAH was detected on postoperative day 7. Careful observation and blood pressure control were maintained. Since follow-up magnetic resonance imaging (MRI) showed no enlarging of the SAH and the patient was asymptomatic, she was discharged on postoperative day 15 with a modified Rankin scale score of 0. LESSONS: This case highlights the potential occurrence of non-aneurysmal SAH as a rare complication of CEA, even in asymptomatic patients. Repeated postoperative MRI is necessary to detect such complications. It is crucial to carefully control blood pressure after CEA regardless of symptoms.

Retrieval of N-Butyl-2-Cyanoacrylate Glue Migrated to the Vertebral Artery via Dangerous Anastomosis, Using the Stent-Retriever Aspiration Technique, during Dural Arteriovenous Fistula Embolization: A Case Report.

Objective: We report a case of accidental N-butyl-2-cyanoacrylate (NBCA) glue migration into the vertebral artery (VA) via dangerous anastomosis during transarterial embolization (TAE) for transverse sinus (TS)-dural arteriovenous fistula (DAVF), which was rescued by mechanical retrieval using a stent retriever and aspiration devices. Case Presentation: A 49-year-old right-handed female patient was admitted to our hospital with motor aphasia. MRI revealed congestion in the left temporal and occipital lobes, involving a small hemorrhage. DSA revealed a DAVF complicated by a sinus thrombus in the left TS. The DAVF was mostly fed by the left occipital artery (OA) and drained into the cortical veins of the temporal and occipital lobes through the patent part of the sinus. TAE was performed via the left OA with low-concentration NBCA. However, NBCA glue migrated into the left VA through a dangerous anastomosis, and a left VA angiogram revealed severe VA stenosis and floating NBCA glue. There was a fragile attachment of the NBCA glue to the arterial inner wall; therefore, we successfully retrieved the NBCA glue with a stent retriever and aspiration devices without complications. Finally, TAE was performed using another feeder, and the DAVF was completely obliterated. Conclusion: TAE using NBCA is useful for the treatment of DAVF; however, it should be noted that there is a risk of migration via potential anastomotic routes. Low-concentration NBCA glue can be retrieved using these devices in limited cases.

Epidemiology of post-suboccipital craniotomy headache: A multicentre retrospective study.

The detailed epidemiology and mechanism of post-craniotomy headaches are not well understood. This study aimed to establish the actual clinical incidence and causes of post-craniotomy headaches. Suboccipital craniotomy surgeries performed in six institutions within the five-year study period were included. This study included 311 patients (138 males, 173 female; mean age, 59.3 years old). A total of 145 patients (49%) experienced post-craniotomy headaches. Microvascular decompression surgery, craniectomy and facial spasms were significant risk factors for post-craniotomy headaches. In most cases, the post-craniotomy headaches disappeared within one month; however, some patients suffered from long-term headaches. The craniotomy site and the methods of dura and skull closures should be individually determined for each patient. However, to prevent post-craniotomy headaches, craniotomy, instead of craniectomy, may be considered.

Location of hemorrhage with nontraumatic acute subdural hematoma due to ruptured microaneurysm.

BACKGROUND: Nontraumatic acute subdural hematoma (ASDH) may be caused by rupture of a microaneurysm of a cortical artery. In some cases, microaneurysms may have been caused by earlier trauma. Although it is difficult to detect microaneurysms on contrast-enhanced computed tomography (CT) angiography or digital subtraction angiography, it may be suspected based on the plain CT scan results and the clinical course. CASE DESCRIPTION: We experienced three cases presumed to be ASDH due to rupture of a microaneurysm. Plain CT scan showed that the midline shift was smaller than the hematoma thickness, and we judged from the clinical course that there was no trauma immediately before the onset. All three patients had decreased consciousness after arrival and underwent craniotomy for hematoma removal. The source of hemorrhage was in the distal part of the cortical artery, and a microaneurysm was found. In one case, histopathological examination was performed, and traumatic pseudoaneurysm was diagnosed. The postoperative course was good in all three cases. CONCLUSION: If nontraumatic ASDH is suspected, the source of hemorrhage may be located more distally to the middle cerebral artery than in traumatic ASDH; hence, extensive craniotomy is required to search for the location of hemorrhage.

Development of Valve Reversal After Lumboperitoneal Shunt Construction.

OBJECTIVE: The current study aimed to assess the risk factors and preventive measures for valve inversion after lumboperitoneal shunt (LPS) construction. METHODS: The medical records of patients who were admitted to Mito Brain Heart Center from July 2015 to October 2018 were retrospectively analyzed. Next, clinical and neuroimaging data were collected from electronic medical charts and operative notes. The cause of valve reversal was investigated. In addition, a simulated shunt device was established and the efficacy of countermeasures was evaluated. RESULTS: The mean age of the participants was 69.3 (range: 46-88) years, and there were 15 men and 22 women. In total, 20 and 17 patients presented with secondary and idiopathic normal pressure hydrocephalus, respectively. Further, 8 patients had valve reversal. CONCLUSIONS: The distance between the valve and spinous process was found to be significantly correlated with valve reversal. However, the condition can be prevented by fixing the tube at the nuchal ligament.

Microvascular Decompression for Trigeminal Neuralgia: A Prospective, Multicenter Study.

BACKGROUND: Microvascular decompression (MVD) is the most effective procedure for the long-term management of trigeminal neuralgia (TGN). However, retrospective and single-center studies are inherently biased, and there are currently no prospective, multicenter studies. OBJECTIVE: To evaluate the short- and long-term outcomes and complications in patients with TGN who underwent MVD at specialized Japanese institutions. METHODS: We enrolled patients with TGN who underwent MVD between April 2012 and March 2015. We recorded their facial pain grade and complications at 7 d (short term), 1 yr (mid-term), and 3 yr (long term) postoperatively. RESULTS: There were 166 patients, comprising 60 men and 106 women (mean age 62.7 yr). Furthermore, 105 patients were aged over 60 yr. We conducted neuromonitoring in 84.3% of the cases. The complete pain relief, mortality, and complication rates at the short-term follow-up were 78.9%, 0%, and 16.3%, respectively. Overall, 155 patients (93.4%) completed the long-term follow-up, with the complete pain relief and complication rates of 80.0% and 5.2%, respectively. CONCLUSION: In the hands of experienced neurosurgeons, MVD for TGN can achieve high long-term curative effects. In addition, complications are uncommon and usually transient. Our results indicate that MVD is an effective and safe treatment for patients with TGN, including elderly patients.

Prospective, Multicenter Clinical Study of Microvascular Decompression for Hemifacial Spasm.

BACKGROUND: Microvascular decompression (MVD) is the most effective procedure for hemifacial spasm (HFS). MVD results from nonspecialized or low-volume institutes are not always reliable. Most studies on MVD for HFS are retrospective and single centered; to the best of our knowledge, no prospective, multicenter studies exist. OBJECTIVE: To evaluate short- and long-term outcomes and complications in patients who underwent MVD for HFS in specialized Japanese institutions, in this multicenter, prospective, cohort study. METHODS: Included patients had undergone MVD for HFS in study centers between April 2012 and March 2015. Patients' postoperative grade of involuntary movements and complications were recorded postoperatively at 7 d (short-term) and at 1 (mid-term) and 3 (long-term) yr. RESULTS: A total of 486 patients (150 men, 336 women; mean age 53.9 yr with 181 patients over 60 yr) were enrolled during the study period. Neuromonitoring was used in 96.3% of the cases. The complete cure rate of symptom relief, mortality rate, and complication rate at short-term follow-up were 70.6%, 0%, and 15%, respectively. The long-term follow-up was completed by 463 patients (95.3%); the complete cure rate of symptom relief and complication rate were 87.1% and 3.0%, respectively. CONCLUSION: Our study revealed that under expert guidance and intraoperative neuromonitoring, the long-term curative effect rate of MVD for HFS is high, while complications are uncommon and usually transient. Our results indicate that MVD is an effective and safe treatment for patients with HFS, including elderly patients.

Emergency embolectomy for acute middle cerebral artery occlusion with chronic common carotid artery occlusion.

Occurrence of acute middle cerebral artery occlusion with common carotid artery occlusion is rare, and its treatment may be complicated. If the approach route cannot be secured because of carotid artery occlusion, endovascular embolectomy may not be indicated. The best treatment approach for such cases remains controversial. A woman in her 70s was transferred to our hospital in ambulance following a sudden onset of dysarthria and left hemiparesis. Magnetic resonance imaging revealed an ischemic lesion in the right basal ganglia and occlusion of the right common carotid and intracranial middle cerebral arteries. Emergency embolectomy was performed for acute middle cerebral artery occlusion. Postoperative magnetic resonance imaging revealed complete recovery of the right middle cerebral artery blood flow. Emergency embolectomy can effectively treat acute middle cerebral artery occlusion with common carotid artery occlusion.

Preoperative risk assessment for predicting the opening of mastoid air cells in lateral suboccipital craniotomy for microvascular decompression.

OBJECTIVE: Opening of mastoid air cells (MACs), a complication of lateral suboccipital craniotomy for microvascular decompression (MVD), might cause cerebrospinal fluid (CSF) leakage and meningitis. Only a few studies have investigated the association of degree of MAC development and actual opening of MACs. The present study focused on preoperative risk assessment for predicting the opening of MACs. PATIENTS AND METHODS: The study included 204 consecutive patients who underwent MVD at our hospital between January 2014 and December 2018. We retrospectively collected clinical and neuroimaging data from electronic medical charts and discharge summaries. MACs were classified into four types according to neuroimaging data. Postoperative computed tomography (CT) was used to assess patients with and without CSF leakage into MACs. RESULTS: No CSF leakage was observed into types 1 and 2 MACs, but it was noted in 14 of 46 patients (30 %) with type 3 and 44 of 58 patients (76 %) with type 4 MACs. Opening of MACs during surgery could not be recognized in 33 (57 %). CSF rhinorrhea was noted in 1 of the 58 patients with CSF leakage into MACs and meningitis was not noted. CONCLUSION: Patients with types 3 and 4 MACs have a high risk of CSF leakage. Complete prevention of mild symptoms, such as ear obstruction, is challenging even if opened MACs are sealed, but serious complications, such as CSF rhinorrhea and meningitis, can be avoided. For cases in which preoperative CT reveals a high risk of opening of MACs, preventive closure should be performed.

Rupture immediately after growth of unruptured intracranial aneurysms during follow-up.

BACKGROUND: The annual rupture rate of small unruptured intracranial aneurysms (UIAs) <5 mm is generally low; further, small UIAs are often treated conservatively. While the growth of aneurysms during follow-up is associated with a high risk of rupture, the urgency for surgical treatment of asymptomatic enlarged UIAs remains controversial. We experienced two patients in whom UIAs ruptured shortly after asymptomatic growth during follow-up. CASE DESCRIPTION: A 1-mm right middle cerebral artery aneurysm was incidentally found in a 63-year-old woman. Preventive surgery was planned because the aneurysm grew rapidly; however, the aneurysm ruptured preoperatively. A 68-year-old woman had a small (4 mm) aneurysm at the left internal carotid-posterior communicating artery. The aneurysm grew rapidly after many years. Several hours after magnetic resonance imaging was performed, she presented to the hospital with loss of consciousness, and a diagnosis of subarachnoid hemorrhage due to the ruptured aneurysm was made. CONCLUSION: UIAs that rapidly increase during follow-up may be regarded as impending ruptured aneurysms.

Prosthesis Used in Microvascular Decompressions: A Multicenter Survey in Japan Focusing on Adverse Events.

OBJECTIVE: To investigate the characteristics of materials used as prostheses for microvascular decompression surgery (MVDs) in Japan and their possible adverse events (AEs) to determine preferable materials for MVDs. METHODS: A questionnaire was sent to all members of the Japanese Society for MVDs, and answers were obtained from 59 institutions. RESULTS: Among a total of 2789 MVDs, 1088 operations for trigeminal neuralgia, 1670 for hemifacial spasm, and 31 others, including 117 reoperations, were performed between April 2011 and March 2014. Nonabsorbable material was used in 96.5% of MVDs, including polytetrafluoroethylene (PTFE) (80.5%), polyurethane (11.9%), expanded PTFE (2.1%), and silk thread (1.47%). The use of absorbable materials, including fibrin glue (87.5%), cellulose (13.5%), gelatin (4,77%), and collagen (1.76%), was reported. The major combinations were PTFE with fibrin glue (58.7%) followed by PTFE alone (7.60%). Eighty-eight AEs in 85 (3.2%) cases were reported among 2672 first operations. AEs included 51 central nervous system dysfunctions, 15 wound infections/dehiscence, and 10 others, which were presumed to be related to the intraoperative procedure. Among relatively high-, moderate-, and low-volume centers, there were no significant differences in the frequency of AEs (P = 0.077). Tissue-prosthesis adhesion and/or granuloma formation were reported in 13 cases of 117 reoperations. The incidence of adhesion-related recurrence was 11.1% of all reoperations. CONCLUSIONS: The number of AEs was quite low in this survey, and intradural use of any prosthesis reported in this paper might be justified; however, further development of easily handled and less-adhesive prosthesis materials is awaited.

Microvascular decompression for intractable singultus.

Intractable singultus due to cerebrovascular disease is very rare. We report a case of intractable singultus that improved after microvascular decompression and present a literature review. The patient was a 58-year-old man with a 30-year history of persistent singultus. Its frequency and duration gradually increased and it was resistant to multiple medical treatments. Microvascular decompression to relieve pressure on the anterolateral surface of the lower medulla oblongata from the vertebral artery resulted in the resolution of singultus. Patients with intractable idiopathic singultus who fail to respond to medical therapy need to be considered for the evaluation of cerebrovascular diseases and microvascular decompression.

Preoperative Three-Dimensional Diagnosis of Neurovascular Relationships at the Root Exit Zones During Microvascular Decompression for Hemifacial Spasm.

OBJECTIVE: Hemifacial spasm occurs when a blood vessel compresses against an area near the root exit zone of the facial nerve. Developments in diagnostic neuroimaging have allowed three-dimensional (3D) observation of artery and nerve locations, an effective aid for treatment selection. However, an accurate interpretation of the 3D data remains challenging because imaging representations of complex small vessels are drowned out by noise. We used a noise elimination method to analyze artery and nerve locations and to determine their 3D relationship. METHODS: Fifteen patients treated for hemifacial spasm were included. Images fused from 3 modalities of magnetic resonance imaging, 3D computed tomography, and angiography were used as source images. Using the images, models of the nerve and candidate vessels were created and shown in 3D to observe how the arteries were compressing the nerve and to identify the portions of the offending vessels that were closest to the nerve. These preoperative results were then compared with operative field observations during surgery. 3D models of the unaffected side were created and evaluated as controls. RESULTS: We confirmed that these models were accurate reconstructions of the source images as the tubular nerve and artery cross-sections showed good alignment onto magnetic resonance imaging axial slice images. The preoperative diagnoses of the compression sites and offending arteries all matched intraoperative findings. CONCLUSIONS: An accurate identification of the offending arteries and compression sites was possible, and this method is anticipated to offer effective means of preoperative simulation.

Abducent nerve palsy treated by microvascular decompression: a case report and review of the literature.

Too few cases of isolated abducent nerve palsy caused by neurovascular compression syndrome have been reported. We here report on a case of abducent nerve palsy caused by neurovascular compression syndrome that was successfully treated by microvascular decompression (MVD). A 46-year-old male presented with a 6-month history of right-sided persistent abducent nerve palsy. High-resolution magnetic resonance imaging revealed a neurovascular contact of the vertebral artery with the right abducent nerve. MVD was performed via a retrosigmoid craniotomy, with remarkable improvement of the palsy. Our report suggests that MVD might be considered as an optional treatment if the symptoms progress or persist.

Indications and Timings of Re-operation for Residual or Recurrent Hemifacial Spasm after Microvascular Decompression: Personal Experience and Literature Review.

We reviewed reports about the postoperative course of hemifacial spasm (HFS) after microvascular decompression (MVD), including in our own patients, and investigated treatment for delayed resolution or recurrence of HFS. Symptoms of HFS disappear after surgery in many patients, but spasm persists postoperatively in about 10-40%. Residual spasm also gradually decreases, with rates of 1-13% at 1 year postoperatively. However, because delayed resolution is uncommon after 1 year postoperatively, the following is advised: (1) In patients with residual spasms after 1 year postoperatively (incomplete cure) or who again experience spasm ≥ 1 year postoperatively (recurrence), re-operation is recommended if the spasms are worse than before MVD. (2) When re-operation is considered, preoperative magnetic resonance imaging (MRI) findings and intraoperative videos should be reviewed to ensure that no compression due to a small artery or vein was missed, and to confirm that adhesions with the prosthesis are not causing compression. If any suspicious findings are identified, the cause must be eliminated. Moreover, because of the risk of nerve injury, decompression of the distal portion of the facial nerve should be performed only in patients in whom distal compression is strongly suspected to be the cause of symptoms. (3) Cure rates after re-operation are high, but complications such as hearing impairment and facial weakness have been reported in 10-20% of cases, so surgery must be performed with great care.

Relation between the persistence of an abnormal muscle response and the long-term clinical course after microvascular decompression for hemifacial spasm.

Mentalis muscle responses to electrical stimulation of the zygomatic branch of the facial nerve are considered abnormal muscle responses (AMRs) and can be used to monitor the success of decompression in microvascular decompression (MVD) surgery. The aim of this study was to compare the long-term outcome of MVD surgery in which the AMR disappeared to the outcome of surgery in which the AMR persisted. From 2005 to 2009, 131 patients with hemifacial spasm received MVD surgery with intraoperative monitoring of AMR. At 1 week postsurgery, spasms had resolved in 82% of cases in the AMR-disappearance group and 46% of cases in the persistent-AMR group, mild spasms were present in 10% of cases in the AMR-disappearance group and 31% of cases in the persistent-AMR group, and moderate were present spasms in 8% of cases in the AMR-disappearance group and 23% of cases in the persistent-AMR group (P < 0.05). At 1 year postsurgery, spasms had resolved in 92% of cases in the AMR-disappearance group and 84% of cases in the persistent-AMR group, mild spasms were present in 6% of cases in the AMR-disappearance group and 8% of cases in the persistent-AMR group, and moderate spasms were present in 3% of cases in the AMR-disappearance group and 8% of the cases in the persistent-AMR group (P = 0.56). These results indicate that the long-term outcome of MVD surgery in which the AMR persisted was no different to that of MVD surgery in which the AMR disappeared.