Anatomical considerations and surgical manipulation of the rhomboid lip in microvascular decompression for hemifacial spasm.

BACKGROUND: In microvascular decompression (MVD) procedures for hemifacial spasm (HFS), surgeons often encounter a rhomboid lip which may obscure the root exit zone (REZ) of the facial nerve. This study aims to explore the anatomical variations of rhomboid lips and their surgical implications to improve safety and effectiveness in MVD surgeries. METHODS: A retrospective analysis was conducted on 111 patients treated for HFS between April 2021 and March 2023. The presence of a rhomboid lip was assessed through operative video records, and its characteristics, dissection methods, and impact on nerve decompression outcomes were further examined. Preoperative magnetic resonance imaging (MRI) scans were reviewed for detectability of the rhomboid lip. RESULTS: Rhomboid lips were identified in 33% of the patients undergoing MVD, with a higher prevalence in females and predominantly on the left side. Two distinct types of rhomboid lips were observed: membranous and cystic variations. The membranous type was noted for its smaller size and position ventral to the choroid plexus. In contrast, the cystic variation was distinguished by its larger size and a thin membrane that envelops the choroid plexus. Preoperative MRI successfully identified rhomboid lips in only 21% of the patients who were later confirmed to have them in the surgical procedures. Surgical approaches primarily involved incisions on the dorsal wall and along the glossopharyngeal nerve root, with only limited need for extensive dissection from lower cranial nerves. Immediate spasm relief was observed in 97% of the patients. One case exhibited a lower cranial nerve deficit accompanied by brainstem infarction, which was caused by the dissection from the lower cranial nerves. CONCLUSIONS: Recognizing the two variations of the rhomboid lip and understanding their anatomical structures are essential for reducing lower cranial nerve injuries and ensuring effective nerve decompression.

[Microsurgical Procedures of Microvascular Decompression for Trigeminal Neuralgia].

Microvascular decompression for trigeminal neuralgia was successfully performed following the secure surgical steps. The most crucial step involves creating a safe operative field in the dural opening. The petrotentorial junction should be identified without cerebellar retraction before proceeding to the deeper areas. Dissecting the petrosal vein and opening the horizontal fissure contributed to the expansion of the operative field. Bleeding often occurs from the dorsal cerebellar bridging vein and junction of the petrosal vein into the superior petrosal sinus. Transposition of the most common offenders, the superior and anterior inferior cerebellar arteries, is effectively achieved by dissecting both the proximal and distal sides of the neurovascular compression site. Teflon should be placed at a sufficient distance to prevent contact with the nerve, which can lead to recurrence. Treating vertebrobasilar artery-related cases is challenging and involves the risk of cranial nerve injuries. Multiple offending vessels are commonly involved. In such cases, it is essential to be aware of the course of the trochlear and abducens nerves during decompression. Applying the most effective and least risky maneuver is necessary for treating cases involving the vertebrobasilar artery.

Analyzing the cost-effectiveness of microvascular decompression and percutaneous radiofrequency rhizotomy for trigeminal neuralgia: the role of clinical classification.

Trigeminal neuralgia (TN) is a neuropathic pain that can be treated with microvascular decompression (MVD) or percutaneous radiofrequency rhizotomy (PRR) when medications fail. However, the cost-effectiveness of these interventions is uncertain, and it is unclear whether TN should be considered as a single entity for cost-effectiveness analysis. To address these issues, a prospective cohort study was conducted between 2017 and 2020, documenting Burchiel et al.'s clinical classification, pain-free survival, complications, and costs. Two models of quality-adjusted life years (QALYs) were calculated: pain-specific (PQALY) and pain-complication-specific (PCQALY), based on pain-free survival and complications data, followed by cost-effectiveness analysis. The study included 112 patients, of whom 70 underwent MVD and 42 underwent PRR. Our findings revealed that MVD was less cost-effective in the PCQALY model than PRR, but more cost-effective in the PQALY model and had an incremental cost-effectiveness ratio (ICER) that met the World Health Organization cost-effectiveness threshold in both models. Further clinical classification analysis showed that MVD was only cost-effective in type 1 TN patients, with an ICER of 0.9 and 1.3 times the GDP/capita, based on PQALY and PCQALY, respectively, meeting the cost-effectiveness criteria. Conversely, MVD was economically dominated by PRR for type 2 TN patients based on PQALY. These findings indicate that PRR may be more cost-effective for type 2 TN patients, while MVD remains the cost-effective option for type 1 TN patients. Our study highlights the importance of clinical classification and complication in determining the cost-effectiveness of MVD and PRR for refractory TN.

Potential reasons for failure and recurrence in microvascular decompression for hemifacial spasm.

BACKGROUND: To examine the factors contributing to persistent and recurrent hemifacial spasms (HFS) following a microvascular decompression (MVD) procedure and to suggest technical improvements to prevent such failures. METHODS: A retrospective review was conducted on fifty-two cases of repeat surgery. The extent of the previous craniotomy and the location of neurovascular compression (NVC) were investigated. The operative findings were categorized into two groups: "Missing Compression" and "Teflon Contact". The analysis included long-term outcomes and operative complications after repeat MVD procedures. RESULTS: Missing compression was identified in 29 patients (56%), while Teflon contact was observed in 23 patients (44%). Patients with missing compression were more likely to experience improper craniotomy (66%) compared to those with Teflon contact (48%). Medially located NVC was a frequent finding in both groups, mainly due to compression by the anterior inferior cerebellar artery. In the missing compression group, during the repeat MVD, Teflon sling retraction was utilized in 79% of cases, while in the Teflon contact group, the most common procedure involved removing the Teflon in contact (65%). After the repeat MVD procedure, immediate spasm relief was achieved in 42 patients (81%), with six (12%) experiencing delayed relief. After a median follow-up of 54 months, 96% of patients were free from spasms. Delayed facial palsy, facial weakness, and hearing impairment were more frequently observed in the Teflon contact group. CONCLUSIONS: A proper craniotomy that provides adequate exposure around the REZ is crucial to prevent missing the culprit vessel during the initial MVD procedure. Teflon contact on the REZ should be avoided, as it poses a potential risk of procedure failure and recurrence.

Common trunk anomaly of the anterior and posterior inferior cerebellar artery in hemifacial spasm.

BACKGROUND: The common trunk anomaly of the anterior and posterior inferior cerebellar artery (APC) is a variant artery that causes a hemifacial spasm (HFS). The anatomical characteristics include a large diameter of the trunk and the existence of the bifurcation near the facial nerve root entry zone (REZ). Despite APC being encountered at a constant rate in microvascular decompression (MVD), the anatomical and technical issues of transposing APC have not been entirely focused on yet. METHODS: We reviewed our 68 cases with APC involvement. Patient background, radiological findings, and operative video recordings were reviewed retrospectively. The location of the bifurcation of APC and the distribution of perforators were investigated. Surgical outcomes were assessed in the long term. RESULTS: APC involvement was diagnosed preoperatively in all cases by careful observation with MRI. Three-dimensional images determined the anatomical characteristics of APC and depicted the relationship with the facial nerve. All patients had a bifurcation close to the root entry zone that was required to transpose, including the common trunk and the distal branches, to achieve sufficient decompression. While adequate transposition from the REZ was accomplished in most cases, it was difficult to complete transposition due to short perforators in 6 patients (8.8%), resulting in interposition. Fifty-three patients (77.9%) became spasm free immediately after surgery, 66 patients (97.1%) were after 6 months, and all patients (100%) became spasm free within a year. Spasm-free status was maintained during the follow-up period (4.7 years) in all patients except one in whom facial spasm recurred 2 years after the initial surgery. CONCLUSIONS: Transposing the common trunk with the bifurcation and distal branches contributes to obtaining favorable surgical outcomes in APC-related HFS.

Effect of high-dose delivery on the attachment of meningiomas in Gamma Knife surgery: a retrospective study.

BACKGROUND: Meningiomas have vascular supply from the tumor attachment on the dura mater. Gamma Knife radiosurgery (GKS) is known to have a vascular obliterating effect. This study aims to determine the benefits of high-dose irradiation to the tumor attachment compared to conventional dose planning in the long-term control of tumor growth with GKS. METHODS: Two different dose plannings were retrospectively compared in 75 patients with meningioma treated with GKS as a primary treatment. Forty-three patients were irradiated over 20 Gy to the tumor attachment. The remaining 32 patients were treated with conventional-dose planning. Tumor growth control, reduction of enhancement on the gadolinium-enhanced magnetic resonance imaging (MRI), and neurological status were retrospectively assessed. RESULTS: The maximum dose on the tumor attachment was significantly higher in the high-dose group (23 Gy) than in the conventional group (16 Gy). The tumor margin was irradiated with the median of the 50% isodose line in both groups. The prescription doses resulted in 14 Gy and 12 Gy, respectively. The tumor control rate achieved 91% in both groups during the median follow-up period of 54 months. A decrease of enhancement on follow-up MRI was noted in one patient in each group. Kaplan-Meier analysis revealed no statistical difference in the progression-free survival between the two groups. The number of patients with improved neurological status showed no statistical difference. CONCLUSIONS: No obvious benefit of high-dose irradiation to the tumor attachment and margin was found in tumor control and neurological status in the long term.

Indication for a skull base approach in microvascular decompression for hemifacial spasm.

BACKGROUND: A thorough observation of the root exit zone (REZ) and secure transposition of the offending arteries is crucial for a successful microvascular decompression (MVD) for hemifacial spasm (HFS). Decompression procedures are not always feasible in a narrow operative field through a retrosigmoid approach. In such instances, extending the craniectomy laterally is useful in accomplishing the procedure safely. This study aims to introduce the benefits of a skull base approach in MVD for HFS. METHODS: The skull base approach was performed in twenty-eight patients among 335 consecutive MVDs for HFS. The site of the neurovascular compression (NVC), the size of the flocculus, and the location of the sigmoid sinus are measured factors in the imaging studies. The indication for a skull base approach is evaluated and verified retrospectively in comparison with the conventional retrosigmoid approach. Operative outcomes and long-term results were analyzed retrospectively. RESULTS: The extended retrosigmoid approach was used for 27 patients and the retrolabyrinthine presigmoid approach was used in one patient. The measurement value including the site of NVC, the size of the flocculus, and the location of the sigmoid sinus represents well the indication of the skull base approach, which is significantly different from the conventional retrosigmoid approach. The skull base approach is useful for patients with medially located NVC, a large flocculus, or repeat MVD cases. The long-term result demonstrated favorable outcomes in patients with the skull base approach applied. CONCLUSIONS: Preoperative evaluation for lateral expansion of the craniectomy contributes to a safe and secure MVD.

Factors affecting global neurocognitive status and frontal executive functions in the early stage after surgical clipping of unruptured anterior circulation aneurysms with respect to keyhole clipping and conventional clipping.

PURPOSE: This study investigated the most significant factor for the preservation of the global neurocognitive status and frontal executive functions in the surgical clipping of unruptured anterior circulation aneurysms, specifically in keyhole and conventional clipping procedures. METHODS: The prospective study that was performed to examine the effects of aneurysm surgery on the patient's global neurocognitive status and frontal executive functions started on April 2016. After exclusion posterior circulation aneurysms, anterior communicating aneurysms treated by interhemispheric approach, giant aneurysms, and paraclinoid aneurysms, 23 patients who were enrolled before May 2017 were treated by conventional clipping, and 18 patients who were enrolled after June 2017 were treated by keyhole clipping. Two patients were excluded from each group due to missing data. Finally, 21 and 16 patients in each group were analyzed, respectively. Three-tesla magnetic resonance imaging was performed before and after surgery to detect the presence of perioperative cerebral infarctions and brain edema. The Mini-Mental State Examination, Frontal Assessment Battery, and Self-Rating Depression Scale scores were obtained before and 1 month after surgery. RESULTS: Logistic regression analyses indicated that anterior communicating and internal carotid artery aneurysms were the most significant factors for poor outcomes and that keyhole clipping for these two types of aneurysm was the most significant factor for the preservation of patient global neurocognitive status. Keyhole clipping was also the most significant factor for the preservation of frontal executive functions in patients. CONCLUSIONS: Keyhole clipping may be more favorable than conventional clipping for the preservation of the global neurocognitive status and frontal executive functions. Moreover, it may be the most effective factor for preservation of global neurocognitive status when it is indicated for anterior communicating or internal carotid artery aneurysms.

Sulforaphane Increase Mitochondrial Biogenesis-Related Gene Expression in the Hippocampus and Suppresses Age-Related Cognitive Decline in Mice.

Sulforaphane (SFN) is a potent activator of the transcriptional factor, Nuclear Factor Erythroid 2 (NF-E2)-Related factor 2 (NRF2). SFN and its precursor, glucoraphanin (sulforaphane glucosinolate, SGS), have been shown to ameliorate cognitive function in clinical trials and in vivo studies. However, the effects of SGS on age-related cognitive decline in Senescence-Accelerated Mouse Prone 8 (SAMP8) is unknown. In this study, we determined the preventive potential of SGS on age-related cognitive decline. One-month old SAMP8 mice or control SAM resistance 1 (SAMR1) mice were fed an ad libitum diet with or without SGS-containing broccoli sprout powder (0.3% w/w SGS in diet) until 13 months of age. SGS significantly improved long-term memory in SAMP8 at 12 months of age. Interestingly, SGS increased hippocampal mRNA and protein levels of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC1α) and mitochondrial transcription factor A (TFAM), which are master regulators of mitochondrial biogenesis, both in SAMR1 and SAMP8 at 13 months of age. Furthermore, mRNAs for nuclear respiratory factor-1 (NRF-1) and mitochondrial DNA-encoded respiratory complex enzymes, but not mitochondrial DNA itself, were increased by SGS in SAMP8 mice. These results suggest that SGS prevents age-related cognitive decline by maintaining mitochondrial function in senescence-accelerated mice.

Double collagen matrix grafting for dural closure in microvascular decompression: an alternative use of autologous fascial grafting.

BACKGROUND: Watertight dural closure is a crucial step in preventing postoperative cerebrospinal fluid (CSF) leak and subsequent infection in posterior fossa surgery. The aim of this study is to assess an alternative use of collagen matrix double grafting in microvascular decompression (MVD). METHODS: Dural closure using double collagen matrix grafts was retrospectively compared with autologous fascial grafting in 120 patients who underwent MVD. Double collagen matrix grafting technique, a combination use of inlay and onlay grafting (DuraGen®, Integra Lifesciences, Plainsboro, NJ, USA, $700-800 for an MVD craniotomy size), was applied in 60 patients (the collagen matrix group). In the remaining 60 patients, an autologous fascial graft was sutured in a watertight fashion to the dural defect (the fascia group). Postoperative wound complications, such as CSF leak and infection, were retrospectively compared between the two groups. RESULTS: CSF leaks were observed in 3 patients (5.0%) in the fascia group and in 2 patients (3.3%) in the collagen matrix group. All cases of CSF leakage presented with pseudomeningoceles except one patient who developed an incisional CSF leak. A repair surgery for CSF leak was required in this one patient in the fascia group. Subcutaneous abscesses were noted in 2 patients (3.3%) in the fascia group. There was no patient who developed a subcutaneous abscess in the collagen matrix group. One patient in each group developed aseptic meningitis. Statistical analyses revealed that the collagen matrix group showed non-inferior outcomes to the fascia group in CSF leaks and infectious complications. CONCLUSIONS: Double grafting technique with a combination of inlay and onlay collagen sheets is a safe and secure alternative for watertight dural closure despite a cost limitation.

Microvascular decompression for trigeminal neuralgia attributable to the vertebrobasilar artery: decompression technique and significance of separation from the nerve root.

BACKGROUND: Separation of the vertebrobasilar artery (VBA) from the trigeminal nerve root in microvascular decompression (MVD) is technically challenging. This study aimed to review the clinical features of VBA involvement in trigeminal neuralgia and evaluate surgical decompression techniques in the long term. METHODS: We retrospectively reviewed the surgical outcomes of 26 patients (4.4%) with VBA involvement in 585 consecutive MVDs for TGN using a Teflon roll for repositioning the VBA. The final operative status of the nerve decompression was categorized into two groups: the separation group and the contact group. Separation of the VBA from the nerve root was completed in 13 patients in the separation group, and slight vascular contact remained in the remaining 13 patients of the contact group. The clinical features of VBA-related TGN were investigated and the operative results were analyzed. RESULTS: Multiple arteries are involved in neurovascular compression (NVC) in most cases. The anterior inferior cerebellar artery was the most common concomitant artery (69%). The site of the NVC varies from the root entry zone to the distal portion of the root. All patients were pain-free immediately after surgery and maintained medication-free status during the follow-up period, except for one patient (3.8%) who had recurrent facial pain 8 years after surgery. Postoperative facial numbness was observed in six patients (23%). Of these, one patient showed improvement within 3 months and the other five patients had persistent facial numbness (19.2%). Other neurological deficits include one dry eye, one diplopia due to trochlear nerve palsy, two decreased hearing (< 50 db), two facial weaknesses, and two cerebellar ataxia. Although most of them were transient, one dry eye, two hearing impairments, and one cerebellar ataxia became persistent deficits. Statistical analyses revealed no difference in surgical efficacy or complications in the long term between the two groups. CONCLUSIONS: Slightly remaining vascular contact does not affect pain relief in the long term. Our study indicated that once the tense trigeminal nerve is loosened, further attempts to mobilize the VBA are not necessary.

Location of the abducens nerve stretched by a tortuous vertebrobasilar artery in trigeminal neuralgia.

BACKGROUND: Trigeminal neuralgia (TGN) caused by the vertebrobasilar artery (VBA) is uncommon. The abducens nerve root is frequently dislocated by a tortuous VBA near the trigeminal nerve root. This unusual location of the root is not well known. This study aimed to investigate the location of the stretched abducens nerve root. METHODS: The objective is 26 patients with VBA-related TGN who underwent microvascular decompression (MVD). We retrospectively investigated the course of the abducens nerve root with magnetic resonance imaging (MRI) with three-dimensional (3D) imaging and surgical findings. The displacement of the abducens nerve root on the affected side was compared to the contralateral side. RESULTS: The abducens nerve root was distorted by a tortuous VBA (46.2%) or the anterior inferior cerebellar artery (53.8%). The average length of the cisternal segment was stretched to 23.4 mm versus 12.4 mm on the contralateral side. The peak point of the elevated abducens nerve root was mostly located rostro-medial (65.4%) or caudo-medial (34.6%) to the neurovascular compression site of the trigeminal nerve with a mean distance of 9.1 mm. Contact with the trigeminal nerve root was observed in 7 patients (26.9%). Three-dimensional imaging was consistent with the surgical findings and useful in predicting the location of the abducens nerve root. No abducens nerve palsy was noted in our series. CONCLUSIONS: The abducens nerve root is located near the trigeminal nerve root in VBA-related TGN. Preoperative understanding of the unusual course of the abducens nerve root contributes to avoiding accidental nerve injury during MVD.

Redo surgery for trigeminal neuralgia: reasons for re-exploration and long-term outcomes.

BACKGROUND: To investigate the causes of failure and recurrence after microvascular decompression (MVD) for trigeminal neuralgia (TGN) and to analyze the results of redo surgery. METHODS: Sixty-three cases of redo surgery were retrospectively reviewed. Reasons for re-exploration were categorized into 4 groups based on the operative findings. Patient characteristics, outcomes of re-exploration, and operative complications were analyzed by Kaplan-Meier and logistic regression analyses. RESULTS: Reasons for redo surgery were divided into arterial compression in 13 patients (21%), venous compression in 11 patients (17%), prosthesis-related in 25 patients (40%), and adhesion or negative exploration in 14 patients (22%). Immediate pain relief was obtained in 59 patients (94%) postoperatively with newly developed facial numbness in 17 patients (27%). Of these, 48 patients (76%) maintained pain-free 1 year postoperatively. Overall recurrence was noted in 17 patients (27%) during the median 49-month follow-up period. Most recurrences occurred within 1 year after redo surgery, but the prosthesis-related patients showed a continuous recurrence up to 4 years. Patients having vascular compression showed significantly better pain control than those without vascular contact in Kaplan-Meier analyses (p = 0.0421). No prognostic factor for pain-free 1 year after redo surgery was found. CONCLUSIONS: Redo surgery is effective for patients with remaining vascular compression rather than those without vascular contact. Teflon contact onto the nerve root should be avoided because it is a potential risk for recurrence and causes poor prognosis after redo surgery.

Bridge technique for hemifacial spasm with vertebral artery involvement.

BACKGROUND: To assess efficacy and safety of a newly developed decompression technique in microvascular decompression for hemifacial spasm (HFS) with vertebral artery (VA) involvement. METHODS: A rigid Teflon (Bard® PTFE Felt Pledget, USA) with the ends placed between the lower pons and the flocculus creates a free space over the root exit zone (REZ) of the facial nerve (bridge technique). The bridge technique and the conventional sling technique for VA-related neurovascular compression were compared retrospectively in 60 patients. Elapsed time for decompression, number of Teflon pieces used during the procedure, and incidences of intraoperative manipulation to the lower cranial nerves were investigated. Postoperative outcomes and complications were retrospectively compared in both techniques. RESULTS: The time from recognition of the REZ to completion of the decompression maneuvers was significantly shorter, and fewer Teflon pieces were required in the bridge technique than in the sling technique. Lower cranial nerve manipulations were performed less in the bridge technique. Although statistical analyses revealed no significant differences in surgical outcomes except spasm-free at postoperative 1 month, the bridge technique is confirmed to provide spasm-free outcomes in the long-term without notable complications. CONCLUSIONS: The bridge technique is a safe and effective decompression method for VA-involved HFS.

Resection of the suprameatal tubercle in microvascular decompression for trigeminal neuralgia.

BACKGROUND: The suprameatal tubercle (SMT) may obscure the neurovascular compression (NVC) in microvascular decompression (MVD) for trigeminal neuralgia (TGN). The aim of this study is to address the necessity of resecting SMT in MVD for TGN. METHODS: We retrospectively analyzed radiological findings of 461 MVDs in patients with TGN, focusing on the relation between SMT and the NVC site. Three-dimensional (3D) images were used for preoperative evaluation. The NVC sites were obscured by SMT in 48 patients (10.4%) via the retrosigmoid approach. This study was conducted to review the management of SMT among these patients. Resection of SMT was performed in 8 patients (resected group) for direct visualization of the NVC site. On the other hand, nerve decompression was achieved without resecting SMT for the rest of the 40 patients (non-resected group). Biographical data, radiological findings, intraoperative findings, and surgical outcomes were retrospectively evaluated. RESULTS: The mean height of SMT obscuring NVC was 5.0 mm (2.8-13.9 mm) above the petrous surface. The NVC was located at a mean of 1.9 mm (0-5.9 mm) from the porous trigeminus. The most common offending vessel was the superior cerebellar artery (SCA, 56.3%), followed by the transverse pontine vein (TPV, 29.2%). In the resected group, the transposing culprit vessels were feasibly performed after direct visualization of the NVC site, whereas in the non-resected group, the SCA was successfully transposed using curved instruments after thorough dissection around the nerve. TPV having contact with the nerve was coagulated and divided. Immediate pain relief was obtained in all patients except one who experienced delayed pain relief 1 month after surgery. Facial numbness at discharge was noted in 9 patients (18.8%); thereafter, numbness diminished over time. Numbness at the final visit was observed in 5 patients (10.4%) at mean of 49 months after MVD. Recurrent pain occurred in 4 patients (8.3%) in total. Statistical analysis showed no significant differences in surgical outcomes between both groups. CONCLUSIONS: Direct visualization of the NVC site by resecting the SMT does not affect surgical outcomes in the immediate and long term. Resecting the SMT is not always necessary to accomplish nerve decompression in most cases by use of suitable instruments and techniques.

Hereditary clear cell meningiomas in a single family: three-cases report.

Clear cell meningiomas (CCMs) are rare subtypes of meningiomas and usually treated by maximum safely achievable tumor resection. We here present three hereditary cases with CCMs which were confirmed by Sanger sequencing of lymphocyte DNA. Gross total resection was achieved in a 5-year-old son with a spinal CCM and a 34-year-old father with a CCM in the cerebellopontine angle (CPA). For a 14-year-old daughter with CCM in the CPA, total resection was not achieved due to its large size. Early detection by screening high-risk family with CCM is strongly recommended.

Single-stage total resection of giant dumbbell-shaped hypoglossal schwannoma: a case report.

Extensive large dumbbell-shaped hypoglossal schwannoma is extremely rare, and total resection is nearly impossible. We present a case of a 61-year-old male with a giant-size hypoglossal schwannoma with moderate tongue atrophy. The tumor extended from the enlarged hypoglossal canal to the brainstem intradurally and the high cervical region extradurally. Through the extreme lateral infrajugular transcondylar (ELITE) skull base approach, the tumor was totally removed in a single-stage operation. Single-stage total resection is feasible by an experienced skull base team utilizing transcondylar skull base techniques and high cervical dissection.

Diagnosis and management for trigeminal neuralgia caused solely by venous compression.

BACKGROUND: Trigeminal neuralgia (TN) caused solely by venous compression is uncommon. An appropriate vein management protocol for microvascular decompression (MVD) has not been established. We evaluated the management of veins for TN solely due to venous involvement. METHOD: We analyzed 31 patients with TN in whom only veins were manipulated during MVD. The culprit veins smaller in diameter than the vein of the cerebellopontine fissure (VCPF) were coagulated and divided in 20 patients (divided group), while transposition was performed for larger veins in the remaining 11 patients (non-divided group). Postoperative outcomes were assessed by Barrow Neurological Institute (BNI) pain intensity score and BNI facial numbness score. RESULTS: Preoperative contrast-enhanced T1 spoiled gradient recalled (SPGR) imaging exhibited higher detection rates for veins (93.5%) than non-contrast fast imaging employing a steady-state acquisition image (74.2%). The transverse pontine vein (TPV) was the most frequently involved vessel. All the divided veins were small TPVs except one. The non-divided group included seven cases of large TPVs and four involving the main trunk of the superior petrosal vein or its large tributaries. The median follow-up duration was 33 months. Pain relief was achieved immediately after the surgery in 28 (90.3%) and within a month in the remaining 3 (9.7%) patients. Numbness was present in seven (22.6%) patients at the final follow-up. Recurrence was observed in only two (10.0%) patients in the divided group compared with four (36.4%) patients in the non-divided group. Comparison at the final follow-up revealed that the divided group had superior outcome compared to the non-divided group. CONCLUSIONS: Contrast-enhanced T1 SPGR imaging is crucial to detect small veins in the preoperative diagnosis. Division of the culprit veins is recommended if the diameter is smaller than the VCPF as it provides a better outcome and lower recurrence rate than transposition.

Long-term outcomes of microvascular decompression and Gamma Knife surgery for trigeminal neuralgia: a retrospective comparison study.

BACKGROUND: There is still no clear guideline for surgical treatment for patients with medically refractory trigeminal neuralgia (TN). When it comes to which surgical treatment to choose, microvascular decompression (MVD) or Gamma Knife surgery (GKS), we should know the long-term outcome of each treatment. METHODS: We analyzed 179 patients undergoing MVD and 52 patients undergoing GKS followed for 1 year or longer. We evaluated the patient's neurological status including pain relief, complications and recurrence. Results were assessed with Barrow Neurological Institute (BNI) pain intensity and facial numbness scores. Overall outcomes were compared between the two groups based on pain relief and complications. RESULTS: BNI pain intensity and facial numbness scores at the final visit were significantly lower in the MVD group than in the GKS group (P < 0.001, P = 0.04, respectively). Overall outcomes were superior following MVD than following GKS (P < 0.001). Following whichever treatment, there were initially high rates of pain-free status "without medication": 96.6% in the MVD group and 96.2% in the GKS group. However, 6.1% in the MVD group and 51.9% in the GKS group fell into a "with medication" state within median periods of 1.83 and 3.92 years, respectively (P < 0.001). Kaplan-Meier analysis revealed that pain recurred more often and later in the GKS group than in the MVD group (P < 0.001). CONCLUSIONS: Considering the long-term outcomes, MVD should be chosen as the initial surgical treatment for patients with medically refractory TN.

The Kumagai Method Utilizing the Pigeon Bottle Feeder with a Long Nipple: A Descriptive Study for the Development of Feeding Techniques for Children with Cleft Lip and/or Palate.

We aimed to identify the steps involved in the Kumagai method-an experimental nursing procedure to feed children with cleft lip and/or palate, using a feeder with a long nipple. We conducted a descriptive study, enrolling five specialist nurses who have mastered the Kumagai method. Their approaches were examined using structured interviews. Moreover, the participants were asked to perform the sequence of actions involved in this method while describing each step. Therefore, we were able to explore the Kumagai method in depth and step-by-step, including the following aspects: correct infant posture; correct feeding bottle holding position; nipple insertion into the child's mouth; and feeding process initiation, maintenance, and termination. Each step comprises several clinically relevant aspects aimed at encouraging the infant to suck with a closed mouth and stimulating chokubo-zui, i.e., simulation of the natural tongue movement during breastfeeding in children without a cleft palate. In conclusion, when performed correctly, the Kumagai method improves feeding efficiency in children with cleft lip and/or palate. Feeders with long nipples are rarely used in clinical practice; the Kumagai method might popularize their use, thereby improving the management of feeding practices for children with cleft lip and/or palate.