A novel non-segmented inverted water outline rendering method can improve the tracking of responsible blood vessels for hemifacial spasm.

This study aimed to explore a novel, non-segmented based on inverted water outline, and rapid 3D rendering method for identifying the responsible blood vessels for hemifacial spasm. First, the software was developed using the free and open-source 3D Slicer to process magnetic resonance images. Outlines of the water region were extracted and rendered in a three-dimensional space. The traditional image re-slicing technique (IMRT) was used for the control group, while non-segmented inverted water outline rendering (NSIWR) was used to observe the relevant blood vessels in the root entry/exit zone (REZ) of patients with hemifacial spasm. The intraoperative exploration results were considered the gold standard for comparing the differences in identifying relevant blood vessels between the two methods. Twenty-five patients were included, and the reconstruction effect evaluation suggested that NSIWR could effectively reconstruct the responsible blood vessels of the cochlea, facial nerve, and REZ. Compared with IMRT, NSIWR effectively improved the diagnosis of the responsible blood vessels in the REZ, clarified their sources and directions, and was consistent with intraoperative results. This study introduced a novel rapid rendering method based on NSIWR, which was successfully applied for hemifacial spasm. The method enhances accuracy in identifying responsible blood vessels in the REZ without needing multi-modal techniques. It has the potential to improve surgical effectiveness and reduce exploration time in treating hemifacial spasm.

Mandan, Hidatsa, and Arikara Nation Perspectives on Rez Dogs on the Fort Berthold Reservation in North Dakota, U.S.A.

The research on the relationships between free-roaming dogs, also referred to as reservation dogs or rez dogs, and Indigenous communities is extremely limited. This study aimed to document the cultural significance of rez dogs, challenges related to rez dogs, and community-specific solutions for rez dog issues affecting community health and safety from members of the Mandan, Hidatsa, and Arikara (MHA) Nation, also referred to as the Three Affiliated Tribes (TAT), who live on the Fort Berthold reservation in North Dakota, U.S.A. One hour semi-structured interviews with 14 community members of the MHA Nation were conducted in 2016. The interviews were analyzed via systematic and inductive coding using Gadamer's hermeneutical phenomenology. The primary intervention areas described by the participants included: culturally relevant information sharing, improved animal control policies and practices, and improved access to veterinary care and other animal services.

Bridge technique for hemifacial spasm with vertebral artery involvement: 2-Dimensional operative video.

Microvascular decompression for hemifacial spasm (HFS) associated with the vertebral artery (VA) is more challenging than that for small arteries. Atherosclerotic VA and tortuous VA are associated with a low success rate and high incidences of complications. Artery relocation employing a Teflon sling is helpful for small arteries. However, a different decompression technique should be considered in VA-related HFS due to the stiffness of the offending artery. With our simple decompression technique providing a secure transposition that can be performed even in the narrow cistern, a rigid Teflon bar is inserted to hold up all offending vessels between the pontine surface and the cerebellar flocculus (the bridge technique). This simple technique easily creates a free space over the root entry zone (REZ), reduces surgical manipulation compared to conventional artery relocation with a Teflon sling, and provides more secure nerve decompression than inserting Teflon pledgets on the REZ. The critical factors for successfully performing the bridge technique are using a rigid Teflon bar that can hold the rebound force of the VA and a length appropriate to generate a free space over the REZ between the pons and the cerebellar flocculus. In this video, we demonstrate our bridge technique for VA-related HFS and discuss the advantages and disadvantages of this novel approach.

Simultaneous microvascular decompression for trigeminal neuralgia and hemifacial spasm involving a dolichoectatic vertebral artery in an elderly patient: illustrative case.

BACKGROUND: Hyperactive cranial neuropathies refractory to medical management can often be debilitating to patients. While microvascular decompression (MVD) surgery can provide relief to such patients when an aberrant vessel is compressing the root entry zone (REZ) of the nerve, the arteries of elderly patients over 65 years of age can be less amenable to manipulation because of calcifications and other morphological changes. A dolichoectatic vertebral artery (DVA), in fact, can lead to multiple cranial neuropathies; therefore, a strategy for MVDs in elderly patients is useful. OBSERVATIONS: A 76-year-old man presented with medically refractory trigeminal neuralgia (TN) and hemifacial spasm (HFS). A DVA was the conflicting vessel at the left REZs of the trigeminal and facial nerves. The authors performed a retrosigmoid craniotomy for MVD of the DVA with Teflon padding at both REZs in approximately 1 hour of operative time. The patient was free of facial pain and spasm immediately after surgery and at follow-up. LESSONS: The authors described the case of an elderly patient with both TN and HFS caused by compression of a DVA. Simultaneous MVD with Teflon padding at both REZs provided symptomatic relief with limited surgical time. This can be a particularly useful and straightforward surgical strategy in the elderly population.

Diabetes and trace elements / Diabetes és a nyomelemek

Ionic or complex compounds of certain trace elements are essential for the proper functioning of the human body in numerous biochemical processes. Their absence or accumulation causes many health problems and diseases. In the past, trace elements have been thought to be a key factor in the treatment of insulin resistance and diabetes, however, the importance and lack of trace elements in the development of diabetes or the assessment of trace element status in the development and treatment of complications are still controversial. Therefore, the authors summarize the role of trace elements in the development, pathogenesis, and progression of diabetes. They briefly report on the most important known processes of zinc(II), manganese(II, III), copper(I, II), chromium(III), iron(II, III), cobalt(II), vanadium(III, IV, V), molybdenum(IV, VI), iodine(I), selenium(II, IV, VI), and lithium(I) in the human body and the biochemical changes associated with diabetes. Differences in trace element status in diabetes, their relationship to free radicals, and the antioxidant defense system are detailed. Some risk factors that lead to more severe micronutrient deficiencies and complications are also discussed.

Intermediate nerve neuralgia developed during hemifacial spasm follow-up: illustrative case.

BACKGROUND: Intermediate nerve neuralgia (INN) is a rare condition believed to be caused by vascular compression, with external auditory canal pain as the chief symptom. The authors reported a rare case of a 78-year-old woman who developed INN during follow-up for hemifacial spasm (HFS). OBSERVATIONS: The patient had been receiving Botox treatment for right HFS for 20 years when she developed paroxysmal electric shock pain in the right external auditory canal and tinnitus induced by opening her mouth. A three-dimensional magnetic resonance fusion image showed the cisternal portion of the facial-vestibulocochlear nerve complex to be compressed by the meatal loop of the anterior inferior cerebellar artery (AICA), which was pressed against by the posterior inferior cerebellar artery. The authors diagnosed INN, and microvascular decompression (MVD) was performed. Surgical findings were consistent with preoperative neuroimaging. In addition, the proximal portion of the meatal loop of the AICA had passed between the facial and vestibulocochlear nerves, compressing both. The AICA was moved and the nerve completely decompressed. All symptoms improved immediately following surgery. LESSONS: When INN occurs during HFS follow-up, aggressive MVD should be considered based on detailed neuroimaging. This treatment is a very effective single-stage cure for INN, HFS, and vestibulocochlear symptoms.

Utility of DTI (Diffusion Tensor Imaging) Metrics to Study Microstructural Changes of Trigeminal Nerve in Patients with Trigeminal Neuralgia (TN).

Aims: To study the trigeminal nerve tractography and assessment of diffusion tensor imaging (DTI) parameters by comparing the values of fractional anisotropy (FA) of trigeminal (V) nerve on the affected side with that of the unaffected opposite side. Materials and Methods: Prospective comparative study done for one year included 30 patients who presented with trigeminal neuralgia and 30 controls who did not have any present or past history of neurological or neurosurgical symptoms were enrolled in the study. Results: Most common age of presentation of TN is >50 years, and the commonly involved branch is V2 (maxillary branch of the trigeminal nerve). Most of the patients were having symptoms for more than 1 year. The superior cerebellar artery was the most common vessel compressing the V nerve at the root entry zone (REZ), followed in the order by anterior inferior cerebellar artery and petrosal vein. Neurovascular compression (NVC) was more commonly seen in the study group when compared with the control group. In all the patients in the study group, fractional anisotropy (FA) was decreased on the affected side as compared to the unaffected side. In the study group, 10 patients were having NVC on both sides, but FA was significantly decreased only on the affected side. No significant difference in FA values at the REZ of bilateral V nerves in the control group. Conclusion: DTI metrics of the trigeminal nerve is a very helpful imaging technique in patients with trigeminal neuralgia. It not only helps in anatomical imaging but also reinforces the association between NVC and TN.

Paroxysmal otalgia treated with microvascular decompression of the intermediate nerve: illustrative case.

BACKGROUND: Intermediate nerve neuralgia is a rare type of cranial neuralgia that causes clinical, therapeutic, and diagnostic challenges. Studies have described pharmacological and surgical treatment options. Surgical treatment ranges from sectioning of neural structures to microvascular decompression. Given the rareness of the disease, there are no clear recommendations concerning treatment. OBSERVATIONS: Reported is the case of a patient with typical intermediate nerve neuralgia. In this particular case, decision-making toward surgical decompression in an earlier stage of the disease could have been beneficial. The authors found excellent results using only microvascular decompression without sectioning of neural structures. LESSONS: Knowledge of intermediate nerve anatomy is essential to understand this complex pain syndrome. This case illustrates that surgery should not only be regarded as a last resort in case of failure of conservative treatment but also should be considered early in the disease course, especially in the case of a clear neurovascular conflict. When no evident cause is found, surgery could be considered as an exploratory option to depict a neurovascular conflict intraoperatively. Microvascular decompression of the intermediate nerve without sectioning of neural structures can obtain excellent results. Since neural structures are saved, postoperative sequelae can be limited.

Computational hemodynamic analysis of the offending vertebral artery at the site of neurovascular contact in a case of hemifacial spasm associated with subclavian steal syndrome: illustrative case.

BACKGROUND: Hemifacial spasm (HFS) is caused by neurovascular contact along the facial nerve's root exit zone (REZ). The authors report a rare HFS case that was associated with ipsilateral subclavian steal syndrome (SSS). OBSERVATIONS: A 42-year-old man with right-sided aortic arch presented with progressing left HFS, which was associated with ipsilateral SSS due to severe stenosis of the left brachiocephalic trunk. Magnetic resonance imaging showed contact between the left REZ and vertebral artery (VA), which had shifted to the left. The authors speculated that the severe stenosis at the left brachiocephalic trunk resulted in the left VA's deviation, which was the underlying cause of the HFS. The authors performed percutaneous angioplasty (PTA) to dilate the left brachiocephalic trunk. Ischemic symptoms of the left arm improved after PTA, but the HFS remained unchanged. A computational fluid dynamics study showed that the high wall shear stress (WSS) around the site of neurovascular contact decreased after PTA. In contrast, pressure at the point of neurovascular contact increased after PTA. LESSONS: SSS is rarely associated with HFS. Endovascular treatment for SSS reduced WSS of the neurovascular contact but increased theoretical pressure of the neurovascular contact. Physical release of the neurovascular contact is the best treatment option for HFS.

The physiological function of copper, the etiological role of copper excess and deficiency / A réz élettani funkciója, a rézfelhalmozódás és a rézhiány kóroktani szerepe.

Copper is an essential micronutrient for the human body, taking part in several metabolic processes. It is required for the terminal oxidation, the elimination of free radicals, the proper functioning of iron metabolism, the synthesis of hormones, neurotransmitters and the stabilization of the extracellular matrix. Copper is a two-faced element. Its significance in protein-bounded form is undeniable, but free copper causes severe cell damage mainly through free radical reactions, substituting other essential metals in protein structure, and it has various effects on cell signaling pathways. The amount of copper present in the human body is part of a delicate balance. Both its deficiency and excess can develop severe symptoms and diseases. The nutritional copper balance is rarely broken, because the average daily consumption excessively covers the needs, and the body's copper stores can tolerate the temporary differences. Genetic diseases (Menkes and Wilson disease) helped to understand the copper metabolism and understand the clinical symptoms of deficiency and excessive intake. The role of copper in the development of chronic diseases is receiving increasing attention. Recent studies show its significance in neurodegenerative and cancerous diseases, both in pathogenesis and as a therapeutic target. Orv Hetil. 2020; 161(35): 1488-1496.

Clinical analysis of microvascular decompression in patients with hemifacial spasm: a retrospective study.

BACKGROUND: Unilateral contractions of the facial muscles characterize hemifacial spasm (HFS). Microvascular decompression (MVD) was widely accepted for the treatment of HFS. To investigate the operative effects and surgical complications in patients with HFS after MVD. METHODS: A retrospective analysis of 540 patients with HFS after MVD was conducted from January 2017 to May 2018. All patients were followed up for 2 years on average. Surgical effects were evaluated on the patients' manifestations according to the Cohen score classification. RESULTS: During the follow-up period, 455 patients (84.26%) were completely cured, 60 patients (11.11%) were partial relief, 25 patients (4.63%) were failed cure. The effective rate was 93.52% on the first day after MVD, and 95.37% on the follow-up period. Ten patients (1.85%) were facial paralysis (FP) on the 1st day of post-operation. Twenty-five patients (4.63%), FP; the patients with delayed facial palsy were all completely cured in 3 months. Fourteen patients (2.59%) were hearing deficit after MVD, in whom 8 patients (1.48%) had good improvement, and 6 patients (1.11%) had no changes. There was no recurrence case or death case recorded. CONCLUSIONS: MVD is the best treatment choice that offers the prospect of a definitive cure for HFS. Skilled microsurgical techniques, as well as identifying and sufficiently decompressing offending vessels, are the key to ensuring a safe and successful MVD. Complications of this surgery are uncommon and transient.

First application of 7-T ultra-high field diffusion tensor imaging to detect altered microstructure of thalamic-somatosensory anatomy in trigeminal neuralgia.

OBJECTIVE: Trigeminal neuralgia (TN) is a debilitating neurological disease that commonly results from neurovascular compression of the trigeminal nerve (CN V). Although the CN V has been extensively studied at the site of neurovascular compression, many pathophysiological factors remain obscure. For example, thalamic-somatosensory function is thought to be altered in TN, but the abnormalities are inadequately characterized. Furthermore, there are few studies using 7-T MRI to examine patients with TN. The purpose of the present study was to use 7-T MRI to assess microstructural alteration in the thalamic-somatosensory tracts of patients with TN by using ultra-high field MRI. METHODS: Ten patients with TN and 10 age- and sex-matched healthy controls underwent scanning using 7-T MRI with diffusion tensor imaging. Structural images were segmented with an automated algorithm to obtain thalamus and primary somatosensory cortex (S1). Probabilistic tractography was performed between the thalamus and S1, and the microstructure of the thalamic-somatosensory tracts was compared between patients with TN and controls. RESULTS: Fractional anisotropy of the thalamic-somatosensory tract ipsilateral to the site of neurovascular compression was reduced in patients (mean 0.43) compared with side-matched controls (mean 0.47, p = 0.01). The mean diffusivity was increased ipsilaterally in patients (mean 6.58 × 10-4 mm2/second) compared with controls (mean 6.15 × 10-4 mm2/second, p = 0.02). Radial diffusivity was increased ipsilaterally in patients (mean 4.91 × 10-4 mm2/second) compared with controls (mean 4.44 × 10-4 mm2/second, p = 0.01). Topographical analysis revealed fractional anisotropy reduction and diffusivity elevation along the entire anatomical S1 arc in patients with TN. CONCLUSIONS: The present study is the first to examine microstructural properties of the thalamic-somatosensory anatomy in patients with TN and to evaluate quantitative differences compared with healthy controls. The finding of reduced integrity of these white matter fibers provides evidence of microstructural alteration at the level of the thalamus and S1, and furthers the understanding of TN neurobiology.

Diffusion tensor imaging reveals microstructural differences between subtypes of trigeminal neuralgia.

OBJECTIVE: Trigeminal neuralgia (TN) is an uncommon idiopathic facial pain syndrome. To assist in diagnosis, treatment, and research, TN is often classified as type 1 (TN1) when pain is primarily paroxysmal and episodic or type 2 (TN2) when pain is primarily constant in character. Recently, diffusion tensor imaging (DTI) has revealed microstructural changes in the symptomatic trigeminal root and root entry zone of patients with unilateral TN. In this study, the authors explored the differences in DTI parameters between subcategories of TN, specifically TN1 and TN2, in the pontine segment of the trigeminal tract. METHODS: The authors enrolled 8 patients with unilateral TN1, 7 patients with unilateral TN2, and 23 asymptomatic controls. Patients underwent DTI with parameter measurements in a region of interest within the pontine segment of the trigeminal tract. DTI parameters were compared between groups. RESULTS: In the pontine segment, the radial diffusivity (p = 0.0049) and apparent diffusion coefficient (p = 0.023) values in TN1 patients were increased compared to the values in TN2 patients and controls. The DTI measures in TN2 were not statistically significant from those in controls. When comparing the symptomatic to asymptomatic sides in TN1 patients, radial diffusivity was increased (p = 0.025) and fractional anisotropy was decreased (p = 0.044) in the symptomatic sides. The apparent diffusion coefficient was increased, with a trend toward statistical significance (p = 0.066). CONCLUSIONS: Noninvasive DTI analysis of patients with TN may lead to improved diagnosis of TN subtypes (e.g., TN1 and TN2) and improve patient selection for surgical intervention. DTI measurements may also provide insights into prognosis after intervention, as TN1 patients are known to have better surgical outcomes than TN2 patients.

A novel scoring system as a preoperative predictor for pain-free survival after microsurgery for trigeminal neuralgia.

OBJECTIVEPain relief following microvascular decompression (MVD) for trigeminal neuralgia (TN) may be related to pain type, degree of neurovascular conflict, arterial compression, and location of compression. The objective of this study was to construct a predictive pain-free scoring system based on clinical and radiographic factors that can be used to preoperatively prognosticate long-term outcomes for TN patients following surgical intervention (MVD or internal neurolysis [IN]). It was hypothesized that contributing factors would include pain type, presence of an artery or vein, neurovascular conflict severity, and compression location (root entry zone).METHODSAt the authors' institution 275 patients with type 1 or type 2 TN (TN1 or TN2) underwent MVD or IN following preoperative high-resolution brain MRI studies. Outcome data were obtained retrospectively by chart review and/or phone follow-up. Characteristics of neurovascular conflict were obtained from preoperative MRI studies. Factors that resulted in a probability value of < 0.05 on univariate logistic regression analyses were entered into a multivariate Cox regression analysis in a backward stepwise fashion. For the multivariate analysis, significance at the 0.15 level was used. A prognostic system was then devised with 4 possible scores (0, 1, 2, or 3) and pain-free survival analyses conducted.RESULTSUnivariate predictors of pain-free survival were pain type (p = 0.013), presence of any vessel (p = 0.042), and neurovascular compression severity (p = 0.038). Scores of 0, 1, 2, and 3 were found to be significantly different in regard to pain-free survival (log rank, p = 0.005). At 5 and 10 years there were 36%, 43%, 61%, and 69%, and 36%, 43%, 56%, and 67% pain-free survival rates in groups 0, 1, 2, and 3, respectively. While TN2 patients had worse outcomes regardless of score, a subgroup analysis of TN1 patients with higher neurovascular conflict (score of 3) had significantly better outcomes than TN1 patients without severe neurovascular conflict (score of 1) (log rank, p = 0.005). Regardless of pain type, those patients with severe neurovascular conflict were more likely to have arterial compression (99%) compared to those with low neurovascular conflict (p < 0.001).CONCLUSIONSPain-free survival was predicted by a scoring system based on preoperative clinical and radiographic findings. Higher scores predicted significantly better pain relief than lower scores. TN1 patients with severe neurovascular conflict had the best long-term pain-free outcome.

Intraoperative Measuring of the Offending Vessel's Pressure on the Facial Nerve at Root Exit Zone in Patients with Hemifacial Spasm During Microvascular Decompression: A Prospective Study.

OBJECTIVE: The compression of the offending vessel on the facial nerve at root exit zone is considered as the leading cause of hemifacial spasm (HFS). However, the correlation between the severity of spasm and the pressure of neurovascular compression (NVC) has not yet been investigated. The aim of this study was to investigate the clinical correlation between the severity of HFS and the pressure of NVC. METHODS: A prospective study was performed, which included 52 of 151 patients who underwent microvascular decompression. We classified the preoperative spasm severity according to the Cohen scores. Codman intracranial pressure monitoring system was used to measure the NVC pressure at the root exit zone during microvascular decompression. All patients were followed up for 12-24 months. RESULTS: Herein, the intraoperative pressure readings of NVC were in the range of 21-63 mmHg. The means of the pressure of NVC that corresponded to the Cohen scores (1-4) were 23.00 ± 1.83, 34.91 ± 12.42, 46.50 ± 9.40, and 55.40 ± 3.03 mmHg, respectively. The Spearman's rank correlation established a strong positive correlation between the pressure and the Cohen scores (r = 0.689, P < 0.0001). The simple linear analysis indicated that sex (P = 0.132), duration (P = 0.304), and delayed relief (P = 0.158) were not significantly associated with the pressure. However, a substantial correlation was determined between the pressure values and the time until the complete recovery (r = 0.949, P < 0.0001) of the delayed healing population. CONCLUSIONS: The severity of HFS exhibited a strong positive correlation with the intraoperative offending vessel's pressure values. Thus, the neurovascular pressure is a significant factor in the pathogenesis of HFS.

Facial motor evoked potential with paired transcranial magnetic stimulation: prognostic value following microvascular decompression for hemifacial spasm.

OBJECTIVE: Microvascular decompression (MVD) is widely considered the treatment of choice for hemifacial spasm (HFS), but not all patients immediately benefit from it. Numerous electrophysiological tests have been employed to monitor the integrity of the facial nerve prior to, during, and after MVD treatment. The authors sought to verify if facial motor evoked potential (FMEP) with paired transcranial magnetic stimulation (pTMS) can be utilized as a tool to predict prognosis following MVD for HFS. METHODS: FMEP using pTMS was performed preoperatively and postoperatively for 527 HFS patients who underwent an MVD treatment. Various interstimuli intervals (ISIs), which included 2, 10, 20, 25, 30, 75, and 100 msec, were applied for each paired stimulation and pTMS(%) was obtained. A graph of pTMS(%) versus each ISI was drawn for every patient and its pattern was analyzed in accordance with patients' clinical outcomes. RESULTS: With ISIs of 75 and 100 msec, pTMS(%) was physiologically further inhibited, whereas it was relatively facilitated under ISIs of 20, 25, and 30 msec; loss of this specific pattern, that is, further inhibition-relative facilitation, indicated impaired integrity of the facial nerve. Those patients who immediately benefited from an MVD and experienced no relapse tended to show proper restoration of this further inhibition-relative facilitation pattern (p = 0.01). Greater resemblance between the physiological pattern of pTMS(%) and postoperative pTMS(%) was correlated to better outcome (p = 0.019). CONCLUSIONS: A simple linear graph of pTMS(%) versus each ISI may be a helpful tool to predict prognosis for HFS following an MVD.

Quantitative analysis of the surgical exposure and surgical freedom between transcranial and transorbital endoscopic anterior petrosectomies to the posterior fossa.

OBJECT: This study proposes a variation of the transorbital endoscopic approach (TOEA) that uses the lateral orbit as the primary surgical corridor, in a minimally invasive fashion, for the posterior fossa (PF) access. The versatility of this technique was quantitatively analyzed in comparison with the anterior transpetrosal approach (ATPA), which is commonly used for managing lesions in the PF. METHODS: Anatomical dissections were carried out in 5 latex-injected human cadaveric heads (10 sides). During dissection, the PF was first accessed by TOEAs through the anterior petrosectomy, both with and without lateral orbital rim osteotomies (herein referred as the lateral transorbital approach [LTOA] and the lateral orbital wall approach [LOWA], respectively). ATPAs were performed following the orbital approaches. The stereotactic measurements of the area of exposure, surgical freedom, and angles of attack to 5 anatomical targets were obtained for statistical comparison by the neuronavigator. RESULTS: The LTOA provided the smallest area of exposure (1.51 ± 0.5 cm2, p = 0.07), while areas of exposure were similar between LOWA and ATPA (1.99 ± 0.7 cm2 and 2.01 ± 1.0 cm2, respectively; p = 0.99). ATPA had the largest surgical freedom, whereas that of LTOA was the most restricted. Similarly, for all targets, the vertical and horizontal angles of attack achieved with ATPA were significantly broader than those achieved with LTOA. However, in LOWA, the removal of the lateral orbital rim allowed a broader range of movement in the horizontal plane, thus granting a similar horizontal angle for 3 of the 5 targets in comparison with ATPA. CONCLUSIONS: The TOEAs using the lateral orbital corridor for PF access are feasible techniques that may provide a comparable surgical exposure to the ATPA. Furthermore, the removal of the orbital rim showed an additional benefit in an enhancement of the surgical maneuverability in the PF.

Stereotactic radiosurgery for trigeminal neuralgia: a systematic review.

OBJECTIVES: The aims of this systematic review are to provide an objective summary of the published literature specific to the treatment of classical trigeminal neuralgia with stereotactic radiosurgery (RS) and to develop consensus guideline recommendations for the use of RS, as endorsed by the International Society of Stereotactic Radiosurgery (ISRS). METHODS: The authors performed a systematic review of the English-language literature from 1951 up to December 2015 using the Embase, PubMed, and MEDLINE databases. The following MeSH terms were used in a title and abstract screening: "radiosurgery" AND "trigeminal." Of the 585 initial results obtained, the authors performed a full text screening of 185 studies and ultimately found 65 eligible studies. Guideline recommendations were based on level of evidence and level of consensus, the latter predefined as at least 85% agreement among the ISRS guideline committee members. RESULTS: The results for 65 studies (6461 patients) are reported: 45 Gamma Knife RS (GKS) studies (5687 patients [88%]), 11 linear accelerator (LINAC) RS studies (511 patients [8%]), and 9 CyberKnife RS (CKR) studies (263 patients [4%]). With the exception of one prospective study, all studies were retrospective.The mean maximal doses were 71.1-90.1 Gy (prescribed at the 100% isodose line) for GKS, 83.3 Gy for LINAC, and 64.3-80.5 Gy for CKR (the latter two prescribed at the 80% or 90% isodose lines, respectively). The ranges of maximal doses were as follows: 60-97 Gy for GKS, 50-90 Gy for LINAC, and 66-90 Gy for CKR.Actuarial initial freedom from pain (FFP) without medication ranged from 28.6% to 100% (mean 53.1%, median 52.1%) for GKS, from 17.3% to 76% (mean 49.3%, median 43.2%) for LINAC, and from 40% to 72% (mean 56.3%, median 58%) for CKR. Specific to hypesthesia, the crude rates (all Barrow Neurological Institute Pain Intensity Scale scores included) ranged from 0% to 68.8% (mean 21.7%, median 19%) for GKS, from 11.4% to 49.7% (mean 27.6%, median 28.5%) for LINAC, and from 11.8% to 51.2% (mean 29.1%, median 18.7%) for CKR. Other complications included dysesthesias, paresthesias, dry eye, deafferentation pain, and keratitis. Hypesthesia and paresthesia occurred as complications only when the anterior retrogasserian portion of the trigeminal nerve was targeted, whereas the other listed complications occurred when the root entry zone was targeted. Recurrence rates ranged from 0% to 52.2% (mean 24.6%, median 23%) for GKS, from 19% to 63% (mean 32.2%, median 29%) for LINAC, and from 15.8% to 33% (mean 25.8%, median 27.2%) for CKR. Two GKS series reported 30% and 45.3% of patients who were pain free without medication at 10 years. CONCLUSIONS: The literature is limited in its level of evidence, with only one comparative randomized trial (1 vs 2 isocenters) reported to date. At present, one can conclude that RS is a safe and effective therapy for drug-resistant trigeminal neuralgia. A number of consensus statements have been made and endorsed by the ISRS.

Volumetric changes and clinical outcome for petroclival meningiomas after primary treatment with Gamma Knife radiosurgery.

OBJECTIVEPetroclival meningiomas (PCMs) can cause devastating clinical symptoms due to mass effect on cranial nerves (CNs); thus, patients harboring these tumors need treatment. Many neurosurgeons advocate for microsurgery because removal of the tumor can provide relief or result in symptom disappearance. Gamma Knife radiosurgery (GKRS) is often an alternative for surgery because it can cause tumor shrinkage with improvement of symptoms. This study evaluates qualitative volumetric changes of PCM after primary GKRS and its impact on clinical symptoms.METHODSThe authors performed a retrospective study of patients with PCM who underwent primary GKRS between 2003 and 2015 at the Gamma Knife Center of the Elisabeth-Tweesteden Hospital in Tilburg, the Netherlands. This study yields 53 patients. In this study the authors concentrate on qualitative volumetric tumor changes, local tumor control rate, and the effect of the treatment on trigeminal neuralgia (TN).RESULTSLocal tumor control was 98% at 5 years and 93% at 7 years (Kaplan-Meier estimates). More than 90% of the tumors showed regression in volume during the first 5 years. The mean volumetric tumor decrease was 21.2%, 27.1%, and 31% at 1, 3, and 6 years of follow-up, respectively. Improvement in TN was achieved in 61%, 67%, and 70% of the cases at 1, 2, and 3 years of follow-up, respectively. This was associated with a mean volumetric tumor decrease of 25% at the 1-year follow-up to 32% at the 3-year follow-up.CONCLUSIONSGKRS for PCMs yields a high tumor control rate with a low incidence of neurological deficits. Many patients with TN due to PCM experienced improvement in TN after radiosurgery. GKRS achieves significant volumetric tumor decrease in the first years of follow-up and thereafter.

Microvascular decompression for hemifacial spasm: can intraoperative lateral spread response monitoring improve surgical efficacy?

OBJECTIVE The purpose of this study was to evaluate whether intraoperative monitoring of lateral spread response (LSR) improves the efficacy of microvascular decompression (MVD) for hemifacial spasm (HFS). METHODS In this prospective study, patients undergoing MVD for HFS were assigned to one of 2 groups, Group A (MVD with intraoperative LSR monitoring) or Group B (MVD without LSR monitoring). Clinical outcome at 12 months after surgery was assessed through telephone survey. Data analysis was performed to investigate the effect of intraoperative LSR monitoring on efficacy of MVD. RESULTS A total of 283 patients were enrolled in the study, 145 in Group A and 138 in Group B. There was no statistically significant difference between the 2 groups with respect to the percentage of patients who had spasm relief at either 1 week (Group A 87.59% vs Group B 83.33%; p = 0.317) or 1 year (93.1% vs 94.2%; p = 0.809) after surgery. A clear-cut elimination of LSR during surgery was observed in 131 (90.34%) of 145 patients; LSR persisted in 14 patients (9.66%) at the end of the surgical procedure. Disappearance of LSR correlated with spasm-free status at 1 week postoperatively (p = 0.017) but not at 1 year postoperatively (p = 0.249). CONCLUSIONS Intraoperative LSR monitoring does not appear to provide significant benefit with respect to the outcome of MVD for HFS in skilled hands. Persistence of LSR does not always correlate with poor outcome, and LSR elimination should not be pursued in all patients after verification of complete decompression.