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Hypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration. It is caused by a damage at the Guillain-Mollaret triangle (GMT), which is defined by three anatomical structures: the dentate nucleus, the red nucleus, and the inferior olivary nucleus (ION). Clinically, it may be revealed by palatal myoclonus. On MRI, it appears as a unilateral or bilateral enlargement of the inferior olivary nucleus which shows a high signal intensity on T2-weighted images, with sometimes a cerebellar atrophy. Here we report 2 cases of healthy patients which present hemorrhagic brainstem cavernomas, complicated later by the development of palatal myoclonus and cerebellar ataxia, with MRI features corresponding to an (HOD) secondary to a (GMT) cavernoma. The purpose is to explain the mechanism of (HOD) subsequent to lesion in (GMT), and to describe magnetic resonance imaging features.

An 8-year-old boy presenting with left-angle paralysis, tremor in upper and lower extremities, and diplopia was diagnosed with hemorrhage from a mesencephalic cavernous hemangioma. He underwent hemangiomectomy through the occipital transtentorial approach 4 weeks post-hemorrhage, after which Holmes tremor (HT) markedly reduced. A year later, hemangioma has not recurred; he is now independent in his daily activities. Early intervention in the subacute stage allows for the complete removal of brainstem cavernomas (BSCs), with minimal risk of complications or sequelae. Proper timing and surgical approach for BSCs can prevent re-bleeding and improve HT after an initial hemorrhage, without any lasting negative consequences. [ABSTRACT FROM AUTHOR]

Objective: Brainstem cavernous malformations (BSCMs) were once considered inoperable. Microsurgical resection now represents a valuable option for treating patients with hemorrhagic or symptomatic lesions. The aim of this study was to provide a practical guide for surgical planning by analyzing postoperative neurological and functional outcomes., Methods: The early- and long-term neurological (National Institutes of Health Stroke Scale [NIHSS] score) and functional (modified Rankin Scale [mRS] and Glasgow Outcome Scale [GOS] scores) outcomes of 32 patients who underwent surgery for hemorrhagic BSCM were reviewed. The three-step surgical planning was based on an anatomosurgical algorithm., Results: Nine lesions (28.1%) were located in the mesencephalon, 19 (59.4%) in the pons, and 4 (12.5%) in the medulla. A fronto-temporo-orbito-zygomatic approach was selected to reach anterior mesencephalic BSCMs (2, 6.3%). A retrosigmoid approach and its extended variant were selected for lateral mesencephalic (6, 18.8%), anterior (2, 6.3%) and lateral (13, 40.6%) pontine, and anterior (1, 3.1%) and lateral (1, 3.1%) medullary BSCMs. A supracerebellar infratentorial approach was selected for posterior mesencephalic BSCMs (1, 3.1%). A telovelar approach was selected for posterior pontine (4, 12.5%) and medullary (2, 6.3%) BSCMs. Total resection was achieved in 29 cases (90.6%), with a 12.5% rate of surgical complications. The NIHSS score progressively improved at both the early (5.16 ± 3.70 vs 4.63 ± 2.78, p = 0.446) and late (4.63 ± 2.78 vs 2.41 ± 2.39, p < 0.001) postoperative evaluations. Functional outcomes showed an initial deterioration followed by a long-term improvement (mRS score: 2.66 ± 1.07 vs 3.06 ± 1.11 vs 2.13 ± 1.29, GOS score: 3.78 ± 0.61 vs 3.59 ± 0.62 vs 4.19 ± 0.78). Time to surgery significantly correlated with early- and long-term NIHSS, mRS, and GOS scores, while the number of hemorrhages before surgery correlated with early- and long-term mRS and GOS scores., Conclusions: Early surgery after the first bleed following systematic surgical planning may be considered as an effective option for managing hemorrhagic BSCMs with acceptable operative morbidity and relatively favorable early- and long-term neurological and functional outcomes.

Introduction: The resection of brainstem cerebral cavernous malformations (CCM) harbors the risk of damaging the corticospinal tract (CST) and other major tracts. Hence, visualization of eloquent fiber tracts supports pre- and intraoperative planning. However, diffusion tensor imaging fiber tracking at brainstem level suffers from distortion due to field inhomogeneities and eddy currents by steep diffusion gradients. Research question: This study aims to analyze the effect of distortion correction for CST tractography in brainstem CCM patients. Material and methods: 25 patients who underwent resection of brainstem CCM were enrolled, 24 suffered from hemorrhage. We performed an anatomically based tractography of the CST with a mean minimal fractional anisotropy of 0.22 ± 0.04 before and after cranial distortion correction (CDC). Accuracy was measured by anatomical plausibility and aberrant fibers. Results: CDC led to a more precise CST tractography, further approximating its assumed anatomical localization in all cases. CDC resulted in a significantly more ventral location of the CST of 1.5 ± 0.6 mm (6.1 ± 2.7 mm before CDC vs. 4.6 ± 2.1 mm after CDC; p

Background: "Thirteen-and-a-half" is a newly described clinical syndrome characterized by the combination of the one-and-a-half syndrome with fifth and seventh cranial nerve nuclei involvement (11/2 + 5 + 7 = 131/2). To the authors' knowledge, this is the first report of the thirteen-and-a-half syndrome secondary to pontine cavernoma and, overall, only the second reported case of this syndrome in the literature till date. Case Report: A 20-year-old man presented with the clinical features suggestive of the thirteen-and-a-half syndrome, explained radiologically by pontine cavernoma. We operated him using a suboccipital transvermian approach and he is doing well at 2.5 years follow-up. Interestingly, his one-and-a-half syndrome has partially improved to left horizontal gaze palsy. Conclusion: The clinical appreciation of the thirteen-and-a-half syndrome precisely localizes the lesion to ipsilateral dorsal pontine tegmentum. Neurosurgeons must be aware of the newly described "one-and-a-half- plus" syndromes as they help in a better understanding of pathoanatomy caused by different disease processes in the brainstem. [ABSTRACT FROM AUTHOR]

Cluster headaches are characterized by painful unilateral periorbital attacks accompanied by dysautonomic symptoms. Although cluster headaches are classified as a primary headache disorder, a few cases of inflammatory, vascular or neoplastic conditions have been reported to cause or mimic cluster headaches. This raises the question as to the possible causal relationship between symptoms and an underlying structural lesion that may potentially interfere with the trigemino-autonomic reflex.We hereby report the first pediatric case of a brainstem cavernoma causing cluster headache-like symptoms. Of note, the child experienced pain relief after surgery.With regards to the pathophysiology, the observed ptosis observed in our child during the painful crises might be explained by mass effect of the cavernorma on the cisternal portion of the third cranial nerve. In addition, chronic inflammation of mesencephalic and motor nuclei of the trigeminal nerve by thalamo-pedoncular edema surrounding the lesion may have participated to painful pathways.This case illustrates that cluster headaches may occasionally be secondary to an underlying lesion. This advocates the need for MRI screening, especially as neurosurgical intervention may offer significant symptomatic relief and an improvement in the quality of life of these patients.

Hypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration. It is caused by a damage at the Guillain-Mollaret triangle (GMT), which is defined by three anatomical structures: the dentate nucleus, the red nucleus, and the inferior olivary nucleus (ION). Clinically, it may be revealed by palatal myoclonus. On MRI, it appears as a unilateral or bilateral enlargement of the inferior olivary nucleus which shows a high signal intensity on T2-weighted images, with sometimes a cerebellar atrophy. Here we report 2 cases of healthy patients which present hemorrhagic brainstem cavernomas, complicated later by the development of palatal myoclonus and cerebellar ataxia, with MRI features corresponding to an (HOD) secondary to a (GMT) cavernoma. The purpose is to explain the mechanism of (HOD) subsequent to lesion in (GMT), and to describe magnetic resonance imaging features., (© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

Background: Holmes tremor is a rare symptomatic movement disorder, characterized by a combination of resting, postural, and intention tremor. It is usually caused by lesions in the brainstem, thalamus, and cerebellum. Despite pharmacological advances, its treatment remains a challenge; many medications have been used with various degrees of effectiveness. Stereotactic thalamotomy and deep brain stimulation in the ventralis intermedius nucleus have been effective surgical procedures in cases refractory to medical treatment. Case Report: Here we report a young woman with topiramate-responsive Holmes tremor secondary to a brainstem cavernoma. Discussion: Herein we report a Holmes tremor responsive to Topiramate.

We present the case of a 64-year-old female, with a 5-year history of symptomatic multiple cerebral cavernomas, who developed paresthesia in the right leg and arm, followed by vertigo, slurred speech and forward gaze diplopia. Brain investigation revealed two lesions with supra- and infratentorial localization with signs of recent hemorrhage of different ages. The localization of the lesions in the midpoints and the basal ganglia imposed a conservative approach.

Surgical resection of brainstem cavernous malformations (BCMs) is a high-risk procedure and can be challenging to the neurosurgeon. Lateral surgical routes are becoming increasingly used to approach ventrolaterally brainstem cavernoma. Surgical approach decision depends on the location of the cavernoma in the brainstem and a possible association with brainstem developmental venous anomalies (DVAs). DVA can affect the formation and clinical course of cavernous malformation (CM). CMs related to DVAs tend to have more aggressive behavior than isolated CM. In cases of DVAs associated with hemorrhage, CMs are most often the site of bleeding rather than DVAs themselves. In this case report, we present a 24-year-old woman with a pontomedullary CM and associated dorsally located DVA. BCM was operated through a far lateral suboccipital craniotomy. Brainstem entry point was at inferior olive with extension to the pontomedullary sulcus. This approach should be preferred as a safe surgical exposure to the central and paramedian pontomedullary cavernoma, especially in the cases with associated intraparenchymal brainstem DVA. Such surgical exposure allows preservation of the concomitant brainstem DVA. [ABSTRACT FROM AUTHOR]

Brainstem cavernoma is a challenging neurosurgical pathology and microsurgery remains the only treatment option. Although the decision-making between interventional and conservative approach to this disease may be complex, malformations presenting multiple bleedings are usually good candidates for surgery. 1 On the other hand, microsurgical resection of cavernomas can offer an effective resolution with acceptable morbidity. In this video, we present a case of pontine cavernoma with multiple hemorrhages in a young patient. The anatomical characteristic of the lesion defines the best suitable craniotomy for surgery. In this case, an anterior petrosal approach 234 was used to access the peritrigeminal area and safely perform the resection. Anatomical considerations are described on this skull base approach along with the rationale and benefits of this exposure. Electrophysiological neuromonitoring is essential for this kind of procedure and preoperative tractography also enabled the best understanding of the disease. Finally, we also discuss alternative managements and potential complications. 5 With the patient's consent, we also show the excellent clinical evolution after few weeks of recovery and the restoration of the corticospinal tract, previously displaced by the cavernoma, to its original position. [ABSTRACT FROM AUTHOR]

We present the case of a 64-year old female, with a 5 year history of symptomatic multiple cerebral cavernomas, who developed paresthesia in the right leg and arm, followed by vertigo, slurred speech and forward gaze diplopia. Brain investigation revealed two lesions with supra- and infratentorial localization with signs of recent hemorrhage of different ages. The localization of the lesions in the midpons and the basal ganglia imposed a conservative approach. [ABSTRACT FROM AUTHOR]

Introduction: The resection of brainstem cerebral cavernous malformations (CCM) harbors the risk of damaging the corticospinal tract (CST) and other major tracts. Hence, visualization of eloquent fiber tracts supports pre- and intraoperative planning. However, diffusion tensor imaging fiber tracking at brainstem level suffers from distortion due to field inhomogeneities and eddy currents by steep diffusion gradients., Research Question: This study aims to analyze the effect of distortion correction for CST tractography in brainstem CCM patients., Material and Methods: 25 patients who underwent resection of brainstem CCM were enrolled, 24 suffered from hemorrhage. We performed an anatomically based tractography of the CST with a mean minimal fractional anisotropy of 0.22 ± 0.04 before and after cranial distortion correction (CDC). Accuracy was measured by anatomical plausibility and aberrant fibers., Results: CDC led to a more precise CST tractography, further approximating its assumed anatomical localization in all cases. CDC resulted in a significantly more ventral location of the CST of 1.5 ± 0.6 mm (6.1 ± 2.7 mm before CDC vs. 4.6 ± 2.1 mm after CDC; p < .0001) as measured by the distance to the basilar artery and of 1.7 ± 0.6 mm (8.9 ± 2.7 mm vs. 7.2 ± 2.1 mm; p < .0001) in relation to the clivus. Aberrant fibers were reduced by CDC in 44% of cases. We found a mean difference in CST volume of 0.6 ± 0.8 ccm. We could not detect motor deficits after resection of irregular fibers., Discussion and Conclusion: CDC effectively corrects tractography for distortion at brainstem level, especially in patients suffering from brainstem CCM, further approximating its actual anatomical localization., Competing Interests: All authors declare that they have no conflict of interest regarding the materials used as well as the results presented in this study., (© 2023 The Authors.)

Abstract Mesencephalic cavernous malformations (MeCMs) account for 4 to 35% of the cavernous malformations of the central nervous system and are generally rare. Surgical resection of brainstem cavernomas are high-risk procedures and can be challenging to the neurosurgeon. Several approaches have been described, but the approach must allow for a straight line of sight in which the surgeon, the pial incision, and the MeCM are all collinear. This alignment provides the best view of the lesion while minimizing the need for brainstem retraction. The pial incision should be chosen to minimize the distance to the lesion while avoiding critical nuclei and tracts. In this case report, we present a 34-year-old woman with a MeCM resected by an anterior transcallosal transchoroidal approach with minimal damage to surrounding brain tissue. Although rarely used, it should be considered a valuable alternative to ventrally located brainstem cavernomas.

Objective In this study, we investigated the potential prognostic role of morphologic and quantitative diffusion tensor imaging (DTI) in patients with brainstem cavernoma (BSC) in terms of postoperative outcome. Methods In this retrospective study of 14 brainstem cavernoma patients, we analyzed pre- and postoperative DTI data. White matter tractography of corticospinal tracts (CSTs) was performed with the Fiber Assignment by Continuous Tracking algorithm, and morphologic characteristics of CSTs were compared with clinically assessed motor strength. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in ipsi- and contralesional regions of interest at the lesion level, as well as levels caudal and rostral to the lesion. Correlation analysis was performed between lateral index (LI) of ipsi-/contralateral FA and ADC values and patients' motor function. Results Preoperatively, normal morphologic features of CSTs corresponded to normal motor function in 4 patients. The other 10 morphologically abnormal preoperative CSTs didn't show corresponding motor impairment either in pre- or postoperative follow-up period. The sensitivity, specificity, positive predictive, and negative predictive values of white matter tractographic morphology on preoperative motor function were 100%, 57.1%, 70%, and 100%, respectively. The corresponding values on follow-up motor function were 100%, 33.3%, 20%, and 100%, respectively. The mean FA at lesion level was significantly lower than the corresponding FA at the contralateral hemisphere ( P = 0.009). In areas caudal to the lesion the same trend yet without statistic significance was observed ( P = 0.23). There was no significant laterality difference of mean FAs rostral to the level of the lesion. No correlation in LI of FA or ADC in the 3 anatomic levels with simultaneous and long-term follow up motor function was observed. Restoration of the morphology of the affected CST postoperatively was associated with a trend for decreasing ADC compared with the preoperative measurements. Conclusion Intact CST morphology in DTI predicts a favorable postoperative outcome in patients with BSC. Interrupted CSTs and decreased FA values correlate well within BSC lesion level; nevertheless, morphologic characteristics and diffusion parameter changes at lesion level cannot predict poor prognosis. Caudal and rostral diffusion parameters can provide more information of the integrity of CSTs compared with morphologic study alone. [ABSTRACT FROM AUTHOR]

The spatial complexity of highly vulnerable structures makes surgical resection of brainstem cavernomas (BSC) a challenging procedure. Diffusion tensor imaging (DTI) allows for the visualization of white matter tracts and enables a better understanding of the anatomical location of corticospinal and sensory tracts before and after surgery.We investigated the feasibility and clinical usefulness of DTI-based fiber tractography in patients with BSC.Pre- and postoperative DTI visualization of corticospinal and sensory tracts were retrospectively analyzed in 23 individuals with BSC. Preoperative and postoperative DTI-fiber accuracy were associated to the neurological findings. Preoperatively, the corticospinal tracts were visualized in 90 % of the cases and the sensory tracts were visualized in 74 % of the cases. Postoperatively, the corticospinal tracts were visualized in 97 % of the cases and the sensory tracts could be visualized in 80 % of the cases. In all cases, the BSC had caused displacement, thinning, or interruption of the fiber tracts to various degrees. Tract visualization was associated with pre- and postoperative neurological findings. Postoperative damage of the corticospinal tracts was observed in two patients. On follow-up, the Patzold Rating (PR) improved in 19 out of 23 patients (83 %, p = 0.0002).This study confirms that DTI tractography allows accurate and detailed white matter tract visualization in the brainstem, even when an intraaxial lesion affects this structure. Furthermore, visualizing the tracts adjacent to the lesion adds to our understanding of the distorted intrinsic brainstem anatomy and it may assists in planning the surgical approach in specific cases. [ABSTRACT FROM AUTHOR]

Cavernous haemangiomas, or cavernous malformations, have been reported during pregnancy, most of which have been either supratentorial or spinal lesions. We encountered a 15-year old pregnant patient with a rapidly progressive and haemorrhagic brainstem cavernous haemangioma. The case presented here describes the history and findings of this patient, as well as the less-commonly utilized technique we used to access the floor of the fourth ventricle via occipital craniotomy for complete macroscopic resection of this lesion, resulting in the gradual return of most of her neurological deficits. [ABSTRACT FROM PUBLISHER]

Abstract: Objective: Cerebral cavernous malformations (CCMs) and especially cavernous malformations (CMs) in highly eloquent brain areas such as brainstem CMs are rare but possible events during pregnancy. Due to the few published cases in literature clear recommendations regarding the management are rare. In this study we evaluate the proceeding decision in pregnant patients with highly eloquent brainstem CMs. Methods: In our series 43 patients with CMs in highly eloquent brain areas, including 39 patients with brainstem CMs, were surgically treated by the senior author between July 2007 and July 2010. Out of these, 29 patients were female and three of them presented with a symptomatic brainstem CMs during pregnancy and were included in this study. According to our experiences and to the available literature we analyzed demographic and clinical variables to provide recommendations for the management of pregnant patients with highly eloquent brainstem CMs. Results: Only one patient was operated during pregnancy the other two patients were surgically treated after delivery, respectively. A thorough review of the literature revealed 12 patients with brainstem cavernomas during pregnancy there of only two patients were operated during pregnancy. Conclusion: Surgical treatment during pregnancy is rarely required, but needs to be performed right away in life-threatening and rapidly progressive clinical situations. Pregnant women with CMs in highly eloquent brain areas such as brainstem CMs need to be treated in specialized centers to assess the best point of time for surgery. Our study offers a useful tool to support the proceeding decision in this rare but important situation. [Copyright &y& Elsevier]

This study reviewed surgical experience with brainstem cavernomas in an attempt to define optimal surgical approaches and risks associated with surgical management. Clinical courses were retrospectively reviewed for 36 consecutive patients (12 men, 24 women; mean age, 42 years) who underwent microsurgical resection of brainstem cavernomas between 1996 and 2006. Medical records, surgical records, and neuroimaging examinations were evaluated. All 36 patients presented with ≥1 hemorrhage from the cavernomas and preoperatively displayed some neurological symptoms. Surgical approach was midline suboccipital for 16 pontine and/or medullary cavernomas under the floor of the fourth ventricle, retrosigmoid for 10 lateral mesencephalic, pontine, and/or medullary cavernomas, occipital transtentorial for 2 thalamomesencephalic and 3 mesencephalic cavernomas, combined petrosal for 2 pontine cavernomas, and other for 3 cavernomas. Complete resection according to postoperative magnetic resonance imaging was achieved in 33 of 36 patients. No mortality was encountered in this study. New neurological deficit occurred in the early postoperative period for 18 patients, but was transient in 15 of these. Neurological state as of final follow-up was improved in 16 patients (44%), unchanged in 17 (47%), and worsened in 3 (8%) compared with preoperatively. In conclusion, symptomatic brainstem cavernomas should be considered for surgical treatment. Careful selection of the optimal operative approach and a meticulous microsurgical technique are mandatory. [ABSTRACT FROM AUTHOR]

The risk of leaving a remnant after surgery for a cavernous malformation in the brainstem is generally not stressed enough, even though such remnants appear to have a high risk of re-bleeding. At least 40% of known cavernoma remnants after surgery have further bleeding episodes. A retrospective analysis of 30 patients with brainstem cavernoma who underwent surgery is presented, focusing on incidence, risk factors and management of post-surgical residuals. The sites were, medulla in three patients, pons-medulla in four, pons in 16, pons-midbrain in four and midbrain in three. All 30 patients came to our clinical observation with at least one episode of acute-onset neurological deficit and all were operated in the sub-acute phase. Only one patient had a worse stable outcome than the pre-surgical state, and 29 did better or were stable. All patients had a brain MRI scan within 72 h after surgery to confirm that complete removal had been achieved. In three, although the surgical cavity and its border appeared clean at the end of surgery, with no lesion remaining, post-operative MRI detected a residuum. These three patients were re-operated, but one had a further bleed prior to excision. In our series, the surgical finding of a multi-lobular cavernoma (as opposed to the more frequent finding of a discrete lesion with a thick capsule), with a thin wall and satellite nodules separated by a thin layer of apparently intact white matter, was common (seven patients). This group included the three patients with evidence of residuum on post-operative MRI. In our experience, the surgical finding of a multi-lobular cavernoma carries a higher risk of residuum and post-surgical re-bleeding. Immediate post-operative brain MRI scans are therefore strongly recommended for their detection, especially in this group of patients, and if a residual is detected early re-intervention is less risky than the natural history. [ABSTRACT FROM AUTHOR]

The purpose of this study was to present our experience in the management of spontaneous brainstem hematomas (BSH). Records of 58 consecutive patients were reviewed, including demographic data, symptoms, Glasgow Coma Scale, treatment, intraoperative findings (in surgical cases), and outcome according to the Glasgow Outcome Scale. Fifteen patients were comatose (GCS 4 or less): 11/15 patients were treated conservatively. Four patients with accompanying acute occlusive hydrocephalus were treated by placement of an external ventricular drainage. None survived. In nine patients (60%), arteriosclerosis and/or long-standing arterial hypertension were known and arteriopathic BSH was suspected. Forty-three patients were not comatose: 37 patients showed no impairment of consciousness (GCS 15), 6 patients presented with mild disturbance of conscious state (GCS 13), progressing to coma (GCS 8) in 1. In the majority (36/43) of the non-comatose patients (83.7%) cavernoma could be revealed and removed surgically. In six patients (14%), an atypically located arteriopathic BSH was assumed and treated medically. One patient had an underlying brainstem arteriovenous malformation and was treated radiosurgically. Many arteriopathic BSH cause immediate coma indicating direct and irreversible damage of midpontine structures. Thus, we suggest not to proceed to surgery, even if the bleeding is accompanied by acute hydrocephalus. The majority of BSH not resulting in immediate coma are caused by underlying cavernomas. In these cases surgery should be considered. [ABSTRACT FROM AUTHOR]

Cerebellar developmental venous anomalies (CDVA) are benign conditions, although sometimes they are associated with haemorrhages and reported to be symptomatic. This is the largest follow-up study to investigate the symptomatology of CDVAs and their association with other malformations. Thirty-two patients were followed for 2 - 9 years. Twenty-eight had isolated asymptomatic CDVA without any neurological condition during follow-up, which might be linked to the CDVA. Four patients had CDVA and an associated vascular pathology: two pontine cavernomas, one asymptomatic arteriovenous malformation (this is the first published case in the literature) and one cerebellar infarct with a developmental variation of the posterior fossa venous circulation. One patient had two CDVAs, while another had a unique draining vein from the upper part of the brainstem too. In conclusion, CDVAs are benign, asymptomatic conditions, but they are sometimes associated with pathogenic malformations requiring detailed neuroradiological investigations. [ABSTRACT FROM AUTHOR]

Brainstem cavernoma is a challenging neurosurgical pathology and microsurgery remains the only treatment option. Although the decision-making between interventional and conservative approach to this disease may be complex, malformations presenting multiple bleedings are usually good candidates for surgery. 1 On the other hand, microsurgical resection of cavernomas can offer an effective resolution with acceptable morbidity. In this video, we present a case of pontine cavernoma with multiple hemorrhages in a young patient. The anatomical characteristic of the lesion defines the best suitable craniotomy for surgery. In this case, an anterior petrosal approach 2 3 4 was used to access the peritrigeminal area and safely perform the resection. Anatomical considerations are described on this skull base approach along with the rationale and benefits of this exposure. Electrophysiological neuromonitoring is essential for this kind of procedure and preoperative tractography also enabled the best understanding of the disease. Finally, we also discuss alternative managements and potential complications. 5 With the patient's consent, we also show the excellent clinical evolution after few weeks of recovery and the restoration of the corticospinal tract, previously displaced by the cavernoma, to its original position., Competing Interests: Conflict of Interest None declared., (Thieme. All rights reserved.)

Given their highly eloquent location, surgical morbidity of brainstem cavernomas (BSCs) remain significant. Currently, there are no clinical factors or imaging techniques that can reliably predict post-operative motor improvement. Diffusion-tensor imaging (DTI) might have some prognostic value. We present a case supporting the use of DTI as predictor of motor recovery following brainstem surgery. [ABSTRACT FROM AUTHOR]

Background: Safe and complete surgical resection of brainstem cavernoma is difficult without injury surrounding normal structures because the lesions are deep and intra-axial. In this article, the authors describe the “microroll retractor” technique for brainstem cavernoma surgery. Methods: The microroll retractor is made of expanded polytetrafluoroethylene sheet. The sheet is cut in several sizes of square piece and transformed into a tubular shape. We insert this roll retractor via minimal brain incision and keep surgical corridor without usual spatulas during lesionectomy. Results: This technique was adopted for 7 patients with brainstem cavernomas. In all patients, we achieved total excision; improvement was recorded in 6 patients, and no change was recorded in 1 patient. Conclusions: The microroll retractor is extremely simple but provides enough surgical corridors for safe total resection of brainstem cavernomas. [ABSTRACT FROM AUTHOR]

Object: Several scientific papers report clinical symptoms, indications, complications and outcomes of brainstem cavernous malformation (BSCM) surgery without reporting on the occurrence of postoperative Holmes tremor (HT). Our purpose is to report our experience with HT in a monocentric series of resected brainstem cavernomas., Methods: We reviewed all the BSCM surgical records between 2002 and 2018 at Saint-Luc University Hospital's Department of Neurosurgery, Brussels and selected patients developing HT postoperatively. Patients' demographics, symptoms, pre- and postoperative imaging, recurrence and complications were analysed. A PubMed literature review was performed to compare our results with those in the existing literature., Results: In a total series of 18 resected BSCM, 5 patients: 1 male and 4 females, with a median age of 51 years (range 29-59 years), developed HT. The median preoperative mRS score was 2 (range 1-4). GTR was achieved in all patients without surgery-related death. BSCM were located in the mesencephalon in 4 patients (80%) who developed HT. Tremor was noticed between ten days and one year after surgery. One patient saw significant improvements to the point of stopping treatment. The median follow-up period was 2 years (range 1-14 years). At the last follow-up, 40% of our patients showed a worse mRS score, 40% stayed unchanged, and 20% improved., Conclusion: We are reporting an original single-center series of patients suffering from HT after BSCM surgery. The risk for HT after surgery is significant for midbrain BSCM. A spontaneous favorable evolution is possible., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Cavernous malformations (cavernomas) of the brain stem with recurrent hemorrhage may be amenable to microsurgical resection if they are present close to the surface. The risks of surgery need to be balanced with the natural history of the lesion and the accumulation of neurological deficits and risk to life with multiple hemorrhages. In this 3D operative video, we illustrate the technique for the resection of a dorsally located midbrain cavernous malformation. Informed consent was obtained for this procedure. The cavernoma is accessed with the use of a supracerebellar infratentorial approach. The infratentorial craniotomy and coagulation of the superior vermian veins is shown. A description is provided of the use of hemosiderin staining and the intercollicular relative "safe zone"1 as landmarks for the neurotomy. The technique of cavernoma dissection from the surrounding gliotic plane is shown and described. In this case, the patient required prolonged rehabilitation but fully recovered without residual deficit 1 yr following surgery., (Copyright © 2019 by the Congress of Neurological Surgeons.)

This 3-dimensional operative video covers the suboccipital approach to a brainstem cavernoma of the floor of the fourth ventricle. Brainstem cavernomas are low-flow vascular lesions associated with a 2% to 6% annual bleed rate. Repeated bleeds typically result in progressive neurological deficit, and especially for exophytic lesions surgery may arrest this progression without significantly exacerbating pre-existing deficits. The approach to these lesions may be via any standard skull base approach, dictated in each lesion by the presentation to the pial surface. Here, we describe a suboccipital approach to an exophytic cavernoma of the floor of the fourth ventricle, arising caudal to the medial longitudinal fasciculus and facial colliculus. The 38-yr-old male patient had suffered a stepwise neurological deterioration secondary to repeated bleeds, and complete resection of the cavernoma demonstrated here arrested this progression. The patient has provided signed consent to video acquisition and storage at operation, and to publication of this material., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Cavernomas at the posterolateral pontomesencephalic surface can be approached from a lateral infratentorial supracerebellar corridor. In this surgical video, we demonstrate two cases of brainstem cavernomas resected through a lateral supracerebellar infratentorial approach. A supine position with lateral turn of the head was used along with significant reverse Trendelenburg to allow the cerebellum to fall away with gravity from the tentorium. After exposure of the posterior surface of the brainstem between the tentorium and the superior cerebellar surface with aid of neuronavigation, the cavernomas were safely resected. The video can be found here: https://youtu.be/fUDdaprg26Y., Competing Interests: Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this article., (© 2019, Karl R. Abi-Aad, MD, Devi P. Patra, MD, Matthew E. Welz, MS, Evelyn Turcotte, and Bernard R. Bendok.)

Abstract: A 53-year-old man presented with a sudden onset severe headache associated with ataxia. His family observed labile emotions and frequent episodes of crying. Investigations revealed a pontine cavernoma with evidence of bleeding. The lesion was treated conservatively. Over approximately 6 months, the patient’s ataxia improved and he recovered from the crying episodes. To our knowledge, pathological crying has not been previously associated with brainstem cavernoma. [Copyright &y& Elsevier]

OBJECTIVE Methods of choice for neurophysiological intraoperative monitoring (IOM) within the infratentorial compartment mostly include early brainstem auditory evoked potentials, free-running electromyography, and direct cranial nerve (CN) stimulation. Long-tract monitoring with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) is rarely used. This study investigated the incidence of IOM alterations during posterior fossa surgery stratified for lesion location. METHODS Standardized CN and SEP/MEP IOM was performed in 305 patients being treated for various posterior fossa pathologies. The IOM data were correlated with lesion locations and histopathological types as well as other possible confounding factors. RESULTS Alterations in IOM were observed in 158 of 305 cases (51.8%) (CN IOM alterations in 130 of 305 [42.6%], SEP/MEP IOM alterations in 43 of 305 [14.0%]). In 15 cases (4.9%), simultaneous changes in long tracts and CNs were observed. The IOM alterations were followed by neurological sequelae in 98 of 305 cases (32.1%); 62% of IOM alterations resulted in neurological deficits. Sensitivity and specificity for detection of CN deficits were 98% and 77%, respectively, and 95% and 85%, respectively, for long-tract deficits. Regarding location, brainstem and petroclival lesions were closely associated with concurrent CN IOM and SEP/MEP alterations. CONCLUSIONS The incidence of IOM alterations during surgery in the posterior fossa varied widely between different lesion locations and histopathological types. This analysis provides crucial information on the necessity of IOM in different surgical settings. Because MEP/SEP and CN IOM alterations were commonly observed during posterior fossa surgery, the authors recommend the simultaneous use of both modalities based on lesion location.

Object: During the surgical removal of infratentorial lesions, intraoperative neuromonitoring is mostly focused on cranial nerve assessment and brainstem auditory potentials. Despite the known risk of perforating vessel injury during microdissection within the vicinity of the brainstem, there are few reports about intraoperative neuromonitoring with somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) assessing the medial lemniscus and corticospinal tract. This study analyses the occurrence of intraoperative changes in MEPs and SEPs with regard to lesion location and postoperative neurological outcome., Methods: The authors analyzed 210 cases in which patients (mean age 49 ± 13 years, 109 female) underwent surgeries involving the skull base (n = 104), cerebellum (n = 63), fourth ventricle (n = 28), brainstem (n = 12), and foramen magnum (n = 3)., Results: Of 210 surgeries, 171 (81.4%) were uneventful with respect to long-tract monitoring. Nine (23%) of the 39 SEP and/or MEP alterations were transient and were only followed by a slight permanent deficit in 1 case. Permanent deterioration only was seen in 19 (49%) of 39 cases; the deterioration was related to tumor dissection in 4 of these cases, and permanent deficit (moderate-severe) was seen in only 1 of these 4 cases. Eleven patients (28%) had losses of at least 1 modality, and in 9 of these 11 cases, the loss was related to surgical microdissection within the vicinity of the brainstem. Four of these 9 patients suffered a moderate-to-severe long-term deficit. For permanent changes, the positive predictive value for neuromonitoring of the long tracts was 0.467, the negative predictive value was 0.989, the sensitivity was 0.875, and the specificity 0.918. Twenty-eight (72%) of 39 SEP and MEP alterations occurred in 66 cases involving intrinsic brainstem tumors or tumors adjacent to the brainstem. Lesion location and alterations in intraoperative neuromonitoring significantly correlated with patients' outcome (p < 0.001, chi-square test)., Conclusions: In summary, long-tract monitoring with SEPs and MEPs in infratentorial surgeries has a high sensitivity and negative predictive value with respect to postoperative neurological status. It is recommended especially in those surgeries in which microdissection within and in the vicinity of the brainstem might lead to injury of the brainstem parenchyma or perforating vessels and a subsequent perfusion deficit within the brainstem.