Midbrain Cavernous Malformations Research Articles

Waxing and waning consciousness in a patient with a midbrain cavernous malformation: illustrative case.

Understanding the intricate relationship between consciousness and the midbrain's structures remains a significant challenge in neuroscience. Transient lesions are perfect examples of the physiological functioning mechanism of these structures. The authors present the case of a 49-year-old female who experienced a transient disorder of consciousness due to a midbrain hematoma following surgical interventions to remove a cavernous malformation in the midbrain. This case explores the interplay between the ascending reticular activating system (ARAS) and the thalamic centers, highlighting the role of structural disruptions in influencing consciousness levels. Notably, the patient's recovery correlated with the resolution of midbrain edema, reinstating normal ARAS function and consciousness. In patients affected by midbrain lesions, edema can lead to a fluctuating neurological status, which can be difficult to diagnose. This case highlights the midbrain's crucial role in the consciousness network and the need to comprehend the intricate connections between subcortical and cortical structures for a comprehensive understanding of human consciousness. https://thejns.org/doi/10.3171/CASE2411.

Intercollicular Approach for Midbrain Cavernous Malformation: 2-Dimensional Operative Video.

Previously reported midbrain cavernous malformations often exhibit lateral expansion, making their excision through the nearest brain surface incision easier.1-5 Nevertheless, excising a midbrain cavernous malformation that lacks lateral extension can be particularly challenging because of limited access.5 The anterior midline approach is typically conducted through the interpeduncular fossa zone.3,5 Still, it restricts surgical maneuverability because of the presence of the posterior communicating artery, the posterior cerebral artery, and the oculomotor nerve. On the other hand, the posterior midline approach through the intercollicular region, although reported in only a single case, lacks technical details and postoperative neurological status.3,5 In this report, we elaborate on the feasibility of surgical manipulations for midline-located midbrain cavernous angiomas through the intercollicular region and discuss the resulting postoperative neurological outcomes.

Cavernous Malformations: What They Have Taught Us.

Cavernous Malformations: What They Have Taught Us.

Resection of Midbrain Cavernous Malformation Associated With Complicated Draining Veins From Coexistent Developmental Venous Anomalies: 360° Virtual Reality Enhanced Operative Video.

Department of Neurosurgery, Saitama Medical Center, Saitama Medical University, Saitama, Japan Correspondence: Soichi Oya, MD, PhD, Department of Neurosurgery, Saitama Medical Center, Saitama Medical University, 1981 Kamoda, Kawagoe, Saitama350-8550, Japan. Email: [email protected]

A taxonomy for brainstem cavernous malformations: subtypes of midbrain lesions.

Anatomical taxonomy is a practical tool that has successfully guided clinical decision-making for patients with brain arteriovenous malformations. Brainstem cavernous malformations (BSCMs) are similarly complex lesions that are difficult to access and highly variable in size, shape, and position. The authors propose a novel taxonomy for midbrain cavernous malformations based on clinical presentation (syndromes) and anatomical location (identified with MRI). The taxonomy system was developed and applied to an extensive 2-surgeon experience over a 30-year period (1990-2019). Of 551 patients with appropriate data who underwent microsurgical resection of BSCMs, 151 (27.4%) had midbrain lesions. These lesions were further subtyped on the basis of predominant surface presentation identified on preoperative MRI. Five distinct subtypes of midbrain BSCMs were defined: interpeduncular (7 lesions [4.6%]), peduncular (37 [24.5%]), tegmental (73 [48.3%]), quadrigeminal (27 [17.9%]), and periaqueductal (7 [4.6%]). Neurological outcomes were assessed using modified Rankin Scale (mRS) scores. A postoperative score ≤ 2 was defined as a favorable outcome; a score > 2 was defined as a poor outcome. Clinical and surgical characteristics and neurological outcomes were compared among subtypes. Each midbrain BSCM subtype was associated with a recognizable constellation of neurological symptoms. Patients with interpeduncular lesions commonly presented with ipsilateral oculomotor nerve palsy and contralateral cerebellar ataxia or dyscoordination. Peduncular lesions were associated with contralateral hemiparesis and ipsilateral oculomotor nerve palsy. Patients with tegmental lesions were the most likely to present with contralateral sensory deficits, whereas those with quadrigeminal lesions commonly presented with the features of Parinaud syndrome. Periaqueductal lesions were the most likely to cause obstructive hydrocephalus. A single surgical approach was preferred (> 90% of cases) for each midbrain subtype: interpeduncular (transsylvian-interpeduncular approach [7/7 lesions]), peduncular (transsylvian-transpeduncular [24/37]), tegmental (lateral supracerebellar-infratentorial [73/73]), quadrigeminal (midline or paramedian supracerebellar-infratentorial [27/27]), and periaqueductal (transcallosal-transchoroidal fissure [6/7]). Favorable outcomes (mRS score ≤ 2) were observed in most patients (110/136 [80.9%]) with follow-up data. No significant differences in outcomes were observed between subtypes (p = 0.92). The study confirmed the authors' hypothesis that taxonomy for midbrain BSCMs can meaningfully guide the selection of surgical approach and resection strategy. The proposed taxonomy can increase diagnostic acumen at the patient bedside, help identify optimal surgical approaches, enhance the consistency of clinical communications and publications, and improve patient outcomes.

Microsurgical management of midbrain cavernous malformations: does lesion depth influence the outcome?

BackgroundThe purpose of this study was to clarify whether the intrinsic depth of midbrain cavernous malformations (MCMs) influenced the surgical outcome.MethodsThe authors conducted a retrospective study of 76 consecutive patients who underwent microsurgical resection of a MCM. The vascular lesions were categorized into 4 distinct groups based on how these lesions had altered the brainstem surface. Additionally, it was verified whether the actual aspect of the brainstem surface could be predicted only by evaluating the pertinent preoperative MRI slices. Clinical outcome was assessed by determining the modified Rankin Scale Score (mRS) before and after surgery.ResultsTwenty-three MCMs (30.3%) were located deeply within the midbrain. The overlying midbrain surface appeared to be normal (group nl). In 33 patients (43.4%), the midbrain surface showed only a yellowish discoloration (group yw). In another 14 individuals (18.4%), the midbrain surface was distorted by the underlying MCM and bulging out while the vascular lesion still remained covered by a thin parenchymal layer (group bg). In the smallest group comprising 6 patients (7.9%), the exophytic MCM had disrupted the midbrain surface and was clearly visible at microsurgical exposure (group ex). The mean mRS decreased in the group nl from 1.43 preoperatively to 0.61 at follow-up.ConclusionThis study demonstrates in a large patient population that a deep intrinsic MCM location is not necessarily associated with an unfavorable clinical outcome after microsurgical lesionectomy. Predicting the aspect of the midbrain surface by evaluating preoperative MR images alone was not sufficiently reliable.

Occipital posterior interhemispheric supratentorial approach for resection of midbrain cavernous malformation.

Approaches to the pineal region are various, and each has its advantages and disadvantages. The authors present a case of a 50-year-old woman who presented with progressive hemiparesis and vertical gaze palsy; she was diagnosed with a midbrain cavernous malformation. The patient underwent an occipital posterior interhemispheric supratentorial transpineal approach with gross-total resection. On long-term follow-up, her symptoms significantly improved. The authors review the regional anatomy and present the operative video. They also discuss the various approaches with their indications, advantages, and disadvantages.The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2133.

Supracerebellar-Infratrochlear Approach for Midbrain Cavernoma: 3-Dimensional Operative Video

Gravity retraction is an underutilized adjunct in neurosurgery. Gravity is gentler than retractor blades; it does not cause brain edema or injury, and it tends to open natural subarachnoidal plans to deep lesions.1-3 A good example of this is the supracerebellar infratrochlear approach4-7 in semisitting position for resection to a midbrain cavernous malformation. This approach was selected because the cavernous malformation was 1 mm under the lateral mesencephalic sulcus. The procedure was developed with the use of transesophageal ultrasound and physiological neuromonitoring. We present a 3-dimensional video of this surgery with all the tricks and details used in the procedure. The patient consented to the procedure and to publication of the photos and surgical video.

Microsurgical Management of Midbrain Cavernous Malformations: Predictors of Outcome and Lesion Classification in 72 Patients.

Due to the complex segmental organization of the brainstem, it is preferable to study midbrain cavernous malformations (MCMs) separately from pontine and medullary lesions. To evaluate clinical results after microsurgical removal of MCMs, assess predictors for outcome and introduce a topographical classification of MCMs. A retrospective study was conducted on consecutive patients who underwent MCM resection. Clinical parameters before and after surgery, morphological CM features, surgical approaches and outcomes were analyzed. MCMs were classified according to their exact location within the midbrain and their axial and sagittal extension. The authors reviewed 72 patients (35 male). Lesions varied in size between 4 and 55 mm. The vast majority of patients benefited from surgery. The mean modified Rankin Scale (mRS) decreased significantly from 1.6 at admission to 1.3 at discharge and to 0.7 at follow-up (6-247 mo postoperatively). Five patients (6.9%) suffered from delayed hypertrophic olivary degeneration as visualized on magnetic resonance imaging. One male suffered from early postoperative re-bleeding that required surgical hematoma evacuation. There were no severe long tract impairment or other disabling complications, no delayed re-bleedings, and no surgical mortality. We present a new topographic classification of MCMs that may be useful for predicting the occurrence of postoperative eye movement disorders. Other predictors of persistent oculomotor disturbances are time interval between onset of symptoms and surgery, and patient's age over 40yr. Early surgery is recommendable in patients with oculomotor disturbances. MCM size over 18 mm, patient age over 40yr, and poor mRS at admission are important predictors for the long-term outcome.

Transsylvian, Carotid-Oculomotor Triangle Approach for Resection of a Rapidly Enlarging Midbrain-Pontine Cavernous Malformation: 3-Dimensional Operative Video.

Cavernous malformations (CM) of the anterior midbrain are best reached through an orbitozygomatic (OZ) approach with removal of the orbital rim and wide Sylvian fissure dissection. Our surgical video demonstrates this approach to resect a ruptured CM in a 36-yr-old woman who presented with headaches, left face and left arm paresthesias/weakness, and right-sided partial oculomotor nerve (CN III) palsy. Initial magnetic resonance imaging (MRI) showed a midbrain CM, and the patient was managed conservatively. However, 1 wk later, she presented again with worsened left arm and leg weakness and complete CN III palsy. Seven Tesla MRI demonstrated a larger hematoma, and the CM with new mass effect and upper pons extension. The patient underwent a right modified OZ craniotomy and Sylvian fissure split under guidance of intraoperative neuronavigation and with neuromonitoring. The carotid-oculomotor triangle and the Liliequist membrane were dissected to access the midbrain, and CN III was identified and followed posteriorly to the midbrain. Confirmed with neuronavigation, a longitudinal incision of the midbrain was performed, and the CM was encountered. The hematoma and CM were debulked and removed in a piece-meal fashion, leaving hemosiderin-stained brain intact to prevent unnecessary additional damage to the midbrain. Postoperative MRI confirmed gross-total resection, and the patient's weakness recovered substantially. In this video, we demonstrate that the brainstem is no longer forbidden surgical territory, and show how the use of neuronavigation for surgical planning, positioning, and approach, in addition to the understanding of safe entry zones and meticulous microsurgical technique have made safe and effective surgery on the brainstem possible.

Subtemporal approach for the resection of a midbrain cavernous malformation: evaluation of safe surgical corridors.

Brainstem cavernous malformation management is complex due to its critical location and deleterious effect when bleeding. Therefore, every case should be thoroughly analyzed preoperatively. We present the case of a female patient with a midbrain cavernous malformation. A comprehensive anatomical and clinical analysis of the surgical corridors is done to decide the safest route. A subtemporal approach was done and the lateral mesencephalic sulcus and vein were important anatomical landmarks to guide the safe entry zone. Nuances of technique and surgical pearls related to the safe entry zones of the midbrain are discussed and illustrated in this operative video.The video can be found here: https://youtu.be/vYA-IgiT2lU.

Microsurgical laser resection of brainstem cavernous malformations.

This operative technique video demonstrates laser microsurgery for brainstem cavernous malformations (CMs). In case 1 we demonstrate CO2 laser microsurgery for a symptomatic pontine CM using far lateral craniotomy and olivary zone entry. Case 2 demonstrates the subtemporal approach and removal of a paratrigeminal CM, and case 3 is a dorsal midbrain CM. We illustrate several advantages of laser microsurgery including improved visualization in narrow corridors, precise cutting with reduced thermal damage, and effective sealing of small vessels. Over the past decade at Stanford University School of Medicine, over 120 brainstem CMs have been removed using laser microsurgery with good results.The video can be found here: https://youtu.be/DwwqWGv_vzo.

Transcallosal Anterior Interforniceal Approach for Removal of Superior Midbrain Cavernous Malformations in Children: A Retrospective Series of 10 Cases in a Single Center

Surgical treatment of brainstem cavernous malformations (CMs) remains a great challenge for neurosurgeons. Several cases published in the literature have addressed surgical approaches. However, no surgical approach has been reported to provide better exposure for CMs located in the superior midbrain. We presented 10 cases of superior midbrain CMs in children treated in Beijing Tiantan Hospital from 2002 to 2016. The most common presenting signs and symptoms were hydrocephalus and cranial nerve deficit. We used the transcallosal anterior interforniceal approach in all patients to remove the CM lesion. Total resection was achieved in all patients. During the follow-up period, temporary short-term memory impairment was present in 5 patients, unilateral ptosis occurred in 1 patient, and upward gaze dysfunction occurred in 2 patients. There was complete neurologic functional improvement for cranial nerves. Exacerbation of hydrocephalus occurred in 4 patients requiring additional ventriculoperitoneal shunt postoperatively. The transcallosal anterior interforniceal approach can provide good exposure and direct visualization to superior midbrain CMs. Complications are short-term and reversible.

Two cases of ventral midbrain cavernous malformations successfully removed through orbitozygomatic interpeduncular approach

Abstract Ventral midbrain cavernous malformations are rare, and annual bleeding rate is higher than supratentorial lesions. Rebleeding rate is also high if surgical resection is incomplete. The ventral midbrain is deeply located and surrounded by many perforators, which make the approach to this region difficult. We experienced two cases of ventral midbrain cavernous malformations successfully removed via orbitozygomatic interpeduncular approach. In these cases, most parts of the lesions exist behind the cerebral peduncle extending interpeduncular fossa. In the first case involving a 15-year-old girl, we removed the lesion completely through an ipsilateral orbitozygomatic interpeduncular approach with minimum sacrifice of the right cerebral peduncle. However, in the second case involving a 43-year-old man, the same approach did not reach the lesion behind the ipsilateral cerebral peduncle. At the second operation, a contralateral orbitozygomatic interpeduncular approach was used to remove the residual lesion completely. Ipsilateral and contralateral orbitozygomatic interpeduncular approaches with minimum destruction of the cerebral peduncle are options for the lesions which exist in the interpeduncular fossa and behind the cerebral peduncle.

Transcallosal approach for third ventriculostomy and removal of midbrain cavernous malformation

Symptomatic brain stem cavernous malformations often present the dilemma of choosing an approach for their resection. Superior midline midbrain lesions are in a particularly challenging location, as they are less accessible via traditional lateral or posterior approaches. The author presents a case of a young woman who presented with a symptomatic cavernous malformation with surface presentation to the floor of the third ventricle. The lesion was causing sensory symptoms from local mass effect and hydrocephalus from occlusion of the Aqueduct of Sylvius. An approach was chosen to both perform a third ventriculostomy and remove the cavernous malformation. Through a right frontal craniotomy, a transcallosal-transforaminal approach was used to perform a third ventriculostomy. Through the same callosal opening, a subchoroidal approach was performed to provide access the cavernous malformation. The details of the procedure and nuances of technique are described in the narration. The video can be found here: http://youtu.be/zKKnehp7l2c. (http://thejns.org/doi/abs/10.3171/2013.V1.FOCUS12348)

Hypertrophic olivary degeneration following surgical resection or gamma knife radiosurgery of brainstem cavernous malformations: an 11-case series and a review of literature

We describe 11 patients with hypertrophic olivary degeneration (HOD) after surgical resection or gamma knife radiosurgery for brainstem cavernous malformations. In addition, we statistically analyzed the predicting factors associated with the development of HOD. From January 2001 to May 2011, a total of 73 patients (30 in the surgical group and 43 in the radiosurgery group) with brainstem cavernous malformations were treated in our institute. Of them, 11 patients (incidence: 15 %) developed HOD with high signal intensity on T2-weighted MRI during follow-up. The predicting factors (location, size, age, and treatment method) associated with the development of HOD were statistically analyzed. Among the 11 HOD patients, seven patients received surgical resection and four patients received gamma knife radiosurgery. Six patients had bilateral HOD and the remaining five patients had unilateral HOD. Overall HOD-associated symptoms presented in four patients, including three palatal tremors and one ataxia. In all four patients with symptoms, these symptoms disappeared incompletely within the clinical follow-up period. The size of the cavernous malformation, age of patient, and treatment methods were not significantly correlated with the development of HOD. A significantly higher incidence of HOD was associated with midbrain cavernous malformations than with pontine or medulla cavernous malformations. HOD should be recognized as a non-infrequent complication of surgical resection or gamma knife radiosurgery within the brainstem, especially for midbrain cavernous malformations. In addition, to the best of our knowledge, this is the first report on HOD development after radiosurgery.

Cavernous Malformations: A Paradigm for Progress

Cavernous Malformations: A Paradigm for Progress

Supracerebellar-Supratrochlear and Infratentorial-Infratrochlear Approaches

Lateral supracerebellar-infratentorial approaches are established for lesions in ambient cistern and posterolateral midbrain, but published surgical experiences do not describe results with this approach in the sitting position. Gravity retraction of the cerebellum opens this surgical corridor and dramatically alters exposure, creating 2 variations of the lateral supracerebellar-infratentorial approach: the supracerebellar-supratrochlear approach and the infratentorial-infratrochlear approach. We reviewed our experience treating cavernous malformations and arteriovenous malformations (AVMs) of the posteroinferior thalamus and posterolateral midbrain by use of supracerebellar-supratrochlear and infratentorial-infratrochlear approaches. Microsurgical technique, clinical data, radiographic features, and neurological outcomes were evaluated. During an 11-year surgical experience with 341 cavernous malformation patients and 402 AVM patients, 8 patients were identified, 6 with cavernous malformations and 2 with AVMs. Infratentorial-infratrochlear approaches were used in 4 patients (50%), including 3 with inferolateral midbrain cavernous malformations. Supracerebellar-supratrochlear approaches were used in 4 patients (50%), including 2 with posterior thalamic lesions surfacing on pulvinar. Resections were radiographically complete in all cases. There were no new, permanent neurological deficits, nor were there any medical or surgical complications. There has been no evidence of rebleeding or recurrence. Gravity retraction of the cerebellum transforms the lateral supracerebellar-infratentorial approach, enhancing exposure and approach trajectories that can be achieved with patients in prone or lateral positions. The increased upward viewing angle of the supracerebellar-supratrochlear approach accesses the posteroinferior thalamus. The increased downward-viewing angle of the infratentorial-infratrochlear approach accesses cerebellomesencephalic fissure and posterolateral midbrain. These approaches open wide corridors for safe surgical resection of symptomatic cavernous malformations and AVMs.

Intraoperative Motor Mapping of the Cerebral Peduncle during Resection of a Midbrain Cavernous Malformation: Technical Case Report

Brainstem cavernous malformations that seem to come to a pial or ependymal surface on preoperative magnetic resonance imaging studies may, in fact, be covered by an intact layer of neural tissue. For cavernous malformations in the cerebral peduncle, intraoperative stimulation mapping with a miniaturized probe can determine whether this overlying tissue harbors fibers in the corticospinal tract. In addition, intermittent monitoring with transcranial motor evoked potentials (TcMEPs) helps to protect this vital pathway during resection of the lesion. A 20-year-old woman collapsed after a cavernous malformation in the left cerebral peduncle hemorrhaged into the pons, midbrain, and thalamus. She presented with right hemiparesis and left oculomotor palsy. The cavernous malformation was completely resected through a left orbitozygomatic craniotomy and transsylvian approach. Stimulation mapping of the cerebral peduncle with a Kartush probe (Medtronic Xomed, Inc., Jacksonville, FL) identified the corticospinal tract lateral to the lesion, and a layer of tissue over the lesion harbored no motor fibers. TcMEP monitoring helped to guide the resection, with increased voltage thresholds and altered waveform morphologies indicating transient impaired motor conduction. All TcMEP changes returned to baseline by the end of the procedure, and the patient's hemiparesis improved after surgery. Stimulation mapping of the corticospinal tract and intermittent TcMEPs is a safe and simple surgical adjunct. Expanded monitoring of the motor pathway during the resection of cerebral peduncle cavernous malformations may improve the safety of these operations.

脳幹部海綿状血管腫の治療戦略 中脳海綿状血管腫の治療戦略

We used a paramedian, infratentorial-supracerebellar, transcollicular approach to resect 6 intrinsic midbrain cavernous malformations. The route of access to the lesions was designed to minimize the anatomic and functional damage to the surrounding structures. Access was through one superior colliculus in 2 cases, through one inferior colliculus in 2 cases, and through the superior and inferior colliculi of one side in 2 cases. All 6 lesions were completely removed; the preoperative ocular symptoms improved in 4 of these 6 patients and did not change in 2. The neurological deficits except ocular symptoms improved in 2 patients. No recurrence of bleeding was observed during the follow-up period (mean 52 months). We conclude that the paramedian, infratentorial-supracerebellar, transcollicular approach permits safe removal of intrinsic midbrain cavernous malformations. Resection of the superior or inferior colliculus, or both, on one side appears to be neurologically well tolerated.