Posterior Inferior Cerebellar Research Articles

Florid Autonomic Features Associated with Medullary Lacunar Stroke

Introduction: Autonomic nuclei affection results in variations in hemodynamics, temperature, sweating and ECG. Medullary strokes are challenging in their presentation, bizarre clinical signs, work and neurological outcome. The commonest cause is infarction of the posterior inferior cerebellar artery (PICA). Anatomical areas affected include the inferior cerebellar peduncle, dorsolateral medulla, nuclei of the Trigeminal, vestibular nuclei, Ninth and Vagus nerves. The descending sympathetic tracts and spin thalamic tracts. Serious cardiopulmonary events can complicate 11% of cases. Case Presentation: A middle-aged female developed sub-acute dizziness associated with vomiting and right head pains. She was unable to walk but remained cognitively clear. Her gastrointestinal symptoms were disabling and this was the main factor for presenting to the emergency room. The risk factors included hypertension and diabetes mellitus. Imaging studies were essential for posterior circulation stroke diagnosis and follow-up. She manifested remarkable autonomic features regarding the skin and hemodynamics. Nevertheless, the hospital course was controllable. Discussion: This case report was consistent with relevant literature in the contra lateral vaso motor changes and drop in body temperature during the acute phase. Moreover, our patient developed clinical and radiological extension through double antiplatelets. Superiority of the magnetic resonance imaging (MRI) scans in this patient enabled better diagnostic accuracy in a brainstem stroke. Conclusion: The autonomic features, in this case, represent major symptomatology and clinical signs. The variation in the hemodynamics and persistence of symptoms is thought provoking. This increases the awareness of emergency doctors for acute stroke presenting with autonomic features will enable early detection and helps outcome.

The cerebral artery in cynomolgus monkeys (Macaca fascicularis).

Cerebral artery structure has not been extensively studied in primates. The aim of this study was to examine the cerebrovascular anatomy of cynomolgus monkeys (Macaca fascicularis), which are one of the most commonly used primates in medical research on human diseases, such as cerebral infarction and subarachnoid hemorrhage. In this study, we investigated the anatomy and diameter of cerebral arteries from 48 cynomolgus monkey brain specimens. We found three anatomical differences in the vascular structure of this species compared to that in humans. First, the distal anterior cerebral artery is single. Second, the pattern in which both the anterior inferior cerebellar artery and posterior inferior cerebellar artery branch from the basilar artery is the most common. Third, the basilar artery has the largest diameter among the major arteries. We expect that this anatomical information will aid in furthering research on cerebrovascular disease using cynomolgus monkeys.

A Case of Ruptured Distal Posterior Inferior Cerebellar Artery Aneurysm with Large Hematoma in the Fourth Ventricle Treated by Coil Embolization after Endoscopic Evacuation of Hematoma

A Case of Ruptured Distal Posterior Inferior Cerebellar Artery Aneurysm with Large Hematoma in the Fourth Ventricle Treated by Coil Embolization after Endoscopic Evacuation of Hematoma

Cervical Myelopathy due to Direct Cord Compression by Posterior Inferior Cerebellar Artery Associated with Aberrant Vertebral Artery

Cervical Myelopathy due to Direct Cord Compression by Posterior Inferior Cerebellar Artery Associated with Aberrant Vertebral Artery

Isolated brainstem congestion caused by craniocervical junction arteriovenous fistula.

Although arteriovenous fistulas (AVFs) at the craniocervical junction (CCJAVFs) are rare, they often develop into a subarachnoid haemorrhage when they have an ascending venous drainage, or cause venous congestion of the spinal cord with descending venous drainage. Isolated brainstem lesions due to CCJAVF are extremely rare, and, to our knowledge, the vascular architectural features that could cause such lesions are unknown. We present a case of CCJAVF manifesting as isolated brainstem congestion and review the literature on the vessel architecture of these rare lesions. A 64-year-old man was admitted to our hospital with gradually worsening nausea, dysphagia, double vision, grogginess, and gait disturbances. On admission, the patient showed dysarthria, horizontal ocular nystagmus to the left, paresis of cranial nerves IX and X, and ataxia on the right side. Magnetic resonance imaging (MRI) revealed an isolated lesion in the medulla. Cerebral angiography (CAG) showed a CCJAVF with the coexistence of intradural AVF and dural AVF, fed by the right first cervical radiculomedullary, right vertebral, and intradural posterior inferior cerebellar arteries, which were drained by the anterior spinal vein in an ascending direction. The patient underwent direct surgery to occlude dural and intradural fistulas. Postoperatively, the patient returned to work with full recovery from the neurological deficits via rehabilitation. MRI revealed vanishing brainstem congestion, and CAG revealed complete disappearance of the AVF. CCJAVFs with venous drainage around the brainstem, regardless of their direction (ascending or descending), can cause isolated brainstem congestion, although this condition is rare.

Internal trapping for ruptured vertebral artery dissecting aneurysm proximal to the posterior inferior cerebellar artery results in infarctions associated with basilar artery fenestration

Internal trapping for ruptured vertebral artery dissecting aneurysm proximal to the posterior inferior cerebellar artery results in infarctions associated with basilar artery fenestration

A case of ruptured vertebral artery dissecting aneurysm treated by internal trapping with posterior inferior cerebellar artery preservation

A case of ruptured vertebral artery dissecting aneurysm treated by internal trapping with posterior inferior cerebellar artery preservation

Anatomical variations of posterior inferior cerebellar artery (PICA) on digital subtraction angiography (DSA)

Introduction: The posterior inferior cerebellar artery (PICA) often exhibits anatomical variations at the craniovertebral junction. Few studies investigated variations of the posterior inferior cerebellar artery, and the prevalence of other variations has not been reported. The study aimed to identify variations of the posterior inferior cerebral artery using cerebral Digital Subtraction Angiography (DSA). Method: 50 patients underwent 64-slice cerebral Digital Subtraction Angiography. Four types of variations were observed. Results: Out of a total of 50 patients, 23 (46%) were males and 27 (54%) females (all age groups). Our study has shown the utility of the 2 sequences - fluoroscopy and cine. All 2 sequences have their significance in evaluating anatomical variations in PICA. Only 20% of the 50 patients had all the posterior inferior cerebellar artery without anatomical variations. Anatomic variations commonly involve the distal segment of the vertebral artery (VA). Most of them are seen arising from the C1, C2, and both C1 and C2 origins. Anatomic variations involve arising from the C1 origin in 9 patients, C2 origin in 11 patients, C1 & C2 origin in 8 patients, and other variations observed in 12 patients. Conclusion: Variations of the posterior inferior cerebellar artery can be easily evaluated by cerebral Digital Subtraction Angiography (CDSA). Recognizing and reporting them at cerebral CDSA may be clinically important. Surgeons should be mindful of this variation during operations.

Predicting Early Loss of Lateral Spread Response before Decompression in Hemifacial Spasm Surgery.

Recent studies have shown the evocation of lateral spread response (LSR) due to the compression of the facial nerve in hemifacial spasm (HFS). Intraoperative monitoring (IOM) of LSR could help locate neurovascular conflicts and confirm adequate micro-vascular decompression (MVD) while treatment of hemifacial spasm (HFS). However, studies on early LSR loss before decompression in HFS surgery are sparse, indicating the need to understand various perceptions on it. Therefore, we retrospectively analyzed 50 adult HFS patients who underwent MVD during the period of September 2018–June 2021. We employed IOM combining traditional LSR (tLSR) and dual LSR (dLSR). One patient was excluded owing to the lack of LSR induction throughout the surgery, while 49 were divided into groups A (n = 14) and B (n = 35), designated as with or without early LSR loss groups, respectively, and offending vessels were analyzed. The mean age of group A patients was significantly younger (47.8 ± 8.6) than that of group B (53.9 ± 10.6) (p = 0.0393). The significant predominating offending vessel in group A was the anterior inferior cerebellar artery (AICA, 78.57%). However, group B included those with AICA (28.57%), posterior inferior cerebellar artery (PICA, 22.86%), vertebral artery (VA) involved (25.71%), and combined AICA and PICA (22.86%). Group B exhibited poorer clinical outcomes with more complications. Conclusively, early LSR loss might occur in the younger population, possibly due to the AICA offending vessel. The compression severity of offending vessels may determine the occurrence of early LSR loss.

A new ocular motor sign in acute vestibular syndrome: Is HINTS plus enough?

A 66-year-old hypertensive and diabetic male presented with acute vestibular syndrome for three days. HINTS plus examination was performed. The horizontal head impulse test was positive on the left side. Video oculography showed centripetal nystagmus on gaze testing in the dark and test of skew was negative. There was no new hearing loss on the finger rub test. On neurological examination, he had severe postural instability and saccadic smooth pursuit. Radio-imaging studies were conducted to rule out the possibility of stroke. CT brain showed infarction in the territory of the medial branch of the right posterior inferior cerebellar artery. MRI brain confirmed the diagnosis. Thus, posterior circulation stroke can present with acute vestibular syndrome mimicking acute unilateral vestibulopathy. However, the presence of associated neurological symptoms like gait ataxia, centripetal nystagmus and vascular risk factors pointed towards a central cause. Clinical evaluation suggesting a peripheral lesion should never be taken in isolation and needs to be correlated with other associated signs. We describe centripetal nystagmus without fixation as a new oculomotor sign in acute vestibular syndrome.

Trapping and P2-P3 Posterior Inferior Cerebellar Artery Reanastomosis for Treatment of a Ruptured Fusiform Aneurysm: Application of Fourth-Generation Technique: 2-Dimensional Operative Video.

Aneurysms of the posterior inferior cerebellar artery (PICA) represent the second most common posterior circulation aneurysm and commonly have complex morphology. Various bypass options exist for PICA aneurysms,1-6 depending on their location relative to brainstem perforators and the vertebral artery, and the presence of nearby donor arteries. We present a case of a man in his late 40s who presented with 3 d of severe headache. He was found to have a fusiform right P2-segment PICA aneurysm. Preoperative angiogram demonstrated the aneurysm and a redundant P3 caudal loop that came in close proximity to the healthy P2 segment proximal to the aneurysm. The risks and benefits of the procedure were discussed with the patient, and they consented for a right far lateral approach craniotomy with partial condylectomy for trapping of the aneurysm with bypass. The aneurysm was trapped proximally and distally. The P3 was transected just distal to the aneurysm and brought toward the proximal P2 segment, facilitated by a lack of perforators on this redundant distal artery. An end-to-side anastomosis was performed. Postoperative angiogram demonstrated exclusion of the aneurysm and patent bypass. The patient recovered well and remained without any neurological deficit at 6-mo follow-up. This case demonstrates the use of a "fourth-generation"5,7,8 bypass technique. These techniques represent the next innovation beyond third-generation intracranial-intracranial bypass. In this type 4B reanastomosis bypass, an unconventional orientation of the arteries was used. Whereas reanastomosis is typically performed end-to-end, the natural course of these arteries and the relatively less-mobile proximal P2 segment made end-to-side the preferred option in this case. Fourth-generation bypass techniques open up more configurations for reanastomosis, using the local anatomy to the surgeon's advantage. The patient consented to the described procedure and consented to the publication of their image.

Foramen Magnum Meningioma-The Attainment of the Intra-Arachnoidal Dissection: 2-Dimensional Operative Video.

Ventral foramen magnum meningiomas are a forbidding lesion. The stake is so high with a risk of devastating paralysis and respiratory failure. Careful preoperative clinical and radiological evaluation is necessary to implement the best treatment plan. Successful surgical intervention depends on paying high attention to minute details throughout the case, from intratracheal intubation to extubation. The neural head-on-neck position is critical to avoid further medullary compression at intubation and positioning.1 Extensive neurophysiological monitoring, including somatosensory, motor, brainstem evoked potential, and cranial nerves, during the positioning and throughout the case, is extremely helpful to detect early signs of dysfunction.1 To expose and access ventral tumors, partial condyle resection and vertebral artery transposition are invaluable techniques.2,3 Preservation and minute manipulation of the vital neurovascular structures at this junction that includes the medullar, anterior spinal artery, posterior inferior cerebellar artery, vertebral junction perforators, and lower cranial nerves are essential for good outcomes. This is achieved by microsurgical intra-arachnoidal dissection under high magnification and after debulking the tumor to establish that plane.1,3,4 The demonstration of this technique is the purpose of this article. We demonstrate these surgical tenets applied to the resection of a large ventral foramen magnum meningioma extending from the midclivus to the C3 vertebral body level in a 54-yr-old female presenting with swallowing difficulties. The patient consented to the surgical intervention and the publication of her images. Image at 1:38 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.

Endoscope-Assisted Resection of Extra-Axial Premedullary Neurenteric Cyst via Far Lateral-Supracondylar Approach: 2-Dimensional Operative Video.

Neurenteric cysts are rare congenital lesions that may compress the ventral brainstem.1-9 In this operative video, we illustrate the surgical treatment of an intradural extra-axial neurenteric cyst extending from the lower pons to the craniocervical junction. The patient, an asymptomatic 52-yr-old female, underwent surveillance imaging of the premedullary lesion for 14 yr without progression. However, after developing progressive strain-induced headaches, imaging revealed a significant enlargement of the lesion with brainstem compression and partial obstruction of the foramen magnum. Therefore, surgical resection was pursued. The patient consented to the procedure. The patient underwent a lateral suboccipital craniotomy and C1 laminectomy through a far lateral approach. The lesion was immediately visualized upon opening the dura. After identifying the cranial nerves, we resected the tumor while taking care to preserve the neurovascular elements of the cerebellopontine angle and foramen magnum. During the resection, we unexpectedly encountered a firm nodule that was adherent to the right posterior inferior cerebellar artery. This was meticulously dissected and removed en bloc using intraoperative indocyanine green (ICG) angiography. The cavity was inspected with 0-degree and 30-degree endoscopes to ensure complete resection of the lesion. Gross total resection was confirmed on postoperative magnetic resonance imaging. The patient was neurologically intact with no cranial nerve abnormalities and discharged home on postoperative day 3. This case demonstrates that the far lateral-supracondylar approach affords safe access to the ventral pontomedullary and craniocervical junctions and that intraoperative adjuncts, including ICG angiography and endoscopic visualization, can facilitate complete lesion resection with excellent clinical outcomes.

A growing aneurysm of the posterior inferior cerebellar artery complicated with cerebellar infarction: A case report.

Introduction and importanceHereby we describe an instructive patient with cerebellar infarction and a growing aneurysm at the posterior inferior cerebellar artery (PICA), which was not a true cause of infarction.Case presentationA 50-year-old female presented with dizziness and posterior neck pain at our hospital (Mitaka city, Tokyo, Japan). Diffusion weighted magnetic resonance (MR) images showed cerebellar infarction in the left PICA territory and MR angiography study showed an aneurysm at the origin of the left PICA, which grew in 2 weeks. Since we considered cerebellar infarction was caused by thrombosis from the aneurysm, trapping of the PICA and occipital artery-PICA bypass was performed to prevent recurrent cerebellar infarction and rupture of the aneurysm by neurosurgeons. During the operation, dissection was observed at the distal PICA, which was diagnosed to be the true cause of cerebellar infarction. By the follow-up for 12 months at an outpatient, there was no recurrence of cerebral infarction.Clinical discussionA specimen of the artery showing the findings of dissection was not obtained, and the pathological diagnosis could not be made. It would be controversial whether a surgical procedure presented here was the most optimal.ConclusionThis is a first reported case of growing aneurysms and cerebral infarction due to arterial dissection. Even if cerebral infarction is accompanied by growing aneurysms, arterial dissection should be included in the differential diagnoses of a cause of infarction. Posterior cervical pain can be a clue for early appropriate diagnosis in such a case.

Abstract 1122‐000052: Endovascular Management of Infectious PICA Aneurysm in the Setting of Recent Dental Work

Introduction : Infectious intracranial aneurysms (IIA) of the posterior inferior cerebellar artery (PICA) are exceedingly rare and have been infrequently reported. IIAs are typically distal and located in the anterior circulation, particularly the middle cerebral artery and its distal branches. Etiology is secondary to hematogenous spread of septic emboli from a proximal source such as infective endocarditis. Few cases have documented an association between IIA and dental disease or procedures. We describe a rare case of an infectious PICA aneurysm in the setting of recent dental work and successfully treated with endovascular intervention. Methods : An 88‐year‐old male with medical history of atrial fibrillation on anticoagulation presented with one month duration of recurrent falls and progressive generalized weakness. CT head demonstrated left cerebral hemorrhage with scattered subarachnoid hemorrhage. MRI brain noted a rounded enhancing intra‐axial lesion located at the left paramedian cerebellum measuring 7 mm in maximal dimension. Further investigation with cerebral angiography demonstrated an infectious intracranial aneurysm of the left PICA. He underwent workup with an echocardiogram that noted a mobile echo density on the aortic valve consistent with a vegetation. Blood cultures were positive for Streptococcus salivarius and viridans. Investigation revealed that he had recent dental work performed and missed taking his prophylactic amoxicillin. Infectious disease was consulted and etiology was determined to be seeding of aortic valve from recent dental procedure that ultimately led to IIA formation. Results : Patient was treated with 6‐week course of intravenous ceftriaxone and underwent glue embolization for his left PICA aneurysm. Post embolization angiogram did not reveal any evidence of contrast filling within the aneurysm. He tolerated the procedure well with no complications and was subsequently discharged to inpatient rehabilitation with a modified Rankin scale (mRS) score of 3. Conclusions : IIAs of PICA in the setting of recent dental procedures are exceptionally rare and challenging to diagnose. They may be clinically silent until rupture and are usually identified incidentally on imaging or during autopsy. Physicians should maintain vigilance for this unique entity as prompt recognition and timely intervention may prevent severe morbidity and mortality.

Abstract 1122‐000148: Rare Anterior Inferior Cerebellar Artery Origin of Middle Meningeal Artery

Introduction : Middle meningeal artery (MMA) anatomy has very important surgical implications during endovascular and open based skull procedures. Various anatomical origins have been identified in the literature besides its most common origin as the largest branch of the maxillary artery. It runs parallel and close contact of the lateral skull face therefore during trauma to this area is prone to rupture resulting in subdural hemorrhage(SDH). In our case report, we present its peculiar origin from anterior inferior cerebellar artery which has never been reported before. The origin of MMA may reflects the risk involved with embolization therapy for chronic SDH. Methods : A case of MMA originated form AICA. A literature review was conducted of reports of MMA origins. Results : A 35‐year‐old male with a history of alcohol abuse presented to the ED after falling down from the stairs. In the ED, the patient had multiple episodes of seizures along with respiratory distress therefore was intubated due to concern of airway protection. CT head showed bilateral SDH. Patient underwent diagnostic angiogram for possible bilateral embolization of MMA. During the procedure, the left MMA origin was seen from the AICA whereas the right MMA arising from the external carotid artery. Embolization of the left MMA was aborted. Patient remained intubated and was later transferred to a long term care facility. Conclusions : In the last 80 years, the anatomy of the MMA has been part of the discussion of various literature. Seeger et.al, highlighted the embryological changes manifested as anastomosis between Sphenomaxillary artery and lateral pontine artery resulting in origin of MMA from Basilar artery along with absence of foramen spinosum. Since 1973, multiple literature highlighted the origin of MMA including the lacrimal artery, ICA, ascending pharyngeal artery, opthalmic and occipital arteries. Recently, In 2011 Kuruvuilla et.al showed the origin of MMA from posterior inferior cerebellar artery. MMA clinical significance can be seen in multiple diseases. Older populations with chronic subdural hematomas, embolization of MMA has shown to be a less invasive and cost effective procedure. In patients with anterior and middle cranial fossa meningiomas embolization of MMA has been a crucial part of management. Similarly, understanding of its anatomy is also important while treating MMA aneurysm or pseudoaneurysms. In our case, the origin of middle meningeal artery from AICA has been significant as it supplies the posterior fossa structures and was not reported in the literature before, hence the procedure was aborted. This anatomical variant has shown us a new light upon embryological evolution and has helped us widen the horizons of our approach towards brain vasculature. This finding will help the future Interventionists to develop new ways of embolization of the MMA and understanding its anatomy.

Cerebral vascular reconstruction in the treatment of abnormal anastomosis of origin posterior inferior cerebellar artery complicated with aneurysms: two cases reports and literature review

Cerebral vascular reconstruction in the treatment of abnormal anastomosis of origin posterior inferior cerebellar artery complicated with aneurysms: two cases reports and literature review

Clipping of Posterior Circulation Intracranial Aneurysms: Maintenance of a Necessary Skill in Low-Resource Settings

The treatment paradigm for intracranial aneurysms has evolved with technological advancements, resulting in improved patient outcomes. In particular, the management of posterior circulation aneurysms has shifted to favor endovascular therapy (EVT). However, this modality is not always accessible in low-resource settings.In our country (Trinidad and Tobago), neuroendovascular services are not readily available. We report a case of a patient with a ruptured left posterior inferior cerebellar artery (PICA) aneurysm (Fisher grade 4) who underwent a far-lateral craniotomy and clip ligation. It was done by a fellowship-trained vascular neurosurgeon in a public hospital and resulted in an excellent patient outcome. This highlights the need to maintain this surgical skill set in resource-poor countries, in spite of the increasing popularity of endovascular therapy.

Unusual collateral channel of ruptured vertebral artery fusiform aneurysm involving the posterior inferior cerebellar artery: a case report

Unusual collateral channel of ruptured vertebral artery fusiform aneurysm involving the posterior inferior cerebellar artery: a case report

Endovascular treatment of posterior inferior cerebellar artery trunk aneurysm.

The posterior inferior cerebellar artery (PICA) generally originates from the vertebral artery (VA) and is the most complex cerebellar artery. Aneurysms can occur at any site along the PICA trunk. Although most PICA aneurysms are located at the VA-PICA junction, a small proportion is located at the PICA trunk. Endovascular treatment (EVT) of aneurysms in the PICA trunk may be difficult and complex. We performed a review to expound upon EVT of PICA trunk aneurysms. The PICA can be divided into five segments (p1-5); the p1-3 segments are proximal segments, and the p4-5 segments are distal segments. Most PICA trunk aneurysms are dissecting aneurysms. Sometimes, the PICA can give rise to flow-related aneurysms in association with cerebellar arteriovenous malformations. Most aneurysms of the PICA trunk require aggressive treatment, especially those that have ruptured. Currently, the EVT mainly includes selective coiling with/without stent assistance and parent artery occlusion. Recently, some new devices, such as flow diversion and Barricade and Kaneka ED coils, can be used to treat PICA trunk aneurysms. The risk of complications with EVT seems to be higher; however, most complications are only transient or mild, and some are even clinically silent. In addition, open surgery is still an important option. For PICA trunk aneurysms, the treatment choice should be assessed on a case-by-case basis. The rate of permanent morbidity of the EVT is low. EVT is an effective method for treating PICA trunk aneurysms.