Bilateral Posterior Inferior Cerebellar Artery Research Articles

Microsurgical anatomical vascular study of the PICA-PICA bypass

ObjectiveTo assess the posterior inferior cerebellar artery (PICA)-PICA bypass possibility. MethodsFifteen adult cadaver heads were used for surgical simulation, and the far-lateral approach was used to expose the surgical field. The bilateral PICA course, diameter, and perforators were observed and measured to evaluate the possibility of a PICA-PICA bypass. ResultsThe PICA-PICA bypass was performed in seven (46.7 %) of the 15 specimens; the procedure was performed easily in three specimens, a little difficult in two, and was difficult in two specimens because of the relationship between the tonsil and the short parallel length of the bilateral tonsillomedullary (p3) segment. In eight (53.3 %) of the 15 specimens, PICA-PICA bypass was not feasible for reasons including 1) the caliber of the bilateral p3 was unmatched for bypass, 2) the distance of bilateral p3 in the midline was > 7 mm, 3) the middle segment of p3 perforating direct arteries limited the buffer length, and 4) single caudal loops. ConclusionThe possibility of PICA-PICA bypass was determined by the proximity of the bilateral p3, caliber match, and mobilization of the bilateral caudal loop due to the perforators. The difficulty of the PICA-PICA bypass mainly depends on the relationship between the cerebellar tonsil and the parallel length of the bilateral PICA in the midline.

Childhood posterior circulation arterial ischemic stroke – An unusual case with a possible COVID-19-related arteriopathy

Viral infections are known to increase predilection to stroke and coronavirus disease 2019 (COVID-19) has proven these concerns true. We are presenting the case of a 6-year-old previously normal male child diagnosed with posterior circulation stroke who had all etiological workups negative except for the COVID antibody. Imaging showed thrombi over the V3 segment of the vertebral artery at C1–C2 level causing near complete occlusion, with embolic infarct in the bilateral posterior inferior cerebellar artery, bilateral posterior cerebral artery, bilateral anterior inferior cerebellar artery, and the left superior cerebellar artery. The child was managed with methylprednisolone, anticoagulation, and supportive care and was able to restore near-normal neurological status within months. This case is unique in terms of the involvement of posterior circulation which is rare in the pediatric population. A possibility of inflammation-related arteriopathy secondary to infection should be considered in the etiological workup of stroke. Anti-inflammatory measures to control cytokine storm along with supportive care will ensure a good outcome.

Comment on Bilateral Anomalous Posterior Inferior Cerebellar Artery-Anterior Inferior Cerebellar Artery Anastomotic Arteries Associate with a Ruptured Cerebral Aneurysm

We previously reported an unusual case of bilateral posterior inferior cerebellar artery (PICA)-anterior inferior cerebellar artery (AICA) anastomosis associate with a ruptured aneurysm. Moreover, also this case had segmental absence of both distal vertebral arteries (VA). During the 7 to 12 mm embryonic stage, the basilar artery is formed by fusion of the longitudinal neural arteries. The VAs is formed by fusion of multiple segmental arteries, from C1 to C6. Inferior cerebellar arteries develop later than VAs. There is no literature concerning bilateral regression of the VAs. There is in contradiction of developmental stage between segmental regression of the VA and formation of VA- PICA-AICA-basilar artery anastomosis. Phylogenetically, PICA and AICA belong to pial arteries of the spinal cord. It is appropriate to consider segmental regression/occlusion of VAs to be acquired, and followed by development of pial collateral network involving the anterior spinal artery, the lateral spinal artery and inferior cerebellar arteries, same as the leptomeningeal anastomosis of the supratentorial circulation.

A Case of Bilateral Medial Posterior Inferior Cerebellar Artery Infarction Associated with Subclavian Steal Syndrome

Subclavian Steal Syndrome (SSS) is the result of reversed ipsilateral vertebral arterial blood flow caused by proximal subclvian artery steno-occlusive disease. A 78-year-old man with a history of hypertension and smoking presented with sudden dizziness, nausea and vomiting; there was no history of recent trauma and arm claudication. Neurologic examination showed no abnormality except for ataxia of both arms. Diffusion Weighted Image (DWI) indicated acute bilateral medial Posterior Inferior Cerebellar Artery (PICA) infarction. Subsequent brain Magnetic Resonance Angiography (MRA) revealed chronic occlusion at the left proximal subclavian artery with decreased left vertebral artery flow and prominent left (PICA) from vertebral artery. Transcranial Doppler (TCD) ultrasonography showed reversal of flow within the left vertebral artery, and reactive hyperemic cuff test of the left arm showed aggravated reverse flow of left vertebral artery following release of blood pressure cuff inflation, which was suggestive of SSS. Although the etiologies of bilateral PICA infarction might be diverse, we experienced a case of acute bilateral medial PICA infarction, which were presumed as hemodynamic insufficiency due to SSS.

保存的治療中に続発した両側性後下小脳動脈解離による小脳梗塞の1 例

保存的治療中に続発した両側性後下小脳動脈解離による小脳梗塞の1 例

Intraoperative visualization of bilateral thrombosis in the posterior inferior cerebellar artery apparent in the telovelomedullary segment.

Unilateral posterior inferior cerebellar artery (PICA) thrombosis is frequent. However, bilateral PICA thrombosis is rare. Herein we report about an intraoperative visualization of a bilateral thrombosis of the telovelomedullary segment of the PICA. A 74-year-old woman was admitted to our department on day two of a bilateral PICA thrombosis with developing cerebellar infarction. Her Glasgow Coma Scale score dropped from 15 to 13, and cranial computed tomography revealed compression of the fourth ventricle with consecutive occlusive hydrocephalus. After the insertion of an external ventricular drainage, the patient underwent urgent suboccipital decompressive craniectomy with removal of infarcted cerebellar tonsils, which allowed the bilateral visualization of the thrombosed telovelomedullary segments. The surgical access may offer surgical therapeutic options in a hyperacute occlusion, such as thromb-/embolectomy or bypass procedures.

Profound Gastroparesis after Bilateral Posterior Inferior Cerebellar Artery Territory Infarcts (P01.030)

Objective: To describe a case of acute gastroparesis as a result of medullary infarction. Background Function of the gastrointestinal system is partially dependent upon the integrity of the lower brain stem. While dysphagia commonly results from strokes of varying locations, acute dysfunction of other segments of the alimentary canal from stroke is not a well-described phenomenon. Design/Methods: Case report. Results: A 65 year old man with a history of diabetes mellitus without previous gastrointestinal difficulty presented with sudden onset vertigo, nausea, vomiting, a left Horner9s syndrome and hemiataxia, as well as gait ataxia. Magnetic resonance imaging (MRI) revealed an acute infarction in the midline cerebellum bilaterally and the left posterior caudal medulla, all within the right and left posterior inferior cerebellar artery (PICA) territories. Over the following week, the persistent nausea, vomiting, and vertigo gave way to severe nausea and vomiting exclusively after eating, accompanied by instantaneous satiety. Brain imaging demonstrated acute infarction of the midline cerebellum bilaterally and the left posterior caudal medulla. Serial cranial CT scans revealed minimal changes; a contrast-enhanced abdominal CT and endoscopy showed severe gastric distention but no anatomical obstruction of the gut. A gastric emptying study demonstrated 99% retention of the radiolabled meal on serial scintigraphy after 2, 3, and 4 hours post-ingestion, with minimal activity seen in the duodenum, consistent with severe gastroparesis. His symptoms were refractory to medical management, and he required a jejunostomy tube for 8 weeks as his oral intake gradually improved. Conclusions: Acute, isolated gastroparesis without gastrointestinal pathology can result from medullary infarctions. A possible explanation may be infarction or edema particularly affecting the pars centralis of the nucleus of the tractus solitarius. Preexisting diabetes mellitus may also have been a predisposing factor. Disclosure: Dr. Liff has received personal compensation for activities with E-Rewards Medical. Dr. Labovitz has nothing to disclose. Dr. Robbins has nothing to disclose.

Somatosensory-Evoked Potential Asymmetry in Medullary Ischemia During Cervical Spine Surgery

This report describes how somatosensory-evoked potentials (SEPs) can detect acute medullary ischemia during cervical spine surgery. This article describes how asymmetric SEP intraoperative monitoring changes can localize medullary ischemia. Localization of change was validated by postoperative magnetic resonance imaging (MRI). A 68-year-old man underwent cervical posterior fusion with monitoring of bilateral SEPs of the upper and lower extremities. The SEPs disappeared during initial exposure of the C1 lamina. Changes were asymmetric in degree and duration. Brain MRI postoperatively demonstrated bilateral posterior inferior cerebellar artery (PICA) territory infarcts involving the left lateral medulla. This illustrates how intraoperative SEP monitoring can provide important information on the functional integrity of brainstem structures even during cervical surgery. A knowledge of medullary anatomy and vascular territories is necessary for interpreting SEP changes. In cervical surgery, SEPs incidentally monitor the integrity of the brainstem while monitoring the spinal cord. The asymmetry of SEP change seen here was consistent with medullary level impairment, where the vascular territory is lateralized in contrast to the symmetric anterior spinal artery territory.

脳室内出血で発症した脈絡叢血管腫の4手術例

In this paper, the authors reported four cases of choroid plexus angioma which were detected by computerized tomography and were excised surgically. These four cases had the following characteristic CT findings. The initial CT scan showed intraventricular hemorrhage with or without intracerebral hematoma in each case. More than two weeks later, when the intraventricular hemorrhage had disappeared completely on the plain CT scan, a small high density area corresponding to the site of the angioma was demonstrated on the contrast enhancement CT scan. An angiomatous stain was also visualized on the angiogram in two of the four cases. In one case, vertebral angiography showed an arteriovenous malformation in the fourth ventricle supplied by the bilateral posterior inferior cerebellar artery, and in the other, right carotid angiography revealed a faint angiomatous stain in the plexal segment of the anterior choroidal artery. Each patient underwent a successful operation on the angioma located in the fourth ventricle, the left trigone, the right trigone and the right trigone of the lateral venticle respectively. The histological diagnosis of the excised specimens was arteriovenous malformation in all four cases.Twelve reported cases with CT findings of choroid plexus angioma were reviewed, which were verified histologically. Among 16 cases including the four present ones, contrast enhancement CT (CE CT) scan was performed in 11 cases. In eight of the 11 cases (73%), a small highly density area corresponding to the site of the angioma was demonstrated on CE CT scan, while angiography revealed an angiomatous stain in only six of 14 cases (43%).Our conclusion is as follows. In cases of intraventricular hemorrhage with or without intracerebral hematoma, choroid plexus angioma should be considered as one of the causes of bleeding, even though it is supposed to be uncommon. In such cases, CE CT scan should be performed to detect the lesion of the angioma, especially in the late stage, when the hemorrhage have disappeared completely on a plain CT scan. Surgical removal of the angioma is recommended because of the high incidence of recurrent and fatal hemorrhage.