Posterior Inferior Cerebellar Artery Dissection Research Articles

Abstract WMP83: Arterial Dissection: A Still Underestimated Cause Of Lateral Medullary Infarction

Introduction: Although the association between vertebral artery or posterior inferior cerebellar artery dissection and lateral medullary infarction (LMI) has been established, the actual prevalence of dissection among patients with LMI may still be underestimated. Methods: Consecutive patients with acute pure LMI admitted between 2010 and 2021 were included. High-resolution vessel wall MRI (VWMRI) and/or transfemoral cerebral angiography (TFCA) were performed in a part of patients and were regarded as gold standard tests for diagnosis of dissection. Factors associated with definite dissection based on VWMRI or TFCA findings were assessed. Risk scoring for dissection was created based on multivariate logistic regression and applied to estimate the number of possible dissection. Results: Eighty-seven LMI patients were eligible and 47 (54.0%) of them underwent VWMRI (n=43) and/or TFCA (n=7). Among these 47 cases, 24 were definite dissection. Three out of 40 patients without gold standard tests were diagnosed with definite dissection based on conventional MRI findings. Preceding headache and normal body weight were independently associated with dissection in LMI patients. A risk scoring which includes age, body mass index, and headache predicted dissection with 91.7% sensitivity and 69.6% specificity (area under the receiver operating characteristic curve, 0.889; 95% confidence intervals, 0.802-0.977) in our population. Additional nine out of 37 patients without gold standard tests nor diagnosis of definite dissection in conventional MRI could be considered as possible dissection based on the scoring. Definite and possible dissections together comprised 41.4% (n=36) of LMI in our study. Conclusions: Arterial dissection may be more prevalent among LMI patients than reported before. Thorough diagnostic effort for dissection is necessary based on scrutinizing risk stratification.

Isolated posterior inferior cerebellar artery dissection with ischaemic stroke: evaluating the radiological features and diagnostic feasibility of high-resolution vessel wall imaging

To evaluate the radiological features of isolated posterior inferior cerebellar artery dissection (PICAD) and the feasibility of using high-resolution vessel-wall imaging (HR-VWI) for diagnosing PICAD. Three hundred and nine patients with arterial dissection involving the posterior cerebral circulation, who underwent HR-VWI between March 2012 and July 2019 were reviewed retrospectively. Among them, 44 patients (14.2%) were diagnosed with isolated PICAD in consensus among a neuroradiologist, a neurointerventionist, and a neurologist. Two neuroradiologists reviewed the vessel wall images independently for evidence of dissection (dissection flap, outer diameter enlargement on T2-weighted imaging [WI], mural haematoma). Diagnostic confidence was also scored on a five-point scale. Intra- and interobserver agreement for diagnosing PICAD and detecting evidence of dissection were evaluated. Dissection flaps were seen on T2WI in all cases (100%) and on contrast-enhanced T1WI in 34 patients (79.1%). Outer diameter enlargement of the steno-occlusive lesions on angiography was detected in most cases (97.7%). A mural haematoma was detected on three-dimensional (3D) contrast-enhanced motion-sensitised driven-equilibrium T1WI in 97.1% of the cases. The mean diagnostic confidence score derived by two neuroradiologists was 4.72. The two reviewers showed substantial to almost perfect agreement (weighted kappa coefficient: 0.62-0.97). Use of HR-VWI as a diagnostic tool for PICAD is feasible, and a dissection flap with outer wall enlargement on HR-T2WI allows confident dissection diagnosis. The present data suggest that PICAD might be considered as a stroke aetiology in patients with unexplained ischaemic stroke in the PICA territory, and that PICA evaluation with HR-VWI is both necessary and feasible.

Utility of T2-weighted high-resolution vessel wall imaging for the diagnosis of isolated posterior inferior cerebellar artery dissection at acute and early subacute stages

Recent advances in magnetic resonance high-resolution vessel wall imaging (HRVWI), which can detect intramural hematomas (IMH), improve the noninvasive diagnostic accuracy of isolated posterior inferior cerebellar artery dissection (iPICA-D). However, despite the risk of overlooking minute IMH, the utility of T2-weighted HRVWI has not been thoroughly evaluated. This study aimed to compare the utility of T2-weighted HRVWI with that of T1-weighted HRVWI, basiparallel anatomical scanning (BPAS), and magnetic resonance angiography (MRA) for the diagnosis of iPICA-D mainly in the acute and early subacute stages in 6 iPICA-D patients (three acute, two early subacute and one late subacute stages on initial examinations). Dissection-related abnormalities included IMH on T1-weighted HRVWI, aneurysmal dilations on T2-weighted HRVWI and discrepancy between BPAS and MRA. On initial examinations, T2-weighted HRVWI revealed iPICA-D-related abnormalities more conspicuously than did T1-weighted HRVWI and combination of BPAS and MRA. Except in a single case with a discrepancy between the outer contour on BPAS and inner contour on MRA, no specific abnormalities were detected besides T2-weighted HRVWI at acute or early subacute stages. In addition to T1-weighted HRVWI, BPAS and MRA, T2-weighted HRVWI should be performed to diagnose acute and early subacute iPICA-D.

Clinical and neuroradiological characteristics of ischemic stroke and subarachnoid hemorrhage in isolated posterior inferior cerebellar artery dissection: Literature review and report of 2 cases

Background/objectiveIsolated dissection of the posterior cerebellar artery (PICA) is very rare, with only few cases reported in the literature. Ischemic stroke or subarachnoid hemorrhage (SAH) may follow isolated PICA dissection depending on the dissection plane of the artery. The aim of this is study is to investigate similarities and variations in clinical, neuroradiological manifestations as well as the management and prognosis of ischemic stroke and SAH events in isolated PICA dissection. MethodWe report 2 cases of PICA dissection treated at our institution, one with ischemic stroke and other with SAH. Peer reviewed articles were used for insight on differences and similarities in presentation, management and prognosis between PICAD with ischemic stroke and SAH event. ResultsOccipital headache was noted to be the most common clinical presentation in both patients groups. Patients with SAH event presented with more severe symptoms compared to those with ischemic stroke. Susceptibility weighted imaging (SWI) was found to be better at detecting PICAD compared to conventional MRI/MRA. Digital Subtraction Angiography remains the gold standard diagnostic test for dissection. PICAD with ischemic stroke is likely under diagnosed. ConclusionPICAD with ischemic stroke is likely under-diagnosed due to the following reasons; 1) patients present with neurological deficits that are non-specific and mild, 2) DSA, which is a gold standard of diagnosing PICAD is not regularly performed in these patients, 3) lack of predisposing factors associated with PICAD in some patients. The mild and non-specific clinical presentation in young adults with PICAD with ischemia probably due to their ability to compensate better given low incidences of other comorbidities. Further investigation regarding the underlying etiology of isolated PICAD, association of proximal PICAD to ischemia and distal PICAD to SAH as well as use of SWI in detecting PICAD is recommended.

Spontaneous healing of an isolated posterior inferior cerebellar artery dissection without stroke: a case report

BackgroundIsolated posterior inferior cerebellar artery dissections can cause subarachnoid hemorrhages or infarctions. Surgical and endovascular treatments for hemorrhagic stroke cases and medical treatments using antithrombotic agents for ischemic stroke cases have been performed, but there are very few reports on nonstroke isolated posterior inferior cerebellar artery dissections, and the treatment strategy for nonstroke cases has not been established.Case presentationA 48-year-old healthy male felt a severe, throbbing headache on the right side and came to our clinic on the fourth day following onset. MRI examinations revealed a right posterior inferior cerebellar artery dissection and showed no infarctions or hemorrhages. He was observed carefully with continuous monitoring of blood pressure, hydrated sufficiently, and given analgesic anti-inflammatory agents. Two weeks later, the dissected vessel’s diameter grew to the maximum size, though the patient’s headache rapidly improved around that day. Surgical or endovascular treatments for prevention of subarachnoid hemorrhage were recommended, but careful conservative therapy was continued in accordance with the patient’s wishes. Gradually, the dissection finding improved. Four months later, MRI examinations showed his right posterior inferior cerebellar artery was almost normal in size and shape.ConclusionsThis is the first detailed report on a nonstroke isolated posterior inferior cerebellar artery dissection that spontaneously occurred and healed, observed by serial high-resolution MRI examinations.

Intimal flap detected by three-dimensional curved multiplanar reconstruction image in isolated posterior inferior cerebellar artery dissection: a report of two cases

BackgroundSpontaneous isolated posterior inferior cerebellar artery (PICA) dissection has been reported more frequently since high-resolution vessel wall magnetic resonance imaging (HR vw-MRI) was introduced to the field. The intimal flap or double lumen, which is commonly reported to be a direct sign of the dissection, is not easily detectable on HR vw-MRI because the size of the PICA is very small and tortuous.Case presentationTwo patients with posterior circulation ischemic stroke due to spontaneous isolated PICA dissection underwent HR vw-MRI. The curved multiplanar reconstruction image reconstructed using three-dimensional (3D) HR vw-MRI (3D curved MPR imaging) is helpful to observe tortuous blood vessels such as the PICA because it can visualize the entire vessel course in a single plane. In this report, routine HR vw-MRI revealed only an intramural hematoma in both patients. However, 3D curved MPR imaging discovered the intimal flap which was not observed on the routine HR vw-MRI. Therefore, these two patients were diagnosed with spontaneous isolated PICA dissection due to the intimal flap that was observed on the 3D curved MPR image.ConclusionHR vw-MRI is useful for the early diagnosis of isolated PICA dissection. Furthermore, we believe that 3D curved MPR imaging could improve the possibility of diagnosing the dissection early because it can easily confirm direct signs such as an intimal flap or double lumen.

Clinical Characteristics of Cerebellar Infarction Due to Arterial Dissection.

Objectives and Background:Arterial dissection (AD) of the vertebral artery (VA) or its branches may cause ischemic stroke of the posterior circulation. However, clinical and radiological characteristics of patients with AD-related cerebellar infarction (CI) have rarely been reported.Methods:Forty-nine patients with CI admitted to our department from April 2008 to March 2015 were identified from our database. After dichotomization into the AD and non-AD group, their demographics and presenting symptoms were compared. Subsequently, a multivariate regression analysis was performed to identify variables that correlated with AD.Results:During the 7-year period, 14 and 35 patients were identified in the AD and non-AD group, respectively. The AD group was significantly younger than the non-AD group (55.0 ± 16.3 vs. 69.7 ± 10.7 years, P = 0.001) and was also more likely to experience acute pain at onset (86% vs. 17%, P < 0.001). Using a multivariate regression analysis, these two variables and the male sex were found to correlate with AD. AD was located in extracranial VA (n = 3); intracranial VA (n = 8); posterior inferior cerebellar artery (PICA) (n = 3); and superior cerebellar artery (n = 1). Identification of AD was delayed in one patient with an extracranial VA and one patient with a PICA dissection.Conclusions:AD was responsible for approximately 30% of CI in our cohort. Pain at onset may be a useful symptom to identify patients with AD-related CI. While intracranial VA was the most common location of AD, physicians should be aware of the possibility of extracranial VA or PICA dissection in patients with seemingly unremarkable radiological findings.

Utility of T1- and T2-Weighted High-Resolution Vessel Wall Imaging for the Diagnosis and Follow Up of Isolated Posterior Inferior Cerebellar Artery Dissection with Ischemic Stroke: Report of 4 Cases and Review of the Literature

An accurate diagnosis of isolated posterior inferior cerebellar artery dissection (iPICA-D) is difficult due to the limitation of spatial resolution on conventional magnetic resonance imaging (MRI) techniques to detect subtle vessel wall abnormalities. The recent development of MRI techniques, including high-resolution vessel wall imaging (HRVWI), has resulted in the improved diagnostic accuracy and efficiency of iPICA-D. In fact, T1-weighted HRVWI, which can reveal intramural hematomas in the posterior inferior cerebellar artery (PICA), is useful for the diagnosis of iPICA-D. However, the utility of T2-weighted HRVWI has not been previously reported. The aim of this study was to investigate the diagnostic utility of T1- and T2-weighted HRVWI for the diagnosis of iPICA-D. We retrospectively evaluated MRI findings including intramural hematomas, dilations, and chronological changes in 4 patients with iPICA-D admitted to our hospital and related facility from January 2015 to August 2016. In addition to T1-weighted HRVWI, T2-weighted HRVWI was performed on isovoxel three-dimensional (3D) fast spin-echo or 3D sampling perfection with application-optimized contrast using different flip-angle evolution. We also reviewed cases of nonhemorrhagic iPICA-D with ischemic onset in which the MRI findings were described. In all 4 patients, in addition to the intramural hematomas on T1-weighted HRVWI, T2-weighted HRVWI clearly showed the fusiform dilation of the external diameter of the PICA. T2-weighted HRVWI was more useful than other techniques, including T1-weighted HRVWI, for the evaluation of arterial shape changes. Like T1-weighted HRVWI, T2-weighted HRVWI is useful for the diagnosis and assessment of chronological changes in vessel wall abnormalities during the follow-up period.

Treatment Strategy for Isolated Posterior Inferior Cerebellar Artery Dissection

Isolated dissections that develop on the posterior inferior cerebellar artery (PICA) require intensive treatment because of their potential fatality. However, because of the rarity of these dissections, the optimal treatment has not yet been established. We retrospectively reviewed the clinical records of all patients who underwent any PICA dissection treatment in our institute over the last 4 years. Ten patients were enrolled, including 7 patients with subarachnoid hemorrhage (SAH) and 3 with PICA territory infarction. Dissection was seen at the proximal portion in 8 patients, whereas the remaining 2 patients showed distal PICA dissecting aneurysms. Among the 7 patients with hemorrhage, 5 were actively treated (trapping and bypass, 2 patients; surgical clipping, 1 patient; coil embolization, 2 patients). Conservative management was performed in the other 2 patients. Among the 3 patients with infarction, 2 received conservative treatment. Endovascular treatment was performed in 1 patient, who showed rapid progression, aneurysm formation, and conversion to massive SAH within 10 days after the initial attack. Although 7 patients showed relatively good outcomes (modified Rankin Scale score, ≤2) after 30 days of follow-up, 1 patient had a final modified Rankin Scale score of 3. In addition, the other 2 patients (1 in each group) died as a result of major SAH. Given the dynamic clinical course and potential fatality of PICA dissection, meticulous evaluation, intensive treatment with a diverse range of modalities, and proper follow-up are required for patients with PICA dissection to achieve favorable outcomes.

Isolated Posteroinferior Cerebellar Artery Dissection Diagnosed by High-Resolution Vessel Wall MRI

Arterial dissection is an important cause of stroke. We report two cases of isolated posterior inferior cerebellar artery (PICA) dissection diagnosed by high-resolution vessel-wall MRI (HRVW-MRI). One subject complained of abrupt-onset vertigo and headache, and the other subject had headache, vertigo, and Horner syndrome. Conventional MRA showed only focal dilatation of the PICA, but HRVW-MRI revealed intramural hematoma and double-lumen contour in the PICA, suggesting arterial dissection. We suggest that the use of HRVW-MRI should be considered when diagnosing isolated PICA dissection in a PICA infarct with an unknown cause. Key Words: Isolated PICA dissection, High-resolution vessel-wall MRI, Arterial dissection

Diagnosis and follow-up of posterior inferior cerebellar artery dissection complicated with ischemic stroke assisted by T1-VISTA: a report of two cases

BackgroundVolume isotropic turbo spin-echo acquisition (VISTA) is a new method similar to the 3D black-blood imaging method that enables visualization of a intramural hematoma. T1-VISTA has recently been applied in the diagnosis of intracranial arterial dissection. However, the identification of an intramural hematoma in posterior inferior cerebellar dissection (PICA-D) by T1-VISTA has only rarely been reported.Case presentationWe herein report two patients who suffered from PICA-D complicated with ischemic stroke. Initial magnetic resonance arteriography was not informative, however, T1-VISTA depicted high-intensity signal areas suggesting an intramural hematoma of PICA-D in both cases. The high-intensity signal areas gradually reduced and finally disappeared at 4 months and 5 months after the onset, respectively.ConclusionOur cases demonstrate that T1-VISTA was able to assist in the diagnosis and follow-up of PICA-D.

Isolated Posterior Inferior Cerebellar Artery Dissection as a Cause of Ischemic Stroke: Clinical Features and Prognosis

Background: The purpose of this study was to clarify the incidence, clinical and radiological features and outcomes of isolated posterior inferior cerebellar artery (PICA) dissection in isolated PICA territory infarctions. Methods: We retrospectively reviewed consecutive inpatients with ischemic stroke secondary to isolated PICA dissection from our stroke database between January 2004 and December 2013 and reviewed the literature with regard to those patients. Results: Of 167 consecutive patients with an isolated PICA territory infarction, a total of 10 patients (6.0%, 3 women, 48.1 ± 7.1 years) were diagnosed as having an isolated PICA dissection. Patients with PICA dissection were younger (p < 0.001), more commonly experienced headache at onset (p = 0.008), less commonly had hyperlipidemia (p = 0.044) and showed a lower modified Rankin Scale score at discharge (p = 0.002) when compared with patients without arterial dissection. In 6 of these 10 patients, PICA dissections had not been suspected on initial magnetic resonance angiography (MRA) and were confirmed by follow-up MRA or digital subtraction angiography. In the follow-up period (median 1.5 years, interquartile range 0.5-6.3 years), there were no recurrent ischemic or hemorrhagic stroke events. Conclusions: Isolated PICA dissection as an etiological mechanism in isolated PICA territory infarctions may be more common than was previously recognized to be. The diagnosis of PICA dissection is often difficult and requires close and repeated morphological evaluation. We should carefully identify PICA dissections as a possible cause of PICA territory infarctions.

Subarachnoid hemorrhage then thrombosis of posterior inferior cerebellar artery dissection: is early surgical exploration warranted?

The natural history of spontaneous cerebral artery dissection and thrombosis remains uncertain. Concurrent subarachnoid hemorrhage further complicates the therapeutic approach. Thus the best strategy for managing patients with acute vessel...

Spontaneous Isolated Dissection of the Posterior Inferior Cerebellar Artery Presenting with Lateral Medullary Infarction

Background: Spontaneous isolated dissection of the posterior inferior cerebellar artery (PICA) is rare and presents with variable clinical course and prognosis. We report a case of spontaneous isolated PICA dissection presenting with lateral medullary infarction. Case Report: A 57-year-old female patient presented with right leg ataxia, headache, nausea and vomiting with a past medical history of hypertension. Neurological examination revealed right leg ataxia and left-side sensory change with right ptosis and miosis. The brain magnetic resonance imaging and magnetic resonance angiography showed an acute infarction in the right lateral medulla with abrupt luminal stenosis and subtle dilatation of the proximal segment of the right PICA. Transfemoral cerebral angiography showed an abrupt segmental stenosis of the right proximal PICA with a pre-stenotic fusiform dilatation, suggestive of dissection. The patient had a good clinical outcome with antiplatelet therapy. Conclusion: We report a rare case of spontaneous isolated PICA dissection with lateral medullary infarction. J Neurocrit Care 2014;7(2):137-140

Do Characteristics of Dissection Differ between the Posterior Inferior Cerebellar Artery and the Vertebral Artery?

The purpose of this study was to clarify the features of posterior inferior cerebellar artery (PICA) dissection. We prospectively registered 93 consecutive patients and 108 arteries with confirmed diagnoses of dissection in the vertebral artery (VA) or PICA between February 2007 and January 2014. Patients were diagnosed with arterial dissection when they had both acute symptoms and radiological characteristics in magnetic resonance imaging or digital subtraction angiography. Patients were divided into 2 groups depending on whether the site of dissection was VA (VA group) or PICA (PICA group). We compared the clinical and radiological characteristics and clinical outcomes of PICA versus VA dissection. Of the 93 patients included in this study, 83 were in the VA group, and 10 had arterial dissection in the PICA. Patients with PICA dissection more frequently suffered from SAH (P < .001), whereas nonstroke symptom was often the initial symptom in the VA group. Pearl sign was seen most frequently at the dissection site of PICA. Surgical or endovascular treatment was performed in 9 of 10 PICA dissections, whereas more than half of the VA dissections were treated conservatively (P < .001). SAH was significantly more severe in the patients with PICA dissection compared with those in the VA group (P = .049). Patients with PICA dissection suffered from subarachnoid hemorrhage more frequently than those with VA dissection. PICA dissection was treated with surgical intervention, whereas VA dissection was treated conservatively.

Spontaneous Isolated Posterior Inferior Cerebellar Artery Dissection: Rare but Underdiagnosed Cause of Ischemic Stroke

Spontaneous isolated posterior inferior cerebellar artery dissection (PICAD) is a very rare cause of ischemic stroke. Clinical and radiologic features of ischemic type of isolated spontaneous PICAD are not well established. We consecutively enrolled patients who had spontaneous isolated PICAD confirmed by digital subtraction cerebral angiography. Clinical manifestation, magnetic resonance imaging (MRI), and angiography were analyzed. Seven patients were diagnosed as ischemic type of spontaneous isolated PICAD. Patients experienced an occipital headache, followed by vertigo, postural imbalance, or Wallenberg syndrome. Six showed medullar, unilateral, or bilateral cerebellar infarctions on diffusion-weighted imaging (DWI). One presented with transient cerebellar ischemia and negative on DWI. T1-weighted imaging showed high signal intensity in posterior inferior cerebellar artery in only 1 patient. Susceptibility-weighted imaging (SWI) revealed hypointense signal with blooming effect in posterior inferior cerebellar artery in 5 patients. The modified Rankin Scale score at 3months was 0 or 1 in all patients. Clinical manifestations in ischemic type of spontaneous isolated PICAD were similar to those of intracranial vertebral artery dissection. Clinical course was relatively stable and benign. SWI was more helpful to suspect abnormality of posterior inferior cerebellar artery than conventional MRI or magnetic resonance angiography in our small series. Cerebral angiography is recommended in patients with clinically suspected spontaneous isolated PICAD for definite diagnosis.

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

Simultaneous Vertebral Artery Dissection and Contralateral Posterior Inferior Cerebellar Artery Dissecting Aneurysm

The optimal treatment and appropriate follow-up period for an unruptured vertebral artery (VA) and/or posterior inferior cerebellar artery (PICA) dissection have not been established. Decisions regarding treatment of these vascular lesions are usually based on the manifesting symptoms and changes in radiologic findings during the follow-up period. We experienced a patient who had a simultaneous unruptured VA dissection and a contralateral PICA dissecting aneurysm. We did not find such a case in other literature.

Dissection of the posterior inferior cerebellar artery in the hypereosinophilic syndrome

Dissection of the posterior inferior cerebellar artery in the hypereosinophilic syndrome

Spontaneous resolution of isolated dissecting aneurysm on the posterior inferior cerebellar artery

The authors report a rare example of an isolated dissecting posterior inferior cerebellar artery (PICA) aneurysm with spontaneous resolution. A 41 year-old male suffered sudden dizziness, nausea and vomiting. An angiogram and magnetic resonance imaging (MRI) detected an isolated PICA dissection. The patient was treated conservatively and recovered without any apparent neurological deficit. MRI detected the self-resolution of the dissecting aneurysm. Dissecting PICA aneurysms, especially non-haemorrhagic lesions, have the possibility of spontaneous resolution resulting in a favorable outcome. The treatment strategy for this vascular lesion may be decided based upon neuroradiological changes on careful follow-up.