Spontaneous intra-cranial arterial dissection frequently causes anterior cerebral artery infarction

Clinical and Radiological Difficulties to Detect Isolated MCA Dissection before Intravenous tPA Therapy

A 64-year-old woman was admitted to our hospital 48 minutes after sudden onset of dysphasia and right hemiplegia. Head computed tomography revealed small infarcts in the left putamen and 4-dimensional computed tomography angiography depicted high-degree stenosis in the left middle cerebral artery and delayed filling of the contrast media in the left middle cerebral artery territory. The patient underwent intravenous tissue plasminogen activator treatment. On day 5 of hospitalization, the patient underwent conventional cerebral angiography, revealing internal carotid artery to middle cerebral artery dissection. Fortunately, subarachnoid hemorrhage as an adverse effect did not occur, although iv-tPA was administered without detecting middle cerebral artery dissection.

The Prevalence of and Factors Related to Vascular Hyperintensity on T1-Weighted Imaging in Acute Ischemic Stroke

BACKGROUND

Thrombus visualization in patients with acute ischemic stroke has been detected and reported using various imaging modalities. T1-weighted imaging (T1-WI) can depict thrombi as hyperintense signals within vessels. Moreover, in addition to thrombi, T1-WI hyperintensities in arteries may suggest arterial dissection. However, the frequency of and factors related to the T1-hyperintense vessel sign (T1-HVS) are not fully known. The aim of this study was to clarify the prevalence of and related factors for the T1-HVS in patients with acute ischemic stroke.

METHODS

From September 2014 through December 2015, consecutive acute ischemic stroke patients who were admitted to our stroke unit within 7 days from symptom onset were retrospectively recruited from the prospective registry. A T1-HVS was defined as the presence of a hyperintense signal, with intensity higher than surrounding brain, within the vessel lumen. Moreover, T1-HVSs were separated into filled T1-HVSs (hyperintensity fills whole vessel lumen) and non-filled T1-HVSs. The frequency of the T1-HVS and the timing of emersion and the relationship between the presence of the T1-HVS and arterial occlusion were assessed.

RESULTS

A total of 399 patients (139 women; median age 73 years; National Institutes of Health Stroke Scale score 3) were enrolled in the present study. Of these, 327 (82%) patients had T1-WI on admission. Two hundred and sixty-seven (67%) subjects had at least one follow-up T1-WI (median 6 days after admission), and 134 (34%) cases had ≥2 follow-up T1-WI examinations. The T1-HVS was observed in 18 patients during admission; therefore, the frequency of the T1-HVS in acute ischemic stroke patients was 4.5% (95% CI 2.5-6.5%). All but one (94%) of the T1-HVSs were first observed on follow-up imaging, and the median number of days from onset to T1-HVS appearance was 9. For patients having initial major artery occlusion and follow-up MRI (n = 95), sensitivity and specificity of the T1-HVS for persistent arterial occlusion on follow-up MR angiography were 22 and 100%, respectively. T1-HVS persisted for a few months and then normalized. Although there were no significant differences between filled and non-filled T1-HVS, more patients with non-filled T1-HVS had arterial dissection (43%) than those with filled T1-HVS (9%, p = 0.245).

CONCLUSION

The T1-HVS was observed in 4.5% of acute ischemic stroke patients. T1-HVSs appeared in the subacute phase in arteries with persistent occlusion and remained for a few months.

Republished: Monotherapy with stenting in subarachnoid hemorrhage (SAH) after middle cerebral artery dissection

Isolated middle cerebral artery dissection is a rare clinical entity, with descriptions limited to a few case reports and case series. Symptomatic dissection in the anterior circulation can present as an ischemic stroke in a young population; however, it is rarely associated with subarachnoid hemorrhage. We describe a young patient who presented with acute headache from a subarachnoid hemorrhage that was ultimately determined to be due to a vascular dissection in the middle cerebral artery. The initial angiogram showed vascular irregularities in this area with stenosis. Repeat imaging 4 days after presentation identified a pseudoaneurysm proximal to the stenosis. The patient was successfully treated with a self-expanding nitinol stent and followed up with serial angiography during postoperative recovery in the hospital; additional angiograms were performed approximately 1 and 6 months after treatment. Serial angiograms demonstrated incremental healing of the dissection. The patient was discharged and remains neurologically intact at the 6-month follow-up.

Monotherapy with stenting in subarachnoid hemorrhage (SAH) after middle cerebral artery dissection

Isolated middle cerebral artery dissection is a rare clinical entity, with descriptions limited to a few case reports and case series. Symptomatic dissection in the anterior circulation can present as an ischemic stroke in a young population; however, it is rarely associated with subarachnoid hemorrhage. We describe a young patient who presented with acute headache from a subarachnoid hemorrhage that was ultimately determined to be due to a vascular dissection in the middle cerebral artery. The initial angiogram showed vascular irregularities in this area with stenosis. Repeat imaging 4 days after presentation identified a pseudoaneurysm proximal to the stenosis. The patient was successfully treated with a self-expanding nitinol stent and followed up with serial angiography during postoperative recovery in the hospital; additional angiograms were performed approximately 1 and 6 months after treatment. Serial angiograms demonstrated incremental healing of the dissection. The patient was discharged and remains neurologically intact at the 6-month follow-up.

Research article: clinical characteristics of isolated anterior cerebral artery territory infarction due to arterial dissection

BACKGROUND

Isolated brain infarction in the anterior cerebral artery (ACA) territory is rare, and its etiology has not yet been fully elucidated. Thus, we aimed to determine the etiologic and clinical characteristics of patients with isolated ACA territory infarction due to arterial dissection.

METHODS

Of 2315 patients with acute cerebral infarction admitted to our hospital between April 2007 and September 2013, 34 patients (1.5%; 28 men, 6 women; mean age, 65 ± 15 years) suffered isolated ACA territory infarction. We performed cranial magnetic resonance (MR) imaging and MR angiography for all the patients. Whenever possible, we also performed 3-dimensional computed tomography angiography, digital subtraction angiography, and MR cisternography to diagnose the stroke subtype.

RESULTS

The stroke subtypes of the 34 patients with isolated ACA territory infarction were atherothrombotic infarction, cardioembolic infarction, arterial dissection, and unclassified in 11 patients (32%), 11 patients (32%), 11 patients (32%), and 1 patient (3%), respectively. The mean ages at onset were 48 ± 9 and 72 ± 11 years in the dissection and nondissection groups, respectively (P < .001). Headaches were present at onset in 4 patients (36%) and 1 patient (4%) with and without dissection, respectively (P = .026). Blood pressure at onset was significantly higher among patients with dissection (systolic, 179 ± 34 mm Hg; diastolic, 102 ± 17 mm Hg) than among patients without dissection (systolic, 155 ± 30 mm Hg; diastolic, 86 ± 21 mm Hg; P < .05), and d-dimer values were significantly lower among patients with dissection (P = .034). Favorable clinical outcome (modified Rankin Scale score, 0-2) at discharge was achieved in 9 patients (82%) and 10 patients (43%) with and without dissection, respectively (P = .035).

CONCLUSIONS

Patients with isolated ACA territory infarction demonstrated a relatively high frequency of dissection (32%). Patients with dissection were younger, had a higher frequency of headaches, and demonstrated more favorable prognoses than patients without dissection.

Anterior cerebral artery dissection presenting subarachnoid hemorrhage and cerebral infarction

A 35-year-old man presented with simultaneous occurrence of subarachnoid hemorrhage (SAH) and cerebral infarction (CI) caused by anterior cerebral artery (ACA) dissection. He complained of sudden onset of left frontal headache and his symptoms progressed to consciousness disturbance and right hemiparesis. Computed tomography and magnetic resonance imaging demonstrated SAH localized in the left interhemispheric fissure and CI in the territory of the left ACA. Right carotid angiography demonstrated a long double lumen sign at the left A2 to A4 segment of the left ACA, leading to a diagnosis of the combined type of CI and SAH caused by ACA dissection. Although many surgeons have previously tried to perform endovascular treatment, we selected only medication in this case, and his neurological findings gradually improved. Only 9 cases including the present case presented with simultaneous occurrence of SAH and CI caused by ACA dissection. Many of these patients showed stenosis with dilatation of ACA on carotid angiography. The prognoses of these patients were good. However, many SAH patients with dissecting aneurysm had poor prognoses. To improve the strategy for managing ACA dissection, we need to accumulate a greater number of such cases in the future. We also recommend that angiography should be performed in the patients with ACA dissection.