Thrombolytic therapy of acute ischemic stroke: correlation of angiographic recanalization with clinical outcome

BACKGROUND AND PURPOSE: The effect of vessel patency, following recombinant tissue plasminogen activator (rtPA) administration, on clinical outcome in acute ischemic stroke (AIS) has been controversial. We studied the effect of recanalization following intraarterial (IA) and intravenous/IA (IV/IA) rtPA on clinical outcome in AIS. METHODS: Recanalization was classified angiographically as complete (as compared with unoccluded vessel, thrombolysis in myocardial infarction classification [TIMI] 3), none (with no change from prethrombolysis, TIMI 0), and partial (when a change in the flow from baseline was noted, TIMI 1-2). Outcomes were symptomatic intracranial hemorrhage (sICH), 90-day modified Rankin scale (< or = 2 as a good outcome), and 3-month mortality. RESULTS: Ninety-six patients had either combined IV/IA (41) or IA (55) rtPA for AIS during a 7-year period. Any recanalization occurred in 69%; 55% of those had a good outcome versus 23% in the rest (Odds ratio = 3.9; 95% confidence interval [CI] = 1.4-11.2; P = .007). Only 24% had complete recanalization; 74% had a good outcome versus 36% in the nonrecanalization group (OR = 5.1; 95% CI = 1.6-16.8; P = .002). When adjusted to time to therapy and vessel occluded, these results lessened but remained significant. The sICH rate with any recanalization was 7.6% versus 13.3% in patients with persistent clot (relative risk (RR) = 0.6; 95% CI = 0.2-2.0; P = .45). Death occurred in 19.7% of those whose vessels recanalized versus 33.3% in the rest (RR = 0.56; 95% = 0.26-1.19; P = .2). CONCLUSION: A total of 24% and 69% of patients had complete and any recanalization, respectively, following endovascular rtPA therapy of AIS. The degree of recanalization was directly related to time to therapy and associated with good clinical outcome without an increase in the rate of adverse effect.     

Thrombectomy for distal medium vessel occlusion with a new generation of Stentretriever (Tigertriever 13)

PurposeTo evaluate the safety and efficacy of the Tigertriever 13 (Rapid Medical, Yoqneam, Israel) stent retriever in acute ischemic stroke (AIS) patients with primary or secondary distal, medium vessel occlusions (DMVO).MethodsWe performed a retrospective analysis of all consecutive AIS patients who underwent thrombectomy with the Tigertriever13 for DMVO. Patients’ characteristics were reviewed, procedural complications, angiographic (modified thrombolysis in cerebral infarction score [mTICI]) and clinical (modified Rankin Scale [mRS]) outcomes were documented.ResultsBetween November 2019 and November 2020, 16 patients with 17 DMVO were included (40% female, median age 60 [50–65] years). The Tigertriever13 was used in 11/17 (65%, median NIHSS of 8 [6–15]) primary DMVO and in 6/17 (35%, median NIHSS of 20 [13–24]) cases of secondary DMVO after a proximal thrombectomy. The successful reperfusion rate (mTICI 2b, 2c, 3) was 94% (16/17) for the dedicated vessel. At day 1, CT imaging showed a subarachnoid hemorrhage in 29% of the cases and a parenchymal hematoma in 12%. At 3 months, 65% of the patients (11/17) had a favorable outcome (mRS 0–2).ConclusionMechanical thrombectomy using the Tigertriever13 appears to be safe and effective for DMVO. Clinical and anatomical results are in line with those of patients with proximal occlusions.     

Intraneural perineurioma of the sciatic nerve: An under-recognized nerve neoplasm with characteristic MRI findings

Intraneural perineurioma is a benign peripheral nerve neoplasm that typically affects teenagers and young adults and tends to result in a motor-predominant neuropathy. The lesion is rare, but has likely been underdiagnosed due to a lack of familiarity among both clinicians and radiologists. There have been few reports in the radiology literature despite the lesion having a fairly characteristic imaging appearance. We report a case of a 26-year-old woman with an intraneural perineurioma of the left sciatic nerve confirmed with excisional biopsy and pathologic analysis.     

Energy metabolism, enzymatic flux capacities, and metabolic flux rates in flying honeybees.

Honeybees rely primarily on the oxidation of hexose sugars to provide the energy required for flight. Measurement of VCO2 (equal to VO2, because VCO2/VO2 = 1.0 during carbohydrate oxidation) during flight allowed estimation of steady-state flux rates through pathways of flight muscle energy metabolism. Comparison of Vmax values for flight muscle hexokinase, phosphofructokinase, citrate synthase, and cytochrome c oxidase with rates of carbon and O2 flux during flight reveal that these enzymes operate closer to Vmax in the flight muscles of flying honeybees than in other muscles previously studied. Possible mechanistic and evolutionary implications of these findings are discussed.     

Is juvenile diabetes determined by a single gene closely linked to HLA?

The transmission behavior of insulin-dependent juvenile diabetes mellitus (JDM) has been studied with respect to its frequency in the relatives of JDM probands and its possible linkage to the HLA complex. Mathematical analysis shows that under a single locus hypothesis a very restricted range of incidence rates is possible in the full siblings of probands once the concordance rate in monozygotic (MZ) twins is specified. Specifically, for a given population prevalence of the disease, high concordance rates in MZ twins require high incidence rates in siblings, and low rates require low incidence rates, if a single locus model is th be valid. Moreover, if these rates do conform to a single locus model, then they give additional information about possible linkage between the purported JDM susceptibility gene and the HLA complex. By using observations on the identity by descent scores at the HLA locus of sibling pairs, both of whom are affected with JDM, it is shown that tight linkage of a disease susceptibility locus is possible only when the MZ twin and sibling incidence rates are low, whereas high rates support loose linkage. If the single locus model is rejected, then an alternative hypothesis, involving epistasis between a JDM susceptibility locus and genes in (or close to) the HLA complex can be suggested as a mechanism whereby JDM would appear to be linked to HLA within families while maintaining an association with HLA at the population level.     

Ultrastructure of the subpial glial limitans in the cerebellum of the lizard (Lacerta lepida)

The subpial glial limitans in the cerebellum of the lizard (Lacerta lepida) is a single layer formed by the extensions of the fibers of Bergmann's glia. These subpial extensions present a prismatic aspect, few organelles and abundant whorls of smooth endoplasmic reticulum. These whorls of endoplasmic reticulum appear as concentric and tubular membranous formations. The glial limitans is not continuous at times.