Giuliano Sette

Hemorrhagic transformation of brain infarct Predictability in the first 5 hours from stroke onset and influence on clinical outcome

Objective: To identify, in the first 5 hours of acute brain infarct, clinical and radiologic predictors of subsequent hemorrhagic transformation (HT), and to evaluate its influence on the clinical course. Background: The identification of early predictors of HT might be important to plan antithrombotic or thrombolytic treatments. Patients: One hundred fifty consecutive patients with cerebral anterior circulation infarct systematically underwent a first CT within 5 hours of onset. During the first week after stroke, we performed a repeat CT or autopsy to look for HT. Outcome measures were early neurologic deterioration within the first week of onset and 30-day case fatality rate and disability. Results: HT was observed in 65 patients (43%): 58 (89%) had a petechial HT and seven (11%) a hematoma. Among initial clinical and CT findings, the only independent predictor of HT was early focal hypodensity. Its presence was associated with subsequent HT in 77% of cases (95% CI, 68 to 86%), whereas its absence predicted the absence of subsequent HT in 94% of cases (95% CI, 89 to 99%). No baseline clinical or CT characteristic differentiated patients with petechial HT from those with hematoma. Antithrombotic and antiplatelet agents did not influence the occurrence of either type of HT. The frequency of early neurologic deterioration and of 30-day death or disability in HT patients was twice as high as in those without HT. However, a large-sized infarct and the presence of mass effect at the repeat CT or autopsy were the only factors independently linked to both the outcome events, irrespective of the development of HT. Clinical evolution of HT patients given antithrombotics was comparable with that of HT patients not receiving these drugs. Conclusions: HT of a brain infarct is a common event that occurs independently of anticoagulation and can be reliably predicted as early as 5 hours from stroke onset by the presence of focal hypodensity at CT. Apart from the infrequent cases of massive hematoma, HT does not influence prognosis, whereas a poor outcome in HT patients is correlated with a higher frequency of large edematous infarcts in this subgroup. The clinical course and final outcome of HT in anticoagulated patients does not differ from that of non-anticoagulated HT patients. NEUROLOGY 1966;46: 341-345

Early Reperfusion in the Anesthetized Baboon Reduces Brain Damage Following Middle Cerebral Artery Occlusion A Quantitative Analysis of Infarction Volume

BACKGROUND AND PURPOSE Because in humans the clinical benefits of reperfusion remain controversial, it is important to determine whether reperfusion per se reduces infarct volume. In the nonhuman primate, mostly semiquantitative assessments of infarction have been performed. When ischemic volumes have been calculated, it has been for the acute or subacute stages of experimental stroke and may thus not adequately reflect the total volume of consolidated infarction. METHODS Anesthetized baboons were subjected to 6 hours of either reversible or permanent middle cerebral artery occlusion (MCAO). Approximately 4 weeks later, the brains were processed for neuropathological examination to allow assessment of the final infarct volume determined by the difference of healthy tissue between occluded and nonoccluded hemispheres. RESULTS Reversible MCAO resulted in a small essentially subcortical infarction (mean+/-SD, 0.58+/-0.31 cm3) in 6 of 10 baboons: the infarct (pannecrosis) was restricted to the head of the caudate nucleus, internal capsule, and putamen; 4 of 10 baboons showed no evidence of macroscopic infarction. Permanent MCAO produced a larger subcortical infarct in all 7 baboons studied (2.37+/-1.32 cm3; P=.0006 by Wilcoxon-Mann-Whitney test); the lesion was more extensive and encompassed the external capsule and, in 2 baboons, the adjacent insular cortex. CONCLUSIONS We conclude that under optimal experimental conditions, an ischemic episode of 6 hours in duration is well tolerated in the anesthetized adolescent baboon, with 4 animals showing no signs of macroscopic brain damage. Thus, early reestablishment of cerebral blood flow after a focal ischemic insult is not detrimental but indeed is beneficial in terms of the final infarct volume (both at the subcortical and cortical levels) produced by occlusion of a major cerebral artery. The data further suggest a feasible time window in which to initiate and continue therapeutic interventions.

A Method for the In Vivo Investigation of the Serotonergic 5‐HT2 Receptors in the Human Cerebral Cortex Using Positron Emission Tomography and 18F‐Labeled Setoperone

Abstract: Following previous validation in baboons, we have studied the characteristics of [18F]setoperone as a radioligand for investigating serotonergic 5‐hydroxytryptamine2 (5‐HT2) receptors in the normal, unmedicated human brain with positron emission tomography (PET); subjects orally pretreated with therapeutic amounts of ketanserin, sulpiride, or prazosin were also studied to evaluate the specificity and sensitivity of [18F]setoperone brain specific binding. In controls (n = 10), the tracer showed a clear‐cut retention in both frontal cortex and striatum (known to contain a high density of 5‐HT2 receptors) relative to cerebellum (known to be devoid of 5‐HT2receptors). In the seven young controls (20–39 years old), the frontal cortex/cerebellum and striatum/cerebellum ratios increased during the first hour to reach similar values of 2.53 ± 0.12 and 2.38 ± 0.11 (mean ± SEM), respectively, and were essentially stable during the second hour. Pretreatment with ketanserin (a 5‐HT2 blocker) significantly reduced the frontal cortex/cerebellum ratio to 0.7–1.0 at 65 min, whereas the striatum/cerebellum ratio was significantly, but only partially, reduced. During sulpiride treatment (a D2 blocker), the frontal cortex/cerebellum ratio was not altered, whereas the striatum/cerebellum ratio was significantly, but only partially, reduced. With prazosin pretreatment (an α1‐adrenergic blocker), neither the frontal cortex/cerebellum nor the striatum/cerebellum ratio was modified. These data in humans with PET demonstrate that [18F]setoperone labels with high sensitivity and selectivity 5‐HT2 receptors in the frontal cortex; in striata, however, binding is to both 5‐HT2 and D2 receptors. The deproteinated‐to‐whole plasma radioactivity concentration ratio increased with time following injection. The mean percentage of intact [18F]setoperone, in deproteinated plasma, was 82, 74, 53, 45, 30, and 22% at 5, 10, 20, 30, 60, and 110 min following injection, respectively. These data indicate that [18F]setoperone (a) is significantly bound to plasma proteins and (b) is significantly metabolized into several labeled metabolites that are much more hydrophilic than setoperone and, hence, presumably do not cross the blood–brain barrier. These results suggest the suitability of [18F]setoperone data for modeling of 5‐HT2 receptor binding in brain.

Acute Ischemic Strokes Improving During the First 48 Hours of Onset: Predictability, Outcome, and Possible Mechanisms A Comparison With Early Deteriorating Strokes

BACKGROUND AND PURPOSE Our aims were to identify predictors of early neurological improvement in acute ischemic stroke patients, to evaluate its impact on clinical outcome, and to investigate possible mechanisms. METHODS A consecutive series of 152 first-ever ischemic hemispheric stroke patients hospitalized within 5 hours of onset underwent a first CT scan within 1 hour of hospitalization, and the initial subset of 80 patients also underwent angiography. During the first 48 hours of hospital stay, an increase or a decrease of 1 or more points in the admission Canadian Neurological Scale (CNS) score was defined as early improvement or early deterioration, respectively. Repeated CT scan or autopsy was performed 5 to 9 days after stroke. RESULTS Thirty-four patients (22%) improved, 84 (56%) remained stable, and 34 (22%) deteriorated. Logistic regression, which took into account vascular risk factors, baseline clinical and CT data, and therapies administered, selected younger age, lower admission CNS score, and absence of early hypodensity at first CT as independent predictors of early improvement. Among the patients who underwent angiography, logistic regression selected arterial patency and presence of collateral blood supply as independent predictors of early improvement. At the repeated CT scan or autopsy, improving patients presented the highest frequency of small infarcts. Thirty-day case-fatality rate and disability were lower in improving patients. Variables independently associated with outcome at logistic regression were admission CNS score, early deterioration, and early improvement. CONCLUSIONS Early improvement can be predicted by the absence of early CT hypodensity and is highly predictive of good outcome. Presence of collateral blood supply and presumably early spontaneous recanalization are likely to be the mechanisms underlying early improvement.

Relationships Between High Oxygen Extraction Fraction in the Acute Stage and Final Infarction in Reversible Middle Cerebral Artery Occlusion: An Investigation in Anesthetized Baboons with Positron Emission Tomography

Studies in humans suggest that regions that show maximal increases in brain oxygen extraction fraction (OEF) in the hours following an ischemic episode are those most vulnerable for infarction and are often, although not always, associated with the final site of infarction. To clarify this issue, we followed the hemodynamic and metabolic characteristics of regions with an initially maximally increased OEF and compared them with the ultimately infarcted region in an experimental stroke model. Positron emission tomography (PET) was used to obtain functional images of the brain prior to and following reversible unilateral middle cerebral artery occlusion (MCAO) in 11 anesthetized baboons. To model early reperfusion, the clips were removed 6 h after occlusion. Successive measurements of regional CBF (rCBF), regional CMRO2 (rCMRO2), regional cerebral blood volume, and regional OEF (rOEF) were performed during the acute (up to 2 days) and chronic (>15 days) stage. Late magnetic resonance imaging (MRI) scans (coregistered with PET) were obtained to identify infarction. Reversible MCAO produced an MRI-measurable infarction in 6 of 11 baboons; the others had no evidence of ischemic damage. Histological analysis confirmed the results of the MRI investigation but failed to show any evidence of cortical ischemic damage. The lesion was restricted to the head of the caudate nucleus, internal capsule, and putamen. The infarct volume obtained was 0.58 ± 0.31 cm3. The infarcts were situated in the deep MCA territory, while the area of initially maximally increased OEF was within the cortical mantle. The mean absolute rCBF value in the infarct region of interest (ROI) was not significantly lower than in the highest-OEF ROI until 1–2 days post-MCAO. Cerebral metabolism in the deep MCA territory was always significantly lower than that of the cortical mantle; decreases in CMRO2 in the former region were evident as early as 1 h post-MCAO. In the cortical mantle, the rOEF was initially significantly higher than in the infarct-to-be zone. Subsequently, the OEF declined in both regions. The differences in the time course of changes in CMRO2 and OEF between these two regions, with the eventually infarcted area showing earlier metabolic degradation and in turn decline in OEF, presumably underlie their different final outcomes. In conclusion, following MCAO, the region that shows an early maximal increase in the OEF is both topographically and physiologically distinct from the region with final consolidated infarction if reperfusion is allowed at 6 h. This high OEF, although indicative of a threatened condition, is not an indicator of inescapable consolidated infarction and is thus a situation in which therapy could be envisaged. Whether or not it is at risk of infarction and thus constitutes one target for therapy remains to be seen.

Primary headache and multiple sclerosis: preliminary results of a prospective study

The aim of this study was to explore the association between different types of headache (HA) and the clinical features of multiple sclerosis (MS). The relationship between HA and MS-specific therapies was also analysed. A total of 102 MS patients were recruited at the MS Centre of S. Andrea Hospital in Rome. According to International Headache Society criteria, the lifetime prevalence of primary HA was 61.8%. Migraine was observed more often in young relapsing-remitting MS patients, whilst tension-type HA was associated with older age, male gender and a secondary progressive course. Sixty-four patients had a history of ongoing or past interferon beta (IFNb) exposure. Of these, 17 subjects did not have a history of HA, while 24 complained of an increase in frequency of migraine attacks and 7 reported an IFNb-induced HA. Investigating and treating HA in MS patients starting IFNb therapy may improve MS-specific medication compliance.

Computed tomography findings in the first few hours of ischemic stroke: implications for the clinician

In order to evaluate the clinical usefulness of emergency computed tomography (CT) in acute ischemic stroke, we assessed whether CT findings within the first few hours of stroke onset reliably predict type, site and size of the index infarction, and risk of death or disability. For this reason we reviewed clinical and CT findings in a cohort of unselected consecutive patients referred to the stroke unit of a large urban hospital because of a presumed ischemic stroke in the anterior circulation (AC), and submitted to CT within 5 h from onset. Out of 158 total patients, emergency CT revealed parenchymal changes compatible with AC focal ischemia in 77 (49%) and a hyperdense middle cerebral artery (MCA) in 41 (26%). Parenchymal changes and hyperdense MCA predicted an AC territorial infarction respectively in 97% of cases (95% C.I. 93% to 100%) and in 95% of cases (95% C.I. 88% to 100%). Site and size of early changes coincided with those of final lesions in 79% of patients with cortical changes and in 95% of patients with cortico-subcortical changes, but only in 37% of patients with initial subcortical changes, the remainder of whom developed a cortico-subcortical infarction. At logistic regression parenchymal changes were the only independent predictor of an AC territorial infarction. Negative predictive power, however, was only 40% (95% C. I. 29% to 51%) for parenchymal changes, and 35% for hyperdense MCA (95% C.I. 26% to 44%). The odds for death or disability at 1 month associated with parenchymal changes were thrice as high as with negative CT, even after adjustment for clinical severity on admission. These results indicate that CT scan adds significantly to the prediction of outcome made on clinical grounds. The frequent development of a territorial infarction in patients with initially negative CT and the subsequent recruitment of the cortex in those initially exhibiting only subcortical changes suggest that the transition from ischemia to infarction often occurs after the first five h following stroke.

Zonisamide for Migraine Prophylaxis in Topiramate-Intolerant Patients: An Observational Study

(Headache 2011;51:287‐291)

Comparison of frovatriptan plus dexketoprofen (25 mg or 37.5 mg) with frovatriptan alone in the treatment of migraine attacks with or without aura: A randomized study

Background Drugs for migraine attacks include triptans and NSAIDs; their combination could provide greater symptom relief. Methods A total of 314 subjects with history of migraine, with or without aura, were randomized to frovatriptan 2.5 mg alone (Frova), frovatriptan 2.5 mg + dexketoprofen 25 mg (FroDex25) or frovatriptan 2.5 mg + dexketoprofen 37.5 mg (FroDex37.5) and treated at least one migraine attack. This was a multicenter, randomized, double-blind, parallel-group study. The primary end point was the proportion of pain free (PF) at two hours. Secondary end points were PF at one and four hours, pain relief (PR) at one, two, four hours, sustained PF (SPF) at 24 and 48 hours, recurrence at 48 hours, resolution of nausea, photophobia and phonophobia at two and four hours, the use of rescue medication and the judgment of the treatment. Results The results were assessed in the full analysis set (FAS) population, which included all subjects randomized and treated for whom at least one post-dose intensity of headache was recorded. The proportions of subjects PF at two hours (primary end point) were 29% (27/93) with Frova compared with 51% (48/95 FroDex25 and 46/91 FroDex37.5) with each combination therapies (p < 0.05). Proportions of SPF at 24 hours were 24% (22/93) for Frova, 43% (41/95) for FroDex25 (p < 0.001) and 42% (38/91) for FroDex37.5 (p < 0.05). SPF at 48 hours was 23% (21/93) with Frova, 36% (34/95) with FroDex25 and 33% (30/91) with FroDex37.5 (p = NS). Recurrence was similar for Frova (22%, 6/27), FroDex25 (29%, 14/48) and FroDex37.5 (28%, 13/46) (p = NS), meaning a lack of improvement with the combination therapy. Statistical adjustment for multiple comparisons was not performed. No statistically significant differences were reported in the occurrence of total and drug-related adverse events. FroDex25 and FroDex37.5 showed a similar efficacy both for primary and secondary end points. There did not seem to be a dose response curve for the addition of dexketoprofen. Conclusion FroDex improved initial efficacy at two hours compared to Frova whilst maintaining efficacy at 48 hours in this study. Tolerability profiles were comparable. Intrinsic pharmacokinetic properties of the two single drugs contribute to this improved efficacy profile.

The Impact of Interferon Beta and Natalizumab on Comorbid Migraine in Multiple Sclerosis

Background.— Some multiple sclerosis (MS)‐specific therapies may exacerbate a comorbid migraine. Whereas data regarding the impact of interferon beta (IFNB) on this comorbidity have been reported, studies on the role of natalizumab (NTZ) are still lacking.