Diffusion-perfusion MR evaluation and spectroscopy before and after surgical therapy for intracerebral hemorrhage

Spreading Depolarizations Suppress Hematoma Growth in Hyperacute Intracerebral Hemorrhage in Mice

BACKGROUND

Spreading depolarizations (SDs) occur in all types of brain injury and may be associated with detrimental effects in ischemic stroke and subarachnoid hemorrhage. While rapid hematoma growth during intracerebral hemorrhage triggers SDs, their role in intracerebral hemorrhage is unknown.

METHODS

We used intrinsic optical signal and laser speckle imaging, combined with electrocorticography, to investigate the effects of SD on hematoma growth during the hyperacute phase (0-4 hours) after intracortical collagenase injection in mice. Hematoma expansion, SDs, and cerebral blood flow were simultaneously monitored under normotensive and hypertensive conditions.

RESULTS

Spontaneous SDs erupted from the vicinity of the hematoma during rapid hematoma growth. We found that hematoma growth slowed down by >60% immediately after an SD. This effect was even stronger in hypertensive animals with faster hematoma growth. To establish causation, we exogenously induced SDs (every 30 minutes) at a remote site by topical potassium chloride application and found reduced hematoma growth rate and final hemorrhage volume (18.2±5.8 versus 10.7±4.1 mm3). Analysis of cerebral blood flow using laser speckle flowmetry revealed that suppression of hematoma growth by spontaneous or induced SDs coincided and correlated with the characteristic oligemia in the wake of SD, implicating the vasoconstrictive effect of SD as one potential mechanism of action.

CONCLUSIONS

Our findings reveal that SDs limit hematoma growth during the early hours of intracerebral hemorrhage and decrease final hematoma volume.

Serial Metabolic Evaluation of Perihematomal Tissues in the Intracerebral Hemorrhage Pig Model

Purpose

Perihematomal edema (PHE) occurs in patients with intracerebral hemorrhage (ICH) and is often used as surrogate of secondary brain injury. PHE resolves over time, but little is known about the functional integrity of the tissues that recover from edema. In a pig ICH model, we aimed to assess metabolic integrity of perihematoma tissues by using non-invasive magnetic resonance spectroscopy (MRS).

Materials and Methods

Fourteen male Yorkshire pigs with an average age of 8 weeks were intracerebrally injected with autologous blood to produce ICH. Proton MRS data were obtained at 1, 7, and 14 days after ICH using a whole-body 3.0T MRI system. Point-resolved spectroscopy (PRESS)-localized 2D chemical shift imaging (CSI) was acquired. The concentration of N-Acetylaspartate (NAA), Choline (Cho), and Creatine (Cr) were measured within the area of PHE, tissues adjacent to the injury with no or negligible edema (ATNE), and contralesional brain tissue. A linear mixed model was used to analyze the evolution of metabolites in perihematomal tissues, with p-value < 0.05 indicating statistical significance.

Results

The perihematoma volume gradually decreased from 2.38 ± 1.23 ml to 0.41 ± 0.780 ml (p < 0.001) over 2 weeks. Significant (p < 0.001) reductions in NAA, Cr, and Cho concentrations were found in the PHE and ATNE regions compared to the contralesional hemisphere at day 1 and 7 after ICH. All three metabolites were significantly (p < 0.001) restored in the PHE tissue on day 14, but remained persistently low in the ATNE area, and unaltered in the contralesional voxel.

Conclusion

This study highlights the potential of MRS to probe salvageable tissues within the perihematoma in the sub-acute phase of ICH. Altered metabolites within the PHE and ATNE regions in addition to edema and hematoma volumes were explored as possible markers for tissue recovery. Perihematomal tissue with PHE demonstrated a more reversible injury compared to the tissue adjacent to the injury without edema, suggesting a potentially beneficial role of edema.

Hemorrhagic Cerebellar Abscess

BACKGROUND

Brain abscess represents a significant medical problem, accounting for 1 in every 10,000 U.S. hospital admissions and imposing a mortality of 17%-32%. Treatment success depends on early diagnosis, allowing for prompt intervention before a potentially catastrophic rupture. However, diagnosis can be difficult because currently no magnetic resonance imaging signal characteristics are pathognomonic. The presence of hemorrhage may further complicate the radiographic detection of an abscess, potentially leading to delayed treatment.

CLINICAL PRESENTATION

A 71-year-old man was diagnosed with hemorrhagic cerebellar abscess as a complication of groin abscess after cardiac catheterization. After surgical resection of the cerebellar abscess and culture-based antibiotic treatment, the patient suffered repeat hemorrhages into the abscess cavity, of which he died. We describe his clinical course with emphasis on radiology-based differential diagnosis. We also describe the possible pathogenesis of this rare case, based on review of the literature.

CONCLUSIONS

To our knowledge, this is the first report on recurrent hemorrhages in a cerebellar abscess. Hemorrhagic brain abscess has a complex radiologic appearance, which may delay diagnosis and treatment. A high degree of clinical suspicion is necessary to ensure timely treatment of this potentially lethal lesion.

Minimally invasive surgery for intracerebral haemorrhage

PURPOSE OF REVIEW

Spontaneous intracerebral haemorrhage (ICH) imposes a significant health and economic burden on society. Despite this, ICH remains the only stroke subtype without a definitive treatment. Without a clearly identified and effective treatment for spontaneous ICH, clinical practice varies greatly from aggressive surgery to supportive care alone. This review will discuss the current modalities of treatments for ICH including preliminary experience and investigative efforts to advance the care of these patients.

RECENT FINDINGS

Open surgery (craniotomy), prothrombotic agents and other therapeutic interventions have failed to significantly improve the outcome of these stroke victims. Recently, the Surgical Trial in Intracerebral Haemorrhage (STICH) II assessed the surgical management of patients with superficial intraparenchymal haematomas with negative results. MISTIE II and other trials of minimally invasive surgery (MIS) have shown promise for improving patient outcomes and a phase III trial started in late 2013.

SUMMARY

ICH lacks a definitive primary treatment as well as a therapy targeting surrounding perihematomal oedema and associated secondary damage. An ongoing phase III trial using MIS techniques shows promise for providing treatment for these patients.

Minimally invasive surgery plus recombinant tissue-type plasminogen activator for intracerebral hemorrhage evacuation decreases perihematomal edema

BACKGROUND AND PURPOSE

Perihematomal edema (PHE) can worsen outcomes after intracerebral hemorrhage (ICH). Reports suggest that blood degradation products lead to PHE. We hypothesized that hematoma evacuation will reduce PHE volume and that treatment with recombinant tissue-type plasminogen activator (rt-PA) will not exacerbate it.

METHODS

Minimally invasive surgery and rt-PA in ICH evacuation (MISTIE) phase II tested safety and efficacy of hematoma evacuation after ICH. We conducted a semiautomated, computerized volumetric analysis on computed tomography to assess impact of hematoma removal on PHE and effects of rt-PA on PHE. Volumetric analyses were performed on baseline stability and end of treatment scans.

RESULTS

Seventy-nine surgical and 39 medical patients from minimally invasive surgery and rt-PA in ICH evacuation phase II (MISTIE II) were analyzed. Mean hematoma volume at end of treatment was 19.6±14.5 cm(3) for the surgical cohort and 40.7±13.9 cm(3) for the medical cohort (P<0.001). Edema volume at end of treatment was lower for the surgical cohort: 27.7±13.3 cm(3) than medical cohort: 41.7±14.6 cm(3) (P<0.001). Graded effect of clot removal on PHE was observed when patients with >65%, 20% to 65%, and <20% ICH removed were analyzed (P<0.001). Positive correlation between PHE reduction and percent of ICH removed was identified (ρ=0.658; P<0.001). In the surgical cohort, 69 patients underwent surgical aspiration and rt-PA, whereas 10 underwent surgical aspiration only. Both cohorts achieved similar clot reduction: surgical aspiration and rt-PA, 18.9±14.5 cm(3); and surgical aspiration only, 24.5±14.0 cm(3) (P=0.26). Edema at end of treatment in surgical aspiration and rt-PA was 28.1±13.8 cm(3) and 24.4±8.6 cm(3) in surgical aspiration only (P=0.41).

CONCLUSIONS

Hematoma evacuation is associated with significant reduction in PHE. Furthermore, PHE does not seem to be exacerbated by rt-PA, making such neurotoxic effects unlikely when the drug is delivered to intracranial clot.

Advances in spontaneous intracerebral haemorrhage

OBJECTIVES

  To assess the evidence and available literature on the clinical, pathogenetic, prognostic and therapeutic aspects of intracerebral haemorrhage.

METHODS

  The most important manuscripts and reviews on the subject were considered. Information was collected from Medline, Embase & National Library of Medicine over the last 40 years up to Oct 2011. The bibliographies of relevant articles were searched for additional references. The most up to date and randomised trials were given preference. Clinical guidelines including AHA/ASA, Royal college of Physicians, NICE, Scottish Intercollegiate guidelines and several others were taken into consideration.

FINDINGS

  There are numerous advances in the understanding of the pathogenesis and management, but hardly any change in the overall mortality in the last few decades. There is a poor understanding of the results of surgical trials that has resulted in a large drop in surgical intervention since 2007. INTERPRETATIONS AND IMPLICATIONS:  Advances in neuroimaging and neurophysiology have improved our understanding of the mechanisms of neuronal injury and existence of perihaematomal 'tissue at risk'. Numerous new therapeutic targets have been identified. There is a lot of misunderstanding of the results of the newer surgical trials which need to be clarified. The importance of cerebral amyloid angiopathy and microbleeds in older patients is increasingly recognised. Control of hypertension is the most important public health measure. Stroke units provide the best outcomes for the patients.