Clinical Neuropathological Analysis of 10 Cases of Cerebral Amyloid Angiopathy-Related Cerebral Lobar Hemorrhage

Molecular basis of the association between transcription regulators nuclear respiratory factor 1 and inhibitor of DNA binding protein 3 and the development of microvascular lesions

The prognosis of patients with microvascular lesions remains poor because vascular remodeling eventually obliterates the lumen. Here we have focused our efforts on vessel dysfunction in two different organs, the lung and brain. Despite tremendous progress in understanding the importance of blood vessel integrity, gaps remain in our knowledge of the underlying molecular factors contributing to vessel injury, including microvascular lesions. Most of the ongoing research on these lesions have focused on oxidative stress but have not found major molecular targets for the discovery of new treatment or early diagnosis. Herein, we have focused on elucidating the molecular mechanism(s) based on two new emerging molecules NRF1 and ID3, and how they may contribute to microvascular lesions in the lung and brain. Redox sensitive transcriptional activation of target genes depends on not only NRF1, but the recruitment of co-activators such as ID3 to the target gene promoter. Our review highlights the fact that targeting NRF1 and ID3 could be a promising therapeutic approach as they are major players in influencing cell growth, cell repair, senescence, and apoptotic cell death which contribute to vascular lesions. Knowledge about the molecular biology of these processes will be relevant for future therapeutic approaches to not only PAH but cerebral angiopathy and other vascular disorders. Therapies targeting transcription regulators NRF1 or ID3 have the potential for vascular disease-modification because they will address the root causes such as genomic instability and epigenetic changes in vascular lesions. We hope that our findings will serve as a stimulus for further research towards an effective treatment of microvascular lesions.

Florbetapir Regional Distribution in Cerebral Amyloid Angiopathy and Alzheimer's Disease: A PET Study

Background:

Sporadic cerebral amyloid angiopathy shows progressive amyloid-β deposition in the wall of small arterioles and capillaries of the leptomeninges and cerebral cortex.

Objective:

To investigate whether amyloid load and distribution, assessed by florbetapir positron emission tomography (PET), differs between patients with probable CAA-related intracerebral hemorrhage (CAA-ICH) and mild cognitive impairment due to Alzheimer’s disease (MCI-AD).

Methods:

We assessed [¹⁸F]florbetapir uptake in 15 patients with probable CAA-ICH and 20 patients with MCI-AD patients. Global and regional florbetapir retention were assessed using standard uptake values ratio (SUVr) in region-based and voxel-wise approaches. Visual reading of florbetapir scans was performed for all participants. Group comparisons were performed using univariate and multivariate analysis.

Results:

Global florbetapir retention was lower in patients with CAA-ICH than MCI-AD (median SUVr, 1.33 [1.21–1.41] versus 1.44 [1.35–1.66]; p = 0.032). In the region-based analysis, regional florbetapir distribution was similar between the two groups. There was a trend for an increased occipital/global ratio in CAA-ICH patients compared to MCI-AD (p = 0.060). In the voxel-wise approach, two clusters, one in parietal regions and the other in temporal regions, had higher uptake in MCI-AD relative to CAA patients.

Conclusions:

Patients with CAA-ICH had a lower global florbetapir PET burden than patients with MCI-AD. Relative florbetapir retention in the posterior regions tended to be higher in CAA patients in region-based analysis but was not statistically different between groups. Investigation on differences in amyloid deposits distribution between groups required a fine-grained voxel-wise analysis. In future studies, selective amyloid tracers are needed to differentiate vascular from parenchymal amyloid.

Cerebrovascular pathology in cerebral amyloid angiopathy presenting as intracerebral haemorrhage

Cerebral amyloid angiopathy (CAA) is the second most common cause of non-traumatic intracerebral haemorrhage (ICH) accounting for 12-15% of lobar haemorrhages in the elderly. Definitive diagnosis of CAA requires histological evaluation. We aimed to evaluate the spectrum of cerebrovascular changes in CAA-related ICH. Between 2011 and 2015, biopsy-confirmed cases of CAA were retrieved and clinical, radiological and pathological features were reviewed. The spectrum of vascular alterations was evaluated and amyloid deposition was graded in accordance with the Greenberg and Vonsattel scale. Seven cases of sporadic CAA [5 males and 2 females] were diagnosed, none of whom were suspected to have CAA pre-operatively. Six presented with large intracerebral haematoma (ICH) requiring neurosurgical intervention (age range: 56-70 years) and one had episodic headache and multiple microhaemorrhages requiring a diagnostic brain biopsy (45 years). In the presence of large ICH, vascular amyloid deposits were of moderate to severe grade (grade 4 in 4, grades 2 and 3 in 1 case each) with predominant involvement of medium (200-500 μm) to large (> 500 μm) leptomeningeal vessels. Fibrinoid necrosis was noted in four. Two were hypertensive and on antiplatelet agents. β-Amyloid plaques were detected in two, one of whom had symptomatic dementia. MRI performed in 3 of 6 cases with ICH did not reveal any microhaemorrhages. Amyloid deposits in small (50-200 μm) to medium (200-500 μm) calibre intracortical vessels produced parenchymal microhemorrhages. Histopathological examination of ICH is essential for diagnosing CAA. The vascular calibre rather than grade of amyloid deposits dictates size of the bleed. Presence of co-morbidities such as antiplatelet agents may predispose to haemorrhage.

Biopsy During Minimally Invasive Intracerebral Hemorrhage Clot Evacuation

BACKGROUND

The safety and efficacy of brain parenchyma biopsy during minimally invasive (MIS) intracerebral hemorrhage (ICH) clot evacuation has not been previously reported. The objective of this study was to establish the safety and diagnostic efficacy of brain biopsy during MIS ICH clot evacuation and to validate the modified Boston criteria as a predictor of cerebral amyloid angiopathy (CAA) in this cohort.

METHODS

From October 2016 to March 2018, superficial and perihematomal biopsies were collected for 40 patients undergoing MIS ICH clot evacuation and analyzed by the pathology department to assess for various ICH etiologies. Additionally, the admission magnetic resonance imaging or computed tomography scan of each patient was analyzed and evaluated for the likelihood of a CAA etiology based on the modified Boston criteria. Student t test was used to analyze intergroup differences in continuous variables, and a 2-tailed Fisher exact test was used to determine intergroup differences of categorical variables, with significance set at P < 0.05.

RESULTS

Two of the 40 patients (5%) experienced postoperative rebleed. Four of the 40 patients (10%) had evidence of CAA on biopsy. Patients with CAA on biopsy were older (P = 0.005) and had a higher prevalence of parietal lobe (P = 0.02) and occipital lobe (P = 0.001) hemorrhage. The modified Boston criteria had a sensitivity of 100% (95% confidence interval [CI], 39.6%-100%) and a specificity of 72.2% (95% CI, 54.6%-84.2%) for predicting CAA on biopsy.

CONCLUSIONS

Brain biopsy in MIS ICH clot evacuation is safe and allows for the diagnosis of various ICH etiologies.

Cerebral Arterial Stenosis in Patients with Spontaneous Intracerebral Hemorrhage

OBJECTIVE

Spontaneous intracerebral hemorrhage (ICH) and ischemic stroke share common vascular risk factors such as aging and hypertension. Previous studies suggested that the rate of recurrent ICH and ischemic stroke might be similar after ICH. Presence of cerebral arterial stenosis is a potential risk factor for future ischemic stroke. This study investigated the prevalence and factors associated with cerebral arterial stenosis in Korean patients with spontaneous ICH.

METHODS

A total of 167 patients with spontaneous ICH were enrolled. Intracranial arterial stenosis (ICAS) and extracranial arterial stenosis (ECAS) were assessed by computed tomography angiography. Presence of ICAS was defined if patients had arterial stenosis in at least one intracranial artery. ECAS was assessed in the extracranial carotid artery. More than 50% luminal stenosis was defined as presence of stenosis. Prevalence and factors associated with presence of ICAS and cerebral arterial stenosis (presence of ICAS and/or ECAS) were investigated by multivariable logistic regression analysis.

RESULTS

Thirty-two (19.2%) patients had ICAS, 7.2% had ECAS, and 39 (23.4%) patients had any cerebral arterial stenosis. Frequency of ICAS and ECAS did not differ among ganglionic ICH, lobar ICH, and brainstem ICH. Age was higher in patients with ICAS (67.6±11.8 vs. 58.9±13.6 years p=0.004) and cerebral arterial stenosis (67.9±11.6 vs. 59.3±13.5 years, p<0.001) compared to those without stenosis. Patients with ICAS were older, more frequently had diabetes, had a higher serum glucose level, and had a lower hemoglobin level than those without ICAS. Patients with cerebral arterial stenosis were older, had diabetes and lower hemoglobin level, which was consistent with findings in patients with ICAS. However, patients with cerebral arterial stenosis showed higher prevalence of hypertension and decreased kidney function compared to those without cerebral arterial stenosis. Multivariable logistic regression analyses showed that aging and presence of diabetes independently predicted the presence of ICAS, and aging, diabetes, and hypertension were independently associated with presence of cerebral arterial stenosis.

CONCLUSION

19.2% of patients with spontaneous ICH had ICAS, but the prevalence of ECAS was relatively lower (7.2%) compared with ICAS. Aging and diabetes were independent factors for the presence of ICAS, whereas aging, hypertension, and diabetes were factors for the cerebral arterial stenosis.