The prevalence of radiological cerebral amyloid angiopathy-related inflammation in patients with cerebral amyloid angiopathy

OBJECTIVES

Cerebral amyloid angiopathy (CAA) related inflammation (CAA-RI) is an autoimmune inflammatory condition occurring in patients with CAA. We aimed to determine the prevalence of radiological CAA-RI amongst patients with CAA and to describe their presenting clinical features.

METHODS

We performed a retrospective review of electronic medical records across multiple centers within a single healthcare network. Patients who met radiological modified Boston 2.0 criteria for CAA and had white matter hyperintensity (WMH) were included. Scans were analyzed by a vascular neurologist and confirmed by a neuroradiologist blinded to clinical information for meeting criteria for possible or probable radiographic CAA-RI.

RESULTS

Out of 1100 patients reviewed, 511 patients met radiological modified Boston criteria for CAA and 193 patients had WMH on MRI. A total of 55 (28.5 % of those with CAA and WMH, and 10.8 % of all CAA with or without WMH) patients had MRI brain imaging suggestive of possible or probable radiographic CAA-RI. The diagnosis of CAA-RI was reported in only 10 (18.2 %) patients initially while 20 (36.4 %) were diagnosed up to 74 months later (median 0, IQR 0-9 months). At the time of earliest probable CAA-RI findings on imaging, the most common concurrent findings were cognitive impairment (74.5 %), macro-hemorrhages (52.7 %), headache (30.9 %), seizures (14.5 %), and ischemic infarcts (14.5 %). Only 18 (32.7 %) patients were treated with immunosuppression.

CONCLUSIONS

The prevalence of radiographic CAA-RI was high, and most cases were unrecognized and untreated. Further studies are needed to assess if earlier detection and treatment of radiologic CAA-RI may halt disease progression and prevent cognitive decline in these patients.

Vessel wall MR imaging of aortic arch, cervical carotid and intracranial arteries in patients with embolic stroke of undetermined source: A narrative review

Despite advancements in multi-modal imaging techniques, a substantial portion of ischemic stroke patients today remain without a diagnosed etiology after conventional workup. Based on existing diagnostic criteria, these ischemic stroke patients are subcategorized into having cryptogenic stroke (CS) or embolic stroke of undetermined source (ESUS). There is growing evidence that in these patients, non-cardiogenic embolic sources, in particular non-stenosing atherosclerotic plaque, may have significant contributory roles in their ischemic strokes. Recent advancements in vessel wall MRI (VW-MRI) have enabled imaging of vessel walls beyond the degree of luminal stenosis, and allows further characterization of atherosclerotic plaque components. Using this imaging technique, we are able to identify potential imaging biomarkers of vulnerable atherosclerotic plaques such as intraplaque hemorrhage, lipid rich necrotic core, and thin or ruptured fibrous caps. This review focuses on the existing evidence on the advantages of utilizing VW-MRI in ischemic stroke patients to identify culprit plaques in key anatomical areas, namely the cervical carotid arteries, intracranial arteries, and the aortic arch. For each anatomical area, the literature on potential imaging biomarkers of vulnerable plaques on VW-MRI as well as the VW-MRI literature in ESUS and CS patients are reviewed. Future directions on further elucidating ESUS and CS by the use of VW-MRI as well as exciting emerging techniques are reviewed.

Case Report of Spinal Cord Involvement in Susac Syndrome Masquerading as a Multiple Sclerosis Mimic

We present a unique case of a 59-year-old woman with atypical Susac syndrome and prominent involvement of the spinal cord. She initially presented with progressive headaches, lower extremity weakness and hearing loss. Her MRI brain showed multiple enhancing lesions and her MRI spine showed a T8 enhancing lesion as well as a C2 cord infarct. She was treated with IV methylprednisolone with initial stabilization. However, she developed worsening encephalopathy and lower extremity weakness. Her repeat MRI brain showed new bilateral enhancing lesions and subacute infarcts. Given the increased burden of new lesions, she underwent a brain biopsy, which showed perivascular chronic inflammation within a small vessel distribution. Additionally, fluorescein angiography revealed bilateral branch retinal arterial occlusion (BRAO) and an audiogram demonstrated bilateral sensorineural hearing loss. She was diagnosed with Susac syndrome and treated with IV cyclophosphamide with improvement in her clinical exam. Spinal cord involvement is extremely rare for Susac syndrome, which commonly manifests as the classic triad of encephalopathy, BRAO and hearing loss. Her presentation with myelopathy highlights the importance of considering atypical presentations of well-established syndromes for optimal diagnosis and management.

Callosal Diffusion-Restriction in Patients with Intracranial Hemorrhage

OBJECTIVE

We aim to report the incidence and clinical characteristics of patients who were found to have diffusion restricting lesions of the corpus callosum (CC) on Diffusion-weighted imaging (DWI) on magnetic resonance imaging (MRI) following intracranial hemorrhage (ICH).

DESIGN/METHODS

A retrospective cross-sectional analysis was performed of medical records of all adult patients admitted to a single tertiary center with a primary diagnosis of ICH and received nicardipine infusion over a 2-year period. Patients without MRI brain available or patients who underwent digital subtraction angiography (DSA) prior to MRI were excluded. ICH and intraventricular hemorrhage (IVH) volumes and scores were calculated. MRI brain scans were evaluated for presence and locations of DWI lesions.

RESULTS

Among 162 patients who met inclusion criteria, 6 patients (4%, median age 53, range 37-71, 100% male, 33% white) were found to have DWI lesions in the CC with a median ICH volume of 17ml (range 1-105ml). The ICH locations were lobar (n=3), deep (n=2) and cerebellum (n=1). All patients (100%) had intraventricular hemorrhage (IVH) with median IVH volume of 25ml (range 2.7-55ml). Four patients were on levetiracetam. No identifiable infections or metabolic abnormalities were found among these patients. All but one patient had normal DSA. Follow up MRI was only available in one patient and showed no reversibility at 14 days.

CONCLUSION

Although rare, diffusion restricting corpus callosum lesions can be seen in patients with ICH, especially in patients with IVH. The etiology and clinical significance of these lesions remains unknown and warrant further research.

Opportunities for intervention: stroke treatments, disability and mortality in urban Tanzania

OBJECTIVE

Given the high post-stroke mortality and disability and paucity of data on the quality of stroke care in Sub-Saharan Africa, we sought to characterize the implementation of stroke-focused treatments and 90-day outcomes of neuroimaging-confirmed stroke patients at the largest referral hospital in Tanzania.

DESIGN

Prospective cohort study.

SETTING

Muhimbili National Hospital (MNH) in Dar es Salaam, July 2016-March 2017.

PARTICIPANTS

Adults with new-onset stroke (<14 days), confirmed by head CT, admitted to MNH.

MAIN OUTCOMES MEASURES

Modified Rankin scale (mRS) and vital status.

RESULTS

Of 149 subjects (mean age 57; 48% female; median NIH stroke scale (NIHSS) 19; 46% ischemic stroke; 54% hemorrhagic), implementation of treatments included: dysphagia screening (80%), deep venous thrombosis prophylaxis (0%), aspirin (83%), antihypertensives (89%) and statins (95%). There was limited ability to detect atrial fibrillation and carotid artery disease and no acute thrombolysis or thrombectomy. Of ischemic subjects, 19% died and 56% had severe disability (mRS 4-5) at discharge; 49% died by 90 days. Of hemorrhagic subjects, 33% died and 49% had severe disability at discharge; 50% died by 90 days. In a multivariable model, higher NIHSS score but not dysphagia, unconsciousness, or patient age was predictive of death by 90 days.

CONCLUSIONS

The 90-day mortality of stroke presenting at MNH is 50%, much higher than in higher income settings. Although severe stroke presentations are a major factor, efforts to improve the quality of care and prevent complications of stroke are urgently needed. Acute stroke interventions with low number needed to treat represent challenging long-term goals.

Peripheral Neuropathies in Infectious Diseases

Peripheral nerve disorders may be the presenting manifestation of a systemic infection, and early recognition of these syndromes is essential for prompt diagnosis and treatment. Mechanisms associated with infectious disorders of the peripheral nerve are often complex and multiple, with secondary inflammation, direct infectious invasion of nerves, and toxicities of antimicrobial medications playing a role. Here, we provide a complete review of the most common infectious pathogens that can affect the peripheral nerves.