Adult primary central nervous system vasculitis: an update

PCNSV With Spinal Cord Involvement: A 40-Year Single-Center Study

BACKGROUND

Spinal cord involvement is infrequently reported in primary central nervous system vasculitis (PCNSV). This study describes the clinical findings, therapeutic responses, and outcomes of spinal cord involvement in a large cohort of patients with PCNSV.

METHODS

We retrospectively studied 216 consecutive patients with PCNSV evaluated at the Mayo Clinic from 1983 to 2023. Spinal cord involvement was documented by histological examination or imaging. The clinical, laboratory, radiological, and pathological findings, along with management and outcomes, were compared between patients with and without spinal cord involvement.

RESULTS

Of 216 patients, 10 (4.6%) had spinal cord involvement, with cerebral involvement in 9 cases. One patient (0.5%) had isolated spinal cord vasculitis. Histological evidence of vasculitis was found in all 10, with necrotizing vasculitis in 5 (50%). Magnetic resonance imaging showed thoracic abnormalities in 8 patients, cervical spine involvement in 2, conus medullaris involvement in 3, and cauda equina enhancement in 4. Compared with the 206 patients without spinal cord involvement, those with spinal cord vasculitis were more likely to present with paraparesis/tetraparesis (P<0.001) and necrotizing vasculitis (P=0.01) and less likely with hemiparesis (P=0.006) and granulomatous vasculitis (P=0.03). Patients with spinal cord involvement were more likely to have at least 1 relapse (P<0.001) or more (P<0.001). No differences between the 2 groups were observed regarding long-term remission, therapy response, and high disability scores (modified Rankin Scale score, 4-6) or death at last follow-up. Spinal cord involvement was associated with meningeal enhancement on brain imaging (odds ratio, 10.50) and the presence of lymphoma (odds ratio, 6.49), specifically Hodgkin lymphoma diagnosed simultaneously with PCNSV. Spinal involvement was negatively associated with increasing age (odds ratio, 0.64) and cerebral infarction on imaging (odds ratio, 0.08).

CONCLUSIONS

Spinal cord involvement defines a distinct subset of patients with PCNSV.

Primary central nervous system vasculitis with intracranial aneurysm

BACKGROUND

Unruptured intracranial aneurysms (UIAs) are rarely reported in primary central nervous system vasculitis (PCNSV). In this study we described the clinical findings, response to therapy, and outcomes of UIA in a large cohort of PCNSV patients.

METHODS

We retrospectively studied 216 consecutive patients with PCNSV, selected by predetermined diagnostic criteria, who were seen during a 40-year period. UIAs were identified on cerebral angiography. The clinical, laboratory, radiologic and pathologic findings, management, and outcomes of patients with UIA were described and compared with those without UIA.

RESULTS

12/216 (5.5 %) PCNSV patients had at least one UIA. Two patients underwent biopsies; one yielded negative results, while the other showed necrotizing vasculitis. Eleven patients had evidence of UIA on angiogram at diagnosis. One patient developed an aneurysm during the follow-up associated with a worsening of vasculitic radiological findings. The most common presenting symptom for PCNSV in the setting of UIA was headache (67 %), followed by persistent neurologic deficit or stroke (50 %). Most patients with UIA presented with multiple cerebral infarcts on MRI (67 %), one patient had subarachnoid hemorrhage, and one left parieto-occipital intracerebral hematoma, both unrelated to the aneurysm. Black blood imaging was performed in 4 patients and 2 showed segmental circumferential mural enhancement involving multiple vessels. Two patients had 2 UIAs, while the other 10 had 1. The most frequent UIA location was internal carotid artery (50 %), followed by anterior cerebral artery (21 %). Ten of the UIAs were < 5 mm in diameter, and 3 were 5-7 mm in diameter; the size was not available for one. All UIAs were unchanged in size and configuration during follow-up (median: 18.5 months; range 1-151 months) and no new aneurysms were detected. Compared to the 204 patients with PCNSV without a UIA, no significant clinical differences were observed, except for a reduced disability at last follow-up (p = 0.038).

CONCLUSIONS

UIAs uncommonly occur in PCNSV.

Temporal evolution of primary angiitis of the central nervous system (PACNS) on MRI following immunosuppressant treatment

PURPOSE

To systematically analyse the time course of vessel wall enhancement and associated stenosis in patients with primary angiitis of the central nervous system (PACNS) following immunosuppressive therapy.

MATERIAL AND METHODS

Two neuroradiologists retrospectively analysed MRIs of patients with PACNS seen at the Bern University Hospital and the St. Gallen Cantonal Hospital between 2015 and 2020. MRIs were examined for the presence of vessel wall enhancement, length of vessel wall enhancement (mm), circumferential extent of enhancement (degree) and degree of stenosis (%). Descriptive statistics and measurements of interobserver reliability were obtained. To investigate the temporal profiles of the variables following the commencement of immunosuppressant treatment, four series of Bayesian generalised multi-level models were generated.

RESULTS

A total of 23 patients with 43 affected vessels identified from 209 MRI exams were evaluated (mean follow-up: 715 days, standard deviation ± 487 days), leading to a complete dataset of 402 entries. Vessel wall enhancement and circumferential extent of enhancement decreased for approximately 1 year after the initiation of immunosuppressant therapy. Changes were more pronounced in younger patients. Disappearance of vessel wall enhancement (in at least one vessel) was seen in about half of patients after a median of 172 days interquartile range 113-244, minimum 54 days, maximum 627 days.

CONCLUSIONS

This study evaluated the typical time course of vessel wall enhancement in patients with PACNS. Our results could be a useful reference for radiologists and clinicians interpreting follow-up imaging in patients with PACNS.

CRITICAL RELEVANCE STATEMENT

Routine clinical exams can be interpreted with more confidence when radiologists are aware of the typical temporal evolution of vessel wall enhancement in patients with primary angiitis of the central nervous system after initiation of immunosuppressive therapy.

KEY POINTS

Few data exist for vessel wall imaging of primary angiitis of the central nervous system. Following immunosuppressant therapy, vessel wall enhancement decreases for approximately one year. These results may serve as a reference for radiologists performing follow-up imaging.

The Contribution of Vessel Wall Magnetic Resonance Imaging to the Diagnosis of Primary and Secondary Central Nervous System Vasculitis

BACKGROUND

To describe high-resolution brain vessel wall MRI (VW-MRI) patterns and morphological brain findings in central nervous system (CNS) vasculitis patients.

METHODS

Fourteen patients with confirmed CNS Vasculitis from two tertiary centers underwent VW-MRI using a 3T scanner. The images were reviewed by two neuroradiologists to assess vessel wall enhancement characteristics and locations.

RESULTS

Fourteen patients were included (six females; average age 48 ± 19 years). Diagnoses included primary CNS vasculitis (PCNSV) in six patients and secondary CNS vasculitis (SCNSV) in eight, half of which were infection-related. Thirteen patients showed vessel wall enhancement, which was intense in eleven patients (84.6%) and concentric in twelve (92.3%), affecting the anterior circulation in nine patients (69.2%), posterior in two patients (15.4%), and both circulations in two patients (15.4%). The enhancement patterns were similar across different CNS vasculitis types. DWI changes corresponded with areas of vessel wall enhancement in 77% of patients. Conclusions: CNS vasculitis is often associated with intense, concentric vessel wall enhancement in VW-MRI, especially in the anterior circulation. The consistent presence of DWI alterations in affected territories suggests a possible link to microembolization or hypoperfusion. These imaging findings complement parenchymal brain MRI and MRA/DSA data, potentially increasing the possibility of a clinical diagnosis of CNS vasculitis.

Cerebral Amyloid Angiopathy-Related Inflammation: A Single-Center Experience and a Literature Review

Background: Limited data exist regarding the prevalence of clinical, neuroimaging, and genetic markers among patients diagnosed with Cerebral Amyloid Angiopathy−related inflammation (CAA-ri). We sought to determine these characteristics in patients diagnosed in our center and to summarize available literature published either as single-case reports or small case series (<5 patients). Methods: We reported our single-center experience of patients diagnosed with CAA-ri according to international criteria during a seven-year period (2015−2022), and we abstracted data from 90 previously published cases. Results: Seven patients (43% women, mean age 70 ± 13 years) were diagnosed with CAA-ri in our center. The most common symptom at presentation was focal neurological dysfunction (71%), and the most prevalent radiological finding was the presence of T2/FLAIR white matter hyperintensities (100%). All patients were treated with corticosteroids and had a favorable functional outcome. Among 90 previously published CAA-ri cases (51% women, mean age 70 ± 9 years), focal neurological dysfunction was the most common symptom (76%), followed by a cognitive decline (46%) and headache (34%). The most prevalent neuroimaging findings were cerebral microbleeds (85%), asymmetric T2/FLAIR white matter hyperintensities (81%), and gadolinium-enhancing T1-lesions (37%). Genetic testing for the Apolipoprotein-E gene was available in 27 cases; 59% carried the APOE ε4/ε4 genotype. The majority of the published CAA-ri cases (78%) received corticosteroid monotherapy, while 17 patients (19%) were treated with additional immunosuppressive treatment. Favorable functional outcome following treatment was documented in 70% of patients. Conclusion: Improving the vigilance of clinicians regarding the early recognition and accurate diagnosis of CAA-ri is crucial for swift therapy initiation, which may result in improved functional outcomes.

Primary central nervous system vasculitis - An update on diagnosis, differential diagnosis and treatment

IMPORTANCE

Primary angiitis of the central nervous system (PACNS) is a rare condition which is often misdiagnosed. In order to avoid mistakes in the management, a step by step approach is necessary.

OBSERVATIONS

The most common presenting symptoms of PACNS are encephalopathy-related cognitive and affective abnormalities, headaches and multifocal symptoms associated with recurrent episodes of ischemia or hemorrhage. Seizures and spinal cord lesions may also occur. Diagnostic work up includes MRI, CSF examination, angiography and brain biopsy. Since all reported signs and findings lack specificity, the exclusion of differential diagnoses is essential before immunosuppressive therapy is started. Important differential diagnoses include reversible cerebral vasoconstriction syndrome, cerebral involvement of systemic vasculitides or rheumatic diseases, moyamoya angiopathy and infectious vasculopathies Effective treatment has been reported with glucocorticoids in combination with cyclophosphamide or rituximab; however, randomized clinical trials of PACNS treatment do not exist.

CONCLUSIONS AND RELEVANCE

PACNS is an important but rare differential diagnosis in daily neurological practice. The strict adherence to diagnostic criteria and the avoidance of inappropriate therapies in non-inflammatory vasculopathies and infectious diseases are essential.

Clinical and Imaging Characteristics in Patients with SARS-CoV-2 Infection and Acute Intracranial Hemorrhage

BACKGROUND AND PURPOSE

Intracranial hemorrhage has been observed in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (COVID-19), but the clinical, imaging, and pathophysiological features of intracranial bleeding during COVID-19 infection remain poorly characterized. This study describes clinical and imaging characteristics of patients with COVID-19 infection who presented with intracranial bleeding in a European multicenter cohort.

METHODS

This is a multicenter retrospective, observational case series including 18 consecutive patients with COVID-19 infection and intracranial hemorrhage. Data were collected from February to May 2020 at five designated European special care centers for COVID-19. The diagnosis of COVID-19 was based on laboratory-confirmed diagnosis of SARS-CoV-2. Intracranial bleeding was diagnosed on computed tomography (CT) of the brain within one month of the date of COVID-19 diagnosis. The clinical, laboratory, radiologic, and pathologic findings, therapy and outcomes in COVID-19 patients presenting with intracranial bleeding were analyzed.

RESULTS

Eighteen patients had evidence of acute intracranial bleeding within 11 days (IQR 9-29) of admission. Six patients had parenchymal hemorrhage (33.3%), 11 had subarachnoid hemorrhage (SAH) (61.1%), and one patient had subdural hemorrhage (5.6%). Three patients presented with intraventricular hemorrhage (IVH) (16.7%).

CONCLUSION

This study represents the largest case series of patients with intracranial hemorrhage diagnosed with COVID-19 based on key European countries with geospatial hotspots of SARS-CoV-2. Isolated SAH along the convexity may be a predominant bleeding manifestation and may occur in a late temporal course of severe COVID-19.

Long-term remission, relapses and maintenance therapy in adult primary central nervous system vasculitis: A single-center 35-year experience

OBJECTIVES

To evaluate long-term treatment and outcomes of patients with primary central nervous system vasculitis (PCNSV).

METHODS

In this cohort of 191 consecutive patients with PCNSV seen at Mayo Clinic, Rochester, MN, over 35 years with long-term follow-up we analyzed response to and duration of therapy, frequency of relapses, long-term remission, efficacy of maintenance therapy and initial intravenous glucocorticoid (GC) pulses, survival and degree of disability. We also compared the efficacy of initial IV and oral cyclophosphamide (CYC).

RESULTS

A favorable initial response was observed in 83% of patients treated with prednisone (PDN) alone, 81% of those treated with PDN and CYC and 95% of those initially treated with PDN and an immunosuppressant other than CYC. One or more relapses were observed in 30% of patients, 35% had discontinued therapy by last follow-up, and 21.5% maintained remission for at least 12 months after discontinuing therapy. Maintenance therapy was prescribed in 19% of all patients and 34% of patients initially treated with CYC and PDN. High disability scores (Rankin 4-6) and deaths were less frequently observed in patients receiving maintenance therapy and more frequently in patients with Aβ-related angiitis. Large vessel involvement and cerebral infarction at diagnosis were associated with a poor treatment response. Aspirin use was positively associated with long-term remission and having gadolinium-enhanced cerebral lesions or meninges was negatively associated. A high disability score at last follow-up and higher mortality rate were associated with increasing age, cerebral infarction and cognitive dysfunction at diagnosis. Lymphocytic vasculitis on biopsy was associated with a more benign course with reduced disability and mortality. Patients initially treated with mycophenolate mofetil had better outcomes compared to those treated with CYC and PDN. No therapeutic advantages were observed in the patients initially treated with intravenous GC pulses. Intravenous and oral CYC were equally effective in inducing the remission.

CONCLUSIONS

The majority of patients with PCNSV responded to treatment. We found patient subsets with different outcomes. Mycophenolate mofetil may be an effective alternative to CYC.

Rituximab therapy for primary central nervous system vasculitis: A 6 patient experience and review of the literature

OBJECTIVES

To assess the efficacy and safety of Rituximab (RTX) in adult primary central nervous system vasculitis (PCNSV).

METHODS

We retrospectively assessed the effect of RTX in 6 patients with PCNSV. Five of the 6 were refractory to high dose glucocorticoids (GCs) and/or conventional immunosuppressants (IS). The sixth was newly diagnosed and received RTX in combination with GCs. Clinical evaluation, laboratory tests, and imaging modalities were performed at initial RTX administration and during the follow-up. Treatment response was assessed using the treating physician's global opinion regarding response and the degree of disability using the modified Rankin scale (mRS). We also performed a literature review for previous use of RTX in PCNSV using PubMed, Ovid Medline, and the Cochrane library.

RESULTS

The six patients (3 females) had a median age at diagnosis of 50.5 years (range 17-68 years). All had active disease when RTX was started. In 4 patients, RTX administration was associated with a marked reduction in the number of flares (from 18 before starting RTX to 3 after). One patient, after an initial improvement, had 2 flares when B cells were depleted and he was not able to reduce prednisone below 20 mg/day. A 6th patient had a flare when B cells recovered and retreatment with RTX re-induced and maintained remission. The median mRS score at last visit (median: 2; range 0-4) was lower than that prior to treatment (median 3; range 1-5). The median prednisone daily dose before RTX administration was significantly higher than that at last follow-up (p = .006). In the literature review, we identified 5 papers describing 7 patients treated with RTX. Six patients responded to RTX with clinical and MRI improvement with no reported flares after RTX treatment.

CONCLUSIONS

Our data support a potential role for RTX treatment in selected patients with PCNSV.

Primary central nervous system vasculitis associated with lymphoma

OBJECTIVES

To record the clinical findings, response to therapy, and course of patients with primary CNS vasculitis (PCNSV) associated with lymphoma.

PATIENTS AND METHODS

We reviewed the histories of 936 patients with a diagnosis of any type of vasculitis and lymphoma who were seen at the Mayo Clinic over a 32-year period. Ten patients with both PCNSV and lymphoma were identified. We compared the findings in these 10 patients with those from 158 patients with PCNSV without lymphoma seen over 29 years.

RESULTS

Ten of a total of 168 (5.9%) patients with PCNSV also had a history of lymphoma: 6 with Hodgkin lymphoma (HL) and 4 with non-HL (NHL). A granulomatous vasculitis was found in all 8 patients with cerebral biopsies, accompanied by vascular deposits of β-amyloid peptide in 2. In 7 patients, medical diagnostic workup for PCNSV revealed the lymphoma. Compared to the 158 patients with PCNSV without lymphoma, patients with lymphoma were more frequently male (p = 0.04), had increased gadolinium leptomeningeal enhancement (p = 0.03) at presentation, and had more neurologic disability at last follow-up (p = 0.01). No significant differences in treatment response were observed in the 2 groups (p = 0.202). Considering all 168 patients, increased disability at last follow-up was associated with increasing age at diagnosis (odds ratio [OR] 1.4), lymphoma (OR 5.9), and cerebral infarction (OR 3.2), while reduced disability was associated with gadolinium-enhanced lesions (OR 0.43) and amyloid angiopathy (OR O.23).

CONCLUSIONS

Lymphoma may be diagnosed simultaneously with PCNSV, suggesting an immunologic paraneoplastic mechanism.

New onset refractory status epilepticus due to primary angiitis of the central nervous system

Primary Angiitis of the central nervous system is a rare and poorly understood variant of vasculitis. We narrate a case of a 46-year-old male who presented with new onset refractory status epilepticus mimicking autoimmune encephalitis. In this case we are reporting clues that could be useful for diagnosis and extensive literature review on the topic.

Subtypes of primary angiitis of the CNS identified by MRI patterns reflect the size of affected vessels

OBJECTIVE

To describe patterns of diagnostic findings, and identify subgroups of primary angiitis of the central nervous system (PACNS).

METHODS

We retrospectively analysed 31 patients with PACNS. Cases were selected by predetermined diagnostic criteria and stratified into biopsy-proven and imaging-based PACNS. We compared clinical characteristics, cerebrospinal fluid (CSF) findings and imaging results including high-resolution vessel wall MRI between groups.

RESULTS

There were 31 cases of PACNS (mean age 45.6 years, 58.1% female), of whom 17 (55%) were biopsy-proven, 14 (45%) were based on imaging findings. Patients with a positive biopsy had fewer infarcts (29.4% vs 85.7%, p=0.003), were more likely to have meningeal and parenchymal contrast enhancement (76.5% vs 28.6%, p=0.012), were less likely to have abnormal MR angiography (11.8% vs 100%, p<0.001) and did not show vessel wall enhancement at the time of diagnosis (0% vs 76.9%, p<0.001). In contrast, patients with imaging-based diagnosis showed more frequently multiple infarcts and vessel abnormalities, with vessel wall enhancement in most of the cases. Clinical characteristics and CSF analysis did not reveal marked differences between groups.

INTERPRETATION

Multi-parametric MRI distinguishes two subtypes of PACNS that most likely differ concerning the affected vessel size. Biopsy-proven PACNS primarily involves smaller vessels beyond the resolution of vascular imaging, while imaging-based PACNS affects predominantly medium-sized vessels leading to false-negative biopsy results. Using distinct MRI patterns may be helpful for selecting patients for appropriate invasive diagnostic modalities.

Role of magnetic resonance imaging in the diagnosis of primary central nervous system angiitis

The present study reported on the use of magnetic resonance imaging (MRI) in the diagnosis of primary angiitis of the central nervous system (PACNS). A total of 19 consecutive patients with a clinical diagnosis of PACNS confirmed by clinical follow-up were enrolled in the present study. All patients underwent unenhanced and enhanced MRI prior to and after steroids or steroids plus immunosuppressive therapy. At baseline, all patients showed lesions on MRI in the grey and white matter. Lesions presented as slightly hypointense on T1-weighted images (T1WI), slightly hyperintense on T2WI, hyperintense on fluid-attenuated inversion recovery, iso- or slightly hyperintense on diffusion-weighted images (DWI) and hyperintense on apparent diffusion coefficient (ADC) mapping. After contrast injection, the lesions showed patchy, cord-like or goral enhancement. Seven cases had unilateral lesions and the other 12 cases had bilateral lesions. On all sequences, indistinct margins characterised most of the lesions, and certain lesions were oedematous. Treatment with steroids or steroids plus immunosuppressive agents resulted in improvement or disappearance of symptoms, and seventeen patients had evidently improved according to MRI. In conclusion, PACNS has unique characteristics on MRI; DWI, ADC mapping and enhanced images are of great importance for the diagnosis and clinical management of early-stage PACNS.

Primary angiitis of the central nervous system in adults and children

Primary angiitis of the central nervous system (PACNS) is a rare disease, although it is increasingly recognized both in adults and children. Little is known about pathogenesis, but efforts at classification into subtypes are being made, and the distinction of PACNS from reversible cerebral vasoconstriction syndrome has been a major advance. The prognosis for improvement, or at least stabilization, of neurologic function is good with prompt and aggressive treatment, but the diagnosis continues to be challenging. Refinement of treatment strategies is needed. Multicenter collaboration may be crucial to make additional progress via randomized trials.

[A case of amyloid-β-related cerebral angiitis with ApoE ε4/ε2 genotype]

A 53-year-old male with a past medical history of hypertension and bipolar disorder gradually developed gait disturbance and cognitive dysfunction over half a year. His cranial MRI showed an area of hyperintensity in the right occipital lobe on T2 weighted images and the surface of the lesion was enhanced along the sulci. We diagnosed his condition as amyloid-β-related angiitis (ABRA) based on brain biopsy. Repeated, frequent seizures resistant to several antiepileptic drugs (AEDs) occurred after the operation. Steroid therapy was effective and the symptoms, including the intractable seizures and MRI abnormalities dramatically improved. In contrast to the common wild type ε3/ε3 ApoE genotype, a majority of ABRA patients have ε4/ε4. However, in this case the rare ε4/ε2 type was detected. The ε4 allele is considered to promote Aβ deposition on the vessel wall, and ε2 is speculated to trigger vessel ruptures or vascular inflammation. Although seizure is not a common complication of brain biopsy, it occurred repeatedly and responded poorly to AEDs in this case. Surgical stress in this patient with ε2 probably induced the uncontrolled seizures. ApoE genotype may be an effective and low-invasive marker in case of suspected ABRA and in predicting the risks of the complication from brain biopsy.

An update of the Mayo Clinic cohort of patients with adult primary central nervous system vasculitis: description of 163 patients

Primary central nervous system vasculitis (PCNSV) is an uncommon condition in which lesions are limited to vessels of the brain and spinal cord. Because the clinical manifestations are not specific, the diagnosis is often difficult, and permanent disability and death are frequent outcomes. This study is based on a cohort of 163 consecutive patients with PCNSV who were examined at the Mayo Clinic over a 29-year period from 1983 to 2011. The aim of the study was to define the characteristics of these patients, which represents the largest series in adults reported to date. A total of 105 patients were diagnosed by angiographic findings and 58 by biopsy results. The patients diagnosed by biopsy more frequently had at presentation cognitive dysfunction, greater cerebrospinal fluid total protein concentrations, less frequent cerebral infarcts, and more frequent leptomeningeal gadolinium-enhanced lesions on magnetic resonance imaging (MRI), along with less mortality and disability at last follow-up. The patients diagnosed by angiograms more frequently had at presentation hemiparesis or a persistent neurologic deficit or stroke, more frequent infarcts on MRI and an increased mortality. These differences were mainly related to the different size of the vessels involved in the 2 groups. Although most patients responded to therapy with glucocorticoids alone or in conjunction with cyclophosphamide and tended to improve during the follow-up period, an overall increased mortality rate was observed. Relapses occurred in one-quarter of the patients and were less frequent in patients treated with prednisone and cyclophosphamide compared with those treated with prednisone alone. The mortality rate and degree of disability at last follow-up were greater in those with increasing age, cerebral infarctions on MRI, angiographic large vessel involvement, and diagnosis made by angiography alone, but were lower in those with gadolinium-enhanced lesions on MRI and in those with cerebral amyloid angiopathy. The annual incidence rate of PCNSV was estimated at 2.4 cases per 1,000,000 person-years. PCNSV appears to consist of several subsets defined by the size of the vessels involved, the clinical characteristics at presentation, MRI findings, and histopathological patterns on biopsy. Early recognition and treatment may reduce poor outcomes.

Immune activation in amyloid-β-related angiitis correlates with decreased parenchymal amyloid-β plaque load

BACKGROUND

Primary angiitis of the central nervous system (PACNS) is a rare but serious condition. A fraction of patients suffering from PACNS concurrently exhibit pronounced cerebral amyloid angiopathy (CAA) which is characterized by deposits of amyloid-β (Aβ) in and around the walls of small and medium-sized arteries of the brain. PACNS with CAA has been identified as a distinct disease entity, termed Aβ-related angiitis (ABRA). Evidence points to an immune reaction to vessel wall Aβ as the trigger of vasculitis.

OBJECTIVE

To investigate whether the inflammatory response to Aβ has (1) any effect on the status of immune activation in the brain parenchyma and (2) leads to clearance of Aβ from brain parenchyma.

METHODS

We studied immune activation and Aβ load by quantitative immunohistochemical analysis in brain parenchyma adjacent to affected vessels in 11 ABRA patients and 10 matched CAA controls.

RESULTS

ABRA patients showed significantly increased immune activation and decreased Aβ loads in the brain parenchyma adjacent to affected vessels.

CONCLUSION

Our results are in line with the hypothesis of ABRA being the result of an excessive immune response to Aβ and show that this can lead to enhanced clearance of Aβ from the brain parenchyma by immune-mediated mechanisms.

Role of imaging in the diagnosis of large and medium-sized vessel vasculitis

In large-vessel vasculitis, imaging studies are useful to document temporal artery involvement and crucial to show large-vessel involvement. Color Doppler sonography, magnetic resonance, and computed tomography show early vasculitic lesions. Angiography delineates later vascular complications well. Color Doppler sonography, magnetic resonance angiography, and computed tomography angiography can also be used to show vascular luminal changes. Positron emission tomography is very sensitive in detecting large-vessel inflammation. Imaging procedures can also be used to monitor the course of large-vessel vasculitis. In medium-vessel vasculitis, imaging studies can be used to show both vascular changes and internal organ changes.

[Neurological manifestations of vasculitis and primary central nervous system vasculitis]

Neurologic complications of vasculitis occur frequently in the form of either peripheral neuropathy or manifestations within the central nervous system (CNS). Primary vasculitis of the CNS is characterized by central nervous system manifestations only with no evidence of systemic disease manifestations. Large vessel vasculitis is particularly associated with central nervous system complications, such as ischemic cerebral infarcts whereas medium size, e.g. polyarteritis nodosa and small vessel vasculitis, e.g. antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis manifest with peripheral neuropathies and central nervous system complications. The same also holds true for Behçet's disease which affects both large, medium and small sized arteries and veins. Due to the severity of nervous system manifestations a highly potent immunosuppressive therapy (e.g. cyclophosphamide and glucocorticoids) is usually required for remission induction. Virus-associated vasculitis (e.g. hepatitis C-associated cryoglobulinemic vasculitis) should receive antiviral therapy as first line treatment. Chronic damage is frequent in spite of swift initiation of immunosuppressive treatment.

Delayed Positivization of Cerebral Angiography in Reversible Cerebral Vasoconstriction Syndrome (RCVS) Presenting with Recurrent Subarachnoid Haemorrhage

Benign angiopathy of the central nervous system is a clinical syndrome with evidence of reversible cerebral vasoconstriction (RCVS). Haemorrhagic stroke, either subarachnoid or intracerebral is an unusual presentation of RCVS. We describe a case of RCVS presenting with a subarachnoid haemorrhage (SAH), with rebleeding and onset of hydrocephalus during the first week, and, notably, delayed evidence of typical angiographic features after two negative prior exams. Normalization of the angiographic vasculitic-like lesions was documented at month +6. Repeated cerebral angiograms are mandatory to exclude this kind of disease, and the uncommon presentation of this case reinforces this concept.

Reversible cerebral vasoconstriction syndrome: an important cause of acute severe headache

Reversible cerebral vasoconstriction syndrome (RCVS) is an increasingly recognized and important cause of acute headache. The majority of these patients develop potentially serious neurological complications. Rigorous investigation is required to exclude other significant differential diagnoses. Differentiating RCVS from subarachnoid haemorrhage (SAH) and primary angiitis of the central nervous system (PACNS) may be difficult but has important therapeutic implications. This paper describes what is currently known about the epidemiology, pathophysiology, clinical, and diagnostic features of the syndrome, an approach to investigation, a summary of treatments, and what is known of prognosis.

Primary central nervous system vasculitis: pathology and mechanisms

Primary vasculitis of the central nervous system (PCNSV) is a rare and diagnostically challenging form of vasculitis limited to the brain and/or spinal cord. It is a complex and often severe disease with multifaceted clinical and pathological appearances, suggesting multiple disease subtypes and the potential existence of multiple etiologic pathways. We describe in detail the clinical, imaging, and neuropathological findings of PCNSV summarizing literature data and our observations from a cohort of 131 patients diagnosed at Mayo Clinic over a 25-year period (1983-2007). Unlike systemic vasculitis, little is known regarding PCNSV pathogenesis and the involved immunological mechanisms. Increased recognition of the disease spectrum and in-depth characterization of its histopathologic and immunological phenotype will be critical to eventually understanding the underlying derangements and mechanisms driving PCNSV. Improved understanding of the pathogenetic mechanisms of the disease may also help determine whether the different histologic patterns and clinical subsets represent more than one disease and ultimately may permit development of novel diagnostic and therapeutic strategies for it.