High-Resolution Vessel Wall Imaging in Primary Angiitis of Central Nervous System

Primary Angiitis of the CNS: Differences in the Profile Between Subtypes and Outcomes From an Indian Cohort

BACKGROUND AND OBJECTIVES

Primary angiitis of the CNS (PACNS) is a rare disease that has significant morbidity and mortality. Subtypes of PACNS can have different presentations that could be missed with certain diagnostic modalities, further increasing diagnostic complexity. We sought to distinguish the subtypes of PACNS and describe their outcomes in an Indian cohort.

METHODS

Adult patients in this retrospective single-center cohort study were reviewed from the PACNS database between 2000 and 2019. Diagnosis was made as per Calabrese and Malleck criteria. Small and medium vessel vasculitis was defined, and their clinical and radiologic profile, treatment, and outcomes were compared. Functional outcomes were noted at 6-month, 1-year, and at last follow-up, while relapses were noted at last follow-up. A poor outcome was defined as modified Rankin Scale >2.

RESULTS

Seventy-two patients fulfilled the inclusion criteria of whom 50 (69.4%) were male. The small vessel vasculitis subtype had a younger age at onset (30.5 vs 40.5 years, p = 0.014), presented less often as a stroke (22% vs 62%, p = 0.001), and had greater delay in diagnosis and treatment initiation (median of 620 days vs 118 days, p = 0.001) compared with medium vessel vasculitis subtype. Although no difference was noted at 6 months, the small vessel vasculitis group had poor outcomes at 1-year and last follow-up (57% vs 20%, p = 0.011 and 72% vs 34%, p = 0.005, respectively) and had more relapses at last follow-up (89% vs 30%, p < 0.001) when compared with the medium vessel vasculitis group. On analyzing the entire cohort, 50 of 72 (69%) and 37 of 53 (69.8%) patients had a good outcome at 6 months and 1 year, respectively. Relapse was noted in 35 of 72 (49%) at final follow-up. The choice of the treatment regimen did not predict outcomes or relapses.

DISCUSSION

The small vessel vasculitis subtype of PACNS is a distinct entity that has diagnostic and treatment delays with poor long-term outcomes and more relapses. Recognizing the different subtypes of PACNS may help to expedite diagnosis and plan treatment.

Imaging of Small Artery Vasculitis

Small artery vasculitis of the CNS is a rare and serious condition characterized by the inflammation of blood vessels within the brain and spinal cord. There are two groups of small artery vasculitis determined by the presence or absence of immunoglobulin complex deposition in the vessel wall. The former includes anti-glomerular basement membrane disease, cryoglobulinemic vasculitis, and IgA vasculitis. Absence of immune complex deposition is associated with anti-neutrophil cytoplasmic antibody (ANCA) and includes microscopic polyangiitis, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and primary angiitis of the CNS. These conditions present a diagnostic challenge in which imaging plays a crucial role.

Neuroimaging Scoring Tools to Differentiate Inflammatory Central Nervous System Small-Vessel Vasculitis: A Need for Artificial Intelligence/Machine Learning?-A Scoping Review

Neuroimaging has a key role in identifying small-vessel vasculitis from common diseases it mimics, such as multiple sclerosis. Oftentimes, a multitude of these conditions present similarly, and thus diagnosis is difficult. To date, there is no standardized method to differentiate between these diseases. This review identifies and presents existing scoring tools that could serve as a starting point for integrating artificial intelligence/machine learning (AI/ML) into the clinical decision-making process for these rare diseases. A scoping literature review of EMBASE and MEDLINE included 114 articles to evaluate what criteria exist to diagnose small-vessel vasculitis and common mimics. This paper presents the existing criteria of small-vessel vasculitis conditions and mimics them to guide the future integration of AI/ML algorithms to aid in diagnosing these conditions, which present similarly and non-specifically.

Vascular and Vasogenic Manifestations of Systemic ANCA-Associated Vasculitis with Renal Involvement in Non-Contrast Brain MRI in Patients with Acute Disease Onset

Background. Data concerning central nervous system (CNS) alterations in ANCA-associated vasculitis with renal involvement (AAVR) are sparse. The study aimed to assess vascular and vasogenic brain alterations in patients with acute onset of AAVR and the applicability of non-contrast magnetic resonance imaging (MRI) techniques in this diagnosis. Methods. Thirty-eight patients with acute onset of AAVR were included in the study. BVAS/WG, c-ANCA, p-ANCA, renal function and perfusion, neurological assessment, and brain MRI were performed. Results. Cerebral vascular alternating narrowing and dilatation (VAND) was detected in 42.1% of patients, and the black-blood was significantly more diagnostic than the TOF technique (p < 0.001). VAND occurrence was independently associated with the concentration of p-ANCA. The vasogenic white matter lesions (VWML) were found in 94.4% of patients, and in their detection, SWAN was significantly better than the FLAIR technique (p = 0.002). The number of VWML correlated with age and cranial nerve damage. Hemosiderin deposits were found in 21.6% of patients and were associated with a gait impairment and paresthesia. Conclusions. Vascular and vasogenic alterations in the CNS are frequent in patients with acute onset of systemic ANCA-associated vasculitis with renal involvement. Non-contrast MRI is useful in the diagnosis of brain vasculitis.

Reversible cerebral vasoconstriction syndrome: review of neuroimaging findings

Reversible cerebral vasoconstriction syndrome (RCVS) is a group of disorders characterized by segmental narrowing and dilatation of medium-to-large cerebral arteries, clinically presenting with recurrent episodes of sudden-onset thunderclap headaches, with or without focal neurological deficits. Cerebral vasoconstriction is typically reversible, with spontaneous resolution within 3 months. Although the syndrome has generally a benign course, patients with neurological deficits may experience worse outcome. The main imaging finding is segmental constriction of intracranial arteries, which can be associated with subarachnoid hemorrhage and/or ischemic foci. Other possible findings are intracranial hemorrhage, subdural bleeding and cerebral edema. The latter may have a pattern which can resemble that of posterior reversible encephalopathy syndrome, a condition that can overlap with RCVS. New imaging techniques, such as vessel wall imaging and arterial spin labeling, are proving useful in RCVS and are giving new insights into the pathophysiology of this condition. In this paper, we aim to review neuroimaging findings of RCVS.