Letter by de Boysson and Pagnoux Regarding Article, “Diagnostic Yield and Safety of Brain Biopsy for Suspected Primary Central Nervous System Angiitis”

Diagnosis and management of adult primary angiitis of the central nervous system: an international survey on current practices

BACKGROUND

Primary angiitis of the central nervous system (PACNS) is a rare disease, for which no validated guidelines exist. We report the findings of a survey on the clinical practice of physicians who manage adults with PACNS.

METHODS

An online survey was distributed through neurology, internal medicine, and rheumatology societies in Canada and Europe. Participants who were directly involved as treating physicians for at least two adult patients with PACNS were eligible for the survey.

RESULTS

Ninety-six physicians completed the survey. Most participants were neurologists (n = 38, 40%), internists (n = 34, 35%) or rheumatologists (n = 22, 23%). Participants obtained a CNS biopsy in a median of 25% (IQR: 5-50%) of suspected PACNS cases. When determining the degree to which eight scenarios justified a CNS biopsy, participants achieved fair inter-rater agreement (Gwet's AC₂ 0.30, 95% CI 0.23-0.41). For induction therapy, 81 (84%) participants reported using glucocorticoids and cyclophosphamide in > 50% of patients. After obtaining remission, 85 (89%) participants systematically introduced or maintained immunosuppressive therapy. Glucocorticoids were prescribed for a median of 12 months. Maintenance therapy with another immunosuppressant was continued for a median of 24 months. In patients who achieved remission, we explored how eight scenarios with different imaging and CSF results supported an increase in treatment. Inter-rater agreement was substantial if the patient was symptomatic (0.66, 95% CI 0.58-0.80) and moderate (0.50, 95% CI 0.45-0.60) if asymptomatic.

CONCLUSION

This survey illustrates current real-world management of PACNS and emphasizes several areas for which physicians still lack study-based evidence and/or clinical practice guidelines.

Adult and childhood vasculitis

Vasculitis refers to heterogeneous clinicopathologic disorders that share the histopathology of inflammation of blood vessels. Unrecognized and therefore untreated, vasculitis of the nervous system leads to pervasive injury and disability, making this a disorder of paramount importance to all clinicians. There has been remarkable progress in the pathogenesis, diagnosis, and treatment of primary CNS and PNS vasculitides, predicated on achievement in primary systemic forms. Primary neurological vasculitides can be diagnosed with assurance after intensive evaluation that incudes tissue confirmation whenever possible. Clinicians must choose from among the available immune modulating, suppressive, and targeted immunotherapies to induce and maintain remission status and prevent relapse, unfortunately without the benefit of RCTs, and tempered by the recognition of anticipated medication side effects. It may be said that efforts to define a disease are attempts to understand the very concept of the disease. This has been especially evident in systemic and neurological disorders associated with vasculitis. For the past 100 years, since the first description of granulomatous angiitis of the brain, the CNS vasculitides have captured the attention of generations of clinical investigators around the globe to reach a better understanding of vasculitides involving the central and peripheral nervous system. Since that time it has become increasingly evident that this will necessitate an international collaborative effort.

[Primary central nervous system vasculitis]

Primary vasculitis (angiitis) of the central nervous system (PACNS) is a rare disease targeting the vessels of the brain, spinal cord and leptomeninges without systemic involvement. The etiology is not clear enough. The authors review clinical, laboratory and radiological features of PACNS. Clinical manifestations are variable and depend on the caliber of affected vessels. The main clinical manifestations of small sized vessel vasculitis include encephalopathy (cognitive disorders, epileptic seizures), headache and transient cerebral ischemia. The main clinical presentation of vasculitis of medium/large cerebral arteries is ischemic strokes, which usually develop in different vascular territories. CSF findings in the majority of patients show modest lymphocytic pleocytosis, elevated protein level and occasionally the presence of oligoclonal bands. MRI data are not specific and include infarcts, hyperintensity (FLAIR) and sometimes tumor-like lesions. The gold standard for the verification of PACNS affected small-sized arteries is brain and leptomeningeal biopsy. Cerebral angiography allows the verification of vasculitis of medium and large cerebral arteries revealing segmental narrowings (beading). High resolution black blood MRI before and after contrast injection may visualize intracranial vessel wall contrast enhancement - the sign of inflammation in intracranial arteries. Treatment of PACNS includes corticosteroids and cyclophosphamide. In the case of patient intolerance, rituximab and blockers of tumor necrosis factor may be used.

Primary angiitis of the CNS and reversible cerebral vasoconstriction syndrome

Objectives

To further improve the distinction between primary angiitis of the CNS (PACNS) and reversible cerebral vasoconstriction syndrome (RCVS).

Methods

We compared 2 large French cohorts of patients with PACNS (n = 110, retrospectively and prospectively enrolled) and RCVS (n = 173, prospectively enrolled).

Results

Patients with RCVS were predominantly female (p < 0.0001), with migraines (p < 0.0001), and were more often exposed to vasoactive substances (p < 0.0001) or postpartum (p = 0.002) than patients with PACNS. Headache, especially thunderclap headache, was more frequent in RCVS (both p < 0.0001). Thunderclap headache was absent in only 6% of patients with RCVS and was mainly recurrent (87%) and provoked (77%) mostly by sexual intercourse, exertion, or emotion. All other neurologic symptoms (motor deficit, seizure, cognitive disorder, or vigilance impairment, all p < 0.0001) were more frequent in PACNS. At admission, brain CT or MRI was abnormal in all patients with PACNS and in 31% of patients with RCVS (p < 0.0001). Acute ischemic stroke was more frequent in PACNS than in RCVS (p < 0.0001). Although intracerebral hemorrhage was more frequent in PACNS (p = 0.006), subarachnoid hemorrhage and vasogenic edema predominated in RCVS (p = 0.04 and p = 0.01, respectively). Multiple small deep infarcts, extensive deep white matter lesions, tumor-like lesions, or multiple gadolinium-enhanced lesions were observed only in PACNS, whereas cervical artery dissection was found only in RCVS.

Conclusions

Our study confirms that careful analysis of clinical context, headache features, and patterns of brain lesions can distinguish PACNS and RCVS within the first few days of admission in most cases. However, diagnosis remains challenging in a few cases.

Maintenance therapy is associated with better long-term outcomes in adult patients with primary angiitis of the central nervous system

Objective

We aimed to analyse the effect of maintenance therapy after induction on the outcomes of adult patients with primary angiitis of the CNS (PACNS).

Methods

We analysed long-term outcomes (relapse, survival and functional status) of patients enrolled in the French multicentre PACNS cohort who achieved remission after induction treatment and with ⩾12 months' follow-up, according to whether or not they received maintenance therapy. Good outcome was defined as relapse-free survival and good functional status (modified Rankin scale ⩽ 2) at last follow-up.

Results

Ninety-seven patients [46 (47%) female, median age: 46 (18-78) years at diagnosis] were followed up for a median of 55 (5-198) months. Induction treatment consisted of glucocorticoids in 95 (98%) patients, combined with an immunosuppressant in 80 (83%) patients, mostly CYC. Maintenance therapy was prescribed in 48 (49%) patients, following CYC in 42 of them. Maintenance therapy was started 4 (3-18) months after glucocorticoid initiation. At last follow-up, good outcomes were observed in 32 (67%) patients who had received maintenance therapy vs 10 (20%) who had not (P < 0.0001). Thirty-two (33%) patients experienced relapse [10 (22%) had received maintenance therapy while 22 (45%) had not, P = 0.01]; four subsequently died from relapse. In the multivariate analysis, maintenance therapy was the only independent predictor of good outcome [odds ratio (OR) = 7.8 (95% CI: 3.21, 20.36), P < 0.0001].

Conclusion

The results of this long-term follow-up study suggest that maintenance therapy in adults with PACNS is associated with better functional outcomes and lower relapse rates. Further studies are needed to confirm these findings.