A key criterion for the diagnosis of primary angiitis of the central nervous system (PACNS) is exclusion of alternative explanations. The number of conditions to exclude is large, and an error of omission can lead to a misdiagnosis.
Groups in the differential diagnosis of PACNS:
(1) secondary vasculitis due to infectious disease
(2) secondary vasculitis due to autoimmune disease
(3) reversible cerebral vasoconstriction syndromes (RCVS), including BACNS and other vasospastic conditions
(4) miscellaneous vasculopathies
(5) demyelinating disorders
Infectious conditions causing cerebral vasculitis:
(1) Actinomcyes species
(2) Aspergillus
(3) Borrelia burgdorferi (Lyme disease)
(4) Candida albicans
(5) Enterovirus
(6) Falciparum malaria
(7) hepatitis C virus (HCV)
(8) HIV
(9) influenza virus
(10) JC virus
(11) Mycobacterium tuberculosis
(12) Mycoplasma pneumoniae
(13) Parvovirus B19
(14) Rickettsia infection
(15) Streptococcus pneumoniae
(16) Treponema pallidum (syphilis)
(17) Varicella zoster
(18) West Nile virus
Immune conditions associated with cerebral vasculitis
(1) Behcet's syndrome
(2) Churg-Strauss syndrome
(3) Cogan's syndrome
(4) graft vs host disease
(5) Hashimoto's encephalitis
(6) Henoch-Schonlein purpura
(7) hypersensitivity vasculitis
(8) inflammatory bowel disease (IBD)
(9) Juvenile dermatomyositis
(10) Kawasaki's disease
(11) microscopic polyarteritis
(12) paraneoplastic angiitis
(13) polyarteritis nodosa (PAN)
(14) sarcoidosis
(15) Sjogren's syndrome
(16) Systemic Lupus Erythematosus (SLE)
(17) urticarial hypocomplementemia
(18) Wegener's granulomatosis
Vasculopathies:
(1) angiotropic and intravascular lymphoproliferative disorders
(2) arterial fibromuscular dysplasia
(3) cardiac myxoma with emboli
(4) cholesterol atheroembolism
(5) hemoglobiopathy
(6) Moyamoya disease
(7) radiation vasculopathy
(8) small vessel arterial dissection
(9) thrombotic disorders (antiphospholipid syndrome, etc)
Demyelinating disorders:
(1) multiple sclerosis
(2) acute demyelinating encephalomyelitis
Purpose: To identify conditions that need to be excluded before the diagnosis of primary angiitis of the CNS (PACNS) can be made.
Specialty: Immunology/Rheumatology
Objective: differential diagnosis and mimics, red flags
ICD-10: I77.6,