Angitis

Definition

Clinical Features

• Uncommon
• Idiopathic1,2
• Any age
• Usually young or middle-aged adults
• Manifestations include:
  • headache
  • mental status changes
  • focal neurologic deficits:
    • particularly hemiparesis
    • may:
      • evolve in progressive fashion
      • present abruptly as stroke
  • myelopathy:
    • occasionally dominates clinical picture
    • rarely is morphologic evidence of vascular injury accentuated at, or confined to, spinal levels3,4
• If not promptly diagnosed and managed generally progressive and fatal

Pathogenesis

• Might be triggered by diverse offenses to cerebrospinal circulation
• Infectious etiology:
  • long suspected
  • remains unproved
• Epidemiologic association with:
  • cutaneous herpes zoster
  • underlying conditions, chiefly:
    • Hodgkin's disease
    • other forms of hematolymphoid neoplasia, predisposing to viral opportunists1,5
  • intriguing in view of undisputed role of varicella zoster virus as agent of large vessel cerebral arteritis that is potentially indistinguishable from primary CNS angitis

Histopathology

• Considerable variation1
• Most frequently:
  • necrotizing, polyarteritis-like, or non-necrotizing lymphoplasmacytic variants
• Granulomatous examples (Fig. 1
  

  Fig. 1: Primary angitis of the CNS. A frankly granulomatous inflammatory infiltrate replete with multinucleated giant cells expands the wall of this penetrating cerebrocortical blood vessel, found in biopsy material from a 34-year-old man with progressive encephalopathy.

  ) characterized by mural infiltration by:
  • histiocytes:
    • including epithelioid forms
  • multinucleated giant cells:
    • foreign body type
    • Langhans’ type
    • when present:
      • not strictly associated with elastic lamina
      • may lie in any part of vessel wall
• Secondary changes include:
  • thrombosis
  • in longstanding cases:
    • mural scarring
    • exuberant fibrointimal hyperplasia

Diagnosis

• Biopsy:
  • regarded by most as sole means of confirming presumptive clinical diagnosis
  • false-negative sampling common due to segmental distribution
  • small and midsized leptomeningeal and intracortical arteries usually bear brunt of injury
  • neighboring veins often involved
  • may affect but rarely confined to large vessels at base of brain

Other investigations

Differential Diagnosis

• Cerebral vasculitides complicating a variety of systemic disorders1

Management

• Angiographic findings typical of vasculitis considered by some as grounds for institution of corticosteroid or cytotoxic therapy when underlying infection and other systemic processes associated with secondary CNS angitis excluded