Patient selection: Henoch-Schonlein purpura
Mechanism: small vessel vasculitis, with ischemic infarcts and/or edema and/or hemorrhages
Often there is involvement of the parieto-occipital region.
Clinical features may include:
(1) headache
(2) behavioral changes including irritability
(3) seizure disorder
(4) posterior reversible encephalopathy syndrome (PRES)
(5) peripheral neuropathy or mononeuritis
(6) transient paresis
(7) confusion or decreased level of consciousness
(8) aphasia
(9) visual disturbances including cortical blindness
(10) focal neurologic deficit
(11) subarachnoid hemorrhage
The diagnosis may be helped by the presence of other manifestations (purpura, nephritis, arthralgia, abdominal pain, etc.).