Friday, April 04, 2014

Uveomeningeal syndromes: ABRA (Amyloid beta related angiitis )

Neurology 2013; 81: 1796-7

ABRA is a subtype of PCNSV (primary CNS vasculitis) with a beta pathology, found in about 18 % of biopsies showing vasculitis.  PNSV has an incidence of about 2.4 per million. Presentation is cognitive impairment, +/- seizures, focal deficits, hallucinations, multifocal or confluent T2 white matter confluence and cortical microbleeds. Often CSF protein is elevated and there is a leukocytosis.  This reported case had uveomeningeal findings clinically and on MRI. 

Diagnosis by biopsy aND MAY BE AUTOIMMUNE AND RESPOND TO IMMUNOTHERAPY IN THIS CASE PREDNISONE 60/ DAY AND CELLCEPT  1500 BID RESULTED IN IMPROVEMENT

SEPARATE ARTICLE
Neurology 2013; 81: 1596-1603

ABRA characteristics of patients:  Authors from Mayo compared  78 patients, 40 with CAA (no inflammation) and 28 with granulomatous vasculitis (ABRA) , 10 with CAA related inflammation, and 118 matched patients with PCNSV with AB seen over 25 years. 

ABRA patients were older, had more altered cognition, seizures and spells, gado positive leptomeninges, ICH, and higher CSF protein.  Response to treatment was similar.

CTM v MRI for orthostatic headache with CSF leak

Neurology 2013; 81: 1789-92. 

Authors did MRI's on 12 patients with CTM proven leaks ("gold standard" test).  11/12 had positive MRI of spine with extradural fluid collections (highly sensitive) and 6/12 having spinal dural enhancement (less sensitive).  The dura is seen as a pencil line on sagittal T1 because its displaced by fluid in the dorsal epidural space.  Other signs to be expected are brain sag, pachymeningeal enhancement, posterior fossa crowding and cerebellar tonsillar descent.

Hemosiderin deposition in brain as footprint of high altitude cerebral edema (HACE)

Neurology 2013; 81: 1776-9.

Idea- hemosiderin does not go away so patients who experience HACE have hemosiderin seen in corpus callosum-- specifically splenium-- months or years after initial injury.  37 mountaineers were studied, 8 of whom had had HACE, 11 acute mountain sickness, and 8 high clims without injury.  Unequivocal microhemorrhages were seen in 8 subjects and equivocal ones in 2 others, 1-35 months after climb.  Severe cases had microhemorrhages outside the splenium. 

Recall that HACE is vasogenic edema that is often fatal within 24-48 hours due to brain herniation.  Authors concluded that the sign of the microhemorrhages in the spleium is very specific  and the severity of the disease correlates with the severity of the microhemorrhages. 

Authors further hypothesize that microhemorrhages are a specific finding due to hypoxic insult of the blood brain barrier due to a hydrostatic leak with extravasation of red blood cells, much as occurs in lungs in patients with high altitude pulmonary edema *HAPE).