Features of microscopic polyangitis

Cited text from Nadeau's

Clinical Neurology chapter from 2000:
This recently recognized variant of PAN52 is defined by inflammation that is largely confined to smaller vessels than in PAN - arterioles, capillaries and postcapillary venules. Angiograms are correspondingly normal. Major organ infarction is rare, glomerulonephritis is universal, and there is a high frequency of pulmonary hemorrhage. MPA is considerably more common than classic PAN and it is a considerably more common cause of a pulmonary-renal syndrome than Goodpasture's syndrome. A forme-fruste of MPA is characterized exclusively by glomerulonephritis. Evidence of hepatitis B infection is usually absent. In contrast to classic PAN as well as such small vessel vasculitides as cryoglobulinemic vasculitis and Henoch-Schönlein purpura, there is little or no evidence of immune deposits. Fifty to 80% of patients with MPA have circulating ANCA - usually myeloperoxidase (perinuclear or p-ANCA)(see WG), a rare phenomenon in classic PAN. Some have antibodies to proteinase-3 (central or c-ANCA) as in WG. Clinical distinction from WG may be difficult. Polyneuropathy is present in only 10-20% of patients, in contrast to the 50% or greater frequency in classic PAN. Patients with MPA have a high early case-fatality rate due to pulmonary and renal failure and they are considerably more prone to relapse after treatment.

Causes of secondary headache to consider

head or neck trauma
dissection
CVT
Low pressure headache
neoplasm
neuroinfectious disease
medication overuse syndrome
systemic infection
acute glaucoma
other disorder of face sinuses
sleep apnea
fasting
somatization
occipital neuralgia

taken from NEJM 2008 359:21:2274

Chronic headaches notes

Case records of MGH nov 20 2008
chronic headaches, negative studies except dural enahncements. Pachymeningitis unlikely to be doe to Wegener's (which is ordinarily the most common cause) due to lack of pulmonary extran CNS signs and because of negative ANCA.

Sarcoid, Churg Strauss considered unlikely (former, no pulmonary findings, latter, normak eosiniphil count). RA has rare meningeal inflammation but this patient lacked arthritis even though RF positive. Sjogren's with dry mouth and eye irritation was considered, but Ro & La antibodies were negative as was a lip biopsy. Sjogren's does not explain pachymeningitis, DI, HA's or jaw claudication.

GCA is consistent with unrelenting headache, myalgia and weakness, PMR< pain in jaw with chewing (is specific but occurs only in 1/3 of patients with disease).

GCA was diagnosed by TA biopsy. Steroids were started with concomitant Calcium, Vitamin D, orla biphosphonate, and antiplatelet therapy, and eventually CPAP for sleep apnea associated with weight gain due to prednisone. They also gave trimethoprim to prevent PCP and PPI's.