Conference Coverage

Expert highlights rare causes of stroke to keep in mind


 

EXPERT ANALYSIS FROM ANA 2018

– According to Peter Berlit, MD, clinicians should think of an underlying rheumatic disease in association with stroke when a patient has younger age, no risk factors, and accompanying headache and encephalopathy.

Dr. Peter Berlit, secretary general of the German Society of Neurology in Berlin

Dr. Peter Berlit

Other factors include combination of ischemic and hemorrhagic stroke, exclusive involvement of intracranial vessels, systemic signs, and lab tests indicating inflammation.

At the annual meeting of the American Neurological Association, Dr. Berlit, secretary general of the German Society of Neurology in Berlin, discussed the diagnosis and management of rare causes of stroke.

Giant cell arteritis (GCA)

One of the rare causes of stroke, GCA can be diagnosed when three of five criteria are met: being 50 years of age or older, having a newly developed headache, tenderness of the superficial temporal artery, elevated sedimentation rate of at least 50 mm per hour, and GCA in a biopsy specimen from the temporal artery.

“What we fear most is sudden blindness due to involvement of arteries serving the eyes, which appears in up to 30% of GCA patients,” said Dr. Berlit, who formerly chaired the department of neurology at Alfried Krupp Hospital, Essen, Germany. “Stroke occurs in approximately 2% of GCA patients, so it’s a lot rarer.” GCA can also be diagnosed by ultrasound. One meta-analysis of 23 studies using halo, stenosis, and occlusion as ultrasound criteria found a sensitivity of 87% and a specificity of 96% (Ann Intern Med. 2005;142[5]:359-69). “You can also use 3-Tesla MRI with the use of contrast agent, which shows inflammation of the temporal artery, but also other large vessels including the aortic arch,” he said. “The treatment of GCA has changed since the end of 2017 and involves starting with prednisolone 1 mg/kg body weight.” After a dose of 30 mg for 4 weeks, reduce the dose by 2.5 mg every 2 weeks. After reaching the dose of 15 mg daily, reduce by 1 mg per month. “The recommended steroid-sparing treatment is subcutaneous tocilizumab at a dose of 162 mg weekly or every other week, combined with a prednisone taper for a minimum of 26 weeks,” he said. Supportive therapies include pantoprazole 20 mg, aspirin 100 mg, calcium, vitamin D, and bisphosphonates.

Primary angiitis of the central nervous system (PACNS)

Next, Dr. Berlit discussed diagnostic criteria for PACNS, an acquired neurological deficit unexplained after complete evaluation. “You should have a diagnostic cerebral angiogram or biopsy demonstrating vasculitis,” he said. “There should be no evidence of systemic vasculitis or any other conditions that could mimic the angiogram findings. Usually you have abnormal CSF findings, including pleocytosis and protein elevation, and a biopsy demonstrating vasculitis.”

MRI studies in suspected vasculitis include fluid-attenuated inversion recovery (FLAIR), diffusion imaging with apparent diffusion coefficient (ADC) maps, gradient ECHO, MR angiography, and contrast-enhanced imaging. “These usually show multifocal lesions of different ages, and hemorrhages occur in about 10% of lesions,” Dr. Berlit said. “Leptomeningeal enhancement is an indicator of good treatment response.”

A brain and leptomeningeal biopsy demonstrating the angiitis remains the preferred method for diagnosis of PACNS. “Open biopsies out of recent MRI lesions are especially diagnostic,” he said. “If there are no lesions accessible for surgery in noneloquent brain areas, a biopsy from the right frontal lobe is recommended.” The histologic findings of PACNS consist of granulomatous inflammation, fibrinoid necrosis of vessel walls, or exclusively lymphocytic cellular infiltrates. “The treatment of choice in PACNS is the combination of steroids and cyclophosphamide pulse therapy,” he said. “There are also data showing that rituximab or methotrexate might be treatment options. With a relapse rate of 25% and a reduced survival rate, a close follow-up of suspected PACNS is mandatory.”

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