A case of cerebral vasculitis due to neurobartonellosis

Discussion

We present an individual with symptoms initially concerning for RCVS vs vasculitis who was subsequently found to have secondary CNS vasculitis due to cat-scratch disease (CSD). To our knowledge, this is the first adult case of Bartonella henselae-associated CNS vasculitis, particularly without encephalopathy as the presenting symptom.

CSD typically presents with self-limited regional lymphadenopathy and fever.¹ Neurologic complications are rare, occurring in 2% of cases with encephalopathy as the most common manifestation.² Neuroretinitis, seizures, coma, myelopathies, and cranial and peripheral nerve involvement have also been reported. CNS vasculitis associated with CSD, however, has only been reported in 2 pediatric cases which presented with strokes.^3,4

Diagnostically, identifying primary and secondary CNS vasculitis can be challenging both clinically and radiographically. No specific studies in serum or CSF are available for the diagnosis of CNS vasculitis. As in neurobartonellosis, CSF may be unremarkable or reveal nonspecific mild lymphocytic pleocytosis. Cerebral vasculopathies can present with similar luminal patterns, and therefore, imaging modalities such as DSA, magnetic resonance angiography (MRA), and CTA provide nonspecific results leading to difficulties identifying and differentiating between common etiologies of intracranial disease including vasospasm, atherosclerosis, and inflammation. Although DSA remains the gold standard for vessel imaging, it is an invasive study that provides information limited to the vessel lumen. Conversely, IVWI allows direct visualization of the vessel wall by subtracting the signal of blood in the vessel lumen and has shown to improve diagnostic specificity.⁵ In CNS vasculitis, IVWI shows multifocal concentric vessel wall enhancement and thickening as seen in our patient. In RCVS, vessel wall thickening may be present but with minimal or no enhancement.⁵

At this time, there is no clear evidence-based treatment regimen or duration for neurologic manifestations of CSD including CNS vasculitis.¹ We recommend concomitant treatment of the infection with antibiotics and secondary vasculitis with high-dose steroids. Our patient received a 2-week combination of doxycycline 100 mg and rifampin 300 mg twice daily per current expert opinion.⁶ In addition, we initiated 5 days of high-dose IV steroids, followed by a 1-week oral steroid taper. To avoid recurrent invasive testing, we repeated IVWI 4 weeks later for treatment monitoring and found significant reduction in vessel wall enhancement (figure).

Our case reiterates the importance of ruling out rare causes of CNS vasculitis including assessing animal exposure before diagnosing PACNS. Detection of the etiology of vasculitis is essential to guide treatment and for prognostication. Noninvasive imaging such as an IVWI provides valuable diagnostic information and can be useful in assessing the treatment response over time by minimizing the need for repeat invasive DSA.