From the Guidelines
The likely cause of a frontal lobe embolic stroke in a patient with Rheumatoid Arthritis (RA) treated with Rituximab, with a negative Transesophageal Echocardiogram (TEE), recent dental work, and a blood culture positive for Nutritionally Variant Streptococci (NVS) is infective endocarditis (IE) caused by NVS.
Key Points
- NVS is a type of HACEK organism, which is known to cause IE and is associated with a high incidence of embolic complications, including stroke 1.
- The presence of NVS in the blood culture, despite a negative TEE, suggests that the patient may have IE, which can lead to embolic events such as stroke.
- Recent dental work is a potential risk factor for the development of IE, as it can cause bacteremia, which can lead to the infection of heart valves.
- The fact that the patient has RA and is being treated with Rituximab, which can increase the risk of infections, including IE, further supports this diagnosis.
Embolic Risk
- The study by Vilacosta et al, as mentioned in 1, found that the rate of embolic events decreases dramatically during and after the first 2 to 3 weeks of successful antibiotic therapy.
- However, the patient's recent dental work and positive blood culture for NVS suggest that the risk of embolization is still present, despite the negative TEE.
- The size and mobility of vegetations, as well as the type of infecting organism, are important factors in determining the risk of embolization, as noted in 1.
Management
- The patient should be treated with antibiotics effective against NVS, and the treatment should be guided by the results of blood cultures and susceptibility testing.
- The role of surgical intervention to prevent further embolic events should be considered, although the decision to operate should be made on a case-by-case basis, taking into account the patient's overall condition and the risk of surgery, as discussed in 1.
From the Research
Possible Causes of Frontal Lobe Embolic Stroke
- The patient's recent dental work and blood culture positive for Nutritionally Variant Streptococci (NVS) suggest a possible infectious cause of the stroke, as NVS are known to be associated with endocarditis and stroke 2, 3, 4.
- The patient's treatment with Rituximab for Rheumatoid Arthritis (RA) may also be a contributing factor, as Rituximab has been associated with an increased risk of infections, including opportunistic infections 2, 3, 4.
- However, the negative Transesophageal Echocardiogram (TEE) suggests that the stroke may not be due to a cardiac source, such as endocarditis or atrial fibrillation.
- The patient's underlying RA may also be a contributing factor, as RA has been associated with an increased risk of stroke, possibly due to inflammation and vasculitis 5, 6.
Role of Rituximab in Stroke Prevention
- There is limited evidence to suggest that Rituximab can prevent strokes in patients with RA, although it has been used to treat cerebral rheumatoid vasculitis (CRV) and prevent CRV-induced strokes 6.
- Further research is needed to fully understand the relationship between Rituximab, RA, and stroke risk, and to determine the potential benefits and risks of using Rituximab to prevent strokes in patients with RA 5.