Hi, I ran this by Claude Opus, in hopes it would have better advice/ideas than me in this circumstance. So for quick feedback until someone with expertise can chime in:
”″” This is a complex and concerning medical situation. A few key points and suggestions based on the information provided:
1. The inconsistent efficacy of acyclovir vs. valacyclovir is indeed very puzzling if this is an HHV encephalitis. Normally they should have equivalent effects once metabolized. I’d recommend closely documenting the timing and dosage of each medication along with detailed symptom progression to see if any patterns emerge that could explain this discrepancy.
2. While the CT and MRI not showing abnormalities seems to argue against encephalitis, as you note, it’s possible they were done early enough in disease progression, or at a time when inflammation was reduced, to not yet show changes. Serial imaging over time may be more informative.
3. The lack of HSV antibodies is concerning for the leading HSV encephalitis theory. As you mention, possibilities include immunodeficiency, false negatives, or a rarer non-HSV HHV encephalitis. Repeating the HSV antibody tests as well as testing for antibodies to other HHVs like VZV may be worthwhile.
4. I would be very cautious about stopping acyclovir for the purpose of “unmasking” the illness prior to a lumbar puncture. HSV encephalitis can progress extremely rapidly and cause permanent damage. It’s crucial to continue presumptive treatment until the diagnosis is certain.
5. Regarding other antivirals—using multiple agents empirically runs risks of unnecessary side effects and drug interactions. I would reserve additional antivirals for cases of confirmed acyclovir resistance or failure of clinical improvement.
6. Continued close follow-up with the neurologist is essential. Push for repeat imaging, LP, and any other indicated testing ASAP. Consider seeking a second opinion from another neurologist or infectious disease specialist if your current providers do not share your sense of urgency.
7. Aside from infectious causes, autoimmune encephalitis is another possibility that can present similarly and is worth evaluating for via LP and antibody tests if infectious work-up is unrevealing.
8. Maintain detailed records of all symptoms, medications, test results etc. to help providers see the full picture.
9. Ensure your brother receives adequate supportive care in the meantime—hydration, rest, safety precautions if mentation is compromised, and management of any comorbidities like hypothyroidism that could complicate his condition.
I commend you for being such a thorough advocate for your brother during this scary time. Keep pushing for answers and comprehensive care. I hope he recovers quickly and completely. Let me know if you have any other questions! ”″”
My own thoughts are that the (other) antiviral might not be being metabolized in the expected fashion, so it’s not working the same as if it were metabolized in the expected fashion. Not sure what this is evidence for or against aside from that sticking with the one that works makes sense.
Thanks. In case this additional detail helps anybody: my brother says he’d take valacyclovir two times a day, and it seemed like his rash (and possibly cognitive symptoms, hard to tell) would get worse a couple hours after, then subside.
Hi, I ran this by Claude Opus, in hopes it would have better advice/ideas than me in this circumstance. So for quick feedback until someone with expertise can chime in:
”″”
This is a complex and concerning medical situation. A few key points and suggestions based on the information provided:
1. The inconsistent efficacy of acyclovir vs. valacyclovir is indeed very puzzling if this is an HHV encephalitis. Normally they should have equivalent effects once metabolized. I’d recommend closely documenting the timing and dosage of each medication along with detailed symptom progression to see if any patterns emerge that could explain this discrepancy.
2. While the CT and MRI not showing abnormalities seems to argue against encephalitis, as you note, it’s possible they were done early enough in disease progression, or at a time when inflammation was reduced, to not yet show changes. Serial imaging over time may be more informative.
3. The lack of HSV antibodies is concerning for the leading HSV encephalitis theory. As you mention, possibilities include immunodeficiency, false negatives, or a rarer non-HSV HHV encephalitis. Repeating the HSV antibody tests as well as testing for antibodies to other HHVs like VZV may be worthwhile.
4. I would be very cautious about stopping acyclovir for the purpose of “unmasking” the illness prior to a lumbar puncture. HSV encephalitis can progress extremely rapidly and cause permanent damage. It’s crucial to continue presumptive treatment until the diagnosis is certain.
5. Regarding other antivirals—using multiple agents empirically runs risks of unnecessary side effects and drug interactions. I would reserve additional antivirals for cases of confirmed acyclovir resistance or failure of clinical improvement.
6. Continued close follow-up with the neurologist is essential. Push for repeat imaging, LP, and any other indicated testing ASAP. Consider seeking a second opinion from another neurologist or infectious disease specialist if your current providers do not share your sense of urgency.
7. Aside from infectious causes, autoimmune encephalitis is another possibility that can present similarly and is worth evaluating for via LP and antibody tests if infectious work-up is unrevealing.
8. Maintain detailed records of all symptoms, medications, test results etc. to help providers see the full picture.
9. Ensure your brother receives adequate supportive care in the meantime—hydration, rest, safety precautions if mentation is compromised, and management of any comorbidities like hypothyroidism that could complicate his condition.
I commend you for being such a thorough advocate for your brother during this scary time. Keep pushing for answers and comprehensive care. I hope he recovers quickly and completely. Let me know if you have any other questions!
”″”
My own thoughts are that the (other) antiviral might not be being metabolized in the expected fashion, so it’s not working the same as if it were metabolized in the expected fashion. Not sure what this is evidence for or against aside from that sticking with the one that works makes sense.
Thanks. In case this additional detail helps anybody: my brother says he’d take valacyclovir two times a day, and it seemed like his rash (and possibly cognitive symptoms, hard to tell) would get worse a couple hours after, then subside.