Continuum Audio Neurologic Complications of Cancer and Its Treatment With Dr. Amy A. Pruitt
Prompt recognition of direct and indirect neurologic complications of systemic cancers and their evolving treatments is essential. Neurologists should be familiar with common and rare neurologic toxicities of conventional chemotherapy, immune checkpoint inhibitors, and CAR T-cell therapy.
In this episode, Teshamae Monteith, MD, FAAN, speaks with Amy A. Pruitt, MD, FAAN, author of the article "Neurologic Complications of Cancer and Its Treatment" in the Continuum® February 2026 Neurology of Systemic Disease issue.
Dr. Monteith is the associate editor of Continuum® Audio and an associate professor of clinical neurology at the University of Miami Miller School of Medicine in Miami, Florida.
Dr. Pruitt is the William N. Kelley Professor of Neurology, Vice Chair for Education, and Division Chief in the Department of General Neurology for the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, Pennsylvania.
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Read the article: Neurologic Complications of Cancer and Its Treatment
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Full episode transcript available here
Dr Monteith: As neurologists, we have a critical role in diagnosing neurologic complications of cancer from metastatic disease, seizures to neuropathies. Increasingly, the rapid development of novel treatments themselves, like immunotherapies, Car-T cells, and targeted drugs are causing new neurologic side effects, which we need to recognize, manage and anticipate as therapeutic developments evolve.
Dr Jones: This is Dr Jones, editor in chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Monteith: Hi, this is Dr Teshamae Monteith. Today I'm interviewing Dr Amy Pruitt about her article on neurologic complications of cancer and its treatment, which appears in the February 2026 issue on neurology of systemic disease. Welcome to our podcast. How are you?
Dr Pruitt: Thanks for having me.
Dr Monteith: Absolutely. Why don't you introduce yourself?
Dr Pruitt: As you said, my name is Dr Amy Pruitt. I'm a professor of neurology at the University of Pennsylvania, where I am also the clerkship director and have been for a long time. I'm the division chief of general neurology and the vice chair for education in my department.
Dr Monteith: You have a lot of hats.
Dr Pruitt: I do.
Dr Monteith: Okay. So, before we dive into all this great work that you did in the article, why don't you just let us know just a little bit about what led you to this career path?
Dr Pruitt: Sure. So, I've always been interested in the intersection between internal medicine and neurology; in fact had I've not been a neurologist. I probably would have been either an oncologist or infectious disease specialist. And that leads to doing neuro oncology and seeing a fair amount of CNS infections. I see both inpatients and outpatients and really enjoy my neuro hospitalist time because, honestly, as all of you who do consults on inpatient services know, there is an incredibly changing landscape of consequences of cancer therapies. And if you haven't been on service for a while, you probably don't even know the name, is much less the adverse effects of these medicines.
Dr Monteith: Okay, so you were just like me to write this article.
Dr Pruitt: Well, I think where it is directed, I think, as I said, that people who are seeing a lot of inpatients and who may not know it's a new consequences of cytotoxic or immunotherapies or T cell therapies and the different appearances and really prognoses, which have changed dramatically in the last few years in the field of systemic cancer.
Dr Monteith: Any other essential points of your article?
Dr Pruitt: So, I think there are certain areas where neurologists are going to intersect with oncologic patients even before oncologists do so, what tumors might present synchronously in the brain and the rest of the body. And those would include things like small cell and non-small cell lung cancer and melanoma, to a lesser extent, women who are surviving much longer now with good therapies for various versions of breast cancers, have one of the solid tumors most likely to present at first relapse in the brain, either in the brain metastases category or in the leptomeninges. So, these are the areas where I think it most likely that our neurologists are going to intersect with oncology. And then there is the burgeoning, thankfully, realm of long-term survivors who have had cancer therapies in young adult lives, sometimes in childhood. And we need to be abreast of the ever-changing spectrum of complications that will plague these people all their lives. And we can do a great deal to improve the quality of survival in these patients.
Dr Monteith: And of course, there has been a lot of great development in cancer research, which has led to novel therapeutics. So, can you tell us about a few of these therapeutics and their complications that neurologists need to know about?
Dr Pruitt: Sure. Well, as I said, some of the cancers you're most likely to encounter are lung cancer and melanoma. And here the prognosis has changed dramatically. A few years ago, someone with metastatic melanoma might have had a couple months prognosis. And now we're talking honestly about long term survivors, complete responses in lung cancer and melanoma, and really good responses in the breast cancer realm as well. So, these are dramatic changes. And these are ways neurologists need to know what the actual nuanced and much more variable prognosis is among patients with brain metastases. In order to give the patients good advice and also to give the radiation oncologist and the oncologist, the medical oncologist, good advice. So, for example, just in the realm of brain metastases, a stage change has been that people with asymptomatic metastases for, let's say, non-small cell lung cancer or melanoma might have systemic therapy rather than local therapy, local therapy being gamma knife radiation or less likely, whole brain radiation therapy, but really systemic therapy with responses and the brands that are nearly as good as those in the rest of the body. And sustained, durable responses. The article goes into great detail about what's available in the way of therapies for these cancers, like breast, HER2-positive breast cancer, like EGFR‑positive lung cancer and melanoma of various types. It's really quite amazing actually, to have anybody quote a seven-year survival of little over 40% in people who presented with non-symptomatic melanoma metastases. Unheard of, really. So, I think if you're still practicing, quote unquote old school neuro-oncology, you need to get up to date because you're giving patients and their caregivers good advice that will lead them to the very important therapies. You mentioned some of the immunotherapies. If we have time, I'm happy to go into those because those are really important for neurologic consultants in the hospital.
Dr Monteith: Yeah. Let's talk about immune checkpoint inhibitors. What do we need to know about them and their complications?
Dr Pruitt: So, they have a novel set of central nervous system and peripheral nervous system complications. These include both acute and subacute presentations. They can arise after the very first dose and usually do so within the first several doses. Importantly, even though the patient may be quite sick, about three quarters will recover entirely. However, the most common ones are actually the peripheral nervous system, and they have the highest morbidity and mortality rate. So, a very unfortunate combination of myasthenia, myocarditis and skeletal myositis has a high mortality rate and is very hard to treat in a group of people who have received these immune checkpoint inhibitors in the central nervous system, there can be cerebellitis, encephalitis. These again can be acute or subacute presentations. And the big discussion with the attending oncologist is, can we continue these therapies after we've withdrawn them, and for instance, treated them with steroids? Because you can imagine that if you knock down the immune system with steroids, you might make the patient temporarily better. But in so doing, you're negating the important consequences of the mechanisms of immune checkpoint inhibitors.
So, I would say probably in a given week on the inpatient service, I'll see five or so. So nearly a daily event when I see some major complication of immune checkpoint inhibitors. And again, I've already mentioned the histology in which those have been useful, but they're not indicated for a variety of other malignancies as well. And the Car-T cell therapies are a whole different set of side effects. And some of your listeners may know about cytokine release syndrome, which is nearly universal right after the infusion of the car T cells. But a few days later is where we come into action with the immune effector cell-associated neurotoxicity syndrome. Or ICANS can say that I'll refer to it as ICANS since then. These include focal neurologic symptoms and the form of what's often a conduction sort of aphasia, a predictable deterioration, and handwriting along with confusion. As far as the radiology of that syndrome, that's really pretty odd. It can range from a dramatic cerebellitis, just a dramatic basal ganglia syndrome, a dramatic and enhancing leptomeningeal syndrome to an absolutely normal MRI scan. And the important thing for our consultant consultants to remember is that the patient can look really, really ill, and you can turn to the team and say, you know what, there's a very good chance that it's going to get all better. So, supporting people through what are very good diagnostic and therapeutic algorithms that exist in the literature and are quoted in the Continuum chapter to help know when you should be giving steroids, when you should be giving tocilizumab, etc. these are tried and true therapies now, and the Car-T world has improved not only the prognosis of patients. And I remember seeing some of the very first Car-T patients, and we really didn't know what to do to help them, how to turn off the cascade of this immunologic reaction. Now we know how to do that. And it's important to stay up to date on those algorithms because you can make a big difference for these patients.
Dr Monteith: Yeah. So, this is great. We're going to dive back into the diagnostics, which is really related to my follow up question. I think you gave a really great pearl. And it's always can we keep going? Do we stop? So, I want to like dive into that question. And I assume that there are categories. Yes. You can, somewhere in between, and absolutely not. And so, tell me a little bit more about that thinking.
Dr Pruitt: Well that's a very nuanced question. And so, the answer that some oncologists will give you as well, they've had such a dramatic response. So maybe we don't need it anymore. It's never the neurologist's decision. It's always the joint decision with the oncologist. So, for instance, with a Merkel cell cancer patient develops a severe anti‑AChR syndrome on an immune checkpoint inhibitor. And we tell the oncologist maybe you shouldn't go back and do that again. And the person says, never mind, he'll be fine. He's already had the response that we want, but that's a difficult question to answer because, for instance, in a slightly different subset, let's look at multiple myeloma patients. And I spent a fair amount of time on multiple myeloma in the article because it affects the nervous system in so many ways. And we have so many different therapies for these patients, one of which is a Car T-cell. And this is a B-cell maturation antigen, Car-T. It's different from the ones that we know for lymphoma and leukemia. And it has a different set of neurologic problems, which unfortunately do preclude going back to taking a Car-T cell therapy again. And just to make a long story short, this particular complication makes the patient look Parkinsonian.
The consult you're probably going to get from the medical services is patients weak. Well, the patient is not exactly weak. He is Parkinsonian. He has a extrapyramidal rigidity, sometimes a tremor a negative cat scan and a B-cell maturation antigen syndrome occurs not at the sort of 5 to 7 day mark about ICANS that we just discussed, but rather a month or so out and a month or so out. It's not when you're expecting to see Car-T cell therapies. So, patients end up getting worked up extensively for, let's say, some sort of infection, when in fact, what we should be looking at is a newly described complication of Car-T cell therapy. So, the part of my article on multiple myeloma is one that's really important because as you know, it's such a common hematologic problem among older people. And many of these people may have direct complications of multiple myeloma, such as direct tumor infiltration of nerves. POEMS syndrome. So, it's really a wealth of neurological issues for us to contend with for these people.
Dr Monteith: Yeah. And I know you've really done a great job of adding lots of wonderful charts, including understanding the time course of some of these complications, when to anticipate, because I think some of it is about when to anticipate some of these complications.
Dr Pruitt: Well, exactly. Yes. Given the time constraints, I've made a lot of tables because there was a lot of information. And those, I think, are the kinds of things that a consultant should know: what should I be thinking about at this point in time? And that sort of leads us to what are the later complications of these things. And those include many medical things, from failure due to neoplasia, morbidity, radiation, chemotherapy agents, the long-term and medium-term consequences of these things for people. Are going to come back to our office as well. Immunocompromised patients, such as the ones and heavily treated patients that I just mentioned, may lack a robust inflammatory response. And they can have infections really at any time out. Some are predictable, as in our leukemia patients who have had hematopoietic cell transplant. So, we kind of know when to expect viral infections, nosocomial infections, progressive multifocal leukoencephalopathy, many other things down the road. But in this era of COVID, we know that these patients are more susceptible to the dire effects of COVID, and they may not mount a good vaccination response. We have seen types of neurologic complications of all sorts of infections, including babesiosis this year, and persistent enteric viral meningitis. So, the patient can present a very atypical fashion. And the neurologic consultant has to keep a really open mind about the broad differential of what might be happening.
Dr Monteith: And you do have a section under imaging and metastatic disease. Are there any like new sequences or a way to kind of tease out complexities?
Dr Pruitt: So, there is marked variability in the radiographic appearance of brain metastases. And I must confess that I made a very large collage of all the different representative types of things. And I think that's important for neurologic consultants to recognize that some metastases don't enhance. They don't all look like ring-enhancing lesions. Some can be much more diffuse, particularly if the patient has received something like a VEGF inhibitor like bevacizumab therapy can look exceedingly different. They can involve the dura, which should be treated differently. There can be simultaneous leptomeningeal and disease. So as far as I know, sequences perhaps not so much. Although if one is thinking about the differential between radiation-related injury and someone who's already been treated versus tumor recurrence, then we have some pretty good microscopic data, some susceptibility weighted images, other ways of getting whether this is really radiation related change or tumor recurrence, a major problem obviously.
What we also know about radiation is kind of a theme of the article is use it as infrequently as possible, because we just talked about some of the other therapies that we have. We may need to give local therapy for symptomatic patients, but we give as little as possible, and we try never to give whole brain radiation therapy. I'll go on record as saying that it's certainly necessary. Sometimes people have diffuse lymphoma, this disease that's recurred, they have multiple metastases in a sort of miliary fashion may be necessary, but if you can use gamma knife radiation, if you cause any use form of focal radiation, new in the leptomeningeal world is proton therapy for spinal metastases. So quick sparing techniques. And this is something that should always be considered when you're consulting on someone in a place in which you have the option of proton therapy. So, I would say that distinguishing between radiation necrosis and recurrent tumor and the use of protons are the big news in the radiation therapy world. And don't give whole brain radiation therapy if you can avoid it.
Dr Monteith: Yeah. I'm getting a flashback from residency because, you know, that always happens. And the radiologist saying, you know, we need more information when you put in those orders. And so, I think with this whole era of new chemotherapeutic agents and how they could present on imaging and give the radiologists as much information, including the type of chemotherapeutic agent used.
Dr Pruitt: Yeah, I think particularly in the transplant world. So, the leukemia lymphoma patients who have received one of the calcineurin inhibitors, like tacrolimus or cyclosporine, that induces a whole set of complications, some of which are visible radiographically. There's a delayed leukoencephalopathy. There can be stroke. There can be SMART syndrome, stroke like migraine after radiation therapy. And perhaps many of our listeners have been confronted with someone who has a prolonged focal deficit, say, a hemianopia and maybe a hemisensory deficit with or without a subsequent headache. It goes on for days to hours. It looks peculiar on the MRI scan because it's not then a vascular distribution. There's sort of diffuse gyral swelling, flattening of the EEG on that side, the patients getting steroids and valproate and anticoagulation and angiography and all. It doesn't need any of that. The syndrome of stroke, like migraine after radiation therapy, needs to be recognized. And best thing to do is don't just do something. Stand there. You should wait until it goes away. And so, I think that's we are seeing this increasingly, that we first reported this in young adults who had been treated years ago for medulloblastoma. So, it was posterior fossa tumors primarily. But this has now been broadened, as you know, to include supratentorial tumors of many types and adults at various times out from their radiation therapy from a few months to many years.
Dr Monteith: I should ask you in writing this article, clearly you have a wealth of knowledge, but in kind of just putting this together, what surprised you?
Dr Pruitt: I think what surprised me is the increasing range of complications and that virtually anything needs to be thought of central nervous system or peripheral nervous system. With some of these newer therapies. There is a chart in there about the conventional cytotoxic therapies, and we're all familiar with things like methotrexate and that sort of thing. But what surprised me really is the increasing diversity of complications of these newer drugs, and also the fact that I didn't know some of the third and fourth generations of the tyrosine kinase inhibitors too. When you look at even the year of 2020, neurologic drugs were second only to oncologic drugs and FDA approval even at the height of COVID. So, don't feel badly if you don't remember any of the drugs really changing so rapidly. And they're better ideas, they're going to be fancier Car-T cells that attempt to get around some of the adverse effects of these and neurologists will retain really important role in following some of these patients, to be sure that these improvements are actually real and durable.
Dr Monteith: Excellent. Thank you so much for this wonderful conversation.
Dr Pruitt: Well, thank you so much for having me. And I hope people do get information from the article. Thanks.
Dr Monteith: Again, today I've been interviewing Dr Amy Pruitt about her article on neurologic complications of cancer and its treatment, which appears in the February 2026 Continuum issue on neurology of systemic disease. Be sure to check out Continuum Audio episodes from this and other issues. And thank you to our listeners for joining today.
Dr Monteith: This is Dr Teshamae Monteith, associate editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe, AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.