Stroke-like migraine attacks after radiation therapy (SMART) syndrome is not always completely reversible: a case series

A Rare Case of Diffuse Leptomeningeal and Cortical Enhancement Secondary to Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome in a Patient With a History of Childhood Medulloblastoma

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare complication of craniospinal irradiation (CSI). Patients commonly present with headaches, seizures, and paroxysmal focal neurological deficits. There is a dearth of studies reported in the literature with an estimated fewer than 100 cases described since it was initially defined in the mid-1990s. The authors present the case of a 23-year-old patient with a history of childhood medulloblastoma and prior ventriculoperitoneal shunt (VPS), chemotherapy, and CSI who presented with headaches and new-onset seizures. Magnetic resonance imaging (MRI) of the brain showed diffuse left temporoparietal and occipital leptomeningeal and cortical enhancement. However, cerebrospinal fluid (CSF) analysis was unremarkable for neoplastic, infectious, or inflammatory etiology. Initiation of systemic steroid therapy resulted in drastic improvement of the patient's symptoms and prompted antiepileptic drug (AED) wean and persistent resolution of leptomeningeal and cortical contrast enhancement on brain MRI. When evaluating MRI evidence of leptomeningeal enhancement, neurosurgeons should consider SMART syndrome in the differential diagnosis, especially when extensive workup rules out more common causes of this finding such as leptomeningeal disease (LMD). Proper identification of SMART syndrome can lead to timely treatment, avoidance of invasive procedures such as tissue biopsy, and improved clinical outcomes.

Post-treatment imaging of gliomas: challenging the existing dogmas

Gliomas are the commonest malignant central nervous system tumours in adults and imaging is the cornerstone of diagnosis, treatment, and post-treatment follow-up of these patients. With the ever-evolving treatment strategies post-treatment imaging and interpretation in glioma remains challenging, more so with the advent of anti-angiogenic drugs and immunotherapy, which can significantly alter the appearance in this setting, thus making interpretation of routine imaging findings such as contrast enhancement, oedema, and mass effect difficult to interpret. This review details the various methods of management of glioma including the upcoming novel therapies and their impact on imaging findings, with a comprehensive description of the imaging findings in conventional and advanced imaging techniques. A systematic appraisal for the existing and emerging techniques of imaging in these settings and their clinical application including various response assessment guidelines and artificial intelligence based response assessment will also be discussed.

Management of Neurologic Complications in Patients with Brain and Spine Tumors

Patients with brain and spine tumors represent a distinct population with unique needs. We provide a practical review of neurologic care in this group with an emphasis on familiarizing the general neurologist to the nuances of neuro-oncologic supportive care. We review the management of cerebral edema, steroid dosing, and pertinent side effects. We discuss seizure management, including choice of anticonvulsants, putative antitumor effects, and important seizure mimics like drop attacks. We review the presentation and symptomatology of stroke-like migraine attack after radiation therapy (SMART syndrome). We describe the signs and symptoms that should prompt concern for metastatic spinal cord compression, as well as both acute and definitive treatment options. Finally, we discuss the underappreciated incidence of venous thromboembolic events, particularly in patients with gliomas, and review the data on management.

Good Gone Bad: Complications of Chemotherapy, Immunotherapy, and Radiotherapy on the CNS

With recent advancements in cancer therapy, especially immunotherapy, overall survival of many cancers has increased and patient toxicity has been reduced. However, many complications of traditional cancer therapy are still prevalent and complications of novel therapies are just beginning to appear. The neuroradiologist may be the first to visualize signs of these complications on imaging. This article describes the notable imaging findings of several unique and characteristic complications of CNS cancer therapy, including toxicities of chemotherapies, immunotherapies, and radiotherapy. Complications of chemotherapeutic agents covered include methotrexate-induced and disseminated necrotizing leukoencephalopathy, and chemotherapy-induced myelopathy. Immunotherapy complications included are Tacrolimus-related Optic Neuropathy, Rituximab and Immune reconstitution inflammatory syndrome-associated Progressive Multifocal Leukoencephalopathy, Bevacizumab-associated late radiation-induced neurotoxicity, and Ipilimumab-induced hypophysitis. Lastly, radiation-induced neurotoxicities are covered, including myelopathy, radiation necrosis, cerebral atrophy, leukoencephalopathy, optic neuropathy, mineralizing microangiopathy, stroke-like migraine attacks, osteonecrosis, and vasculopathies. Neuroradiologists will increasingly encounter patients who have undergone treatment with more than 1 therapeutic modality, resulting in overlapping findings as well. Recognition of the common complications of these therapies on imaging is critical to minimizing the effects of these potential short- and long-term complications.

Mitigating Radiotoxicity in the Central Nervous System: Role of Proton Therapy

OPINION STATEMENT

Central nervous system (CNS) radiotoxicity remains a challenge in neuro-oncology. Dose distribution advantages of protons over photons have prompted increased use of brain-directed proton therapy. While well-recognized among pediatric populations, the benefit of proton therapy among adults with CNS malignancies remains controversial. We herein discuss the role of protons in mitigating late CNS radiotoxicities in adult patients. Despite limited clinical trials, evidence suggests toxicity profile advantages of protons over conventional radiotherapy, including retention of neurocognitive function and brain volume. Modelling studies predict superior dose conformality of protons versus state-of-the-art photon techniques reduces late radiogenic vasculopathies, endocrinopathies, and malignancies. Conversely, potentially higher brain tissue necrosis rates following proton therapy highlight a need to resolve uncertainties surrounding the impact of variable biological effectiveness of protons on dose distribution. Clinical trials comparing best photon and particle-based therapy are underway to establish whether protons substantially improve long-term treatment-related outcomes in adults with CNS malignancies.

Case Report: Stroke-like migraine attacks after radiation therapy syndrome: a rare complication 26 years after cranial radiotherapy

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare delayed complication of cranial radiotherapy, that may present decades after brain irradiation. Here we present a case of 41-year old patient with a history of grade 3 oligodendroglioma, epilepsy and migraine, 26 years after brain radiation therapy, who was admitted with right hemicranial headache, nausea, left homonymous hemianopsia, weakness of the left arm and left-sided hemihypesthesia. After considering alternate diagnoses, we ultimately diagnosed SMART syndrome. Despite its rare occurrence and unknown pathophysiology, there are more case reports of SMART syndrome reported due to advancements in oncology treatment and increasing patients' survival rates. Therefore, diagnosis of SMART syndrome should always be considered in patients with a history of cranial radiation presenting with focal neurologic deficits and migraine, especially with a change in pattern of their usual migraine attack.

Complications of Cancer Therapy in Children: A Comprehensive Review of Neuroimaging Findings

ABSTRACT

Complications of cancer therapy in children can result in a spectrum of neurologic toxicities that may occur at the initiation of therapy or months to years after treatment. Although childhood cancer remains rare, increasing survival rates mean that more children will be living longer after cancer treatment. Therefore, complications of cancer therapy will most likely occur with increasing frequency.At times, it is very difficult to differentiate between therapeutic complications and other entities such as tumor recurrence, development of secondary malignancy, and infection (among other conditions). Radiologists often play a key role in the diagnosis and evaluation of pediatric patients with malignancies, and thus, awareness of imaging findings of cancer complications and alternative diagnoses is essential in guiding management and avoiding misdiagnosis. The aim of this review article is to illustrate the typical neuroimaging findings of cancer therapy-related toxicities, including both early and late treatment effects, highlighting pearls that may aid in making the appropriate diagnosis.

SMART Syndrome: Case Report and Review of the Literature

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare condition characterized by stroke-like deficits, seizures, and headache that can occur years after radiation therapy (RT) to the brain. RT is a cornerstone in the treatment of primary brain tumours and is indicated in more than 90% of patients. It is therefore essential to be aware of this entity to prevent misdiagnosis leading to inappropriate treatment. In this article, typical imaging findings of this condition are presented through a case report and review of the literature.

Comprehensive Update and Review of Clinical and Imaging Features of SMART Syndrome

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a delayed complication of cranial irradiation, with subacute onset of stroke-like symptoms including seizures, visual disturbance, speech impairment, unilateral hemianopsia, facial droop, and aphasia, often associated with migraine-type headache. The diagnostic criteria were initially proposed in 2006. However, the diagnosis of SMART syndrome is challenging because clinical symptoms and imaging features of SMART syndrome are indeterminate and overlap with tumor recurrence and other neurologic diseases, which may result in inappropriate clinical management and unnecessary invasive diagnostic procedures. Recently, various imaging features and treatment recommendations for SMART syndrome have been reported. Radiologists and clinicians should be familiar with updates on clinical and imaging features of this delayed radiation complication because recognition of this entity can facilitate proper clinical work-up and management. This review provides current updates and a comprehensive overview of the clinical and imaging features of SMART syndrome.

Arterial spin labeling clinical applications for brain tumors and tumor treatment complications: A comprehensive case-based review

Arterial spin labeling (ASL) is a noninvasive neuroimaging technique that allows for quantifying cerebral blood flow without intravenous contrast. Various neurovascular disorders and tumors have cerebral blood flow alterations. Identifying these perfusion changes through ASL can aid in the diagnosis, especially in entities with normal structural imaging. In addition, complications of tumor treatment and tumor progression can also be monitored using ASL. In this case-based review, we demonstrate the clinical applications of ASL in diagnosing and monitoring brain tumors and treatment complications.

SMART syndrome: two cases highlighting a complex and rare complication of brain irradiation

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare complication of radiotherapy with complex neurological impairment. Patients present with neurological symptoms and signs such as migraine, hemianopsia, hemiplegia, aphasia and/or seizures-without recurrence of neoplastic disease. In this report, we describe SMART syndrome in two adult patients 4 and 14 years following brain irradiation, respectively.

Case Report: SMART ANTON: Anton-Babinski Syndrome in Stroke-Like Migraine Attacks (SMART) After Radiation Therapy: Two Rare Syndromes, One Case

Introduction

We describe the case of a 57-years-old patient who presented an Anton-Babinski syndrome in the context of a stroke-like migraine attack after radiation therapy (SMART).

Case Report

The patient was brought to the emergency room following a sudden loss of vision in the context of a pre-existing left-sided hemianopia after excision of a right occipital astrocytoma followed by radio-chemotherapy 35 years prior to his admission in our services. At admittance, he also presented hyperthermia, hypertension, and a GCS of 7. The MRI showed a leptomeningeal enhancement in the left temporal, parietal, and occipital lobes. After exclusion of other differential diagnoses, we diagnosed a cortical blindness in the context of a SMART syndrome affecting the left hemisphere. While the symptoms improved under corticosteroid therapy, the patient successively presented an Anton-Babinski syndrome, a Riddoch syndrome and a visual associative agnosia before finally regaining his usual sight.

Discussion

This is, to our knowledge, the first report of an Anton-Babinski syndrome in the context of a SMART syndrome. A dual etiology is mandatory for cortical blindness in SMART syndrome since the latter affects only one hemisphere. A SMART syndrome affecting the contralateral hemisphere in respect to the radiation site seems to be uncommon, which makes this case even more exceptional.

Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome Presenting With Recurrent Seizures: A Case Study

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare, delayed complication of radiation therapy to the brain. We present a case of a 49-year-old female with a past medical history of malignant neoplasm of the brain status following resection and radiation. She initially presented with increased work of breathing. Initial labs and a chest X-ray were suggestive of aspiration pneumonia leading to sepsis. Upon hospitalization, seizure-like activity was noted. Electroencephalogram showed electrographic seizures originating from the left occipital and parietal lobe. She received numerous medications to control the seizures with minimal improvement. Magnetic resonance imaging was performed to characterize the origin of seizures, which showed extensive post-radiation changes including a new meningioma. The patient was subsequently managed with magnesium and Solu Medrol. After this regimen, her condition improved and there were no clinical seizures present.

SMART syndrome: a case report

INTRODUCTION

Stroke-like migraine attacks after radiation therapy (SMART) syndrome, is a late complication of brain radiotherapy (1). Symptoms are commonly subacute in onset and involve migraine type of headache, seizures, focal neurologic deficits (2). Magnetic resonance imaging (MRI) findings are usually unilateral and posterior predominant cortical-subcortical hyperintensity, swelling and prominent gyriform (cortical and leptomeningeal) gadolinium enhancement in the areas of the brain that underwent irradiation with or without diffusion restriction (1). There is no standard treatment protocol for SMART syndrome. Antiepileptics and corticosteroids are commonly used drugs.

CASE REPORT

A 65 years old woman was diagnosed with breast cancer with brain metastases and treated with more than 50 Gy brain radiotherapy. The patient presented with acute right-sided weakness and numbness, episodic myoclonic jerking of the right arm and leg, and gait instability five months later. MRI and magnetic resonance angiography of the brain with gadolinium revealed left parietooccipital cortical diffusion restriction and accompanying dilatation of the left posterior cerebral artery as new findings. Computed tomography (CT) perfusion revealed increased perfusion in the affected area. The patient was diagnosed with SMART syndrome.

MANAGEMENT AND OUTCOME

The patient was treated with dexamethasone (16 mg/day) and anticonvulsant therapy. Myoclonic seizures had almost completely remitted. However, her cognitive impairment persisted, then the patient was arrested because of aspiration a month later.

DISCUSSION

Besides confirming SMART syndrome, diagnostic investigations are also important to exclude other etiologies. Posterior reversible encephalopathy syndrome, post-ictal changes, meningoencephalitis, and cerebrovascular diseases are radiological differential diagnoses considered (3). Proper and early diagnosis of SMART syndrome is significant in preventing unnecessary aggressive approaches and appropriate treatment to avoid lesions of sequela.

Stroke-Like Migraine Attacks After Radiation Therapy Syndrome and Radiation Necrosis After Cerebral Proton Beam Radiation: A Case Report of Dual Radiotherapy Complications

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare, delayed complication of cranial radiation therapy that consists of migraine-like headaches and focal neurologic deficits such as visual loss, aphasia, hemiparesis, hemisensory loss, and unconsciousness. SMART syndrome may be mistaken for tumor recurrence, radiation necrosis, and stroke. Timely recognition of SMART syndrome prevents unnecessary brain biopsies and enables appropriate anticipatory guidance. We present a 38 year-old right handed male with new headaches, vertigo, visual symptoms, and left-sided paresthesias. Neuroimaging revealed a heterogeneously enhancing mass with invasion into the transverse sinus, diagnosed as an epithelioid hemangioendothelioma by surgical pathology. After resection, the patient underwent proton beam radiation for maximal tissue-sparing. Six months later, he developed radiation necrosis. After another year, he developed recurrent headaches with transient language difficulties and blurry vision during each headache. Neuroimaging was consistent with SMART syndrome, and the patient was started on valproate. Verapamil was added after a second attack. The patient’s headaches improved, but he remains dyslexic. Subsequent imaging shows resolution of gyriform contrast enhancement and continued left temporo-occipital T2/FLAIR hyperintensity. We present a case of early SMART syndrome following proton beam radiotherapy, as well as the dual occurrence of radiation necrosis and SMART syndrome in this individual. Radiation necrosis and SMART syndrome are known complications of radiotherapy, with the latter less well-described. We discuss a possible shared pathophysiology involving endothelial cell dysfunction and impaired cerebrovascular autoregulation, and we question whether proton RT increases risk of early SMART syndrome development.

Short and Long-Term Toxicity in Pediatric Cancer Treatment: Central Nervous System Damage

Simple Summary

The purpose of this review is to describe central nervous system side effects in the treatment of pediatric cancer patients. Unfortunately, we must consider that the scarce data in the literature does not allow us to expand on some issues, especially those related to innovative immunotherapy. We have described the major neurotoxicities arising with the various types of treatment to help specialists who approach these treatments recognize them early, prevent them, and treat them promptly.

Abstract

Neurotoxicity caused by traditional chemotherapy and radiotherapy is well known and widely described. New therapies, such as biologic therapy and immunotherapy, are associated with better outcomes in pediatric patients but are also associated with central and peripheral nervous system side effects. Nevertheless, central nervous system (CNS) toxicity is a significant source of morbidity in the treatment of cancer patients. Some CNS complications appear during treatment while others present months or even years later. Radiation, traditional cytotoxic chemotherapy, and novel biologic and targeted therapies have all been recognized to cause CNS side effects; additionally, the risks of neurotoxicity can increase with combination therapy. Symptoms and complications can be varied such as edema, seizures, fatigue, psychiatric disorders, and venous thromboembolism, all of which can seriously influence the quality of life. Neurologic complications were seen in 33% of children with non-CNS solid malign tumors. The effects on the CNS are disabling and often permanent with limited treatments, thus it is important that clinicians recognize the effects of cancer therapy on the CNS. Knowledge of these conditions can help the practitioner be more vigilant for signs and symptoms of potential neurological complications during the management of pediatric cancers. As early detection and more effective anticancer therapies extend the survival of cancer patients, treatment-related CNS toxicity becomes increasingly vital. This review highlights major neurotoxicities due to pediatric cancer treatments and new therapeutic strategies; CNS primary tumors, the most frequent solid tumors in childhood, are excluded because of their intrinsic neurological morbidity.

Cognitive Impairment in Primary and Secondary Headache Disorders

Purpose of Review

To critically evaluate the recent literature on cognitive impairment and headache.

Recent Findings

Neurocognitive symptoms are prevalent, debilitating, and occur often with both primary and secondary headache disorders.

Summary

This is a “narrative review of the current literature in PubMed on cognitive function and headache.” Migraine is associated with cognitive impairment years before a migraine diagnosis. In young and middle-aged adults, migraine is associated with deficits in attention, executive function, processing speed, and memory. It is unlikely that migraine is associated with dementia. Although methodologically difficult to assess, there does not seem to be an association between tension-type headache and cognitive dysfunction. In early to midlife, cluster headache seems to be associated with executive dysfunction. Several secondary headache syndromes relevant to clinicians managing headache disorders are associated with poorer cognitive performance or distinctive cognitive patterns, including those attributed to chronic cerebral or systemic vascular disorders, trauma, and derangements of intracranial pressure and volume, including frontotemporal brain sagging syndrome.

Prognostic Factors of Stroke-Like Migraine Attacks after Radiation Therapy (SMART) Syndrome

BACKGROUND AND PURPOSE

Prognostic factors of stroke-like migraine attacks after radiation therapy (SMART) syndrome have not been fully explored. This study aimed to assess clinical and imaging features to predict the clinical outcome of SMART syndrome.

MATERIALS AND METHODS

We retrospectively reviewed the clinical manifestations and imaging findings of 20 patients with SMART syndrome (median age, 48 years; 5 women) from January 2016 to January 2020 at 4 medical centers. Patient demographics and MR imaging features at the time of diagnosis were reviewed. This cohort was divided into 2 groups based on the degree of clinical improvement (completely versus incompletely recovered). The numeric and categoric variables were compared as appropriate.

RESULTS

There were statistically significant differences between the completely recovered group (n = 11; median age, 44 years; 2 women) and the incompletely recovered group (n = 9; median age, 55 years; 3 women) in age, months of follow-up, and the presence of steroid treatment at diagnosis (P = .028, .002, and .01, respectively). Regarding MR imaging features, there were statistically significant differences in the presence of linear subcortical WM susceptibility abnormality, restricted diffusion, and subcortical WM edematous changes in the acute SMART region (3/11 versus 8/9, P = .01; 0/11 versus 4/9, P = .026; and 2/11 versus 7/9, P = .022, respectively). Follow-up MRIs showed persistent susceptibility abnormality (11/11) and subcortical WM edematous changes (9/9), with resolution of restricted diffusion (4/4).

CONCLUSIONS

Age, use of steroid treatment at the diagnosis of SMART syndrome, and MR imaging findings of abnormal susceptibility signal, restricted diffusion, and subcortical WM change in the acute SMART region can be prognostic factors in SMART syndrome.

Stroke-like migraine attacks after radiation therapy (SMART) syndrome presenting as a migraine copycat: A case report

Background:

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a possible long term consequence of cranial beam radiation therapy and may present as a perfect mimic of migraine with or without aura.

Methods and Results:

We present a 57-year-old man suffering from diffuse astrocytoma and presenting with SMART syndrome perfectly mimicking his antecedent migraine with visual aura. He was treated with intravenous steroid therapy inducing rapid response.

Conclusion:

SMART syndrome is a rare complex delayed complication of brain radiation therapy, which may present as an isolated migraine with or without aura even decades after cranial radiation. Thus, a sudden intensification or relapse of a previous migraine in a patient with remote cranial radiotherapy constitutes a red flag even decades after cranial irradiation and cured or stable tumor disease on a recent brain MRI. Moreover, SMART syndrome adds to the list of secondary headaches not yet listed in the current International Classification of Headache Disorders, 3rd edition (ICHD3).

Stroke-Like Migraine after Radiation Treatment Syndrome in Children with Cancer

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a symptom complex of transient neurological deficits, headache, and abnormal cortical contrast enhancement on brain MRI. Pathophysiology is unclear, but exposure to cranial radiation (RT) is a sine qua non. We report five children with SMART syndrome treated with RT therapy for medulloblastoma (n = 3), atypical teratoid rhabdoid tumor (n = 1), and pleomorphic xanthoastrocytoma (n = 1). Median age at tumor diagnosis was 9.4 years (range 5.1–14.7). Median follow-up from cancer diagnosis was 3.1 years (range 1.4–12.9). All patients had 54 Gy focal RT treatment and medulloblastoma children had additional 36 Gy craniospinal irradiation. Median time from the end of RT to first transient neurological deficit was 1 year (range 0.7–12.1). The median follow-up since first SMART episode was 0.6 years (range 0.3–2.6). Presenting symptoms included the gradual development of unilateral weakness (n = 4), non-fluent dysphasia (n = 1), somnolence (n = 1), and headaches (n = 3). Neurological deficits resolved within 30 minutes to 10 days. Transient cortical enhancement on magnetic resonance imaging (MRI) was confirmed in two children and was absent in the other three. Two children had a single and three had multiple episodes over the next few months. Two children with protracted symptoms responded to 3 days treatment with high dose intravenous methylprednisolone. Symptoms ultimately resolved in all patients. SMART syndrome is a rare disorder characterized by slow evolution of neurological deficits with variable abnormal cortical contrast enhancement. The use of steroids may improve symptoms and speed resolution.

A Case of Postoperative SMART Syndrome in a Medulloblastoma Survivor

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare neurological phenomenon characterized by reversible symptoms of headache, seizure, hemiparesis, and visual changes associated with a remote history of cranial irradiation. We describe a case of a medulloblastoma survivor, presenting with postoperative neurological deficits, along with neuroimaging findings and subsequent resolution of symptoms, highly suggestive of SMART syndrome. We have also reviewed the common epidemiological and diagnostic factors associated with this rare disease, as well as discussed pathophysiological mechanisms.

SMART Syndrome (Stroke-like migraine attacks after radiation therapy): When to suspect it?

Background:

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a benign complication of brain radiation therapy, which presents circa a decade after radiation treatment. Symptoms are stroke-like deficits, epileptic seizures, and migraine. Cranial magnetic resonance imaging is characteristic for alterations in the form of unilateral cortical hyperintensities and gyriform enhancement, most prominent in the parieto-occipital regions. Prompt diagnosis is essential to avoid unnecessary investigations (e.g., brain biopsy and angiography).

Case Description:

We describe a 51-year-old female patient treated initially with cranial irradiation for a left-sided occipital metastatic lung adenocarcinoma. Five years later, she presented with migraine headache, aphasia, and a right sided hemiparesis.

Conclusion:

The triad of migraine, seizure, and hemiparesis within the context of a prior brain radiotherapy should promptly raise the suspicion of SMART syndrome. Prompt diagnosis is essential to avoid unnecessary invasive investigations.

Central Nervous System Complications Among Oncology Patients

Cancer treatment related injury to the central nervous system (CNS) is well-recognized in the setting of brain-directed radiation therapies and conventional and novel systemic anticancer therapies. Late-delayed treatment-induced CNS complications frequently result in permanent neurologic disability. Therapeutic options are supportive with limited clinical benefit, whereby alteration or discontinuation of the overall antineoplastic treatment plan is frequently necessary to prevent further neurologic injury. Better identification of patients at high risk for developing late CNS toxicities, neuroprotective strategies with modification of existing antineoplastic treatment regimens, and research efforts directed at earlier recognition and improved treatment of central neurologic complications are paramount.

Persistent Nontumoral High-Amino-Acid Uptake on Brain [11C]Methionine PET/CT in a Patient After Combined Glioma Treatment

ABSTRACT

A 44-year-old man after combined left temporal low-grade glioma treatment presented with daily multiple series of seizures. MRI demonstrated diffuse cortical swelling in the left frontal lobe with intensive gyral enhancement. PET with [11C]methionine (PET-MET) revealed increased radiotracer uptake strictly confined to the cortical ribbon of the left cerebral hemisphere, which persisted for 3 months. Tumor recurrence was suggested, and biopsy was performed. No evidence of recurrent tumor was found. During a 2-year follow-up, a diffuse gyral enhancement in the left hemisphere has persisted on MRI; PET has shown high [11C]methionine uptake in the left frontal and parietal cortex with gradual positive dynamics.

Late vascular complications after cranial radiotherapy: A report of two illustrative cases

Cranial radiotherapy (CRT) is used to treat a large variety of benign and malignant disorders. We present two cases of late neurological complications after CRT and briefly discuss its diagnosis and their shared pathophysiological aspects. The first case is a patient with cognitive impairment associated to mineralizing microangiopathy ten years after CRT for nasopharyngeal carcinoma and the second one is a woman with Stroke-like Migraine Attacks after Radiation Therapy (SMART) syndrome two years after CRT for anaplastic meningioma. Nowadays, higher survival rates might cause an increase in appearance of late neurological complications after CTR. These reported cases show that late complications can mimic a wide variety of neurological conditions and the importance of magnetic resonance image (MRI) to get a diagnosis.

SMART syndrome: a late-onset and not always reversible complication of radiotherapy

Stroke-like migraine attacks after radiation (SMART) syndrome is a rare and late complication of cerebral radiotherapy of unknown pathophysiology. It is characterised by hemicranial headache associated with persistent unilateral focal neurological signs and, occasionally, epileptic seizures. An increase in the frequency of SMART syndrome can be attributed to an increase in the survival rate of patients undergoing radiation therapy This study details the case of a 60-year-old woman with a history of small-cell lung carcinoma, who, in her late forties, was treated with prophylactic cranial irradiation. She presented at the emergency room with acute onset of global aphasia, lethargy and headache that started a few days before.

Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome: A Comprehensive Review

PURPOSE OF REVIEW

SMART syndrome is a delayed complication of cranial irradiation that can be misconstrued as tumor recurrence or some other intracranial neurological disease. Recognition of this clinical syndrome is imperative as it can obviate the need for invasive diagnostic testing and can provide reassurance to both the patient and their loved ones.

RECENT FINDINGS

SMART syndrome is generally considered a reversible clinical syndrome; however, neurological deficits may become permanent. Pathophysiology of SMART syndrome may involve cerebrovascular autoregulation impairment, neuronal dysfunction leading to trigeminovascular system impairment and/or cortical spreading depression, and seizures. In addition to MRI brain with gadolinium, other imaging modalities, such as CT perfusion, MR perfusion, MR spectroscopy, and FDG PET/CT, aid in arriving to the diagnosis sooner. Patients should also undergo electroencephalogram in order to promptly identify and treat seizures. There are currently no clear guidelines on how to effectively treat SMART syndrome, but treatment may involve anti-seizure medication, anti-hypertensives, anti-platelet, and steroid therapy. This review provides a comprehensive understanding of the clinical characteristics of SMART syndrome from presentation to diagnostic evaluation. We also discuss radiographic features and treatment strategies for this rare disease. With increased radiotherapy utilization, prompt clinical recognition of SMART syndrome and further development of a comprehensive diagnostic approach to SMART syndrome utilizing newer radiographic modalities as well as treatment algorithms to effectively treat this clinical condition will be imperative.

Imaging of Neurologic Injury following Oncologic Therapy

Neurologic injury arises from treatment of central nervous system malignancies as result of direct toxic effects or indirect vascular, autoimmune, or infectious effects. Multimodality treatment may potentiate both therapeutic and toxic effects. Symptoms range from mild to severe and permanent. Injuries can be immediate or delayed. Many early complications are nonspecific. Other early and delayed neurologic injuries, such as posterior reversible encephalopathy syndrome, dural sinus thrombosis, infarctions, myelopathy, leukoencephalopathy, and hypophysitis, have unique imaging features. This article reviews treatment options for neurologic malignancies and common and uncommon neurologic injuries that can result from treatment, focusing on radiologic features.

Atypical imaging findings of presumed stroke-like migraine attacks after radiation therapy syndrome in the brainstem

The authors present an atypical case of presumed stroke-like migraine attacks after radiation therapy (SMART) syndrome in the brainstem. A 29-year-old male, who had been treated with resection and subsequent craniospinal radiation for posterior fossa medulloblastoma 21 years before, presented with subacute progressive left hemiparesis evolving over 4 days. Hematological findings, cerebrospinal fluid (CSF), and electroencephalogram (EEG) were unremarkable. Magnetic resonance imaging (MRI) showed a round area of hyperintense FLAIR signal centered within the pons associated with central restricted diffusion, peripheral enhancement, and small paramagnetic low susceptibility signal foci consistent with petechial hemorrhage. Positron emission tomography (PET), perfusion MRI, and MR spectroscopy revealed no evidence of tumor recurrence. The diagnosis of SMART syndrome is presumed from the conventional and advanced imaging findings, clinical history, and clinical course.

Perampanel in brain tumor and SMART-syndrome related epilepsy - A single institutional experience

Epilepsy is common in patients with brain tumors and frequently presents as the first clinical manifestation of an underlying tumor. Despite a number of available antiepileptic drugs (AED), brain tumor related epilepsy (BTRE) may still be difficult to control. Recently, the AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)-type glutamate receptor antagonist perampanel (PER) is increasingly acknowledged as an attractive novel add-on AED for seizure control in BTRE. We present a single institutional experience reporting five individual cases with refractory BTRE treated with PER. In two of these five brain tumor patients, worsening of seizure control was caused by SMART-syndrome (stroke-like migraine attacks after radiation therapy). Efficacy of PER was assessed by the responder rate and by evaluating overall changes in seizure frequency before and during PER treatment. In our case series, a reduction in seizure frequency was observed in four out of five patients and the responder rate was 40%. In addition, both cases with symptomatic epilepsy associated with SMART-syndrome were successfully treated with PER. This case series supports the growing evidence that PER may become a promising add-on AED for the treatment of refractory BTRE as well as for seizure control in SMART-syndrome.

SMART Syndrome Identification and Successful Treatment

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare late complication of brain irradiation. Patients commonly present recurrent attacks of headaches, seizures, and paroxysmal focal neurological deficits including aphasia, negligence, or hemianopsia. We report a 41-year-old male patient admitted to our emergency room with a reduced level of consciousness and global aphasia. One month prior to admission, he started with frequent headache attacks of moderate intensity and paroxysmal behavioral alterations, advancing to confusion, gait instability, language impairment, and somnolence. He had a history of medulloblastoma treated with surgical resection followed by craniospinal irradiation 21 years before symptom onset. After excluding more frequent causes for the patient's symptoms along with a suggestive image pattern, we started treatment for SMART syndrome with high-dose corticosteroid and calcium channel blocker verapamil. The patient gradually improved his level of consciousness and recovered from aphasia and gait instability without new seizures or neuropsychiatric symptoms. Follow-up brain magnetic resonance imaging showed resolution of the typical findings. This case displays a successful clinical evolution of a patient treated for SMART syndrome in which identification of previous radiation treatment, exclusion of other etiologies, and prompt treatment institution were key for effectively tackling this disease.

Very late complications of oncotherapy in glioblastoma patients: A case series

BACKGROUND

Stroke-like syndrome is defined as a rare, delayed complication of brain oncotherapy. Cases with more favorable brain cancer diagnoses and longer life expectancy have been previously reported, but here we present, for the first time, three long-term survivors of glioblastoma with stroke-like syndromes.

METHODS AND RESULTS

Three young or middle-aged patients underwent tumor resection and chemoradiotherapy. They received regular clinical and imaging follow-up with stable neurological status and no signs of tumor recurrence. They exhibited varied signs and symptoms (motor and sensory deficits, aphasia, memory and cognitive disorders, seizures, and headache) accompanied by imaging abnormalities. Stroke-like syndromes developed within 2-5 days and resolved in 2-6 weeks. Diffusion-weighted MRI and T2 brain perfusion abnormalities were demonstrated in all patients. In addition, there was focal T1 MRI contrast enhancement due to blood-brain barrier disruption. In addition to tumor recurrence, classic stroke, encephalitis, metabolic and mitochondrial disorders, and post-seizure swelling should be excluded. The imaging indicated intensive MRI scanning and symptomatic medication (steroids supplemented by antiepileptics, vasoactive agents, etc.) for judicious management. With respect to the course, an invasive procedure was still considered an option.

CONCLUSION

All stroke-like syndromes are diagnoses of exclusion. To avoid misinterpretation of imaging findings as glioblastoma recurrence and avert recall oncotherapy or redundant interventions, better understanding of delayed complications of brain tumor therapy is crucial.

Intracranial long-term complications of radiation therapy: an image-based review

BACKGROUND AND PURPOSE

Radiation therapy is commonly utilized in the majority of solid cancers and many hematologic malignancies and other disorders. While it has an undeniably major role in improving cancer survival, radiation therapy has long been recognized to have various negative effects, ranging from mild to severe. In this manuscript, we review several intracranial manifestations of therapeutic radiation, with particular attention to those that may be encountered by radiologists.

METHODS

We conducted an extensive literature review of known complications of intracranial radiation therapy. Based on this review, we selected complications that had salient, recognizable imaging findings. We searched our imaging database for illustrative examples of these complications, focusing only on patients who had a history of intracranial radiation therapy. We then selected cases that best exemplified expected imaging findings in these entities.

RESULTS

Based on our initial literature search and imaging database review, we selected cases of radiation-induced meningioma, radiation-induced glioma, cavernous malformation, enlarging perivascular spaces, leukoencephalopathy, stroke-like migraine after radiation therapy, Moyamoya syndrome, radiation necrosis, radiation-induced labyrinthitis, optic neuropathy, and retinopathy. Although retinopathy is not typically apparent on imaging, it has been included given its clinical overlap with optic neuropathy.

CONCLUSIONS

We describe the clinical and imaging features of selected sequelae of intracranial radiation therapy, with a focus on those most relevant to practicing radiologists. Knowledge of these complications and their imaging findings is important, because radiologists play a key role in early detection of these entities.

SMART syndrome: retrospective review of a rare delayed complication of radiation

BACKGROUND

SMART (stroke-like migraine attacks after radiation therapy) is a rare, delayed complication of brain radiation. In this study, we wanted to review the spectrum of symptoms, neuroradiological findings, autoimmune status, and outcomes in SMART syndrome patients.

METHODS

We conducted a retrospective cohort study of all consecutive adult patients (≥18 years) diagnosed with SMART syndrome at Mayo Clinic, Rochester between January 1995 and December 2018.

RESULTS

We identified 25 unique patients with SMART syndrome and a total of 31 episodes and 15 (60%) patients were male. The median age at onset was 46 (interquartile range [IQR] 43-55) years and the median latency of onset after the initial radiation was 21.6 (IQR 14.4-28.2) years. Magnetic resonance imaging (MRI) showed gyral edema and enhancement in all cases with the temporal (25, 80.6%) and parietal (23, 74.2%) lobes being the most commonly affected. The median follow-up of the patients in our cohort was 10 (IQR 6-32) weeks. On univariate analysis, factors associated with an increased risk of recurrent SMART episodes were female gender (odds ratio [OR] 8.1, 95% confidence interval [95% CI] 1.1-52.6, p = 0.019) and absence of electrographic seizure discharges during initial symptoms (OR 7.4, 95% CI 1.1-45.9, p = 0.032). We could not identify an autoimmune etiology. Longer duration of symptoms (>10 weeks) correlated with an older age (p = 0.049), temporal lobe involvement (p < 0.001), and diffusion restriction (p = 0.043).

CONCLUSIONS

SMART is a syndrome with characteristic imaging findings and clinical features. Incomplete recovery by 10 weeks occurred in one-third of individuals and was associated with older age, temporal lobe involvement, and restricted diffusion on MRI.

Recognizing Radiation-induced Changes in the Central Nervous System: Where to Look and What to Look For

Radiation therapy (RT) continues to play a central role as an effective therapeutic modality for a variety of tumors and vascular malformations in the central nervous system. Although the planning and delivery techniques of RT have evolved substantially during the past few decades, the structures surrounding the target lesion are inevitably exposed to radiation. A wide variety of radiation-induced changes may be observed at posttreatment imaging, which may be confusing when interpreting images. Histopathologically, radiation can have deleterious effects on the vascular endothelial cells as well as on neuroglial cells and their precursors. In addition, radiation induces oxidative stress and inflammation, leading to a cycle of further cellular toxic effects and tissue damage. On the basis of the time of expression, radiation-induced injury can be divided into three phases: acute, early delayed, and late delayed. Acute and early delayed injuries are usually transient and reversible, whereas late delayed injuries are generally irreversible. The authors provide a comprehensive review of the timeline and expected imaging appearances after RT, including the characteristic imaging features after RT with concomitant chemotherapy. Specific topics discussed are imaging features that help distinguish expected posttreatment changes from recurrent disease, followed by a discussion on the role of advanced imaging techniques. Knowledge of the RT plan, the amount of normal structures included, the location of the target lesion, and the amount of time elapsed since RT is highly important at follow-up imaging, and the reporting radiologist should be able to recognize the characteristic imaging features after RT and differentiate these findings from tumor recurrence. ^©RSNA, 2020.

Late effects of cancer treatment: consequences for long-term brain cancer survivors

Late adverse effects of cancer treatments represent a significant source of morbidity and also financial hardship among brain tumor patients. These effects can be produced by direct neurologic damage of the tumor and its removal, and/or by complementary treatments such as chemotherapy and radiotherapy, either alone or combined. Notably, young adults are the critical population that faces major consequences because the early onset of the disease may affect their development and socioeconomic status. The spectrum of these late adverse effects is large and involves multiple domains. In this review we classify the main long-term adverse effects into 4 sections: CNS complications, peripheral nervous system complications, secondary neoplasms, and Economic impact. In addition, CNS main complications are divided into nonfocal and focal symptoms. Owing to all the secondary effects mentioned, it is essential for physicians to have a high level of clinical suspicion to prevent and provide early intervention to minimize their impact.

Fundamentals of Radiation Oncology for Neurologic Imaging

Although the physical and biologic principles of radiation therapy have remained relatively unchanged, a technologic renaissance has led to continuous and ever-changing growth in the field of radiation oncology. As a result, medical devices, techniques, and indications have changed considerably during the past 20-30 years. For example, advances in CT and MRI have revolutionized the treatment planning process for a variety of central nervous system diseases, including primary and metastatic tumors, vascular malformations, and inflammatory diseases. The resultant improved ability to delineate normal from abnormal tissue has enabled radiation oncologists to achieve more precise targeting and helped to mitigate treatment-related complications. Nevertheless, posttreatment complications still occur and can pose a diagnostic challenge for radiologists. These complications can be divided into acute, early-delayed, and late-delayed complications on the basis of the time that they manifest after radiation therapy and include leukoencephalopathy, vascular complications, and secondary neoplasms. The different irradiation technologies and applications of these technologies in the brain, current concepts used in treatment planning, and essential roles of the radiation oncologist in the setting of brain disease are reviewed. In addition, relevant imaging findings that can be used to delineate the extent of disease before treatment, and the expected posttreatment imaging changes are described. Common and uncommon complications related to radiation therapy and the associated imaging manifestations also are discussed. Familiarity with these entities may aid the radiologist in making the diagnosis and help guide appropriate management. ^©RSNA, 2020.

SMART (Stroke-Like Migraine Attacks After Radiation Therapy) Syndrome: A Case Study with Imaging Supporting the Theory of Vascular Dysfunction

Patient: Male, 28-year-old

Final Diagnosis: SMART syndrome

Symptoms: Seizure

Medication: —

Clinical Procedure: —

Specialty: Neurosurgery

Stroke-Like Migraine Attacks after Radiation Therapy Syndrome: Clinical and Imaging Characteristics

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare, reversible phenomenon that occurs several years after radiotherapy in patients treated for intracranial neoplastic lesions. Patients typically present with symptoms of headache, seizures, and other focal neurologic deficits concerning for stroke or disease recurrence. In this report, we describe SMART syndrome in a 70-year-old male who developed a persistent right temporal headache, right-sided neck pain, and new-onset seizures 12 years after surgical resection of a temporal anaplastic ependymoma followed by irradiation. We present this case to highlight typical disease presentation, imaging characteristics, and important differential radiologic considerations. Recognition of this delayed complication of brain tumor radiation is paramount given its self-limited course and favorable response to conservative therapy and to avoid misinterpreting imaging findings as tumor recurrence.