Acute late-onset encephalopathy after radiotherapy: An unusual life-threatening complication

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.

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.

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.

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.

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.

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.

SMART (stroke-like migraine attacks after radiation therapy) syndrome responded to steroid pulse therapy: Report of a case and review of the literature

This report presents a case of stroke-like migraine attacks after radiation therapy (SMART) syndrome in a 31-year-old man in whom symptoms and radiological findings resolved with steroid pulsed therapy and reviews the literatures with special emphasis on the use of steroids against SMART syndrome. The patient had a past history of left temporal anaplastic astrocytoma and was treated with surgery followed by local 72 Gy radiation therapy and chemotherapy using Nimustine Hydrochloride. Four years after the surgery, he was suffering from subacute progressing symptoms of headache, right hemianopia, right hemiparesis and aphasia from 2 to 4 days before admission to our hospital. At first he was diagnosed as symptomatic epilepsy but after extensive examination, the final diagnosis was SMART syndrome. His symptoms soon improved with steroid pulse therapy. In the literature, steroid pulse therapy is not necessarily a standard of care for SMART syndrome, but it seemed to decrease the need of biopsy. As the lesions of SMART syndrome require differential diagnosis from recurrences, biopsy was performed in some cases. However, lack of benefit and possible detriment is reported with biopsy of SMART lesions. Through this experience we suggest that steroid pulse therapy may provide speedy recovery from symptoms, and it should be considered before other invasive investigations or treatments.

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Report a case of stroke-like migraine attacks after radiation therapy (SMART) syndrome in a 31-year-old man in whom symptoms and radiological findings resolved with steroid pulsed therapy.

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Lack of benefit and possible detriment is reported with biopsy of SMART lesions.

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Steroid pulse therapy is not necessarily a standard of care for SMART syndrome, but it seemed to decrease the need of biopsy.

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Steroid pulse therapy may provide recovery from symptoms of SMART, and should be considered before invasive investigations.

Neurological Complications Involving the Central Nervous System After Allogeneic Hematopoietic Stem Cell Transplantation During a Period of Evolution in Transplant Modalities: A Cohort Analysis

BACKGROUND

Neurological complications (NC) after hematopoietic stem cell transplantation (HSCT) are rare events. The evolution of transplant procedures has resulted in improved survival and has allowed elderly patients or those with comorbidity to receive an HSCT. The risk of NC in these patients has still not been well defined. Therefore, we carried out an observational study to estimate the occurrence and identify the risks associated with NC.

METHODS

The study cohort included 452 adult-allogeneic HSCT recipients, transplanted from 1997 to 2012. The median follow up was 1.3 year (0-15.7). A myeloablative regimen was used in 307 patients. Two hundred patients were grafted from matched unrelated donor (MUD), of these, 129 (64.5%) received an in vivo T-cell depletion.

RESULTS

Out of 452 patients, 30 (6.6%) developed NC. Infections were the most frequent causes of NC (30%). Overall survival decreased in patients developing NC (P < 0.001). Univariate survival regression on the cumulative incidence of NC identified period of transplant, linear trend between 4-year periods (1997-2012) (P < 0.001), MUD (P < 0.001), and recipient's age (P = 0.034) as significant risk factors. In multivariate analysis, period of transplant (P < 0.001) and MUD (P = 0.004) remained significant independent risk factors. Matched unrelated donor recipients showed a 3.8-fold elevated risk of developing NC.

CONCLUSIONS

Analysis highlights a temporal trend of incidence of NC that progressively increased over time and confirms a strong association between donor type and risk of NC. Our observations suggest that, although relatively uncommon, NC after allo-HSCT, may become more frequent due to the improved overall survival in recent years.

Unusual case of recurrent SMART (stroke-like migraine attacks after radiation therapy) syndrome

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare delayed complication of cerebral radiation therapy. A 53-year-old female initially presented with headache, confusion and left homonymous hemianopia. Her medical history was notable for cerebellar hemangioblastoma, which was treated with radiation in 1987. Her initial brain MRI (magnetic resonance imaging) revealed cortical enhancement in the right temporo-parieto-occipital region. She improved spontaneously in 2 weeks and follow-up scan at 4 weeks revealed no residual enhancement or encephalomalacia. She presented 6 weeks later with aphasia. Her MRI brain revealed similar contrast-enhancing cortical lesion but on the left side. Repeat CSF studies was again negative other than elevated protein. She was treated conservatively and recovered completely within a week. Before diagnosing SMART syndrome, it is important to rule out tumor recurrence, encephalitis, posterior reversible encephalopathy syndrome (PRES) and stroke. Typically the condition is self-limiting, and gradually resolves.

Refractory status epilepticus due to SMART syndrome

INTRODUCTION

Stroke-like migraine attacks after radiation therapy (SMART) is a late-onset complication of brain irradiation of unknown physiopathology. Our aim was to present three patients with SMART syndrome who had clinical and neuroimage studies suggestive of status epilepticus.

PATIENTS

Patient 1. A 69-year-old woman, who was treated with radiation therapy 14 years before her first admission to the Neurology Department, presented with several episodes of headache, speech disturbances, and weakness of left limbs with altered awareness. Patient 2. A 49-year-old man, who was treated with whole brain radiation 20 years before the onset of symptoms, developed some episodes consisting of headache and numbness of the right side of face and right arm; the latest episodes were accompanied by visual disturbances followed by generalized tonic-clonic seizures. Patient 3. A 40-year-old man, who received cranial irradiation 20 years before, suffered three episodes of behavioral disturbance, aphasia, headache, and visual aura followed by left homonymous hemianopia.

RESULTS

All three patients suffered seizures mostly with visual aura. Electroencephalography showed interictal epileptiform discharges or focal slowing. Brain magnetic resonance image (MRI), positron emission tomography (PET), or ictal-single-photon emission computed tomography (SPECT) showed focal cortical hyperperfusion. Focal diffusion restriction and focal gadolinium-enhancement were observed on MRI. All patients were treated with antiepileptic drugs, being effective in one of them. One patient needed anesthesic coma, and the other patient responded to therapy with corticosteroids.

CONCLUSIONS

Taking into account clinical evolution and ictal neuroimaging studies, status epilepticus could explain the origin of these episodes in SMART syndrome. Although most patients have reversible symptoms, in some cases, aggressive treatment to avoid sequelae is needed. This article is part of a Special Issue entitled "Status Epilepticus".