First-Time Seizure Patients have High Rate of Abnormalities on Emergency Department Performed Brain Computed Tomography: A Prospective Study

BACKGROUND

First-time seizures comprise 15% to 35% of all seizure-related complaints in the emergency department (ED). Emergent neuroimaging of first-time seizure patients is recommended by both the American Academy of Neurology and American College of Emergency Physicians. However, most of these studies are over 10 years old and included both adults and children.

OBJECTIVES

The goal of this investigation is to determine the rate of abnormal neuroimaging in adults with first-time seizures presenting to the ED during the current era.

METHODS

This was a prospective observational study of patients presenting to three urban EDs with a chief complaint of seizure over 18 months. Abnormal neuroimaging findings were defined a priori and were dichotomized into acute and subacute/chronic categories.

RESULTS

Of the 2505 patients who presented with a seizure, 242 patients (9.7%) presented with a first-time seizure. The most common etiologies for first-time seizures were drug intoxication and drug withdrawal. Of those 242 patients, 29 (11.9%) patients had abnormal findings on brain computed tomography (CT). Brain CT demonstrated an acute finding in 13 (45%) patients and a subacute/chronic finding in 16 (55%) patients. The most common abnormality overall and the most common chronic finding was ischemic changes. The most common acute findings were traumatic intracranial hemorrhage and intracranial metastases.

CONCLUSIONS

This study demonstrated that 11.9% of first-time seizure patients presenting to the ED had abnormal findings on neuroimaging. Our findings support current recommendations to obtain emergent neuroimaging for adult patients with first-time seizures.

Imaging of central nervous system emergencies in oncology

Central nervous system (CNS) may be predisposed to devastating complications in cancer patients which may add to morbidity and mortality in this group. Majority of the complications are vascular in nature due to the altered coagulation profile and pro-inflammatory state in these patients. However, there are a host of other conditions which may affect the clinical course of these patients including metabolic and toxic encephalopathies, infections, and paraneoplastic syndromes. Moreover, multimodality management of these patients, which is often used in majority of the cancers, exposes them to treatment related complications. This pictorial review aims to enlighten the reader regarding the various complications affecting the CNS as seen at our tertiary cancer care institute. We aim to highlight the emergent nature of these complications and the need to identify them quickly and accurately on imaging which helps to institute early appropriate management and prevents further morbidity and mortality.

Imaging in medically refractory epilepsy at 3 Tesla: a 13-year tertiary adult epilepsy center experience

Objectives

MRI negative epilepsy has evolved through increased usage of 3 T and insights from surgically correlated studies. The goal of this study is to describe dedicated 3 T epilepsy MRI findings in medically refractory epilepsy (MRE) patients at a tertiary epilepsy center to familiarize radiologists with an updated spectrum and frequency of potential imaging findings in the adult MRE population.

Methods

Included were all patients with MRE admitted to the epilepsy monitoring unit who were discussed at weekly interdisciplinary imaging conferences at Toronto Western Hospital with MRI studies (3 T with dedicated epilepsy protocol) performed between January 2008 and January 2021. Lesion characterization was performed by two readers based on most likely imaging diagnosis in consensus. Lobes involved per case were recorded.

Results

A total of 738 patients (386 female; mean age 35 years, range 15–77) were included. A total of 262 patients (35.5%) were MRI negative. The most common imaging finding was mesial temporal sclerosis, seen in 132 patients (17.9%), followed by encephalomalacia and gliosis, either posttraumatic, postoperative, postischemic, or postinfectious in nature, in 79 patients (10.7%). The most common lobar involvement (either partially or uniquely) was temporal (341 cases, 58.6%). MRE patients not candidates for surgical resection were included in the study, as were newly described pathologies from surgically correlated studies revealing findings seen retrospectively on reported MRI negative exams (isolated enlargement of the amygdala, temporal pole white matter abnormality, temporal encephalocele).

Conclusion

This study provides an updated description of the spectrum of 3 T MRI findings in adult MRE patients from a tertiary epilepsy center.

Focal-onset seizure due to left internal carotid artery dissection in the context of confounding hyperglycaemia

A 36-year-old diabetic woman presented to hospital with a seizure that started with shaking of the right hand which sequentially progressed to the entire right side of the body with associated loss of consciousness. Capillary Blood Glucose was 29 mmol/L. HbA1c was 133 mmol/L. Non-contrast computerised tomography (CT) scan of the brain was normal suggesting that the cause of her seizure was hyperglycaemia. However, Magnetic Resonance Imaging (MRI) of the brain showed infarcts in the left paracentral lobule and caudate nucleus. It also identified loss of signal flow void in the intracranial segment of the left internal carotid artery (ICA) raising the suspicion for thrombosis secondary to dissection. This was later confirmed on CT angiogram. This case demonstrates how the initial CT Head was non-diagnostic. We stress the importance of taking a careful seizure history and subsequently obtaining an MRI scan to fully exclude structural pathology.

An audit of CT brain findings in adults with new-onset seizures in a resource restricted setting in South Africa

Background

Globally, adults presenting with seizures account for 1% – 2% of visits to emergency departments (EDs), of which 25% are new-onset seizures. Neuroimaging is essential as part of the initial workup. Multiple studies have demonstrated abnormal CT brain (CTB) findings in these patients.

Objectives

To review the CTB findings in adults presenting with new-onset seizures in a resource restricted setting.

Method

A retrospective review of 531 CTBs was conducted at a tertiary hospital in Gauteng on adults presenting to the ED with new-onset seizures.

Results

The mean age of the patients was 45.6 ± 17.1 years, and the male to female ratio was 1.2:1. Generalised and focal seizure types were almost equally represented. Of the total 531 patients, 168 (31.6%) were HIV positive. The CTB findings were abnormal in 257 (48.4%) patients, albeit vascular pathology accounted for 21.9%. Infective pathology accounted for 14.1% with a statistically significant association with HIV (p = 0.003). Trauma related pathology was 2.4%, whilst neoplastic pathology was seen in 3.0%. Other causes included congenital pathology, calcifications, atrophy and gliosis. Clinical factors associated with abnormal CTB findings were age ≥ 40 years, HIV infection, hypertension, focal seizures, low Glasgow Coma Scale (GCS), raised cerebrospinal fluid (CSF) protein and presence of lymphocytes.

Conclusion

A high yield of abnormal CTB findings was noted in adult patients who presented with new-onset seizures, supporting the use of urgent CTB in patients with certain clinical risk factors. Patients without these risk factors can be scanned within 24–48 h in a resource restricted setting.

Etiological profile of new-onset seizures among adult Egyptians

Background

New-onset seizure (NOS) is defined as the first seizure within a 24-h period ever experienced by the patient. A first-ever seizure can be the first manifestation of epilepsy. Or it may be a symptom of a brain tumor, a systemic disorder, an infection, or a syndrome that deserves special attention and treatment. This study aims to identify the etiology of NOS among different age and sex groups of adult Egyptian patients. A hundred and twenty adult Egyptian patients (> 18 years) presented with acute NOS were enrolled in a hospital-based cross-sectional observational study from the emergency room and neurology outpatient clinics of our hospitals within a time period of 6 months from March till September 2018. All patients were subjected to neurological examination, laboratory, neuroimaging, and electroencephalogram investigations.

Results

Among 120 adult patients presented with NOS, males were prevalent (63%). Older adults (age group > 55 years) were the most prevalent cohort (60%). Cerebrovascular diseases (CVDs) were the most common identified etiology of NOS (44.17%), followed by idiopathic epilepsy syndrome (18.33%), symptomatic mainly “metabolic” (11%), brain tumors (9.17%), post-traumatic epilepsy (6.67 %), encephalitis (5.83%), and cryptogenic (5%). Idiopathic epilepsy syndrome was the most common etiology (55.56%) of new-onset seizures among the young adult age group (< 36 years), while CVDs were the most common etiology (65.28%) among older adults (> 55 years). Also, CVDs were the most common etiology among males (43.4%) as well as females (45.4%). However, male predominance was the highest among post-traumatic seizures (87.5%). And female predominance was the highest among brain tumors identified etiology of NOS (54.5%).

Conclusion

NOS among adults are prevalent in elder males. CVDs are the most commonly identified etiology of adult NOS across males and females. Idiopathic epilepsy syndromes are the predominant etiology among younger adults.

Toward individualized prediction of seizure recurrence: Hippocampal neuroimaging features in a cohort of patients from a first seizure clinic

PURPOSE

We performed an exploratory analysis of electroencephalography (EEG) and neuroimaging data from a cohort of 51 patients with first seizure (FS) and new-onset epilepsy (NOE) to identify variables, or combinations of variables, that might discriminate between clinical trajectories over a one-year period and yield potential biomarkers of epileptogenesis.

METHODS

Patients underwent EEG, hippocampal and whole brain structural magnetic resonance imaging (MRI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS) within six weeks of the index seizure, and repeat neuroimaging one year later. We classified patients with FS as having had a single seizure (FS-SS) or having converted to epilepsy (FS-CON) after one year and performed logistic regression to identify combinations of variables that might discriminate between FS-SS and FS-CON, and between FS-SS and the combined group FS-CON + NOE. We performed paired t-tests to assess changes in quantitative variables over time.

RESULTS

Several combinations of variables derived from hippocampal structural MRI, DTI, and MRS provided excellent discrimination between FS-SS and FS-CON in our sample, with areas under the receiver operating curve (AUROC) ranging from 0.924 to 1. They also provided excellent discrimination between FS-SS and the combined group FS-CON + NOE in our sample, with AUROC ranging from 0.902 to 1. After one year, hippocampal fractional anisotropy (FA) increased bilaterally, hippocampal radial diffusivity (RD) decreased on the side with the larger initial measurement, and whole brain axial diffusivity (AD) increased in patients with FS-SS; hippocampal volume decreased on the side with the larger initial measurement, hippocampal FA increased bilaterally, hippocampal RD decreased bilaterally and whole brain AD, FA and mean diffusivity increased in the combined group FS-CON + NOE (corrected threshold for significance, q = 0.017).

CONCLUSION

We propose a prospective, multicenter study to develop and test models for the prediction of seizure recurrence in patients after a first seizure, based on hippocampal neuroimaging. Further longitudinal neuroimaging studies in patients with a first seizure and new-onset epilepsy may provide clues to the microstructural changes occurring at the earliest stages of epilepsy and yield biomarkers of epileptogenesis.

New-onset seizures in adults: Low diagnostic yield of gadolinium contrast in initial brain MRI evaluation

BACKGROUND AND PURPOSE

The diagnostic utility of contrast MR-imaging in adult new-onset seizures without clinically suspected neoplasia or infection is not well defined in the literature. Imaging guidelines consider both contrast and noncontrast MR-imaging examinations appropriate in this clinical scenario. The purpose of this study was to evaluate the utility of contrast MR-sequences in evaluation of seizure in patients without suspicion for neoplasia or infection.

METHODS

Imaging and clinical data were reviewed for 103 consecutive patients admitted for phase-1 seizure monitoring with the following criteria: (1) MRI-brain performed with/without intravenous contrast; (2) no clinical suspicion for central nervous system (CNS) infection; and (3) no history of CNS neoplasia, or suspected metastatic disease. Readers designated cases as lesional or nonlesional. Lesional cases were further categorized as either visualized on noncontrast sequences only, contrast sequences only, or both.

RESULTS

29/103 (28%) patients had epileptogenic lesions, 74/103 (72%) were nonlesional studies. 29/29 (100%) lesional abnormalities were detected on noncontrast sequences (sensitivity 100% [95 confidence interval (CI): 88-100], specificity 100% [95 CI: 95-100]). 23/29 (79.3%) lesional cases were visualized on both noncontrast and postcontrast sequences. 6/29 (20.7%) were visualized only on noncontrast sequences. No lesional cases were detected exclusively on postcontrast MR sequences. With an observed nonlesional extraneous contrast MR-imaging rate of 72%, estimated excess cost of contrast MR-imaging per 1000 patients using Medicare data was $103,680 USD.

CONCLUSIONS

Contrast MR-imaging has limited diagnostic utility in initial screening of adult new-onset seizure patients without clinically suspected neoplasia or infection. More judicious use of contrast MR-imaging in this patient population may reduce unnecessary exposure to gadolinium and lower associated healthcare costs.