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

Abstract

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.

Keywords: CT findings; adult-onset; first-onset; new-onset; seizure.

FIGURE 1

Vascular pathology as a cause of adult-onset seizures. (a and b) Hypertensive intraparenchymal haemorrhage in a 56-year-old male with newly diagnosed hypertension. Axial non-enhanced CT (NECT): Left thalamic haemorrhage with minimal surrounding oedema. Associated intraventricular blood. (c and d) Chronic right middle cerebral artery territory infarction in an adult patient with index episode of seizures. Axial and coronal NECT: Right MCA territory wedge-shaped hypodensity with mild right lateral ventricular ex vacuo dilatation. (e) Right occipital lobe arteriovenous malformation in a 53-year-old female with no background medical history. Axial contrast enhanced CT (CECT): ‘Bag of worms’ appearance of draining and feeding vessels in the right occipital lobe.

FIGURE 2

Infective pathology as a cause of adult-onset seizures. (a and b) Herpes Simplex (HSV) encephalitis in a young immunocompromised female patient. Axial NECT: Bilateral anterior temporal lobe oedema with hyperdense foci in keeping with microhaemorrhages. (c and d) Neurocysticercosis in a 47-year-old male with newly diagnosed HIV. Axial - contrast enhanced CT (CECT): Multiple bilateral non-enhancing round CSF density cystic intra-axial lesions of varying sizes with central hyperdense scolices (dot sign). (e and f) HIV positive patient on tuberculosis treatment. Coronal and axial CECT: Large right frontal lobe ring-enhancing lesion adjacent to the right lateral ventricle. Surrounding vasogenic oedema with associated mass effect. A differential diagnosis of a pyogenic or a tuberculous abscess was given. (g and h) A 53-year-old HIV positive male patient. CD4 = 26 cells/μL. Axial CECT: Multiple ring-enhancing lesions with vasogenic oedema in the cerebellum and corticomedullary junction of cerebrum. A differential of toxoplasmosis and tuberculomas was given.

FIGURE 3

Neoplastic pathology as a cause of adult-onset seizures. (a and b) Meningioma in a 64-year-old female with worsening of left arm weakness and new-onset seizures. Sagittal contrast enhanced CT (CECT). (brain and bone window): Large right frontal avidly enhancing extra-axial mass with associated hyperostosis of the adjacent skull inner table as well as mass effect and oedema of the adjacent parenchyma. (c and d) Left frontal lobe mass in a 59-year-old female who presented with new-onset seizures. Axial and coronal non-contrast CT (NCCT): Large left frontal lobe solid round intra-axial heterogeneously hyperdense mass with surrounding vasogenic oedema and mass effect on the frontal horn of the left lateral ventricle. A differential diagnosis of metastases or lymphoma was given. e: Metastasis from endometroid adenocarcinoma of the endometrium. 69-year-old female with endometroid adenocarcinoma of the endometrium who presented with first onset seizures. Axial CECT: Large ring-enhancing solid-cystic intra-axial mass in the left temporal lobe corticomedullary junction with surrounding oedema.

FIGURE 4

Trauma related pathology as a cause of adult-onset seizures. (a and b) Bilateral rectus gyri gliosis in a 49-year-old male with new-onset seizures. Sagittal and coronal contrast enhanced CT (CECT): Hypodensities of bilateral rectus gyri consistent with gliosis. (c and d) Left acute subdural hematoma in a 72-year-old male with new-onset seizures and confusion. Axial and coronal non-enhanced CT (NECT): Large left mixed density subdural hematoma with a haematocrit level. Associated subfalcine and uncal herniation with right lateral ventricle entrapment hydrocephalus.