Brain Lesions Attributed to Acute Seizures

Abstract

Brain lesions may be detected by magnetic resonance imaging (MRI) during acute seizures or just after the seizures. Lesions are associated with restriction of diffusion, increment of T2 signals, and increment of contrast enhancement (CE) in MRI. Magnetic resonance angiography (MRA) and brain perfusion images are useful for distinguishing brain lesions attributed to acute seizures (BLASs) from acute ischemic lesions. BLASs can be distinguished from acute cerebral infarction with the following features. MRA may indicate that cerebral blood vessels in the regions of BLASs are prominent or have an increased diameter. A distinct emergence of vascular branches may also be observed at the regions in MRA. In addition, the early break-down of blood brain barrier in the BLASs and their surrounding areas may lead to CE of leptomeninges. Increase of local perfusion during the ictal phase also makes BLASs different from acute cerebral infarction. The differentiation of BLASs from other pathological conditions such as cerebral infarction and encephalitis is not straightforward. Misinterpretation of brain imaging may lead to failure to provide adequate managements or overuses of diagnostic methods and overtreatments. To reduce these clinically critical errors, we must have a multidisciplinary approach to diagnose patients’ conditions. Most BALSs are transient and reversible. Thus, follow-up studies of MRI are needed to confirm the lesions. However, the duration of the existence of the lesions are variable. Some lesions may remain while other may not.

Keywords

• Seizures
• Magnetic resonance imaging
• Physiopathology
• Diagnosis