From the Guidelines
Focal seizures and simple partial seizures are not the same, although they share some similarities.
Key Differences
- Focal seizures are defined as those with onset limited to one hemisphere of the brain, and can be further characterized by having motor onset or nonmotor onset symptoms, and by being aware or having impaired awareness 1.
- Simple partial seizures, also known as focal aware seizures, are a type of focal seizure where the patient retains awareness during the seizure 1.
Seizure Classification
- The International League Against Epilepsy (ILAE) classifies seizures as focal onset, generalized onset, or unknown onset 1.
- Focal seizures can be further subdivided into focal aware seizures (simple partial seizures) and focal impaired awareness seizures (formerly known as complex partial seizures) 1.
Clinical Implications
- Focal seizures, including simple partial seizures, have a higher frequency of recurrence and are more likely to have a structural cause, such as a tumor or cortical dysplasia, compared to generalized seizures 1.
- Neuroimaging, such as MRI, is often used to evaluate patients with focal seizures to identify any underlying structural abnormalities 1.
From the Research
Definition of Focal Seizures and Simple Partial Seizures
- Focal seizures are characterized by an initial seizure onset in one hemisphere of the brain, and can be further classified based on the presence or absence of awareness and motor signs 2
- Simple partial seizures, also known as focal aware seizures, are a type of focal seizure where the individual remains conscious and aware during the seizure, and are typically characterized by simple, unnatural movements such as myoclonic, tonic, clonic, and tonic-clonic movements 3, 4
Key Differences
- The main difference between focal seizures and simple partial seizures is the level of consciousness during the seizure, with simple partial seizures being characterized by retained consciousness and focal seizures having impaired consciousness 5
- Focal seizures can be further classified into those with impaired consciousness (Focal Impaired Consciousness Seizures, FICS) and those with retained consciousness (Focal Aware Conscious Seizures, FACS) 5
- Simple partial seizures are typically short in duration and consist primarily of motor symptoms, whereas complex partial seizures (a type of focal seizure with impaired consciousness) are longer and can be categorized into different subgroups based on initial clinical manifestations 4
Classification
- The International League Against Epilepsy (ILAE) classification system recognizes focal seizures as a distinct category, and further classifies them based on the presence or absence of awareness and motor signs 2
- The ILAE classification system also recognizes simple partial seizures as a type of focal seizure, characterized by retained consciousness and simple motor symptoms 3, 6