A focal onset seizure refers to abnormal neural activity in only one brain area within one brain hemisphere with a fixed focal or localized onset. Focal onset seizures are divided into 2 subtypes: motor onset and nonmotor onset. Both focal motor and focal nonmotor onset seizures can be further classified based on level of awareness: aware, impaired, and unknown awareness. The motor manifestations of focal motor onset seizures can be characterized as automatism, atonic, clonic, epileptic spasms, hyperkinetic, myoclonic, or tonic movements. The behavioral manifestations of focal nonmotor onset seizures can be described by autonomic, behavioral arrest, cognitive, emotional, or sensory symptoms. Some focal onset seizures can be preceded by an "aura," which refers to symptoms and signs that occur before the onset of seizure activity. These symptoms may include vision changes, dyspepsia, déjà vu, paresthesias, hearing disturbances, and sensation of abnormal taste or smell. A seizure is a sign that refers to a transient occurrence of signs and symptoms due to episodic, excessive, and disorderly neuronal activity within the brain. Epilepsy is a brain disorder "characterized by an enduring predisposition to generate epileptic seizures and by this condition's neurobiological, cognitive, psychological, and social consequences. The definition of epilepsy requires the occurrence of at least one epileptic seizure." These events have traditionally been classified into partial and generalized seizures. However, the International League Against Epilepsy (ILAE) in 2017 reclassified seizures into 3 types: generalized onset seizures (formerly known as grand-mal seizures), focal onset seizures (formerly known as simple partial seizures or complex partial seizures), and unknown onset seizures.  Focal motor seizures occur due to an epileptogenic lesion on the contralateral frontal lobe. They usually originate from the supplementary motor area. The excitatory focus is generally around the rolandic (motor) cortex. Temporal lobe seizures can also have motor symptoms. These symptoms include turning the head and neck to the opposite side and sometimes tonic contractions of the limbs and trunk. The motor manifestations of focal motor onset seizures can be characterized by tonic, clonic, atonic, myoclonic, hyperkinetic, epileptic spasms, and automatisms.  Motor manifestations of focal motor onset seizures include the following: Abnormal sustained contractions and posturing of the limbs characterize tonic movements. Clonic movements are characterized by repeated, short contractions of various muscle groups characterized by twitching movements or rhythmic jerking. Atonic movements are characterized by loss of tone in a limb. Myoclonic movements are characterized by irregular, nonrhythmic jerking of the limbs. Abnormal regular or irregular excess involuntary movements of the limbs characterize hyperkinetic movements. Epileptic spasms are characterized by repetitive flexion of the waist and flexion or extension of the arms. Automatisms are characterized by coordinated, repetitive motor activities such as lip-smacking, tapping, or swallowing. Following focal motor seizures, patients may have transient, functional, and localized paralysis of the affected muscles, known as Toddparalysis. This paralysis can last minutes to hours, usually in proportion to the duration of the focal motor seizure. This postepileptic paralysis occurs due to persistent focal dysfunction of the affected epileptogenic area and is the signature of a focal seizure. The significant clinical value lies in lateralizing the hemisphere of seizure onset, and it is often mistaken for a stroke. The clinical manifestations of focal nonmotor seizure include autonomic, behavioral arrest, cognitive, emotional, or sensory symptoms. Autonomic seizures are characterized by changes in blood pressure, heart rate, sweating, skin color, or gastrointestinal upset. Behavioral arrest seizures are characterized by cessation of movement. Cognitive seizures are characterized by abnormal language or thinking, eg, jamais vu, déjà vu, hallucinations, and visualization of illusions. Emotional seizures are characterized by emotional changes such as fear, dread, anxiety, or pleasure. Nonmotor seizures that manifest as laughing are called gelastic, and those that manifest as crying are called dacrystic. Sensory seizures are characterized by changes in sensation, such as abnormal sensations of vision, paresthesias, hearing, smell, or pain. At times, focal motor and focal nonmotor seizures can evolve into bilateral tonic-clonic seizures.