The seizure commences in one hemisphere but involves bilateral muscle groups rapidly at seizure onset. Certain frontal lobe seizure sub-types have bilateral motor features at onset, often with asymmetric posturing. Typically, there is extension of the upper limb (at the elbow) contralateral to the hemisphere of seizure onset (often with a clenched fist and flexion at the wrist) and flexion of the ipsilateral upper limb at the elbow. This type of seizure is also described as a 'fencer's posture' or a figure of 4. Awareness can be preserved during the bilateral movement, resulting in misdiagnosis of the seizure as a non-epileptic seizure. These seizures can progress to a focal to bilateral tonic-clonic seizure.