Focal seizures (also called
partial seizures and
localized seizures) are
seizures which affect initially only one hemisphere of the brain. The brain is divided into
two hemispheres, each consisting of
four lobes – the frontal, temporal, parietal and occipital lobes. In partial seizures the seizure is generated in and affects just one part of the brain – the whole hemisphere or part of a lobe. Symptoms will vary according to where the seizure occurs. In the
frontal lobe symptoms may include a wave-like sensation in the head; in the
temporal lobe, a feeling of
déjà vu; in the
parietal lobe, a numbness or tingling; and in the
occipital lobe, visual disturbance or hallucination.