Seizures and Epilepsy: Parietal Lobe Epilepsy

Parietal lobe epilepsy (PLE) is characterized by frequent auras and diverse semiologies that may be difficult to diagnose, especially in children, because of the subjective nature of the experience. Positive and/or negative sensory features occur. Paresthesia, disorientation, complex visual hallucinations, vertigo, visual illusions, and disturbance of body image (somatic illusion) can occur. Proprioceptive-induced seizures are a rare but unique expression of PLE.

Receptive language impairment can occur with dominant hemisphere involvement. Ipsilateral or contralateral rotatory body movements can occur. They are characterized by motor seizure attacks precipitated by proprioceptive stimuli of the extremities. There is often involvement of other lobes as the seizure spreads.

Abnormalities can be enhanced by sleep deprivation and sleep. Sometimes the EEG abnormality and ictal events may be precipitated by sensory stimulation e.g. movement/touch of a body part. EEG abnormalities (spike-and-wave or sharp slow waves) may be seen in a posterior distribution in lateral parietal lobe abnormalities. The EEG may be normal in structural brain abnormalities affecting mesial parietal areas. Surface ictal EEG in parietal lobe seizures can be unhelpful, the ictal EEG may be normal in up to 80% of seizures, or there may be lateralized slow activity. Central parietal rhythmic spike or spike-and-wave is occasionally seen. The EEG patterns may instead reflect the seizure spread, which may be to the temporal or frontal lobes or bilaterally. Seizures arising in mesial parietal areas are often associated with secondary bilateral synchrony.

‍