Parietal Lobe Epilepsy
What is Parietal Lobe Epilepsy?
Parietal lobe epilepsy is a relatively rare form of epilepsy, comprising about 5% of all epilepsy, in which seizures arise from the parietal lobe of the brain. Parietal lobe epilepsy can start at any age and occurs in both males and females equally. It may be a result of head trauma, birth difficulties, stroke, or tumor, though the cause is unknown in 20% of patients.
Where is the Parietal Lobe Located in the Brain?
The parietal lobe is located just behind the frontal lobe and it plays important roles in touch perception, the integration of sensory information and in visual perception of spatial relationships among objects (visuospatial processing). In the language dominant side of the brain (the left side for most right-handed individuals), the parietal lobe is also involved with language, planned movements such as writing, as well as mathematical skills.
What are Parietal Lobe Seizures Like?
Since the parietal lobe involves the processing and integration of sensory and visual perception, seizures originating from the parietal lobe can involve both sensory and visual sensations. Seizure duration varies, from a few seconds in some patients to a few minutes in others. The following are the different types of symptoms associated with parietal lobe seizures:
Somatosensory Seizures: These are the most common type of seizure in parietal epilepsies. Patients with these types of seizures describe feeling physical sensations of numbness and tingling, heat, pressure, electricity and/or pain. Pain, though a rare symptom in seizures overall, is quite common in parietal seizures, occurring in up to one quarter of patients. Some patients describe a typical “Jacksonian march”, in which the sensation “marches” in a predictable pattern from the face to the hand up the arm and down the leg. Rarely, a patient will describe a sensation in the genitalia, occasionally leading to orgasm.
Somatic Illusions: During a somatic illusion, another common symptom of parietal seizures, patients may experience a feeling like their posture is distorted, that their arms or legs are in a weird position or are in motion when they are not, or that a part of their body is missing or feels like it does not belong.
Vertigo: Patients with parietal seizures may experience a sensation of movement or spinning of the environment, or of their body within the environment.
Visual Illusions and Hallucinations: Patients with visual illusions report a distortion of visual perception: objects seem too close, too far, too large, too small, slanted, moving or otherwise not right. A patient with hallucinations describes seeing objects that seem very real, though in fact they do not exist.
Language Disturbances: Rarely, a patient with a parietal seizure will report difficulty understanding spoken words or language, difficulty reading or performing simple math.
