Parietal Lobe Epilepsy

Parietal Lobe Epilepsy

Parietal lobe epilepsy is relatively uncommon. Any structural lesion, such as stroke, tumor, infection, vascular malformation, developmental anomaly, may be responsible seizures originating in the parietal lobe. Unlike other lobes, there are no specific genetic syndromes in parietal lobe epilepsy.

Symptoms of Parietal Lobe Epilepsy

The most typical auras in parietal epilepsy are sensations of numbness, tingling, electric sensation, heat, cold, and pain more commonly in the face, hand and arm.
There may be an illusion of distorted body position in space or an illusion of movement in some body part, a perception of absent limb or “alien limb” (non-dominant side). There could be a sense of spatial disorientation.
The dominant parietal lobe produces disturbance of language and calculations.
Less common are vertigo, visual hallucinations (more complex than in occipital lobe), variable sensations in the genital area, and orgasm.

Spread of epileptic activity produces automatisms similar to temporal lobe epilepsy, body parts posturing, focal clonic or versive seizures. The majority will experience generalized tonic-clonic seizures.

Seizure frequency is variable and they may run in series. Seizures last from seconds to minutes.
Todd’s paralysis (temporarily inability to move a body part after seizure) occurs in about 1/5 of the patients.
Parietal seizures are mostly diurnal and may be provoked by sensations or movements in the affected body part.

Diagnosis of Parietal Lobe Epilepsy

Brain MRI statistically demonstrates abnormalities in 60% of the patients – tumors, vascular malformations, and nonspecific gliosis are most common.
Both ictal and inter-ictal EEGs are not reliable in localization. EEG is normal in 80%.
Parietal lobe epilepsy symptoms are often misdiagnosed as psychogenic or as transient ischemic attacks.

Treatment and Prognosis

Antiepileptic drugs, intended for treatment of focal epilepsy, specifically Carbamazepine, Levetiracetam and Lamotrigine, offer variable seizure control.
There is a favorable response to neurosurgical intervention with 65% becoming seizure free or having seizure frequency reduction.
The prognosis largely depends on the underlying cause.