Frontal Lobe Epilepsy Clinical Presentation

The majority of frontal lobe seizures are thought to be symptomatic, although many patients with frontal lobe seizures have no obvious lesions on magnetic resonance imaging (MRI) scans.

A careful history should focus on specific characteristics of seizure episodes, including a detailed description by eyewitnesses, time and pattern of occurrence, precipitating factors, and response to medication.

Features that help to distinguish frontal lobe seizures from nonepileptic events include stereotyped semiology, occurrence during sleep, brief duration (often < 30 seconds), rapid secondary generalization, prominent motor manifestations, and complex automatisms.

Even when such characteristics are present, however, distinguishing frontal lobe seizures from nonepileptic events remains difficult based on history alone, and patients with frontal lobe epilepsy are often directed first to psychiatrists rather than to neurologists. Details obtained about the seizure semiology may help to identify the specific frontal region of onset.^{[5, 6]}

Other history findings may include the following:

• Dominant hemisphere involvement - May be indicated by prominent speech disturbances
• Supplementary motor area (SMA) - Typically involves unilateral or asymmetrical, bilateral tonic posturing; may be associated with facial grimacing, vocalization, or speech arrest; seizures frequently preceded by a somatosensory aura; complex automatisms, such as kicking, laughing, or pelvic thrusting, may be present; responsiveness often preserved
• Primary motor cortex - Usually simple partial motor seizures with clonic or myoclonic movements and preserved consciousness; jacksonian spread to adjacent cortical areas may occur, and secondary generalization is frequent; speech arrest and contralateral adversive or dystonic posturing may be present
• Medial frontal, cingulate gyrus, orbitofrontal, or frontopolar regions - Complex behavioral events characterized by motor agitation and gestural automatisms; viscerosensory symptoms and strong emotional feelings often described; motor activity repetitive and may involve pelvic thrusting, pedaling, or thrashing, often accompanied by vocalizations or laughter/crying; seizures often bizarre and may be diagnosed incorrectly as psychogenic
• Dorsolateral cortex - Tonic posturing or clonic movements often associated with either contralateral head and eye deviation, or less commonly, ipsilateral head turn
• Operculum - Swallowing, salivation, mastication, epigastric aura, fear, and speech arrest often associated with clonic facial movements; gustatory hallucinations also may occur
• Nonlocalizable frontal seizures - Rare, manifesting as brief staring spells accompanied by generalized spike/wave on EEG, which may be difficult to distinguish from primarily generalized absence seizures; may present as generalized tonic-clonic seizures without obvious focal onset
• Nocturnal frontal lobe epilepsy - Autosomal dominant inheritance; seizures occur mainly during sleep; characterized by marked motor manifestations, including dystonic posturing, jerking, bending, and rocking; difficult to distinguish from parasomnias

A general physical and thorough neurologic examination should be performed in all patients with epilepsy.

General examination

General examination may reveal signs suggestive of syndromes that may be associated with epilepsy, such as facial dysmorphisms. Skin abnormalities, such as cafe-au-lait spots, hypomelanotic macules, or neurofibromas suggesting neurocutaneous syndromes, may also be found.

Neurologic examination

As structural lesions are common, neurologic abnormalities are common in patients with frontal lobe epilepsy. Pay particular attention to the motor examination.