Frontal lobe epilepsy

Clinic

• FLE is a subtype of the larger group of epilepsy and then focal epilepsy
• It is characterized by brief, recurring seizures that arise in frontal lobes, often while the patient is sleeping. (Sleep-related hypermotor epilepsy)
• It is the second most common type of focal epilepsy after temporal lobe epilepsy (TLE)
• There are many FLE variations due to many cognitive / Motor functions of frontal lobes

Four different types

1. Focal aware = Simple Partial seizures (Do not affect awareness or memory)
2. Focal unaware the = Complex partial seizures (Affect Awareness / Memory Before /During /After seizure).

1. Secondarily generalized
2. Combination of the three

Signs / Symptoms

Symptoms can range from Asymmetric / Abnormal body positioning to repetitive vocal outbursts and repetitive jerking movements.

• Head and eye movements to one side

• Complete or partial unresponsiveness or difficulty speaking
• Aware / Non-aware depending on the patient and type of seizure.
• Repetitive movements such as rocking, bicycle pedaling or pelvic thrusting
• Brief Postictal confusion: TLE has more longer periods of confusion
• Tingling / Numbness / Tension aura
• Tonic-clonic seizure

Unusual symptoms

Since frontal lobe has many different eras with different unknown functions, seizures may produce unusual symptoms:

• Psychiatric disorder (psychogenic seizures): Physical /Emotional Aura
• Non-epileptic seizure
• Sleep disorder: Typically short bursts (Less than a minute) and often occur while a patient is sleeping.
• Abnormal body posturing esp fencing position
• Sensorimotor tics: Explosive Screams / Crying / Profanities / Laughing

FLE vs TLE

• Dystonic motor movements are common to both TLE and FLE, but are usually the first symptom in FLE episodes where they are quite brief and do not affect consciousness.
• Fear is associated with TLE and FLE, but in FLE the fear is predominantly expressed on the person's face whereas in TLE the fear is subjective and internal, not perceptible to the observer.

Entities / Miasms

	JE	RBS	PLV	TBE	WEE EEE
Seizure Coma	+++	+++	+++	+++	+++
Aphasia	+++		++	++
Rigidity	+++	+++
Fear		+++	++	++
Tonic- Clonic					+++

Note

• Here is a good question. What kind of speech problem is more dominant in FLE? Aphasia or Dysarthria? Of course both of them are probable but Aphasia is more common.
• I use Rigidity for Abnormal body posturing
• There is high similarity between NREM Related Parasomnias and FLE

Supplementary motor area (SMA)

• The onset and relief of the seizure are quite abrupt.
• The tonic posturing in this area is unilateral or asymmetric between the left and right hemispheres.
• A somatosensory aura frequently precedes many large motor and vocal symptoms and most often the affected person is responsive.
• Motor symptoms: Facial grimacing and complex automatisms like kicking and pelvic thrusting
• Vocal symptoms: Laughing, yelling, or speech arrest.

Case presentation Asymmetric tonic posturing of the extremities

• Abduction and elevation of the contralateral upper extremity
• Speech arrest with preserved consciousness
• Auras and vocalization occur less frequently.
• These seizures tend to be brief and to have an abrupt onset and cessation.
• They are more common during sleep than during wakefulness, and they tend to occur multiple times per night

Related disease

• ASD
• Tourette syndrome

Primary motor cortex

• The primary motor cortex has jacksonian seizures that spread to adjacent areas of the lobe which often trigger a second round of seizures originating in another cortical area.
• The seizures are much simpler than those that originate in the SMA and are usually clonic or myoclonic movements with speech arrest.
• Some dystonic or contralateral adversive posturing may also be present.

Medial frontal, Cingulate gyrus, orbitofrontal, or frontopolar regions

• Motor symptoms of seizures in this area are accompanied by emotional feelings and viscerosensory symptoms.
• Motor and vocal agitation are similar to that of SMA with short repetitive thrashing, pedaling, thrusting, laughing, screaming and/or crying.
• This is some of what can cause the misdiagnosis of a psychological disorder.

Case presentation

Mesial frontal lobe epilepsy provokes a complex clinical syndrome characterized by

• Mainly nocturnal occurrence of seizures
• Stereotyped patterns of repetitive rhythmic movements
• Diffuse or collateralize postures.
• DD: Hysteria and parasomnia.
  

Case 2

Cingulate gyrus epilepsy is controversial because it may overlap with other frontal lobe epilepsy syndromes. We report 3 surgically treated cases of cingulate gyrus epilepsy.

• Two patients had auras (fear and laughter) previously associated with cingulate gyrus epilepsy.
• All patients had clinical features consistent with frontal lobe epilepsy, including hyperkinetic behavior and ictal vocalization.
• Two patients had behavioral changes with aggression, personality disorder, and poor judgment
• One patient, a commercial pilot, showed behavior as a passenger that resulted in a diversionary landing. The other patient demonstrated behavior that led to his arrest, and he was almost arrested again in the hospital for threatening security officers. Aberrant behaviors in all 3 patients completely resolved after lesionectomy.

The commission first described general features that strongly suggest an epilepsy diagnosis of frontal origin (short seizures, minimal or no postictal confusion, rapid progression to secondary generalized seizures, prominent motor manifestations, complex gestural automatisms, and frequent falling when the discharge is bilateral), and then briefly described seizure subtypes.

Cingulate gyrus epilepsies were described as consisting of complex partial seizures with complex motor gestural automatisms at onset, autonomic signs, and changes in mood and affect.

Orbitofrontal epilepsy Case

16 cases of orbitofrontal epilepsy were identified from our databases.

• 50% had predominantly sleep-related seizures
• 56% had no aura
• 62.5% featured Hyperkinetic behaviors.
• Interictal epileptiform discharges over frontal and temporal derivations always allowed lateralization.
• Orbitofrontal epilepsy should be suspected with sleep-related, hyperkinetic seizures with no specific aura, and frontotemporal interictal discharges. Several patients have nonmotor seizures with or without auras which may resemble temporal lobe seizures.

Entities

• Sleep seizure
• Hyperkinetic behaviors
• Asymmetric

Case 4

Seizures may be characterized by forced thoughts, impaired awareness, ipsilateral head and eye version with possible progression to contralateral version, autonomic features and axial tonic-clonic movements resulting in falls.

Dorsolateral cortex

• This area does not seem to have many motor symptoms beyond tonic posturing or clonic movements.
• Contralateral or less commonly ipsilateral head turn and eye deviation are commonly associated with this area as well.

Operculum

• Many of the symptoms associated with this area involve the head and digestive tract:
  • Swallowing
  • Salivation
  • Mastication
  • Possibly gustatory hallucinations
  • Preceding the seizure the person is fearful and often has an epigastric aura.
  • There is not much physical movement except clonic facial movements.
  • Speech is often arrested

Anatomic categorization

Frontal lobes have traditionally been divided into two major areas known as the precentral cortex and prefrontal cortex.

Precentral cortex

It is located directly anterior to the central sulcus and includes both the primary motor cortex and the supplementary motor area.

Inputs from

• Primary motor cortex
• Thalamus
• Corticospinal projections.

Their main function is control and preparation of motor movement and execution of movements. They are crucial to the development of the motor related symptoms associated with frontal lobe epilepsy focally when seizures are located within these defined areas. Major functional areas include:

Primary motor cortex

Contains large neurons that project axons down to the spinal cord where they synapse onto alpha motor neurons. These neurons are involved in the planning of motor movements and the refining of motor movements based on sensory inputs that are received from the cerebellum.

Supplementary motor area

Area anterior to the primary motor cortex that is involved in planning complex motor movements and coordinating movements along both hands. The main inputs for this area are received from the thalamus.

Frontal eye field

FEF is a posterior part of the middle frontal gyrus and is involved in the control of saccadic, contralateral and conjugate eye movement. This area receives its main inputs from both the occipital cortex and dorsal thalamus.

Broca's area

Controls the motor movements of both the tongue and larynx that enables speech formation. This area receives direct inputs from the primary motor area as well as Wernicke's area located in the temporal lobe.

Prefrontal cortex

The prefrontal cortex, the most anterior region of the brain, comprises several key areas that are particularly important for higher mental functions that control various aspects of human personality including anticipation and planning, initiative/judgement, memory and the control of decision making. Damage or lesions to this region of the brain can result in major changes in personality. A classic example is Phineas Gage, who exhibited a change in behavior after one or both frontal lobes were destroyed by a large iron bar accidentally driven through his head (though Gage, despite conventional presentations of his case, did not exhibit the aggression, antisocial behavior, or loss of impulse control sometimes reported in patients with similar injuries).

There are two main regions of the prefrontal cortex that each control various aspects of behavior and personality:

Dorsolateral prefrontal cortex

This area is associated with the impairment of the cognitive abilities that control and regulate behavior and long-term memory formation (esp relating to procedural sequence memory)

Orbitofrontal cortex

Similar functions as the dorsolateral prefrontal cortex but is thought to be mainly responsible for the ability to make choices and determine right from wrong.