User:Lavallco/Frontal Lobe Epilepsy

Frontal lobe epilepsy, is a neurological disorder that is characterized by brief, recurring seizures that arise in the frontal lobes of the brain often while the patient is sleeping. It is the second most common type of epilepsy after temporal lobe epilepsy, and is related to the temporal form by the fact that they are both characterized by the occurrence of partial (focal) seizures. Partial seizures occuring in the frontal lobes can occur in one of two different forms; either simple partial seizures (that do not affect awareness or memory) or complex partial seizures (that affect awareness or memory either before, during or after a seizure). The symptoms and clinical manifestations of frontal lobe epilepsy can differ depending on which specific area of the frontal lobe is affected. (cite e-medicine). The onset of a seizure may be hard to detect since the frontal lobes contain and regulate many structures and functions about which relatively little is known. Due to the lack of knowledge surrounding the functions associated with the frontal lobes, seizures occuring in these regions of the brain may produce unusual symptoms which can often be misdiagnosed as a psychiatric disorder, non-epileptic seizure or a sleep disorder. (cite mayoclinic).

During the onset of a seizure, the patient may exhibit abnormal body posturing, sensorimotor tics, or other abnormalities in motor skills. In rare cases, uncontrollable laughing or crying may occur during a seizure. Afflicted persons may or may not be aware that they are behaving in an abnormal manner, depending on the patient and type of seizure. A brief period of confusion known as a postictal state may sometimes follow a seizure occuring in the frontal lobes. However these postictal states are often times undetectable and generally do not last as long as the periods of confusion following seizures that occur in the temporal lobes.

There are a variety of different causes for frontal lobe epilepsy ranging from genetics to head trauma resulting in lesions to the frontal lobes. Although frontal lobe epilepsy is often misdiagnosed, tests such as prolonged EEG monitoring and/or an MRI scan of the frontal lobes can be administered in order to reveal the presence of a tumor or vascular malformation. Medications such as anticonvulsants can typically control the onset of seizures, however if medications are ineffective the patient may undergo surgery to have focal areas of the frontal lobe removed.

Symptoms

Dermatological symptoms of frontal lobe epilepsy used in diagnosis include café-au-lait, hypomelanotic macules, and neurofibromas. General symptoms of a frontal lobe seizure include asymmetric and abnormal body positioning, vocal outbursts, and repetitive jerking movements. The symptoms come in short bursts that usually last less than a minute and often occur during sleep. In most cases a physical or emotional aura precedes the seizure.

Tonic posture and clonic movements are common symptoms among most of the areas of the frontal lobe, therefore the type of seizures associated with frontal lobe epilepsy are commonly called tonic-clonic seizures. A wide range of more specific symptoms arise when different parts of the frontal cortex are affected.

• Supplementary motor area (SMA)
  • 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 afflicted person is responsive.
  • Motor symptoms: Facial grimacing and complex automatisms like kicking and pelvic thrusting
  • Vocal symptoms: Laughing, yelling, or speech arrest

• 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 the 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.

• 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 have to do with the head and digestive tract: swallowing, salivation, mastication and 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.

Causes

The origins of frontal lobe seizures range from tumors to head trauma to genetics. Tumors account for about one third of all frontal lobe epilepsy cases. Low-grade tumors such as gangliogliomas, low-grade gliomas, and epidermoid tumors are most common, but many high-grade tumors were most likely once involved with seizures. Other lesions on the frontal lobe such as hamartomas and nodular heterotopias can cause frontal lobe symptoms as well. Vascular malformation can cause seizures, especially arteriovenous malformations and cavernous angiomas. Head trauma frequently causes damage to the frontal lobe and can cause seizures directly or indirectly through gliosis. Seizures originating directly from head trauma usually occur within months but occasionally it can take years. On occasion encephalitis can cause frontal lobe seizures but it is most often associated with temporal lobe affliction. The main genetic cause of frontal lobe epilepsy is an autosomal dominant disease called Autosomal Dominant Nocturnal Frontal Lobe Epilepsy, which involves mutations in 2 nicotinic acetylcholine receptor genes. Another genetic mutation on chromosome 22 has also been associated with another genetic form of the disorder.

Treatments

There are several different ways to treat frontal lobe epileptic seizures however the most common form of treatment is through the use of anticonvulsant medications that help to prevent seizures from occuring. In some cases however when medications are ineffective a neurologist may choose to operate on the patient in order to remove the focal area of the brain in which the seizures are occuring. Other treatments that can be administered to aid in reducing the occurence of seizures include the implementation of a specific, regimented diet and/or the implantation of a vagus nerve stimulator.

Medications

Anticonvulsants are the most successful medication that seem to have the greatest affect on preventing and terminating the reoccurance of seizures

See also

• Absence seizure
• Psychogenic non-epileptic seizures
• Clonus (e.g. tonic-clonic, or grand mal, seizure)
  • cf. Fasciculation

External links

• Frontal Lobe Epilepsy on Epilepsy.com
• Epilepsy on Neurology Channel
• Frontal Lobe Epilepsy on emedicine.com