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Focal impaired awareness seizures are seizures which impair consciousness to some extent: they alter the person's ability to interact normally with their environment. They usually begin with a focal aware seizure, then spread to a larger portion of the temporal lobe, resulting in impaired consciousness. They may include autonomic and psychic features present in focal aware seizures.
Signs may include:
- Motionless staring
- Automatic movements of the hands or mouth
- Confusion and disorientation
- Altered ability to respond to others, unusual speech
- Transient aphasia (losing ability to speak, read, or comprehend spoken word)
These seizures tend to have a warning or aura before they occur, and when they occur they generally tend to last only 1–2 minutes. It is not uncommon for an individual to be tired or confused for up to 15 minutes after a seizure has occurred, although postictal confusion can last for hours or even days. Though they may not seem harmful, due to the fact that the individual does not normally seize, they can be extremely harmful if the individual is left alone around dangerous objects. For example, if a person with complex partial seizures is driving alone, this can cause them to run into the ditch, or worse, cause an accident involving multiple people. With this type, some people do not even realize they are having a seizure and most of the time their memory from right before or after the seizure is wiped. First-aid is only required if there has been an injury or if this is the first time a person has had a seizure.
"Focal aware" means that the level of consciousness is not altered during the seizure. In temporal lobe epilepsy, a focal seizure usually causes abnormal sensations only.
These may be:
- Sensations such as déjà vu (a feeling of familiarity), jamais vu (a feeling of unfamiliarity)
- Amnesia; or a single memory or set of memories
- A sudden sense of unprovoked fear and anxiety
- Nausea
- Auditory, visual, olfactory, gustatory, or tactile hallucinations.
- Visual distortions such as macropsia and micropsia
- Dissociation or derealisation
- Synesthesia (stimulation of one sense experienced in a second sense) may transpire.
- Dysphoric or euphoric feelings, fear, anger, and other emotions may also occur. Often, the patient cannot describe the sensations.
Olfactory hallucinations often seem indescribable to patients beyond "pleasant" or "unpleasant".
Focal aware seizures are often called "auras" when they serve as a warning sign of a subsequent seizure. Regardless an "aura" is actually a seizure itself, and such a focal seizure may or may not progress to a focal impaired awareness seizure. People who only experience focal aware seizures may not recognize what they are, nor seek medical care.
Epileptic symptoms are frequently the product of the spread of overactivation occurring within one central foci that travels to lateral brain regions thereby causing an array of symptoms. Due to the massive amount of diversity in both the cognitive and motor functions that occur within the frontal lobes, there is an immense variety in the types of symptoms that can arise from epileptic seizures based on the side and topography of the focal origin. In general these symptoms can range anywhere from asymmetric and abnormal body positioning to repetitive vocal outbursts and repetitive jerking movements. The symptoms typically come in short bursts that last less than a minute and often occur while a patient is sleeping. In most cases, a patient will experience a physical or emotional Aura of tingling, numbness or tension prior to a seizure occurring. Fear is associated with temporal and frontal lobe epilepsies, 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.
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. 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. The seizures are complex partial, simple partial, secondarily generalized or a combination of the three. These partial seizures are often misdiagnosed as psychogenic seizures. A wide range of more specific symptoms arise when different parts of the frontal cortex are affected.
- 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 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 involve 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.
Seizures are purely occipital and primarily manifest with elementary visual hallucinations, blindness or both.
They are usually frequent and diurnal, develop rapidly within seconds and are brief, lasting from a few seconds to 1–3 min, and, rarely, longer.
Elementary visual hallucinations are the most common and characteristic ictal symptoms, and are most likely to be the first and often the only clinical manifestation. They consist mainly of small multicoloured circular patterns that often appear in the periphery of a visual field, becoming larger and multiplying during the course of the seizure, frequently moving horizontally towards the other side.
Other occipital symptoms, such as sensory illusions of ocular movements and ocular pain, tonic deviation of the eyes, eyelid fluttering or repetitive eye closures, may occur at the onset of the seizures or appear after the elementary visual hallucinations. "Deviation of the eyes", often associated with ipsilateral turning of the head, is the most common (in about 70% of cases) nonvisual ictal symptom. It is often associated with ipsilateral turning of the head and usually starts after visual hallucinations, although it may also occur while the hallucinations still persist. It may be mild, but more often it is severe and progresses to hemiconvulsions and secondarily generalised tonic clonic seizures (GTCS). Some children may have seizures of eye deviation from the start without visual hallucinations.
"Forced eyelid closure and eyelid blinking" occur in about 10% of patients, usually at a stage at which consciousness is impaired. They signal an impending secondarily GTCS.
"Ictal blindness", appearing from the start or, less commonly, after other manifestations of occipital seizures, usually lasts for 3–5 min. It can occur alone and be the only ictal event in patients who could, at other times, have visual hallucinations without blindness.
Complex visual hallucinations, visual illusions and other symptoms resulting from more anterior ictal spreading rarely occur from the start. They may terminate in hemiconvulsions or generalised convulsions.
Ictal headache, or mainly orbital pain, may occur and often precedes visual or other ictal occipital symptoms in a small number of patients.
Consciousness is not impaired during the visual symptoms (simple focal seizures), but may be disturbed or lost in the course of the seizure, usually before eye deviation or convulsions.
Occipital seizures of ICOE-G may rarely progress to extra-occipital manifestations, such as hemiparaesthesia. Spread to produce symptoms of temporal lobe involvement is exceptional and may indicate a symptomatic cause.
Post-ictal headache, mainly diffuse, but also severe, unilateral and pulsating, or indistinguishable from migraine headache, occurs in half the patients, in 10% of whom it may be associated with nausea and vomiting.
Circadian distribution: Visual seizures are predominantly diurnal and can occur at any time of the day. Longer seizures, with or without hemi or generalised convulsions, tend to occur either during sleep, causing the patient to wake up, or after awakening. Thus, some children may have numerous diurnal visual seizures and only a few seizures that are exclusively nocturnal or occur on awakening.
Frequency of seizures: If untreated, patients experience frequent and brief visual seizures (often several every day or weekly). However, propagation to other seizure manifestations, such as focal or generalised convulsions, is much less frequent.
As of 2017, focal seizures are split into two main categories, "focal onset aware", and "focal onset impaired awareness". What was previously termed a "secondary generalised seizure" is now termed a "focal to bilateral seizure".
In focal onset aware seizures, a small part of one of the lobes may be affected and the person remains conscious. This can often be a precursor to a larger focal onset impaired awareness seizure. When this is the case, the focal aware seizure is usually called an aura.
A focal impaired awareness seizure affects a larger part of the hemisphere and the person may lose consciousness.
If a focal seizure spreads from one hemisphere to the other side of the brain, this will give rise to a "focal to bilateral seizure". The person will become unconscious and may well have a tonic clonic seizure. When people have multiple focal seizures they generally have a condition known as temporal lobe epilepsy. (A generalized seizure is one that involves both sides of the brain from the onset).
Frontal lobe epilepsy, usually a symptomatic or cryptogenic localization-related epilepsy, arises from lesions causing seizures that occur in the frontal lobes of the brain. These epilepsies can be difficult to diagnose because the symptoms of seizures can easily be confused with nonepileptic spells and, because of limitations of the EEG, be difficult to "see" with standard scalp EEG.
Juvenile absence epilepsy is an idiopathic generalized epilepsy with later onset than CAE, typically in prepubertal adolescence, with the most frequent seizure type being absence seizures. Generalized tonic-clonic seizures can occur. Often, 3 Hz spike-wave or multiple spike discharges can be seen on EEG. The prognosis is mixed, with some patients going on to a syndrome that is poorly distinguishable from JME.
Juvenile myoclonic epilepsy (JME) is an idiopathic generalized epilepsy that occurs in patients aged 8 to 20 years. Patients have normal cognition and are otherwise neurologically intact. The most common seizure is myoclonic jerks, although generalized tonic-clonic seizures and absence seizures may occur as well. Myoclonic jerks usually cluster in the early morning after awakening. The EEG reveals generalized 4–6 Hz spike wave discharges or multiple spike discharges. These patients are often first diagnosed when they have their first generalized tonic-clonic seizure later in life, when they experience sleep deprivation (e.g., freshman year in college after staying up late to study for exams). Alcohol withdrawal can also be a major contributing factor in breakthrough seizures, as well. The risk of the tendency to have seizures is lifelong; however, the majority have well-controlled seizures with anticonvulsant medication and avoidance of seizure precipitants.
Focal aware seizures are seizures which affect only a small region of the brain, often the temporal lobes or structures found there such as the hippocampi. People who have focal aware seizures remain conscious. Focal aware seizures often precede larger focal impaired awareness seizures, where the abnormal electrical activity spreads to a larger area of the brain. This can result in a tonic-clonic seizure.
- Presentation
Focal onset aware seizures are a very subjective experience, and the symptoms vary greatly between people. This is due to the varying locations of the brain the seizures originate in e.g.: Rolandic. A focal aware seizure may go unnoticed by others or shrugged off by the sufferer as merely a "funny turn." Focal aware seizures usually start suddenly and are very brief, typically lasting 60 to 120 seconds.
Some common symptoms of a focal onset aware seizure, when the person is awake, are:
- preserved consciousness
- sudden and inexplicable feelings of fear, anger, sadness, happiness or nausea
- sensations of falling or movement
- experiencing of unusual feelings or sensations
- altered sense of hearing, smelling, tasting, seeing, and tactile perception (sensory illusions or hallucinations), or feeling as though the environment is not real (derealization) or dissociation from the environment or self (depersonalization)
- a sense of spatial distortion—things close by may appear to be at a distance
- déjà vu (familiarity) or jamais vu (unfamiliarity)
- laboured speech or inability to speak at all
- usually the event is remembered in detail
When the seizure occurs during sleep, the person will often become semi-conscious and act out a dream they were having while engaging with the real environment as normal. Objects and people usually appear normal or only slightly distorted to them, and will be able to communicate with them on an otherwise normal level.
However, since the person is still acting in the dream-like state from which they woke, they will assimilate any hallucinations or delusions into their communication, often speaking to a hallucinatory person or speaking of events or thoughts normally pertaining to the dream they were having or other hallucination.
While asleep symptoms include:
- onset usually in REM sleep
- dream like state
- appearance of full consciousness
- hallucinations or delusions
- behavior or visions typical in dreams
- ability to engage with the environment and other people as in full consciousness, though often behaving abnormally, erratically, or failing to be coherent
- complete amnesia or assimilating the memory as though it was a normal dream on regaining full consciousness
Although hallucinations may occur during focal aware seizures they are differentiated from psychotic symptoms by the fact that the person is usually aware that the hallucinations are not real.
- Jacksonian march
Jacksonian march or Jacksonian seizure is a phenomenon where a focal aware seizure spreads from the distal part of the limb toward the face (on same side of body). They involve a progression of the location of the seizure in the brain, which leads to a "march" of the motor presentation of symptoms.
Jacksonian seizures are initiated with abnormal electrical activity within the primary motor cortex. They are unique in that they travel through the primary motor cortex in succession, affecting the corresponding muscles, often beginning with the fingers. This is felt as a tingling sensation, or a feeling of waves through the fingers when touched together. It then affects the hand and moves on to more proximal areas on the same side of body. Symptoms often associated with a Jacksonian seizure are sudden head and eye movements, tingling, numbness, smacking of the lips, and sudden muscle contractions. Most of the time any one of these actions can be seen as normal movements, without being associated with the seizure occurring. They occur at no particular moment and last only briefly. They may result in secondary generalized seizure involving both hemispheres. They can also start at the feet, manifesting as tingling or pins and needles, and there are painful cramps in the foot muscles, due to the signals from the brain. Because it is a partial seizure, the postictal state is of normal consciousness .
Episodes that include complex hyperactivity of the proximal portions of the limbs that lead to increased overall motor activity are called hypermotor seizures. When associated with bizarre movements and vocalizations these seizures are often misdiagnosed as pseudoseizures or other episodic movement disorders such as psychogenic movement disorders, familial paroxysmal dystonic choreoathetosis, paroxysmal kinesogenic choreoathetosis, or episodic ataxia type 1. Hypermotor seizure in children are often confused with pavor nocturnus (night terrors). Paroxysmal nocturnal dystonia or hypnogenic paroxysmal dystonia are other names given to describe FLE symptoms but are simply just FLE.
Autosomal Dominant Nocturnal Frontal Lobe Epilepsy (ADNFLE) is the best understood form of frontal lobe epilepsy but is often misdiagnosed as sleep apnea. Both disorders are characterized by awakening during the night which leads to daytime sleepiness. Some symptoms of sleep apnea overlap with those of ADNFLE, such as sudden awakening accompanied by a feeling of choking and on occasion motor activity which makes diagnosis difficult based on symptoms alone. Video surveillance as well as EEG is occasionally needed to differentiate between the two disorders. It has been reported that sleep apnea might be associated with epilepsy which would account for some of the misdiagnoses.
The cardinal features of Rolandic epilepsy are infrequent, often single, focal seizures consisting of:
Hemifacial sensorimotor seizures are often entirely localised in the lower lip or spread to the ipsilateral hand. Motor manifestations are sudden, continuous or bursts of clonic contractions, usually lasting from a few seconds to a minute. Ipsilateral tonic deviation of the mouth is also common. Hemifacial sensory symptoms consist of unilateral numbness mainly in the corner of the mouth.
Hemifacial seizures are often associated with an inability to speak and hypersalivation:
"The left side of my mouth felt numb and started jerking and pulling to the left, and I could not speak to say what was happening to me."
Negative myoclonus can be observed in some cases, as an interruption of tonic muscular activity
Oropharyngolaryngeal ictal manifestations are unilateral sensorimotor symptoms inside the mouth. Numbness, and more commonly paraesthesias (tingling, prickling, freezing), are usually diffuse on one side or, exceptionally, may be highly localised even to one tooth. Motor oropharyngolaryngeal symptoms produce strange sounds, such as death rattle, gargling, grunting and guttural sounds, and combinations:
"In his sleep, he was making guttural noises, with his mouth pulled to the right, ‘as if he was chewing his tongue’". "We heard her making strange noises ‘like roaring’ and found her unresponsive, head raised from the pillow, eyes wide open, rivers of saliva coming out of her mouth, rigid."
Arrest of speech is a form of anarthria. The child is unable to utter a single intelligible word and attempts to communicate with gestures.
"My mouth opened and I could not speak. I wanted to say I cannot speak. At the same time, it was as if somebody was strangling me."
Hypersalivation , a prominent autonomic manifestation, is often associated with hemifacial seizures, oro-pharyngo-laryngeal symptoms and speech arrest. Hypersalivation is not just frothing:
"Suddenly my mouth is full of saliva, it runs out like a river and I cannot speak."
Syncope-like epileptic seizures may occur, probably as a concurrent symptom of Panayiotopoulos syndrome:
"She lies there, unconscious with no movements, no convulsions, like a wax work, no life."
Consciousness and recollection are fully retained in more than half (58%) of Rolandic seizures.
"I felt that air was forced into my mouth, I could not speak and I could not close my mouth. I could understand well everything said to me. Other times I feel that there is food in my mouth and there is also a lot of salivation. I cannot speak."
In the remainder (42%), consciousness becomes impaired during the ictal progress and in one third there is no recollection of ictal events.
Progression to hemiconvulsions or generalised tonic–clonic seizures occurs in around half of children and hemiconvulsions may be followed by postictal Todd’s hemiparesis .
Duration and circadian distribution: Rolandic seizures are usually brief, lasting for 1–3 min. Three quarters of seizures occur during nonrapid eye movement sleep, mainly at sleep onset or just before awakening.
Status epilepticus: Although rare, focal motor status or hemiconvulsive status epilepticus is more likely to occur than secondarily generalised convulsive status epilepticus, which is exceptional. Opercular status epilepticus usually occurs in children with atypical evolution or may be induced by carbamazepine or lamotrigine. This state lasts for hours to months and consists of ongoing unilateral or bilateral contractions of the mouth, tongue or eyelids, positive or negative subtle perioral or other myoclonus, dysarthria, speech arrest, difficulties in swallowing, buccofacial apraxia and hypersalivation. These are often associated with continuous spikes and waves on an EEG during NREM sleep.
Other seizure types: Despite prominent hypersalivation, focal seizures with primarily autonomic manifestations (autonomic seizures) are not considered part of the core clinical syndrome of Rolandic epilepsy. However, some children may present with independent autonomic seizures or seizures with mixed Rolandic-autonomic manifestations including emesis as in Panayiotopoulos syndrome.
Atypical forms: Rolandic epilepsy may present with atypical manifestations such early age at onset, developmental delay or learning difficulties at inclusion, other seizure types, atypical EEG abnormalities.
These children usually have normal intelligence and development. Learning can remain unimpaired while a child is afflicted with Rolandic epilepsy.
The inter-ictal EEG shows occipital paroxysms, often demonstrating fixation-off sensitivity. However, some patients may only have random occipital spikes, whereas others may have occipital spikes only in the sleep EEG, and a few may have a consistently normal EEG. Photoparoxysmal abnormalities occur in patients whose seizures are triggered by lights.
Ictal EEG, preceded by regression of occipital paroxysms, is characterised by the sudden appearance of an occipital discharge that consists of fast rhythms, fast spikes or both. Ictal EEG during blindness show pseudo-periodic slow waves and spikes, which differ from those seen in ictal visual hallucinations. There are usually no postictal abnormalities.
The age of onset of seizures is typically between three and five, though onset can occur at an earlier or later age. The syndrome shows clear parallels to West syndrome, enough to suggest a connection.
Daily multiple seizures are typical in LGS. Also typical is the broad range of seizures that can occur, larger than that of any other epileptic syndrome. The most frequently occurring seizure type is tonic seizures, which are often nocturnal (90%); the second most frequent are myoclonic seizures, which often occur when the person is over-tired.
Atonic, atypical absence, tonic, complex partial, focalized and tonic–clonic seizures are also common. Additionally, about half of patients will have status epilepticus, usually the nonconvulsive type, which is characterized by dizziness, apathy, and unresponsiveness. The seizures can cause sudden falling (or spasms in tonic, atonic and myoclonic episodes) and/or loss of balance, which is why patients often wear a helmet to prevent head injury.
In addition to daily multiple seizures of various types, children with LGS frequently have arrested/slowed psycho-motor development and behavior disorders.
The syndrome is also characterized by an (between-seizures) EEG featuring slow spike-wave complexes.
The hallmark characteristic of PCDH19 gene-related epilepsy is early-onset cluster seizures that often cause cyanotic spells, which start in infancy or early childhood. The onset of the first cluster of seizures usually coincides with a fever (febrile seizures), however subsequent seizures may be febrile or afebrile. The seizure clusters are generally brief seizures, lasting 1–5 minutes, often accompanied by fearful screaming observed in 63% of girls. These cluster seizures can occur more than 10 times a day over several days, with varying amounts of time between seizure clusters.
Over time, children with PCDH19 gene-related epilepsy tend to exhibit multiple seizure types, including focal, generalized tonic-clonic, tonic, atonic, myclonus, and absence seizures. In a small study of 35 female patients with PCDH19 gene-related epilepsy, rare episodes of status epilepticus occurred in about 30% of patients in the early course of the disorder.
In PCDH19 gene-related epilepsy, the seizures are often refractory to treatment, especially in infancy and childhood. Additionally, seizures are usually characterized by persistence of cluster seizures, with variable frequency. In a study of 35 female patients with PCDH19 gene-related epilepsy, approximately 30% had become seizure free in the girl's childhood (mean age of 12 years), yet some continued into adulthood. In the same study, a few patients still had recurrent cluster seizures that evolved into status epilepticus in childhood or early adolescence.
Musicogenic epilepsy is a form of reflex epilepsy with seizures elicited by special stimuli.
It has probably been described for the first time in 1605 by the French philosopher and scholar Joseph Justus Scaliger (1540-1609). Later publications were, in the eighteenth century, among others, by the German physician Samuel Schaarschmidt, in the nineteenth century 1823 by the British physician John C. Cooke, 1881 by the British neurologist and epileptologist William Richard Gowers, as well as in 1913 by the Russian neurologist, clinical neurophysiologist and psychiatrist Vladimir Mikhailovich Bekhterev. In 1937 the British neurologist Macdonald Critchley coined the term for the first time and classified it as a form of reflex epilepsy.
Most patients have temporal lobe epilepsy. Listening, probably also thinking or playing, of usually very specific music with an emotional content triggers focal seizures with or without loss of awareness, occasionally also evolving to bilateral tonic-clonic seizures.
Although musicality is at least in non-musicians predominantly located in the right temporal lobe, the seizure onset may also be left-hemispherical. Of the approximately 100 patients reported in the literature so far, about 75% had temporal lobe epilepsy, women were slightly more affected, and the mean age of onset was about 28 years. Ictal EEG and SPECT findings as well as functional MRI studies localized the epileptogenic area predominantly in the right temporal lobe. Treatment with epilepsy surgery leading to complete seizure freedom has been reported.
Beyond early-onset and treatment-resistant cluster seizures, PCDH19 gene-related epilepsy is usually, but not always, associated with cognitive and sensory impairment of varying degrees, and psychiatric and behavioral problems. It is estimated that up to 60 to 75% of the females have cognitive deficits, ranging from mild to severe intellectual disability, which do not appear to be related to frequency or severity of seizures. Development over the course of a female patients’ childhood can follow one of three courses: delays from birth that persist into adulthood, normal development and then regression, or normal intellectual development. It is not yet clear why some people experience delayed intellectual growth and others regress with epilepsy.
From the University of Melbourne study, two-thirds of PCDH19 gene-related epilepsy patients have borderline intellectual functioning or intellectual disability, while one third have normal intelligence. A connection to depression, autism, obsessive and aggressive behaviors and other disorders has been observed in PCDH19 gene-related epilepsy. Approximately 40-60% of girls diagnosed with a PCDH19 mutation are on the autism spectrum.
Many of those with PCDH19 gene mutations also exhibit behavioral and psychological problems – including ADHD, aggression, obsessive-compulsive disorder, and anxiety. Other neurological abnormalities may present, including sleep disturbances, ictal apnea, motor deficits, hypotonia, language delay, sensory integration problems and dysautonomia.
The signs of vertiginous epilepsy often occur without a change in the subject’s consciousness so that they are still aware while experiencing the symptoms. It is often described as a sudden onset of feeling like one is turning in one direction, typically lasting several seconds. Although subjects are aware during an episode, they often cannot remember specific details due to disorientation, discomfort, and/or partial cognitive impairment. This sensation of rotational movement in the visual and auditory planes is also known as a vertiginous aura (symptom), which can precede a seizure or may constitute a seizure itself. Auras are a “portion of the seizure that occur before consciousness is lost and for which memory is retained afterwards.” Auras can be focused in different regions of the brain and can thus affect different functions. Some such symptoms that may accompany vertiginous epilepsy include:
- Auditory hallucination
- Cognitive impairment
- Motor activity
- Ictal behavior
- Limbic auras
Many people tend to mistake dizziness as vertigo, and although they sound similar, dizziness is not considered a symptom of vertiginous epilepsy. Dizziness is the sensation of imbalance or floating, impending loss of consciousness, and/or confusion. This is different from vertigo which is characterized by the illusion of rotational movement caused by the “conflict between the signals sent to the brain by balance- and position-sensing systems of the body”.
A differential diagnosis should include:
- Thrombosis of the basilar artery
- Cardioembolic stroke
- Complex partial seizures
- Frontal lobe epilepsy
- Lacunar syndromes
- Migraine variants
- Posterior cerebral artery stroke
- Syncope and related paroxysmal spells
- Temporal lobe epilepsy
If the event lasts less than one hour, transient epileptic amnesia (TEA) might be implicated.
If the condition lasts longer than 24 hours, it is not considered TGA by definition. A diagnostic investigation would then probably focus on some form of undetected ischemic attack or cranial bleed.
The diagnosis or suspicion of LGS is often a question of probability rather than certainty. This is because the varied presentations of LGS share features with other disorders, many of which may be said to have overlapping characteristics.
The diagnosis is more obvious when the epilepsy has frequent and manifold attacks, with the classic pattern on the electro-encephalogram (EEG); the latter is a slowed rhythm with Spike-wave-pattern, or with a multifocal and generalizing Sharp-slow-wave-discharges at 1.5–2.5 Hz. During sleep, frequently, tonic patterns can be seen. But variations of these patterns are known in patients with no diagnosis other than LGS, and they can differ bilaterally, and from time to time, within the same patient.
General medical investigation usually reveals developmental delay and cognitive deficiencies in children with true LGS. These may precede development of seizures, or require up to two years after the seizures begin, in order to become apparent.
Exclusion of organic or structural brain lesions is also important in establishing a correct diagnosis of LGS; this may require magnetic resonance imaging (MRI) or computerized tomography (CT). An important differential diagnosis is 'Pseudo-Lennox-Syndrome', which differs from LGS, in that there are no tonic seizures; sleeping EEG provides the best basis for distinguishing between the two.
A person having an attack of TGA has almost no capacity to establish new memories, but generally appears otherwise mentally alert and lucid, possessing full knowledge of self-identity and identity of close family, and maintaining intact perceptual skills and a wide repertoire of complex learned behavior. The individual simply cannot recall anything that happened outside the last few minutes, while memory for more temporally distant events may or may not be largely intact. The degree of amnesia is profound, and, in the interval during which the individual is aware of his or her condition, is often accompanied by anxiety.
The diagnostic criteria for TGA, as defined for purposes of clinical research, include:
- The attack was witnessed by a capable observer and reported as being a definite loss of recent memory (anterograde amnesia).
- There was an absence of clouding of consciousness or other cognitive impairment other than amnesia.
- There were no focal neurological signs or deficits during or after the attack.
- There were no features of epilepsy, or active epilepsy in the past two years, and the patient did not have any recent head injury.
- The attack resolved within 24 hours.
A gelastic seizure is typically caused by a hypothalamic hamartoma, or a brain tumor. A hypothalamic hamartoma is defined as a benign mass of glial tissue on or near the hypothalamus. The size of the hamartoma can vary from one centimeter to larger than three centimeters. They can cause several different types of seizures including a Gelastic Seizure. These structures can be detected with different imaging modalities such as computed tomography and magnetic resonance imaging. A computed tomography scan of an individual with a hypothalamic hamartoma would reveal an suprasellar mass with the same density as brain tissue. Images of these masses are not enhanced with the use of contrast. However, although a computed tomography scan may be useful in diagnosing the cause of a seizure, in the case of a hypothalamic hamartoma, magnetic resonance imaging is the tool of choice due to the cerebrospinal fluid which defines these masses. Photon emission computed tomography may also be used. This involves the use of a radiotracer which is taken up by the ictal region of the brain which is typically where the tumor lies. Gelastic seizures have been observed after taking a birth control pill (Maxim (R)).
Optic nerve hypoplasia is the only reported condition with gelastic seizures without hypothalamic hamartomas, suggesting that hypothalamic disorganization alone can cause gelastic seizures.
The most common symptom of abdominal epilepsy is abdominal pain followed by uncontrollable vomiting, usually preceded by lethargy. Symptoms also include generalized tonic-clonic seizures followed by sleep, confusion, and unresponsiveness.
The main sign of a gelastic seizure is a sudden outburst of laughter or crying with no apparent cause. The laughter may sound unpleasant and sardonic rather than joyful. The outburst usually lasts for less than a minute. During or shortly after a seizure, an individual might display some twitching, strange eye movements, lip smacking, fidgeting or mumbling. If a person who suffers from the seizures is hooked up to an electroencephalogram it will reveal interictal epileptic discharges. This syndrome usually manifests itself before the individual reaches the age of three or four. The temporal lobes, and the hypothalamus are the areas of the brain with the most involvement with these seizures. This may cause learning disabilities, and faulted cognitive function as well. It is not uncommon for children to have tonic-clonic seizures, and atonic seizures directly following the seizure. Those that are associated with hypothalamic hamartomas may occur as often as several times hourly and typically begin during infancy. Seizures that occur in infancy may include bursts of cooing, respirations, giggling, and smiling. Due to early hypothalamic-pituitary-gonadal axis activation in girls who suffer from the seizures, it is not uncommon for them to display secondary sex characteristics before the age of eight.
Most people with PNES (75%) are women, with onset in the late teens to early twenties being typical.
Some studies have reported an elevated frequency of childhood abuse in people with PNES. However, others that have controlled for other demographic factors have failed to find a higher rate of reported childhood abuse than in a comparable groups with organic disease (usually epilepsy).
A number of studies have also reported a high incidence of abnormal personality traits or personality disorders in people with PNES such as borderline personality. However, again, when an appropriate control group is used, the incidence of such characteristics it not always higher in PNES than in similar illnesses arising due to organic disease (e.g., epilepsy).
Other risk factors for PNES include having a diagnosis of epilepsy, having recently had a head injury or recently undergone neurosurgery.
The Landau–Kleffner syndrome is characterized by the sudden or gradual development of aphasia (the inability to understand or express language) and an abnormal electroencephalogram (EEG). LKS affects the parts of the brain that control comprehension and speech (Broca's area and Wernicke's area). The disorder usually occurs in children between the ages of 3 and 7 years. There appears to be a male dominance in the diagnosis of the syndrome (ratio of 1.7:1, men to women).
Typically, children with LKS develop normally, but then lose their language skills. While many affected individuals have clinical seizures, some only have electrographic seizures, including electrographic status epilepticus of sleep (ESES). The first indication of the language problem is usually auditory verbal agnosia. This is demonstrated in patients in multiple ways including the inability to recognize familiar noises and the impairment of the ability to lateralize or localize sound. In addition, receptive language is often critically impaired, however in some patients, impairment in expressive language is the most profound. In a study of 77 cases of Landau–Kleffner syndrome, 6 were found to have this type of aphasia. Because this syndrome appears during such a critical period of language acquisition in a child's life, speech production may be affected just as severely as language comprehension. The onset of LKS is typically between 18 months and 13 years, the most predominant time of emergence being between 3 and 7 years.
Generally, earlier manifestation of the disease correlates with poorer language recovery, and with the appearance of night seizures that last for longer than 36 months. LKS has a wide range of symptom differences and lacks a uniformity in diagnostic criteria between cases, and many studies don't include follow-ups on the patients, so no other relationships between symptoms and recovery have been made known.
Language deterioration in patients typically occurs over a period of weeks or months. However, acute onset of the condition has also been reported as well as episodic aphasia.
Seizures, especially during the night, are a heavily weighted indicator of LKS. The prevalence of clinical seizures in acquired epileptic aphasia (LKS) is 70-85%. In one third of patients, only a single episode of a seizure was recorded. The seizures typically appear between the ages of 4 and 10 and disappear before adulthood (around the age of 15).
Often, behavioral and neuropsychologic disturbances accompany the progression of LKS. Behavioral issues are seen in as many as 78% of all cases. Hyperactivity and a decreased attention span are observed in as many as 80% of patients as well as rage, aggression, and anxiety. These behavior patterns are considered secondary to the language impairment in LKS. Impaired short-term memory is a feature recorded in long-standing cases of acquired epileptic aphasia.
The diagnosis can be confirmed when the characteristic centrotemporal spikes are seen on electroencephalography (EEG). Typically, high-voltage spikes followed by slow waves are seen. Given the nocturnal activity, a sleep EEG can often be helpful. Technically, the label "benign" can only be confirmed if the child's development continues to be normal during follow-up. Neuroimaging, usually with an MRI scan, is only advised for cases with atypical presentation or atypical findings on clinical examination or EEG.
The disorder should be differentiated from several other conditions, especially centrotemporal spikes without seizures, centrotemporal spikes with local brain pathology, central spikes in Rett syndrome and fragile X syndrome, malignant Rolandic epilepsy, temporal lobe epilepsy and Landau-Kleffner syndrome.