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An epileptic aura is the consequence of the activation of functional cortex by abnormal, unilateral, and brief neuronal discharge. In addition to being a warning sign to an upcoming seizure, the nature of an aura can give insight into the localization and lateralization of the seizure or migraine.
Not everyone experiences an aura with a seizure, but the most common auras include motor, somatosensory, visual, and auditory symptoms. The activation in the brain during an aura can spread through multiple regions continuously or discontinuously, on the same side or to both sides.
Auras are particularly common in focal seizures. If the motor cortex is involved in the over excitation of neurons, motor auras can result. Likewise, somatosensory auras (such as tingling, numbness, and pain) can result if in the somatosensory cortex. When the primary somatosensory cortex is activated, more discrete parts on the opposite side of the body and the secondary somatosensory areas result in symptoms ipsilateral to the seizure focus.
Visual auras can be simple or complex. Simple visual symptoms can include static, flashing, or moving lights/shapes/colors caused mostly by abnormal activity in the primary visual cortex. Complex visual auras can include people, scenes, and objects which results from stimulation of the temporo-occipital junction and is lateralized to one hemifield. Auditory auras can also be simple (ringing, buzzing) or complex (voices, music). Simple symptoms can occur from activation in the primary auditory cortex and complex symptoms from the temporo-occipital cortex at the location of the auditory association areas.
An aura is a perceptual disturbance experienced by some with migraines or seizures before either the headache or seizure begins. It often manifests as the perception of a strange light, an unpleasant smell, or confusing thoughts or experiences. Some people experience aura without a subsequent migraine or seizure (see silent migraine). Auras vary by individual experience; some people experience smells, lights, or hallucinations. Less known symptoms of the eye include disturbances, where the eyes roll in the back of the head caused by photosensitivity. A sufferer of this type of aura may experience tearfulness of the eyes and uncontrollable sensations of light followed by reduced symptoms after approximately 20 minutes; it is the rarest type of aura.
When occurring, auras allow people who have epilepsy time to prevent injury to themselves and/or others. The time between the appearance of the aura and the migraine lasts from a few seconds up to an hour. The aura can stay with a migraine sufferer for the duration of the migraine; depending on the type of aura, it can leave the person disoriented and confused. It is not uncommon for migraine sufferers to experience more than one type of aura during the migraine. Most people who have auras have the same type of aura every time.
Auras can also be confused with sudden onset of panic, panic attacks or anxiety attacks creating difficulties in diagnosis. The differential diagnosis of patients who experience symptoms of paresthesias, derealization, dizziness, chest pain, tremors, and palpitations can be quite challenging.
An aura is a transient focal neurological phenomenon that occurs before or during the headache. Auras appear gradually over a number of minutes and generally last less than 60 minutes. Symptoms can be visual, sensory or motor in nature and many people experience more than one. Visual effects occur most frequently; they occur in up to 99% of cases and in more than 50% of cases are not accompanied by sensory or motor effects.
Vision disturbances often consist of a scintillating scotoma (an area of partial alteration in the field of vision which flickers and may interfere with a person's ability to read or drive). These typically start near the center of vision and then spread out to the sides with zigzagging lines which have been described as looking like fortifications or walls of a castle. Usually the lines are in black and white but some people also see colored lines. Some people lose part of their field of vision known as hemianopsia while others experience blurring.
Sensory aurae are the second most common type; they occur in 30–40% of people with auras. Often a feeling of pins-and-needles begins on one side in the hand and arm and spreads to the nose–mouth area on the same side. Numbness usually occurs after the tingling has passed with a loss of position sense. Other symptoms of the aura phase can include speech or language disturbances, world spinning, and less commonly motor problems. Motor symptoms indicate that this is a hemiplegic migraine, and weakness often lasts longer than one hour unlike other auras. Auditory hallucinations or delusions have also been described.
Prodromal or premonitory symptoms occur in about 60% of those with migraines, with an onset that can range from two hours to two days before the start of pain or the aura. These symptoms may include a wide variety of phenomena, including altered mood, irritability, depression or euphoria, fatigue, craving for certain food(s), stiff muscles (especially in the neck), constipation or diarrhea, and sensitivity to smells or noise. This may occur in those with either migraine with aura or migraine without aura.
Acephalgic migraines can occur in individuals of any age. Some individuals, more commonly male, only experience acephalgic migraine, but frequently patients also experience migraine with headache. Generally, the condition is more than twice as likely to occur in females than males. Pediatric acephalgic migraines are listed along with other childhood periodic syndromes by W.A. Al-Twaijri and M.I. Shevell as "migraine equivalents" (although not listed as such in the "International Classification of Headache Disorders"), which can be good predictors of the future development of typical migraines. Individuals who experience acephalgic migraines in childhood are highly likely to develop typical migraines as they grow older. Among women, incidents of acephalgic migraine increase during perimenopause.
Scintillating scotoma is the most common symptom which usually happens concurrently with Expanding Fortification Spectra. Also frequently reported is monocular blindness. Acephalgic migraines typically do not persist more than a few hours and may last for as little as 15 seconds. On rare occasions, they may continue for up to two days.
Acephalgic migraines may resemble transient ischemic attacks or, when longer in duration, stroke. The concurrence of other symptoms such as photophobia and nausea can help in determining the proper diagnosis. Occasionally, patients with acephalgic migraine are misdiagnosed as suffering epilepsy with visual seizures, but the reverse misdiagnosis is more common.
Abdominal aura (also known as visceral aura and epigastric aura) is used to denote a type of somatosensory or somaesthetic aura that typically manifests itself as a rising epigastric sensation. The term is indebted to the Latin words abdomen (belly) and aura (wind, smell).
Other presentations of the abdominal aura include viscerosensitive sensations such as abdominal discomfort, visceromotor symptoms presenting in the form of tachycardia, borborygmi or vomiting, and vegetative symptoms such as blushing and sweating.
Pathophysiologically, the abdominal aura is associated with aberrant neuronal discharges in sensory cortical areas representing the abdominal viscera. Etiologically, it is associated primarily with paroxysmal neurological disorders such as migraine and epilepsy. The abdominal aura can be classified as a somatic or coenesthetic hallucination.
The term is used in opposition to various terms denoting other types of somatosensory aura, notably splitting of the body image and paraesthesia.
Acephalgic migraine (also called acephalalgic migraine, migraine aura without headache, amigrainous migraine, isolated visual migraine, and optical migraine) is a neurological syndrome. It is a relatively uncommon variant of migraine in which the patient may experience aura, nausea, photophobia, hemiparesis, and other migraine symptoms, but does not experience headache. It is generally classified as an event fulfilling the conditions of migraine with aura with no (or minimal) headache. It is sometimes distinguished from visual-only migraine aura without headache, also called ocular migraine.
General symptoms of migralepsy are:
- Flashes of light
- Geometric or animate forms
- Visual hallucinations
- Vomiting
- Headache
- Blindness
- Loss of consciousness
- Convulsions
Many variations occur, but scintillating scotoma usually begins as a spot of flickering light near or in the center of the visual field, which prevents vision within the scotoma area. The affected area flickers but is not dark. It then gradually expands outward from the initial spot. Vision remains normal beyond the borders of the expanding scotoma(s), with objects melting into the scotoma area background similarly to the physiological blind spot, which means that objects may be seen better by not looking directly at them in the early stages when the spot is in or near the center. The scotoma area may expand to completely occupy one half of the visual area, or it may also be bilateral. It may occur as an isolated symptom without headache in acephalgic migraine.
As the scotoma area expands, some people perceive only a bright flickering area that obstructs normal vision, while others describe seeing various patterns. Some describe seeing one or more shimmering arcs of white or colored flashing lights. An arc of light may gradually enlarge, become more obvious, and may take the form of a definite zigzag pattern, sometimes called a fortification spectrum (i.e. teichopsia, from Greek τεῖχος, town wall), because of its resemblance to the fortifications of a castle or fort seen from above. It also can resemble the dazzle camouflage patterns used on ships in World War I. Others describe patterns within the arc as resembling Widmanstätten patterns.
The visual anomaly results from abnormal functioning of portions of the occipital cortex at the back of the brain, not in the eyes nor any component thereof, such as the retinas. This is a different disease from retinal migraine, which is monocular (only one eye).
It may be difficult to read and dangerous to drive a vehicle while the scotoma is present. Normal central vision may return several minutes before the scotoma disappears from peripheral vision.
Sufferers can keep a diary of dates on which the episodes occur to show to their physician, plus a small sketch of the anomaly, which may vary between episodes.
Animated depictions
Migralepsy is a rare condition in which a migraine is followed, within an hour period, by an epileptic seizure. Because of the similarities in signs, symptoms, and treatments of both conditions, such as the neurological basis, the psychological issues, and the autonomic distress that is created from them, they individually increase the likelihood of causing the other. However, also because of the sameness, they are often misdiagnosed for each other, as migralepsy rarely occurs.
Scintillating scotoma, also called visual migraine, is the most common visual aura preceding migraine and was first described by 19th-century physician Hubert Airy (1838–1903). It may precede a migraine headache, but can also occur acephalgically (without headache). It is often confused with ocular migraine, which originates in the eyeball or socket.
Retinal migraine is associated with transient monocular visual loss (scotoma) in one eye lasting less than one hour. During some episodes, the visual loss may occur with no headache and at other times throbbing headache on the same side of the head as the visual loss may occur, accompanied by severe light sensitivity and/or nausea. Visual loss tends to affect the entire monocular visual field of one eye, not both eyes. After each episode, normal vision returns.
It may be difficult to read and dangerous to drive a vehicle while retinal migraine symptoms are present.
Retinal migraine is a different disease than scintillating scotoma, which is a visual anomaly caused by spreading depression in the occipital cortex at the back of the brain, not in the eyes nor any component thereof. Unlike in retinal migraine, a scintillating scotoma involves repeated bouts of temporary diminished vision or blindness and affects vision from both eyes, upon which sufferers may see flashes of light, zigzagging patterns, blind spots, or shimmering spots or stars.
The diagnosis of abdominal migraines is controversial. Diagnostic criteria from the ICHD2 are:
The medical exam should rule out any underlying causes, such as blood clot, stroke, pituitary tumor, or detached retina. A normal retina exam is consistent with retinal migraine.
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.
Persistent aura without infarction (PAWOI) is a little-known condition, first described under the designation prolonged migraine aura status, that is not yet fully understood. PAWOI is said to be a possible cause of a variety of neurological symptoms, including visual snow, loss of vision, increased afterimages, tinnitus, and others. However, the pathogenesis of PAWOI is unknown; in other words, it is not known exactly what causes these symptoms. Furthermore, it is not clear which medical examinations are useful in diagnosing PAWOI. At present, PAWOI is usually diagnosed solely based on the patient's present and past symptoms. It may be possible that an overactive brain or a chemical imbalance is partly to blame for the disorder.
Different medication has been tried as treatment, notably acetazolamide, valproate, lamotrigine, topiramate, and furosemide.
Micropsia can occur during the aura phase of a migraine attack, a phase that often precedes the onset of a headache and is commonly characterized by visual disturbances. Micropsia, along with hemianopsia, quadrantopsia, scotoma, phosphene, teicopsia, metamorphopsia, macropsia, teleopsia, diplopia, dischromatopsia, and hallucination disturbances, is a type of aura that occurs immediately before or during the onset of a migraine headache. The symptom usually occurs less than thirty minutes before the migraine headache begins and lasts for five to twenty minutes. Only 10-20% of children with migraine headaches experience auras. Visual auras such as micropsia are most common in children with migraines.
The most frequent neurological origin of micropsia is a result of temporal lobe seizures. These seizures affect the entire visual field of the patient. More rarely, micropsia can be part of purely visual seizures. This in turn only affects one half of the visual field and is accompanied by other cerebral visual disturbances. The most common cause of seizures which produce perceptual disturbances such as micropsia and macropsia is medial temporal lobe epilepsy in which the seizures originate in the amygdala-hippocampus complex. Micropsia often occurs as an aura signalling a seizure in patients with medial temporal lobe epilepsy. Most auras last for a very short period, ranging from a few seconds to a few minutes.
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.
Palinopsia necessitates a full ophthalmologic and neurologic history and physical exam. There are no clear guidelines on the work-up for illusory palinopsia, but it is not unreasonable to order automated visual field testing and neuroimaging since migraine aura can sometimes mimic seizures or cortical lesions. However, in a young patient without risk factors or other worrisome symptoms or signs (vasculopathy, history of cancer, etc.), neuroimaging for illusory palinopsia is low-yield but may grant the patient peace of mind.
The physical exam and work-up are usually non-contributory in illusory palinopsia. Diagnosing the etiology of illusory palinopsia is often based on the clinical history. Palinopsia is attributed to a prescription drug if symptoms begin after drug initiation or dose increase. Palinopsia is attributed to head trauma if symptoms begin shortly after the incident. Continuous illusory palinopsia in a migraineur is usually from persistent visual aura. HPPD can occur any time after hallucinogen ingestion and is a diagnosis of exclusion in patients with previous hallucinogen use. Migraines and HPPD are probably the most common causes of palinopsia. Idiopathic palinopsia may be analogous to the cerebral state in persistent visual aura with non-migraine headache or persistent visual aura without headache.
Due to the subjective nature of the symptoms and the lack of organic findings, clinicians may be dismissive of illusory palinopsia, sometimes causing the patient distress. There is considerable evidence in the literature confirming the symptom legitimacy, so validating the patient’s symptoms can help ease anxiety. Unidirectional visual trails or illusory symptoms confined to part of a visual field suggest cortical pathology and necessitate further work-up.
Abdominal migraine is a disorder primarily of children which presents with episodes of abdominal pain without an accompanying headache. It is difficult to confirm the diagnosis as there are not a set of features that is specific and thus it can take time before the diagnosis is made. The condition is rare in adults.
"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.
Abdominal epilepsy, also known as autonomic epilepsy, is a rare condition most frequently found in children, consisting of gastrointestinal (GI) disturbances caused by epileptiform seizure activity.
It has been described as a type of temporal lobe epilepsy. Responsiveness to anticonvulsants can aid in the diagnosis.
Most published medical literature dealing with abdominal epilepsy is in the form of individual case reports. A 2005 review article found a total of 36 cases described in the medical literature.
A cold-stimulus headache, also known as brain freeze, ice-cream headache, trigeminal headache or its given scientific name sphenopalatine ganglioneuralgia (meaning "pain of the "sphenopalatine ganglion""), is a form of brief pain or headache commonly associated with consumption (particularly quick consumption) of cold beverages or foods such as ice cream and ice pops. It is caused by having something cold touch the roof of the mouth, and is believed to result from a nerve response causing rapid constriction and swelling of blood vessels or a "referring" of pain from the roof of the mouth to the head. The rate of intake for cold foods has been studied as a contributing factor. An cold-stimulus headache is distinct from dentin hypersensitivity, a type of pain that can occur under similar circumstances.
Cats and other animals have been observed experiencing a similar reaction when presented with a similar stimulus.
The term "ice-cream headache" has been in use since at least January 31, 1937, contained in a journal entry by Rebecca Timbres published in the 1939 book "We Didn't Ask Utopia: A Quaker Family in Soviet Russia".
Diagnostic criteria require motor symptoms and at least one visual, sensory, or speech symptom, resembling basilar migraine. They may also be associated with cerebellar signs.