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The Value of Auras
by John Stern, MD
Sometimes, and not infrequently, the diagnosis of epilepsy is entirely based on the descriptions provided by the patient and witnesses. Diagnostic testing, including both EEG and MRI, can fail to help, and an accounting of the episodes is the basis for the diagnosis. In the telling, the details are critical and the details of auras can be invaluable. To some, auras are a peripheral aspect of the diagnosis; however, this seems to be an underappreciation. Auras can distinguish seizures from other causes for loss of consciousness. Auras can identify the seizure-onset as focal (not generalized) and they can indicate a possible localization. Auras also can be fascinating hints at the potential for human perception beyond conventional experience.
Synesthethetic auras bridge the relatable and the unrelatable. Synesthesias most often occur as isolated phenomena that are not associated with epilepsy or other neurologic abnormality. They are the combining of two, independent sensory modalities, such as vision and hearing. Associating specific colors with specific musical notes is a classic synesthesia. When auras have synesthetic aspects, the component senses may help localize the aura. One example is a patient who described an aura during which whatever object she happened to be seeing would become heavier on one side. The object would not move or change form, but it would seem unbalanced with a shift of its center of gravity. The patient visually perceived weight, which is a tactile sensation, and her epileptogenic zone was found to be parietal-occipital association cortex, which makes sense considering the functions subserved by these cerebral regions. Another patient described fear behind his eyes, that is, he had a somatotopic localization for an emotion. He had a neocortical epileptogenic zone that spanned the Sylvian region. Potentially valuable clinical information can be gained by encouraging patients to speak openly about their auras. With greater detail, the description may be localizing or help avoid a false localization based on a misunderstanding.
Arguably, everyone who regularly interviews patients with auras often encounters patients who have difficulty giving a detailed description of the aura. Often, the patient is clear about having a stereotyped experience at the seizure onset, but pauses and falters when asked to describe it. Many patients can articulate descriptions of epigastric rising (or falling), primary sensory hallucinations, déjà vu, and fear, and these auras are relatable to normal experiences. However, many other patients cannot find a description and instead repeat knowing it when it happens and simply say that the experience is indescribable. Even the guidance by offering specific questions, such as whether the experience is an emotion, a thought, or a sensation somewhere on or in the body often does not help. This is different from fainting, a common alternative diagnosis when evaluating the new onset seizure. The onset of a faint is not nearly as indescribable, and the association of the difficulty in description with seizures is somewhat helpful. My estimation for whether the episode was a seizure increases when an otherwise articulate person has considerable difficulty communicating the experience of the onset. My estimation also increases when the patient gestures with a movement of the hand vertically across the chest. This seems to be the non-verbal correlate to the reported epigastric experience and akin to Levine’s sign of a fist across the chest that is commonly used to non-verbally communicate the experience of angina. Sometimes gestures supplant words and this may be due to the patient’s recognition that the words are not working.
Words work by referencing something that is commonly known or experienced. Specific words come to exist only when people need a way to reference something. My sense is that the indescribable nature of auras is partly due to the experience being uniquely individual. The experience does not exist in the world shared with others. How could a word exist for an experience that is due to one person’s abnormal neuronal activity? As such, perhaps auras are often indescribable because words do not exist for the experiences and not because patients are lacking in descriptive ability. Sometimes patients provide descriptions that are impressively detailed but still not communicating a relatable experience. These descriptions are seemingly metaphoric and using words beyond their immediate definitions. This may be as simple as a recent, highly educated patient’s description of an aura as the experience of ”tilting.” When questioned in detail, “tilt” here was not intended to indicate any change in position or orientation with regard to gravity. Ultimately, the patient said that she meant “tilt” to mean that her experience of the world was changed in a way that the word “tilt” came to mind even if the definition of tilt did not apply. The world was “off.” A more intriguing description, from another patient, is feeling during the auras that she was perched on her own lower lip, facing into her mouth, and crying out loudly. This congers an image that is impossible but it still is an exact experience for the patient. It is a metaphoric expression for an experience that cannot be described any other way.
The experiences during auras are due to cerebral dysfunction and they demonstrate the brain’s capacity to generate experiences beyond what is conceivable in a normally restricted, external world experience. Discussing the details of these experiences with patients can lead to a more accurate diagnosis and also can help build a better relationship of understanding between the clinician and patient, who may feel that the experience is too indescribable to share. In building this understanding, the clinician also gets the opportunity to hear examples of the brain’s tremendous potential for creating experiences.
by John Stern, MD
Sometimes, and not infrequently, the diagnosis of epilepsy is entirely based on the descriptions provided by the patient and witnesses. Diagnostic testing, including both EEG and MRI, can fail to help, and an accounting of the episodes is the basis for the diagnosis. In the telling, the details are critical and the details of auras can be invaluable. To some, auras are a peripheral aspect of the diagnosis; however, this seems to be an underappreciation. Auras can distinguish seizures from other causes for loss of consciousness. Auras can identify the seizure-onset as focal (not generalized) and they can indicate a possible localization. Auras also can be fascinating hints at the potential for human perception beyond conventional experience.
Synesthethetic auras bridge the relatable and the unrelatable. Synesthesias most often occur as isolated phenomena that are not associated with epilepsy or other neurologic abnormality. They are the combining of two, independent sensory modalities, such as vision and hearing. Associating specific colors with specific musical notes is a classic synesthesia. When auras have synesthetic aspects, the component senses may help localize the aura. One example is a patient who described an aura during which whatever object she happened to be seeing would become heavier on one side. The object would not move or change form, but it would seem unbalanced with a shift of its center of gravity. The patient visually perceived weight, which is a tactile sensation, and her epileptogenic zone was found to be parietal-occipital association cortex, which makes sense considering the functions subserved by these cerebral regions. Another patient described fear behind his eyes, that is, he had a somatotopic localization for an emotion. He had a neocortical epileptogenic zone that spanned the Sylvian region. Potentially valuable clinical information can be gained by encouraging patients to speak openly about their auras. With greater detail, the description may be localizing or help avoid a false localization based on a misunderstanding.
Arguably, everyone who regularly interviews patients with auras often encounters patients who have difficulty giving a detailed description of the aura. Often, the patient is clear about having a stereotyped experience at the seizure onset, but pauses and falters when asked to describe it. Many patients can articulate descriptions of epigastric rising (or falling), primary sensory hallucinations, déjà vu, and fear, and these auras are relatable to normal experiences. However, many other patients cannot find a description and instead repeat knowing it when it happens and simply say that the experience is indescribable. Even the guidance by offering specific questions, such as whether the experience is an emotion, a thought, or a sensation somewhere on or in the body often does not help. This is different from fainting, a common alternative diagnosis when evaluating the new onset seizure. The onset of a faint is not nearly as indescribable, and the association of the difficulty in description with seizures is somewhat helpful. My estimation for whether the episode was a seizure increases when an otherwise articulate person has considerable difficulty communicating the experience of the onset. My estimation also increases when the patient gestures with a movement of the hand vertically across the chest. This seems to be the non-verbal correlate to the reported epigastric experience and akin to Levine’s sign of a fist across the chest that is commonly used to non-verbally communicate the experience of angina. Sometimes gestures supplant words and this may be due to the patient’s recognition that the words are not working.
Words work by referencing something that is commonly known or experienced. Specific words come to exist only when people need a way to reference something. My sense is that the indescribable nature of auras is partly due to the experience being uniquely individual. The experience does not exist in the world shared with others. How could a word exist for an experience that is due to one person’s abnormal neuronal activity? As such, perhaps auras are often indescribable because words do not exist for the experiences and not because patients are lacking in descriptive ability. Sometimes patients provide descriptions that are impressively detailed but still not communicating a relatable experience. These descriptions are seemingly metaphoric and using words beyond their immediate definitions. This may be as simple as a recent, highly educated patient’s description of an aura as the experience of ”tilting.” When questioned in detail, “tilt” here was not intended to indicate any change in position or orientation with regard to gravity. Ultimately, the patient said that she meant “tilt” to mean that her experience of the world was changed in a way that the word “tilt” came to mind even if the definition of tilt did not apply. The world was “off.” A more intriguing description, from another patient, is feeling during the auras that she was perched on her own lower lip, facing into her mouth, and crying out loudly. This congers an image that is impossible but it still is an exact experience for the patient. It is a metaphoric expression for an experience that cannot be described any other way.
The experiences during auras are due to cerebral dysfunction and they demonstrate the brain’s capacity to generate experiences beyond what is conceivable in a normally restricted, external world experience. Discussing the details of these experiences with patients can lead to a more accurate diagnosis and also can help build a better relationship of understanding between the clinician and patient, who may feel that the experience is too indescribable to share. In building this understanding, the clinician also gets the opportunity to hear examples of the brain’s tremendous potential for creating experiences.
