Alice in Wonderland syndrome (AIWS), also known as Todd's syndrome or dysmetropsia, is a neurological disorder that distorts perception. People with this syndrome may experience distortions in their visual perception of objects, such as appearing smaller (micropsia) or larger (macropsia), or appearing to be closer (pelopsia) or farther (teleopsia) than they are. Distortion may also occur for senses other than vision.
The cause of Alice in Wonderland syndrome is unknown, but it is often associated with migraines, head trauma, or viral encephalitis caused by Epstein–Barr Virus Infection. It is also theorized that AIWS can be caused by abnormal cerebral electrical activity, resulting in abnormal blood flow in the parts of the brain that process visual perception and texture. Alice in Wonderland syndrome is also possible to be experienced temporarily under the use of certain psychoactive drugs. Although Alice in Wonderland syndrome can occur in both adolescents and adults, it is more commonly seen in children.
Classification Though not agreed upon in literature, some authors classify only symptoms involving changes in perception of a person's body image as true Alice in Wonderland syndrome and instead use the term "Alice in Wonderland-like syndrome" to classify any symptoms involving other changes in perception of vision, time, hearing, touch or other perceptions. Due to the classification of all the clinical features seen in Alice in Wonderland, the table below illustrates theses features and symptoms by type with Type C having a combination of Type A and Type B symptoms.
Types Obligatory symptoms Facultative symptoms Type A Aschematia: partial or total macrosomatognosia or microsomatognosia; paraschematiaDerealization, depersonalization, somatopsychic duality, aberration in judgement of time Type B Macro- and micropsia and/or tele- and pelopsia. When micropsia and telopsia appear at the same time and for the same object: porropsia Lilliputianism (people appearing smaller) Type C Type A + Type B symptoms
Signs and symptoms With over 60 associated symptoms, AIWS affects the sense of vision, sensation, touch, and hearing, as well as the perception of one's body image. Migraines, nausea, dizziness, and agitation are also commonly associated symptoms with Alice in Wonderland syndrome. Less frequent symptoms also include: loss of limb control and coordination, memory loss, lingering touch and sound sensations, and emotional instability. Alice in Wonderland syndrome is often associated with distortion of sensory perception, which involves visual, somatosensory, and non-visual symptoms. AIWS is characterized by the individual being able to recognize the distortion in the perception of their own body and is episodic. AIWS episodes vary in length from person to person. Episodes typically last from a few minutes to an hour, and each episode may vary in experience.
Visual distortions Individuals with AIWS can experience illusions of expansion, reduction, or distortion of their body image, such as microsomatognosia (feeling that their own body or body parts are shrinking), or macrosomatognosia (feeling that their body or body parts are growing taller or larger). These changes in perception are collectively known as metamorphopsias, or Lilliputian hallucinations, which refer to objects appearing either smaller or larger than reality. People with certain neurological diseases may also experience similar visual hallucinations.
Within the category of Lilliputian hallucinations, people may experience either micropsia or macropsia. Micropsia is an abnormal visual condition, usually occurring in the context of visual hallucination, in which the affected person sees objects as being smaller than they are in reality. Macropsia is a condition where the individual sees everything larger than it is. These visual distortions are sometimes classified as "Alice in Wonderland-like syndrome" instead of true Alice in Wonderland syndrome but are often still classified as Alice in Wonderland syndrome by health professionals and researchers since the distinction is not official. Other distortions include teleopsia (objects are perceived further than they actually are) and pelopsia (objects are perceived closer than they actually are).
Depersonalization and derealization Along with size, mass, and shape distortions of the body, those with Alice in Wonderland syndrome often experience a feeling of disconnection from one's own body, feelings, thoughts, and environment known as depersonalization-derealization disorder. Depersonalization is a term specifically used to express a true detachment from their personal self and identity. It is described as being an observer completely outside of their own actions and behaviors. Derealization is seen as "dreamlike, empty, lifeless, or visually distorted."
Hearing and time distortions Individuals experiencing Alice in Wonderland syndrome can also often experience paranoia as a result of disturbances in sound perception. These disturbances can include the amplification of soft sounds or the misinterpretation of common sounds. Other auditory changes include distortion in pitch and tone and hearing indistinguishable and strange voices, noises, or music. A person affected by AIWS may also lose a sense of time, a problem similar to the lack of spatial perspective brought on by visual distortion. This condition is known as tachysensia. For those with tachysensia, time may seem to pass very slowly, similar to an LSD experience, and the lack of time and space perspective can also lead to a distorted sense of velocity. For example, an object could be moving extremely slowly in reality, but to a person experiencing time distortions, it could seem that the object was sprinting uncontrollably along a moving walkway, leading to severe, overwhelming disorientation. Having symptoms of tachysensia is correlated with various underlying conditions, including substance use, migraine, epilepsy, head trauma, and encephalitis. Regardless of an individual's disease diagnosis, tachysensia is often included as a symptom associated with Alice in Wonderland syndrome since it is classified as a perceptual distortion. Therefore, a person can be described as having Alice in Wonderland syndrome even if that person is experiencing tachysensia due to an underlying condition.
Causes Because AIWS is not commonly diagnosed and documented, it is difficult to estimate what the main causes are. The cause of over half of the documented cases of Alice in Wonderland syndrome is unknown. Complete and partial forms of the AIWS exist in a range of other disorders, including epilepsy, intoxicants, infectious states, fevers, and brain lesions. Furthermore, the syndrome is commonly associated with migraines, as well as excessive screen use in dark spaces and the use of psychoactive drugs. AIWS has been suggested to be an initial symptom of the Epstein–Barr virus and mononucleosis. Epstein–Barr virus appears to be the most common cause in children, while for adults it is more commonly associated with migraines.
Infectious diseases A 2021 review found that infectious diseases are the most common cause of Alice in Wonderland syndrome, especially in pediatrics. Some of these infectious agents included Epstein–Barr virus, Varicella Zoster virus, Influenza, Zika, Coxsackievirus, Plasmodium falciparum protozoa, and Mycoplasma pneumonia/Streptococcus pyogenes bacteria. The association of Alice in Wonderland syndrome is most commonly seen with the Epstein–Barr virus; however, pathogenesis is not well understood beyond these reviews. In some instances, Alice in Wonderland syndrome was reported to be associated with an Influenza A infection.
Cerebral hypotheses Alice in Wonderland syndrome can be caused by abnormal amounts of electrical activity resulting in abnormal blood flow in the parts of the brain that process visual perception and texture. Nuclear medical techniques using technetium, performed on individuals during episodes of Alice in Wonderland syndrome, have demonstrated that Alice in Wonderland syndrome is associated with reduced cerebral perfusion in various cortical regions (frontal, parietal, temporal and occipital), both in combination and in isolation. One hypothesis is that any condition resulting in a decrease in perfusion of the visual pathways or visual control centers of the brain may be responsible for the syndrome. For example, one study used single photon emission computed tomography to demonstrate reduced cerebral perfusion in the temporal lobe in people with Alice in Wonderland syndrome.
Other theories suggest the syndrome is a result of non-specific cortical dysfunction (e.g. from encephalitis, epilepsy, decreased cerebral blood flow), or reduced blood flow to other areas of the brain. Other theories suggest that distorted body image perceptions stem from within the parietal lobe. This has been demonstrated by the production of body image disturbances through electrical stimulation of the posterior parietal cortex. Other researchers suggest that metamorphopsias, or visual distortions, may be a result of reduced perfusion of the non-dominant posterior parietal lobe during migraine episodes. Throughout all the neuroimaging studies, several cortical regions (including the temporoparietal junction within the parietal lobe, and the visual pathway, specifically the occipital lobe) are associated with the development of Alice in Wonderland syndrome symptoms.
Migraines 1 in 10 people who experience migraines have symptoms of Alice in Wonderland syndrome. The role of migraines in Alice in Wonderland syndrome is still not understood, but both vascular and electrical theories have been suggested. For example, visual distortions may be a result of transient, localized ischemia in areas of the visual pathway during migraine attacks. In addition, a spreading wave of depolarization of cells (particularly glial cells) in the cerebral cortex during migraine attacks can eventually activate the trigeminal nerve's regulation of the vascular system. The intense cranial pain during migraines is due to the connection of the trigeminal nerve with the thalamus and thalamic projections onto the sensory cortex. Alice in Wonderland syndrome symptoms can precede, accompany, or replace the typical migraine symptoms. Typical migraines (aura, visual derangements, hemicrania headache, nausea, and vomiting) are both a cause and an associated symptom of Alice in Wonderland syndrome. Alice in Wonderland syndrome is associated with macrosomatognosia which can mostly be experienced during migraine auras.
Genetic and environmental influence While there currently is no identified genetic locus/loci associated with Alice in Wonderland syndrome, observations suggest that a genetic component may exist but the evidence so far is inconclusive. There is also an established genetic component for migraines which may be considered to be a possible cause and influence for hereditary Alice in Wonderland syndrome. Though most frequently described in children and adolescents, observational studies have found that many parents of children experiencing Alice in Wonderland syndrome have also experienced similar symptoms themselves, though often unrecognized.