Macropsia

There are a broad range of psychological and emotional effects that a person with macropsia may experience. One competing theory has radically stated that macropsia may be an entirely psychological pathological phenomenon without any structural defect or definite cause.[5] They may be in an irritable or angry state, or in contrast, a euphoric state. There is evidence that those who experience Alice in Wonderland Syndrome and associated macropsia are able to recount their experiences with thorough detail. There may be no evidence of psychiatric disturbance and, as a result, no psychiatric therapy may be required.[6] Psychological conditions often arise from macropsia, but the general consensus is that they do not cause macropsia. Those affected may experience extreme anxiety both during and after episodes as a result of the overwhelming nature of his or her distorted visual field. Due to the fear and anxiety associated with the condition, those who have previously had an episode hesitate to recount the episode, although retain the ability to do so.[2] Psychologically, a person with macropsia may feel separation and dissociation from the outside world and even from immediate family. This feeling of dissociation has mostly been noted in child or adolescent patients. The patient may feel that he or she must unfairly contend with hostile and aggressive forces due to the gigantic nature of the surrounding environment.[2] The defense against said forces is usually expressed verbally. The patient may falsely present an outgoing or flamboyant persona, while remaining fearful of people internally. He or she, in an attempt to balance the size distortion, may try to make others feel small in size through insult or hostile behavior. The psychological impact of macropsia on long-time people who have had the condition since childhood may be greater and lead to severe ego-deficiencies.[2] An alternative interpretation of the condition is that macropsia is a response to biophysiological contraction and has no psychological roots. Thus, when a patient reaches for an enlarged object, he or she is overcoming that physiological contraction.[5] However, this theory has been under much scrutiny.

In cases where macropsia affects one eye resulting in differences in the way the two eyes perceive the size or shape of images, the condition is known as aniseikonia.[1] Aniseikonia is known to be associated with certain retinal conditions. Epiretinal membrane has been found to cause metamorphopsia and aniseikonia.[1][7][8][9][10] Vitreomacular traction caused by the excessive adhesion of vitreous fluid to the retina is related to aniseikonia due to the separation and compression of photoreceptor cells.[7] Macular edema[11] and surgical re-attachment for macula-off rhegmatogenous retinal detachment[4] can also cause an increased separation of macular photoreceptor cells resulting in dysmetropsia. Retinoschisis is another eye disease that has been shown to cause aniseikonia.[3]

There is evidence that a lesion appearing in the posterior area of the ventral occipitotemporal visual pathway can cause macropsia. This lesion can be due to an ischemic cell death after an acute posterior cerebral infarction.[12]

The most prevalent research on prescription drugs with side effects of macropsia deals with zolpidem and citalopram. Zolpidem is a drug prescribed for insomnia, and although it has proven beneficial effects, there have been numerous reported cases of adverse perceptual reactions.[13] One of these cases discusses an anorexic woman's episode of macropsia, which occurred twenty minutes after taking 10 mg zolpidem. The same woman later had two more episodes of zolpidem-induced macropsia, after taking 5 mg and 2.5 mg zolpidem, respective to each episode. The intensity of the macropsia episodes decreased with the decreasing amount of zolpidem administered; it is implied in the article that the level of intensity was based on the patients accounts of her macropsia episodes, and that no external diagnosis was used.[14] Hoyler points out notable similarities among the different reported cases of zolpidem-induced disorganization. The similarities were that all the cases were reported by women, the disorganization and agitation followed the first administration of zolpidem, and once zolpidem was discontinued, there were no lasting residual effects. It is believed that zolpidem-related macropsia is more prevalent in women because plasma zolpidem concentration is 40% higher in women, a concentration that further increases in anorexic women.[14]

Citalopram-induced macropsia is similar to zolpidem-induced macropsia since both types have been observed in relatively few cases, and neither of the drugs' side effects can be supported by experimental evidence. Citalopram is an antidepressant that inhibits serotonin reuptake.[15] The first case of macropsia thought to be induced by citalopram involves a woman who experienced macropsia after her first administration of 10 mg citalopram. Just as with zolpidem, after the immediate discontinuation of citalopram, there were no further episodes of macropsia.[16]

There are suggestions that visual distortions, such as macropsia, can be associated with cocaine use.[17] Episodes of temporary drug-induced macropsia subside as the chemicals leave the body.

Past research has linked macropsia to migraine. One of these studies was conducted on Japanese adolescents who reported visual episodic illusions with macropsia and showed that illusions are three times more likely to occur in association with migraine. The illusions were most prevalent among girls between the ages of 16 and 18. It is unlikely that macropsia in Japanese adolescents could be due to epileptic seizure since only 0.3% of Japanese adolescents have epilepsy.[18] No evidence of drugs was found, which eliminates the possibility of the macropsia in the adolescents being drug-induced. It is also unlikely for macropsia in adolescent children to be associated with a serious disease.[18] It is usually the macropsia or other visual disturbance which precedes the painful migrainous headaches. The episodes of macropsia can occur as part of the aura in a migraine. These episodes are often brief, lasting only a few minutes. Adolescents who are deemed to have multiple distortions per episode, such as slow motion vision and macropsia, are even more likely to be people with migraine.[18] The macropsia episodes associated with migraine are typically equivalent to the duration of the aura, which can range from moments to 15 minutes. Non-migrainous headaches are not known to be associated with episodic illusions.[18] Even in the absence of a migraine, a fever or a hypnogogic state can provoke visual illusions, which one might claim to be macropsia. A person with macropsia may fail to see the connection between the migraine and the macropsia, since the conditions may not elicit symptoms at the same time. The pathophysiology of the condition is not fully understood, but the timing of some episodic occurrences with the headaches suggests that there is a connection between macropsia and the vasoconstrictive phase of a migraine.[6] The differences in visual phenomena, such as macropsia with slow motion versus macropsia without slow motion, may result from different areas of the brain being affected by migraine.[6]

Macropsia may present itself as a symptom of both frontal lobe epilepsy and temporal lobe epilepsy, which may actually help in the diagnosis of those diseases. Children who experience nocturnal hallucinations accompanied by macropsia may seek medical care for panic attack disorders and instead are diagnosed with forms of epilepsy. Epilepsy patients may have no memory of the seizure, but can remember the hallucinations and aura which proceed the attack. Electroencephalography, or EEG imaging, can then be utilized while the patient experiences the episode. It may be subsequently concluded that the EEG is congruent with temporal or frontal lobe seizure.[19] Anxiety and headaches accompany the episodes of visual distortion associated with epilepsy. While Valproic acid has been used to treat this type of seizure,[20] anti-seizure medications appropriate for focal-onset seizures, like oxcarbazapine, have also been used successfully in the treatment of epilepsy-related macropsia.

Endogenous hypoglycaemia can result in number of visual disturbances and sometimes macropsia. This kind of hypoglycaemia is defined as having an abnormally low blood-sugar level due to anything other than the exogenous administration of insulin.[21] Macropsia has been observed in experimental hypoglycaemia and in patients receiving insulin therapy.[22]

Patients with both Epstein-Barr virus and infectious mononucleosis have cited an increase in the sizes of perceived objects, coinciding with other symptoms of Alice in Wonderland Syndrome.[23] Additionally, it has been observed that Epstein-Barr patients who cite hallucinations display abnormal MRI scans. The MRI may show swelling of the cerebral cortex, transient T2 prolongation, and transient lesions. Unlike in MRI's, no abnormalities have been reported in CT scans. It is thus recommended that an Epstein-Barr patient who cites visual hallucinations have an MRI scan.[24] Macropsia may appear either before the onset, or after the resolution, of all clinical symptoms associated with the illness.[25] The duration of the disturbances have been shown to range between two weeks and seven months.[25] Almost all patients with macropsia due to infectious mononucleosis make full recoveries. Patients with Coxsackievirus B1 have reported numerous symptoms of Alice in Wonderland Syndrome, the most common of which being macropsia and micropsia.[20]