Ataque de nervios was first mentioned in Puerto Rico by US military psychiatrists who observed a young Puerto Rican experiencing unusual illness.

Reported aspects of the syndrome include uncontrollable screaming or shouting, crying, trembling, sensations of heat rising in the chest and head, dissociative experiences, and verbal or physical aggression. The reaction is usually associated with a stressful event relating to the family, although it is not specifically defined as arising from such occurrences.

MdDS is diagnosed several ways, one being by the symptoms: in particular, the "constant rocking, swaying feeling" and the abatement of this feeling when in motion again and as a matter of exclusion. There are no definitive tests that confirm MdDS, only tests that rule out other conditions. Tests include hearing and balance, and MdDS is generally diagnosed by either a neurologist or an ear nose & throat specialist.

At least one clinical trial on readaptation of the vestibulo-ocular reflex undertaken by Dr Mingjia Dai from Mount Sinai Hospital in New York City has produced results for a significant percentage of patients who have participated in the program.

Dai has developed an intervention that provided improvement in symptoms for 70% of the patients in the clinical trial phase. The protocol involves a physical manipulation of the patient intended to readapt the vestibulo-ocular reflex. While the program is no longer in the research phase, Dai continues to accept patients. According to Dai, "success" is measured as a 50% reduction of symptoms.

Recent research reveals a very small percentage of MdDS cases may be related to optokinetic nystagmus (OKN).

In medicine and medical anthropology, a culture-bound syndrome, culture-specific syndrome, or folk illness is a combination of psychiatric and somatic symptoms that are considered to be a recognizable disease only within a specific society or culture. There are no objective biochemical or structural alterations of body organs or functions, and the disease is not recognized in other cultures. The term "culture-bound syndrome" was included in the fourth version of the "Diagnostic and Statistical Manual of Mental Disorders" (American Psychiatric Association, 1994) which also includes a list of the most common culture-bound conditions (DSM-IV: Appendix I). Counterpart within the framework of ICD-10 () are the "culture-specific disorders" defined in Annex 2 of the "Diagnostic criteria for research".

More broadly, an epidemic that can be attributed to cultural behavior patterns or suggestion is sometimes referred to as a behavioral epidemic. As in the cases of drug or alcohol abuse or smoking, transmission can be determined by communal reinforcement as well as by person-to-person interactions. On etiological grounds, it can be difficult to distinguish the causal contribution of culture in disease from other environmental factors such as toxicity.

The 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD) classifies the below syndromes as culture-specific disorders:

The diagnosis of CdLS is primarily a clinical one, based on medical signs that are evident in a medical history, physical examination, and laboratory tests. Since 2006, testing for NIPBL and SMC1A has been available through the University of Chicago. This is best accomplished through a referral to a genetics specialist or clinic.

CdLS is thought to be underdiagnosed and frequently misdiagnosed.

Paris syndrome (, , "Pari shōkōgun") is a transient mental disorder exhibited by some individuals when visiting or going on vacation to Paris, as a result of extreme shock derived from their discovery that Paris is not what they had expected it to be. The syndrome is characterized by a number of psychiatric symptoms such as acute delusional states, hallucinations, feelings of persecution (perceptions of being a victim of prejudice, aggression, or hostility from others), derealization, depersonalization, anxiety, and also psychosomatic manifestations such as dizziness, tachycardia, sweating, and others, such as vomiting. Similar syndromes include Jerusalem syndrome and Stendhal syndrome. The condition is commonly viewed as a severe form of culture shock. It is particularly noted among Japanese travelers.

Professor Hiroaki Ota, a Japanese psychiatrist working in France, is credited as the first person to diagnose the condition in 1986. However, later work by Youcef Mahmoudia, physician with the hospital Hôtel-Dieu de Paris, indicates that Paris syndrome is "a manifestation of psychopathology related to the voyage, rather than a syndrome of the traveller." He theorized that the excitement resulting from visiting Paris causes the heart to accelerate, causing giddiness and shortness of breath, which results in hallucinations in the manner similar to the Stendhal syndrome described by Italian psychiatrist Graziella Magherini in her book "La sindrome di Stendhal".

Jumping Frenchmen of Maine syndrome must be distinguished from other conditions involving the startle reflex or tics.

Tourette syndrome is characterized by multiple physical (motor) tics and at least one vocal (phonic) tic. There are many overlaps when compared clinically, but the abnormal "jumping" response is always provoked, unlike the involuntary tics in Tourette syndrome.

Latah from Southeast Asia is a disorder where one's startle response is similar to a state of trance with repetitive speech or movements. Miryachit is a disorder found in Siberia that also displays an action similar to "jumping". Neurasthenia is a disorder with a startle response during periods of great fatigue.

Hyperekplexia is an extremely rare autosomal dominant neurological disease. The symptoms start in infancy with hypertonia, an abnormal muscle tension that decreases flexibility, and an exaggerated startle in all ages of life.

The Cornelia de Lange Syndrome (CdLS) Foundation is a nonprofit, family support organization based in Avon, Connecticut, that exists to ensure early and accurate diagnosis of CdLS, promote research into the causes and manifestations of the syndrome, and help people with a diagnosis of CdLS, and others with similar characteristics, make informed decisions throughout their lives.

Egomania is also known as an obsessive preoccupation with one's self and applies to someone who follows their own ungoverned impulses and is possessed by delusions of personal greatness and feels a lack of appreciation. Someone suffering from this extreme egocentric focus is an egomaniac. The condition is psychologically abnormal.

The term "egomania" is often used by laypersons in a pejorative fashion to describe an individual who is intolerably self-centred. The clinical condition that most resembles the popular conception of egomania is narcissistic personality disorder.

The cause of Jumping Frenchmen syndrome is unknown. One theory is that it is a genetic condition. Observation of 50 cases found the disorder to be remotely located and concentrated in the northern regions of Maine. Fourteen of these cases were found in four families. Another set of cases were found in a single family where the father, his two sons, and his two grandchildren exhibited "jumping" behavior.

It may also be a culture-bound syndrome or a formed habit. These French "jumpers" lived in a very remote region and most were lumberjacks. This type of small community would allow for a majority to adapt to this sort of reaction. Also, instances of many being shy may imply that the "jumper" was positively reinforced by the sudden attention as the entertainment for a group.

In 1885, Georges Gilles de la Tourette included Jumping Frenchmen syndrome in the typology of "convulsive tic illness"; studies of the condition in the 1980s cast doubt on whether the phenomenon was in fact a physical condition similar to Tourette syndrome. Documentation of direct observation of "Jumping Frenchmen" has been scarce, and while videotape evidence was recorded by several researchers that showed the condition to be real, MH and JM Saint-Hilaire concluded from studying eight affected people that it was brought on by conditions at their lumber camps and was psychological, not neurological.

Victor Khrisanfovich Kandinsky () (1849, Byankino, Siberia - 1889) was a Russian physician, and was 2nd cousin to famed artist Wassily Kandinsky. He was born in Siberia into a large family of extremely wealthy businessmen.

In 1877 as a military physician in the Balkans during the Russo-Turkish War, he began experiencing mood swings and hallucinations. Kandinsky performed self-diagnosis, and he referred to his mental condition as "Primäre Verrücktheit" (primary paranoid psychosis) which has been anachronistically translated into modern terms as a "schizophrenic-like state". In 1885 Kandinsky published a book written in German on "pseudohallucinations" in which he describes and details hallucinations largely based on his personal experiences. In September 1889, feeling that his psychotic symptoms were returning, he took his own life by taking an overdose of morphine. He died as a patient in the institution he had formerly run as the medical superintendent, the St. Nicholas Asylum in St. Petersburg.

In a monograph published posthumously in 1890, Kandinsky described a condition which involved being alienated from one's personal mental processes, combined with delusions of being physically and mentally influenced by external forces. The syndrome he described is now known as Kandinsky-Clérambault syndrome, named along with French psychiatrist Gaëtan Gatian de Clérambault. The syndrome also known as "syndrome of psychic automatism".

Diagnosis is based on the distinctive cry and accompanying physical problems. These common symptoms are quite easily observed in infants. Affected children are typically diagnosed by a doctor or nurse at birth. Genetic counseling and genetic testing may be offered to families with individuals who have cri du chat syndrome. Prenatally the deletion of the cri du chat related region in the p arm of chromosome 5 can be detected from amniotic fluid or chorionic villi samples with BACs-on-Beads technology. G-banded karyotype of a carrier is also useful. Children may be treated by speech, physical and occupational therapists. Heart abnormalities often require surgical correction.

MRI will help with the diagnosis of structural abnormality of the brain. Genetic testing may also be pursued.

“Mongrel complex" ("Complexo de vira-Lata" in Portuguese) is an expression used to refer to a collective inferiority complex felt by some Brazilian people in comparison to Europe or the United States. The reference to a "mongrel" (as opposed to "pure-bred") carries negative connotations attributed to most Brazilians being racially mixed as well as a perception of lacking cultural refinement.

Intermetamorphosis is a delusional misidentification syndrome, related to agnosia. The main symptoms consist of patients believing that they can see others change into someone else in both external appearance and internal personality. The disorder is usually comorbid with neurological disorders or mental disorders.

An example from medical literature is a man who was diagnosed with Alzheimer's disease. After some time he mistook his wife for his deceased mother and later for his sister. As an explanation, he stated that he had never been married or that his wife had left him. Later he mistook his son for his brother and his daughter for another sister. Visual agnosia or prosopagnosia were not diagnosed, as the misidentification also took place during phone calls. On several occasions he mistook the hospital for the church he used to go to.

The disorder was first described in 1932 by P. Courbon and J. Tusques ("Illusions d'intermétamorphose et de la charme"), in the Journal: Annales Medico-Psychologiques issue 14, page 401-406.

Erotomania is a type of delusional disorder where the affected person believes that another person is in love with him or her. This belief is usually applied to someone with higher status or a famous person, but can also be applied to a complete stranger. Erotomanic delusions often occur in patients with schizophrenia and other psychotic disorders, but can also occur during a manic episode in the context of bipolar I disorder. During an erotomanic delusion, the patient believes that a secret admirer is declaring his or her affection for the patient, often by special glances, signals, telepathy, or messages through the media. Usually the patient then returns the perceived affection by means of letters, phone calls, gifts, and visits to the unwitting recipient. Even though these advances are unexpected and often unwanted, any denial of affection by the object of this delusional love is dismissed by the patient as a ploy to conceal the forbidden love from the rest of the world.

Erotomania is also called de Clérambault's syndrome, after French psychiatrist Gaëtan Gatian de Clérambault (1872–1934), who published a comprehensive review paper on the subject ("Les Psychoses Passionnelles") in 1921. Erotomania should not be confused with obsessive love or obsession with unrequited love, neither of which involves delusion.

Egomania has also been linked with alcoholism. 'Egomania drives many young alcoholics...alcoholism-created egomania'. A recovering alcoholic may well look back at the past as 'the land of self-loathing, egomania, and decay'.

The danger with the egomaniac is always that 'underneath the apparent over-confidence and bravado lies a fragile personality', driven by 'grandiose fantasies of boundless success or power or perfect love' which cannot be fulfilled.

Weber's syndrome is the only form of alternating hemiplegia that is somewhat easy to diagnose beyond the general criteria. Although Weber's syndrome is rare, a child born with the disorder typically has a port-wine stain on the face around the eye. While the port-wine stain does not necessarily mean the child has Weber's syndrome, if the port-wine stain involves the ophthalmic division of the trigeminal nerve than the likelihood of it being weber's syndrome greatly increases. If a port-wine stain around the eye is found, the patient should be screened for intracranial leptomeningeal angiomatosis. Magnetic resonance imaging (MRI)can be used to determine the presence and severity while computed cranial tomography can be used to determine the effect. MRI is the preferred diagnostic test on children presenting with port-wine stain. Other imaging techniques can be used in addition to further determine the severity of the disorder. The initial diagnosis is made based on the presence of neurologic and ophthalmic disease but the disease progresses differently in each patient so after initial diagnosis the patient should be monitored frequently in order to handle further complications resulting from the syndrome.

Gueules cassées (broken faces) is a French expression for facially disfigured servicemen which originated in World War I. Colonel Yves Picot is said to have coined the term when he was refused passing a checkpoint to a party.

There is no diagnostic test for alternating hemiplegia, which makes it very difficult to diagnose. Also, because alternating hemiplegia is extremely rare, it is frequently missed and the patient is often misdiagnosed. Proper diagnosis, however, is critical for early treatment of the disorder. There are many criteria that can help in the proper general diagnosis of alternating hemiplegia.

RSIs are assessed using a number of objective clinical measures. These include effort-based tests such as grip and pinch strength, diagnostic tests such as Finkelstein's test for De Quervain's tendinitis, Phalen's Contortion, Tinel's Percussion for carpal tunnel syndrome, and nerve conduction velocity tests that show nerve compression in the wrist. Various imaging techniques can also be used to show nerve compression such as x-ray for the wrist, and MRI for the thoracic outlet and cervico-brachial areas.

The core symptom of the disorder is that the sufferer holds an unshakable belief that another person is secretly in love with them. In some cases, the sufferer may believe several people at once are "secret admirers". The sufferer may also experience other types of delusions concurrently with erotomania, such as delusions of reference, wherein the perceived admirer secretly communicates his or her love by subtle methods such as body posture, arrangement of household objects, and other seemingly innocuous acts (or, if the person is a public figure, through clues in the media). Erotomanic delusions are typically found as the primary symptom of a delusional disorder or in the context of schizophrenia and may be treated with atypical antipsychotics.