Frequency

Movement disorder specialists are seeing increasing numbers of patients with movement disorders whose problems are secondary to psychogenic factors. As one might expect, bradykinetic disorders are less likely than hyperkinetic ones to have a psychogenic etiology unless one were to consider the phenomenon of deliberate slowness to be a bradykinetic disorder. Although deliberate slowness is common in psychogenic disorders, it is not usually the dominant feature, but when it is pure and without accompanying abnormal movements, it is considered in the category of psychogenic parkinsonism. Fixed postures, fairly common in psychogenic dystonia, account for a sizable proportion of psychogenic movement disorders, so a separate section of this chapter is devoted to the psychogenic dystonias.

Psychogenic disorders in neurology have been estimated to occur in 1–9% of all neurologic diagnoses (Marsden, 1986; Lempert et al., 1990). Neurologists usually and appropriately recognize patients with psychogenic movement disorders, but the patients often do not accept this diagnosis and seek other opinions, going from physician to physician, seeking a diagnosis that is more to their liking. Therefore, a strategy is necessary for the best way to inform the patients of the diagnosis. This issue is discussed in this chapter. Another common situation is that many physicians do not offer the time-consuming care that is necessary to restore such patients to normality, preferring instead merely to diagnose the condition and have the referring physician deal with the healing.

Like other subspecialties in neurology, psychogenic movement disorders are not uncommon. In one large movement disorder clinic, such patients account for 10% of all non-parkinsonian new patient visits (Portera-Cailliau et al., 2006). Typically, patients are diagnosed by the predominant movement feature, e.g., psychogenic tremor, psychogenic dystonia, psychogenic myoclonus, etc. When evaluated this way, tremor is the most common psychogenic phenomenology, followed by dystonia.

Importance of an accurate diagnosis

The diagnosis of a psychogenic movement disorder is a two-stage process (Lang, 2006). First is to make a positive diagnosis that the movements are psychogenic and not due to an organic illness. Second is to identify a psychiatric disorder or the psychodynamics that could explain the etiology of the abnormal movements and prepare the way to deciding the best course for therapy of the individual patient. Deciding between abnormal movements due to a psychogenic cause and an organic one can be extremely difficult. Never having seen strange movements before and pronouncing them to be psychogenic therefore is not a satisfactory method because not even senior movement disorder specialists have seen the whole gamut of organic abnormal movements. An organic cause of the movements needs to be excluded (Fahn, 1994; Williams et al., 2005). But this alone is insufficient and neurologists in times past and present advise that making a diagnosis of a psychogenic disorder depends on finding positive criteria and not simply failing to finding an organic cause (for historical review, see Fahn 2006a).

An accurate diagnosis of a psychogenic movement disorder, as opposed to diagnosing an organic movement disorder, is often one of the most difficult tasks there is in the movement disorder specialty. It is extremely important to be correct in the diagnosis because only then can the appropriate therapy be initiated. The results of an incorrect diagnosis are detrimental. If a patient has a psychogenic disorder that is misdiagnosed, the patient will be given inappropriate and potentially harmful medication and is also denied the proper treatment to overcome the disabling symptoms. By postponing the appropriate psychiatric treatment, the cycle of disability is perpetuated. Untreated patients with psychogenic movement disorders are at risk for becoming career invalids with chronic disability.

If the obverse occurs – that is, if a patient is given a diagnosis of a psychogenic movement disorder when, in fact, he or she suffers from an organic one – again the wrong treatment is given. In this situation, time-consuming and expensive psychotherapy, psychiatric medications, and possibly electroconvulsive therapy might be initiated instead of more appropriate pharmacotherapeutic agents that could provide relief. Moreover, a diagnosis of a psychogenic disorder can create emotional trauma for the patient and his or her family (Cooper, 1976). It is important to point out that no matter how much experience a clinician has had, encountering a new type of movement disorder for the first time does not automatically make this a psychogenic movement disorder. For example, task-specific jaw tremor (Miles et al., 1997) is rare, and even when it is encountered for the first time, a wise clinician should consider it to be organic (Video 25.1) and not psychogenic (Video 25.2).

Neurologic symptoms and signs are a common result of hysteria, and neurologists have long been fascinated by the brain’s ability to be able to produce such clinical expressions on the basis of psychological disturbances. Many great neurologists, such as Charcot and Freud, intensively studied hysterical conversion reactions, using hypnosis as a tool in their investigations and treatment (Goetz, 1987). In their training, neurologists-to-be are taught to differentiate the clinical findings of psychogenic etiology from those of organic disorders (Gowers, 1893; Oppenheim, 1911a; DeJong, 1958a). However, textbooks in the past often considered some dyskinesias, recognized today as organic, such as tics, writer’s cramp and other occupational cramps, and some other forms of dystonia, to be examples of hysteria (DeJong, 1958b).

Although there is a modest neurologic literature on psychogenic phenomenology, the literature dealing specifically with psychogenic movement disorders is rather sparse. For example, tremor as the result of a conversion reaction has been long recognized, at least since the days of Gowers (1893), but scientific reports on psychogenic tremor or other movement disorders are rarely described in the literature. Campbell (1979) pointed out that the amplitude of psychogenic tremor is more pronounced when attention is paid to it, and that it lessens and may even disappear when the patient’s attention is diverted to another subject or other part of the body. Distraction is a useful part of the examination, and lessening of severity by distraction can be very helpful diagnostically in trying to establish a diagnosis of psychogenic tremor. But in our experience, distraction does not always succeed in making the tremor disappear, so this maneuver is often not successful. Therefore, additional findings on examination are often necessary and can be just as helpful in considering the diagnosis of a psychogenic movement disorder; these are discussed in this chapter.

Although in the great majority of patients with a psychogenic movement disorder, all their clinical features result only from a psychogenic problem, some may have the psychogenic movement disorder on top of an organic movement disorder, as seen in Patient 5 in the series of psychogenic dystonias reported by Fahn and Williams (1988) and the cases of Ranawaya and colleagues (1990). Perhaps 10–15% of patients with a psychogenic movement disorder have an underlying organic movement disorder as well. This overlap is seen in patients with psychogenic seizures (“pseudoseizures”); 10–37% of patients have organic seizures as well (Krumholz and Niedermeyer, 1983; Lesser et al., 1983). Nevertheless, a useful rule of thumb is that if one part of the examination reveals nonorganicity, it is likely that other “abnormalities” on the examination might also be nonorganic.

Perhaps the movement disorders with the highest prevalence rate of a psychogenic origin are the nonfamilial, “idiopathic”, paroxysmal nonkinesigenic dyskinesias, as surveyed by Bressman and colleagues (1988). They found that of 18 patients with paroxysmal nonkinesigenic dystonias and with no known symptomatic etiology or positive family history for a paroxysmal dyskinesia, the dystonias were due to psychogenic causes in 11 patients. This represents 61% of such cases. The age at onset in these patients ranged from 11 to 49 years; 8 of the 11 patients were female. Thus, unless accompanied by a clear-cut family history, these paroxysmal dystonias are commonly psychogenic, and their diagnosis is extremely difficult to make for reasons that are explained later in the chapter (Fahn and Williams, 1988).

Kotagal and colleagues (2002) conducted a study of paroxysmal events in children. Over a 6-year period, 883 patients were monitored in their pediatric epilepsy monitoring unit; 134 patients (15.2%) were documented to have paroxysmal nonepileptic events. Children in the preschool group (age: 2 months to 5 years) (n = 26) were eventually diagnosed with stereotypies, hypnic jerks, parasomnias, and Sandifer syndrome. The school-age group (age: 5–12 years) (n = 61) had diagnoses of psychogenic seizures, inattention or daydreaming, stereotypies, hypnic jerks, and paroxysmal dyskinesias. The adolescent group (age: 12–18 years) (n = 48) had a diagnosis of psychogenic seizures in 40 patients (83%). The authors concluded that in patients with paroxysmal nonepileptic events, conversion disorder was seen in children older than 5 years of age, and its frequency increased with age, becoming the most common type of paroxysmal nonepileptic events among adolescents. In adolescents, conversion disorder was more common in females, whereas males predominated in the school-age group. Concomitant epilepsy with nonepileptic events occurred in all three age groups to a varying extent.

Mass hysteria

Today, neurologists encounter individual patients with psychogenic movement disorders. But historically, mass hysteria was common, probably more so than it is today. Mass hysteria still occurs, such as “shell shock” in wartime, as well as during current environmental events such as mass inoculations (Kharabsheh et al., 2001; Khiem et al., 2003). Symptoms can also be generated from mass concerns about medications and breast implants, in part owing to widespread publicity, although legal liability issues may also drive the development of symptoms. Mass hysteria resembling seizures occurred recently in 10 high school girls following the development of organic absence seizures in another student (Roach and Langley, 2004).

It is interesting to note on a historical level that the term chorea, meaning dancing in Latin, comes from the dancing mania (a mass hysteria) that was seen in the Middle Ages, and from which the term St Vitus’ dance was coined; this term subsequently was applied by Sydenham to describe the condition now referred to as Sydenham chorea (Hayden, 1981).

For further information, see the 2001 monograph by Halligan and colleagues, which is devoted to the topic of hysteria.

Physiologic basis for psychogenic neurologic dysfunctions – neuroimaging

It is intellectually intriguing that the brain can create neurologic deficits – such as paralysis, sensory loss, blindness, seizures, and movement disorders – from psychological factors. This mysterious ability fascinated pioneers working on hysteria, such as Charcot and Freud. We have not been much enlightened over the ensuing 100-plus years until recently, when newer imaging technologies have shed some light on the mechanism. As stated by Hallett (2010), physiologically, we cannot tell the difference between voluntary and involuntary. The exceptions are electrophysiologic measurements of myoclonus, startle, tremor and blepharospasm. The fast 50–100 ms contractions of organic myoclonus cannot be duplicated by psychogenic myoclonus. Psychogenic startle responses are too delayed and variable to be a physiologic reflex (Thompson et al., 1992). Psychogenic tremor can often be detected by variable width on spiral analysis (Hsu et al., 2009) and by other tests like coactivation sign and tapping (Deuschl et al., 1998, 2006; Zeuner et al., 2003; Criswell et al., 2010). The R2 recovery in the blink reflex is disinhibited in organic blepharospasm and is normal in psychogenic blepharospasm (Schwingenschuh et al., 2011). The Bereitschaftspotential (BP) (readiness potential) is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary (Hallett, 2010). The electrophysiology of psychogenic dystonia resembles that of organic dystonia (Espay et al., 2006; Quartarone et al., 2009), except for findings of increased plasticity in the latter.

Vuilleumier and colleagues (2001) utilized single photon emission computed tomography (SPECT) to measure regional cerebral blood flow with and without bilateral vibration in seven patients with unilateral psychogenic sensory loss and then again in four subjects after full recovery. These studies revealed a consistent decrease of regional cerebral blood flow in the thalamus and basal ganglia contralateral to the deficit, which reverted to normal when the patients recovered. These results suggest that hysterical conversion deficits might entail a functional disorder in striatothalamocortical circuits controlling sensorimotor function and voluntary motor behavior. The same subcortical premotor circuits are involved in unilateral motor neglect after organic neurologic damage.

In an analogous situation, a patient who was diagnosed with psychogenic reduced visual acuity underwent a SPECT scan that revealed reduced regional cerebral blood flow in the bilateral visual association areas but not in the primary visual areas (Okuyama et al., 2002). The authors concluded that psychogenic visual disturbance is associated with functional suppression of the visual association area. A listing of functional imaging studies carried out in hysteria has been collated by Fink and colleagues (2006). These studies indicate that alterations in regional brain activity may accompany the expression of conversion symptoms. Since then, another study utilizing positron emission tomography (PET) in patients with hysterical anesthesia showed lack of response in the contralateral cortex to sensory stimulation of the affected limb, again indicating the brain physiologically shuts down as a result of the hysterical anesthesia (Ghaffar et al., 2006). Yet when bilateral stimulation is applied, there is bilateral activation of the cortex, indicating that the cortex is indeed intact.

The results in functional imaging studies are complemented by motor physiology studies. When cortical and spinal inhibition was evaluated in psychogenic and organic dystonia, both groups had similar results of reduced inhibition (Espay et al., 2006). Again, this suggests that the central nervous system accommodates its physiology to follow the motor pattern, or the reverse, i.e., that the abnormal psychological problem alters brain physiology, which then produces the abnormal motoric effect.

Documented psychogenic movement disorder

Just being suspicious that the signs and symptoms are psychogenic is insufficient for the diagnosis of documented psychogenic disorder. For the disorder to be documented as being psychogenic, the symptoms must be completely relieved by psychotherapy, by the clinician utilizing psychological suggestion including physiotherapy, or by administration of placebos (again with suggestion being a part of this approach), or the patient must be witnessed as being free of symptoms when left alone, supposedly unobserved. This last feature would be a major factor in proving psychogenicity in those who are malingering or have a factitious disorder, since such patients would not likely obtain relief of symptoms by manipulation of the examiner. Insurance companies are increasingly using videotaped surveillance to protect themselves against fraud. There is now a published report of a patient with a clinical diagnosis of reflex sympathetic dystrophy who sued for financial compensation despite features of psychogenicity and was videotaped while under surveillance by a private investigator to be completely free of the abnormal movements, allowing the case to be settled for a reduced amount (Kurlan et al., 1997). If the signs and symptoms disappear and do not return, that is fairly good evidence that the underlying psychiatric problem has been relieved. But it is not uncommon for the psychogenic movement disorder to return if the patient does not obtain complete relief of the psychiatric factors that led to the neurologic dysfunction.

A critical issue for using the relief of signs as a criterion for the definition is that most organic movement disorders rarely remit spontaneously and completely except for tics, tardive dyskinesia, infectious (e.g., Sydenham chorea), and drug-induced reactions, and rarely, essential myoclonus (Fahn and Sjaastad, 1991). Other organic disorders, such as Parkinson disease, Huntington disease, and essential tremor, are persistent and even progressive. Idiopathic torsion dystonia, except for torticollis (Jayne et al., 1984; Friedman and Fahn, 1986; Jahanshahi et al., 1990), rarely totally remits. On occasion, patients with other types of dystonia will show improvement, but this improvement is typically incomplete and temporary (Marsden and Harrison, 1974), although gradual, prolonged, incomplete improvement has been encountered in at least one patient (Eldridge et al., 1984).

The degree of remission that is seen in cases with documented psychogenic movement disorders is usually the dramatic, sudden improvement that occurs within a few days with supportive suggestion or placebo treatment. In a few patients with more chronic symptoms, improvement can be more gradual, occurring over weeks to months of “physiotherapy” used as a means of allowing the patient to relinquish the symptoms in a face-saving manner. Physiotherapy also can have physical benefits for patients who had developed weakness, spasms, or contractures based on chronic disuse and/or abnormal postures for extended periods, even though these were on a psychogenic basis.

Clinically established psychogenic movement disorder

When the movement disorder is inconsistent over time (the features are different when the patient is observed at subsequent examinations) or is incongruent with a classic movement disorder, one becomes suspicious that the movements are psychogenic. If either inconsistency or incongruity is present and, in addition the patient has any of the manifestations listed in Table 25.1, one can feel comfortable in believing that the disorder is psychogenic, and this has been referred to as clinically established psychogenic movement disorder.

Table 25.1 Additional manifestations besides inconsistency and incongruity for the diagnosis of clinically established psychogenic movement disorder

It should be noted that item 4 in Table 25.1 by itself is insufficient for a diagnosis of a documented or clinically established psychogenic disorder. This is because some organic movement disorders can be temporarily and voluntarily suppressed (Koller and Biary, 1989). Similarly, akathitic movements and paradoxical dystonia (Fahn, 1989) also tend to disappear with active voluntary movement. The difficulty establishing psychogenic paroxysmal dyskinesias which have a normal interictal pattern is covered below. Fortunately, myoclonus has such a short-duration contraction that it cannot be purposely produced, so electrophysiologic evidence against organic myoclonus could be one of the factors along with inconsistency and incongruity that can lead to a clinically established diagnosis of a psychogenic myoclonus. Psychogenic tremors have features such as a coactivation sign (Deuschl et al., 1998, 2006) or a change in tremor frequency due to entrainment by tapping the contralateral limb (Zeuner et al., 2003). These features would establish the tremor as psychogenic.

Probable psychogenic movement disorder

This definition contains four categories of patients:

The last two subdivisions contain psychiatric manifestations that make the clinician highly suspicious that the movements might also be psychogenic, but by themselves they are insufficient to give a higher degree of certainty to the diagnosis of a psychogenic movement disorder.

Possible psychogenic movement disorder

One can be suspicious that the movements are psychogenic if an obvious emotional disturbance is present, but this is not as compelling as the psychiatric features listed above. For the category of a possible psychogenic disorder, the movements would be consistent and congruent with an organic movement disorder.

Summary on the degree of certainty of the diagnosis of a psychogenic paroxysmal movement disorder

Paroxysmal movement disorders present a special and difficult problem. Their natural history characteristically shows prolonged periods of cessation of the abnormal movements, so its disappearance with placebo or by suggestion cannot by itself establish the diagnosis of a psychogenic disorder, since the remission could have been coincidental. However, if the paroxysms are frequent and the attacks are prolonged, then repeated trials with placebo can be informative. If such trials consistently produce remissions, then one can be convinced that the diagnosis is a documented psychogenic disorder.

The criteria for clinically established, probable, and possible psychogenic movement disorders would be the same for paroxysmal movement disorders and continual movement disorders. It is likely when both a paroxysmal movement disorder and a continual movement disorder are present in the same patient that the etiology is psychogenic.

Somatoform disorder

A somatoform disorder is one in which the physical symptoms are linked to psychological factors, yet the symptom production is not under voluntary control (i.e., not consciously produced). The two main types of somatoform disorders that produce psychogenic neurologic problems are conversion disorder and somatization disorder; the latter is also known as hysteria or as Briquet syndrome. Other somatoform subsets are hypochondriasis, somatoform pain disorder, and body dysmorphic disorder.

In conversion disorder, psychological factors may be judged to play a primary etiologic role in a variety of ways. This may be suggested by a temporal relationship between the onset or worsening of the symptoms and the presence of an environmental stimulus that activates a psychological conflict or need. Alternatively, the symptom may be noted to free the patient from a noxious activity or encounter. Finally, the symptom may be noted to enable the patient to get support from the environment that otherwise might not be forthcoming.

A somatization disorder involves recurrent and multiple complaints of several years’ duration for which medical care has been sought, but that are apparently not due to any physical disorder. The dynamics are presumably the same as those of conversion disorder, and the symptoms may emerge from chronic, recurrent, untreated conversion disorder. There are four separate categories of symptoms that need to be present at some time for the diagnosis of a somatization disorder according to the DSM-IV-TR. They are (1) four sites or functions of pain, (2) two gastrointestinal symptoms, (3) one symptom related to sex or reproduction, and (4) at least one of 13 neurologic complaints, namely problems with coordination, paralysis or weakness, feeling of an object in the throat, aphonia, urinary retention, hallucinations, anesthesia, diplopia, blindness, deafness, seizures, amnesia, and loss of consciousness. It should be noted that various movement disorders, such as tremor and sustained contractions, are not on this list of 13, and they should be included as one of the neurologic complaints. Other requirements are age at onset under 30 years and severe enough symptomatology that the patient has taken medications, consulted a physician, or altered his or her lifestyle because of it.

The abnormal movements of somatoform disorders are involuntary. The knowledge that one is the cause of one’s own actions is known as self-agency. Thus, people with abnormal movements due to a somatoform disorder lack self-agency. The right inferior parietal cortex is the brain area believed to play a role in self-agency. Voon and her colleagues (2010) utilized functional magnetic resonance imaging in eight subjects with a conversion disorder (tremor). The right temporoparietal junction was found to be hypoactive compared to those purposefully mimicking the same type of tremor (P < 0.05). There was an associated reduced connectivity between this cortical area and the sensorimotor areas and the limbic system.

Factitious disorder

A factitious disorder is one in which the physical symptoms are intentionally produced (hence are under voluntary control) owing to psychological need. This group includes Munchausen syndrome. Factitious disorders are due to a mental disorder. They are generally associated with severe dependent, masochistic, or antisocial personality disorders.

Malingering

Malingering refers to voluntarily produced physical symptoms in pursuit of a goal such as financial compensation, avoidance of school or work, evasion of criminal prosecution, or acquisition of drugs. Malingering is not considered to be a mental disorder.

When a physician is faced with a patient who has a psychogenic movement disorder, it is often not possible to distinguish with certainty among somatoform, factitious, and malingering disorders. A patient’s volitional intent is often impossible to determine with certainty.

Depression

It is worth making some comment about depression. In our experience, many patients with a psychogenic movement disorder also have concurrent depression. Treatment of this depression is essential and is part of the overall strategy in outlining a treatment program for the patient. Often, lifting of the depression is necessary for the patient to obtain relief of the motor symptoms.