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Neurology

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© Springer-Verlag1991 J Neurol (1991) 238 : 140-146

How to identify psychogenic disorders of stance and gait A video study in 37 patients T. Lempert*, T. Brandt, M. Dieterich, and D. Huppert Neurologische Universitfitsklinik, Klinikum Grosshadern, Marchioninistrasse 15, W-8000 Mtinchen, Federal Republic of Germany Received May 23, 1990 / Received in revised form September 15, 1990 / Accepted October 22, 1990

Summary. Thirty-seven patients with psychogenic disorders of stance and gait were clinically evaluated, recorded on video, and analysed with regard to clinical phenomenology. Characteristic, suggestive and unspecific features were identified. Six characteristic features proved most valuable for diagnosis of psychogenesis, as they occurred alone or in combination in 97% of patients: (1) m o m e n t a r y fluctuations of stance and gait, often in response to suggestion; (2) excessive slowness or hesitation of locomotion incompatible with neurological disease; (3) "psychogenic" R o m b e r g test with a build-up of sway amplitudes after a silent latency or with improvement by distraction; (4) uneconomic postures with wastage of muscular energy; (5) the "walking on ice" gait pattern, which is characterized by small cautious steps with fixed ankle joints; (6) sudden buckling of the knees, usually without falls. Seventy-three percent of patients had additional suggestive features. Classification into characteristic subtypes was not found useful because p r e d o m i n a n t features varied from patient to patient and occurred in various combinations. Factitious impairment of stance and gait was studied in 13 healthy drama students. Simulated gait dysfunction appeared less conspicuous and m o r e difficult to diagnose than the clinical psychogenic disorders.

These 1.5% come close to the proportion of parkinsonian patients (2.2%) in the same series of consecutive patients. In clinical practice, diagnosis relies mainly on the observation of bizarre m o t o r behaviour, discrepancy between obvious dysfunction and normal diagnostic evaluation, and evidence of psychiatric abnormalities. Some cases remain obscure despite careful investigations and are clarified only on follow-up. The importance and frequency of psychogenic disorders of stance and gait are not reflected in the recent literature or textbooks. For general descriptions, neurologists have to search through old textbooks [1, 2, 7, 15]. With the exception of Keane's survey of 60 cases [8], authors have recently reported only single cases [13, 17, 18]. Systematic studies are still lacking. We have tried to establish diagnostic criteria for psychogenic disorders of stance and gait by analysing a series of video-documented cases as previous authors have done for psychogenic seizures [3, 5, 6, 11]. The point in question was whether diagnosis is possible on phenomenological grounds alone and whether an analysis of single features or a classification into characteristic subtypes is more practical for diagnosis. It was not our intention to analyse the aetiology and pathophysiology of these disorders but to define phenomenological clues for diagnosis.

Key words: Hysteria - Conversion - Gait Patients and methods Introduction Psychogenic disorders are not u n c o m m o n in neurological settings. They were the primary cause of admission in 9% of 4470 neurological inpatients of the Munich University Clinic between 1985 and 1987 [10]. Psychogenic dysfunction of stance and gait was observed in 68 patients. * Present address and address for offprint requests': Neurologische Abteilung, Universit~its-Klinikum Rudolf Virchow, Spandauer Damm 130, W-1000 Berlin 19, Federal Republic of Germany

Between January 1988 and March 1989, we prospectively studied 22 patients with psychogenic dysfunction of stance and gait. After informed consent had been obtained, each patient was video-taped for 5-10min according to a standardized programme which included standing, walking with eyes open and closed, tandem walking, walking on toes and heels, a full knee bend and Romberg testing. We retrospectively analysed 15 additional cases documented between 1980 and 1984 which fulfilled comparable technical and diagnostic standards. The video of each patient was reviewed and analysed several times by all authors. Diagnosis was based on unusual phenomena, inconsistencies and contradictions which were incompatible with neurological disease. Each patient had an ade-

141 quate diagnostic work-up to exclude an underlying organic disease. In about half of the cases diagnosis was confirmed by a rapid response to suggestive therapy which included encouragement, physiotherapy and placebo medication. Results

Patients The study comprises 37 patients between 19 and 78 years of age (mean 46 years). Patients were evenly distributed among all age groups. Twenty-two (62%) were female, 15 (38%) male.

General features In 27 patients (73%), the psychogenic nature of the disturbance was suggested by its bizarre, non-neurological appearance. In 10 patients (27%), the disordered walk resembled more or less an organic neurological disease, such as Parkinson's syndrome (4 cases), normal-pressure hydrocephalus (2), polyneuropathy (2), pareses of the quadriceps muscle (1) and sciatica (1). The severity of gait dysfunction was assessed according to the functional and social impairment it caused. Eighteen cases (49%) were rated as "severe". These patients were either completely unable to stand or walk or accomplished only a few steps. Common sequelae were use of the wheelchair, temporary or permanent disability and retreat from social activites. Fifteen cases were classified as "moderate", which meant marked gait dysfunction with fairly well preserved mobility. Four cases (10%) were rated as "slight". These patients had unobtrusive gait abnormalities which caused only negligible functional impairment. Psychogenic gait disturbance was combined with neurological gait dysfunction in 1 patient who had mild congenital tetraspasticity and fluctuating psychogenic astasia. Four patients had neurological disorders which did not affect standing and walking.

Characteristic features Reviewing our patients we identified clinical features of psychogenic gait disorders and classified them into two categories: characteristic and suggestive. Characteristic symptoms are listed with their respective frequency in Table 1 and are delineated in the following. Fluctuations of gait and stance of performance incompatible with neurological disease occurred in more than half of our patients within the 5-10 rain of evaluation. Repeated examinations on several occasions increased the yield. Fluctuations either appeared spontaneously or could be provoked by the physician. Encouragement and distraction by certain tasks such as finger-nose testing might improve the disturbance considerably. Sometimes gait returned to normal when walking was rendered more difficult, e.g. in walking on tiptoe. Fluctuations also may occur in neurological disease such as myasthenia gravis, dyskalaemic paralysis and extrapyramidal disorders. Momentary to-and-fro fluctu-

Table 1. Characteristic features of psychogenic dysfunction of stance and gait in 37 patients n

Fluctuation of impairment Excessive slowness of movements Hesitation "Psychogenic Romberg" test "Walking on ice" gait pattern Uneconomic postures with waste of muscle energy Sudden buckling without falls with falls Astasia Vertical shaking tremor

19 13 6 12 11 11 8 2

10 4 3

ations, however, are indicative of a psychogenic origin (Fig. 1). Excessive slowness of movements resembling slowmotion was seen in 13 patients. Usually, it is brought about by simultaneous innervation of antagonist muscles which may reflect the conflict between voluntary intention and subconscious restraint. Slow gaits due to neurological disease may result from decreased stride length as in Parkinson's syndrome or from extended inter-stride intervals to compensate for postural instability as in ataxia or paresis. Increase of muscle tone may decelerate movements to a certain degree, but excessive slowing does not occur. Orthopaedic patients may walk slowly to avoid movement-induced pain. None of our "psychogenic" patients, however, complained of pain. A related p h e n o m e n o n likewise caused by co-innervation of antagonist muscles is hesitation, which occurred in 6 cases. In these patients initiation of intended movement is either delayed or impossible. Small forward and backward movements of the leg may be observed while the feet seem to stick on the ground. In contrast to Parkinson's syndrome the inhibition is not overcome once the first step is done but recurs with every step. Romberg testing was performed in 25 patients, 12 of whom showed one or more features of a "psychogenic" Romberg test: 1. Constant falls towards (3 patients) or away from (4 patients) the observer, irrespective of his position. Falls are usually avoided by clutching the physician. 2. Large amplitude body sway, building up after a silent latency of a few seconds. 3. Improvement of postural balance when the patients are distracted, e.g. by asking them to recognize numbers written by finger on their skin or by other manoeuvres (Fig. 2).

"Walking on ice" - a characteristic gait pattern used by normal people on slippery grounds - was seen constantly in 11 patients. It consists of cautious, usually broadbased steps with decreased stride length and height, stiffening of knees and ankles, some degree of antagonist innervation and (in some patients) shuffling of the feet

Fig. 1. Fluctuating gait disturbance with waste of muscular energy: patient starts walking upright, then goes slowly into a full knee bend and becomes erect again on her way back Fig. 2. Psychogenic instability of stance with "non-neurological" stiff leaning to the side, which stops with distraction by finger-nose testing Fig. 3. "'Walking on ice": hesitant, slow gait with anxious balancing, stiff knees and ankles, and reduced step height and stride length

143 (Fig. 3). The gait abnormality of patients with normalpressure hydrocephalus shares some of these features, but lacks the anxious balancing usually with abduction of the arms which characterizes these patients. In 11 patients uneconomic postures with waste of muscle energy in order to maintain balance were noted. Examples are assumption and maintenance of postures with an eccentric displacement of the centre of gravity, standing and walking with flexion of hips and knees (Fig. 1) and slowing or arresting a knee bend half-way down. Repeated sudden buckling of the knees occurred in 10 patients with (2) and without (8) falls. Patients usually prevented themselves from falling by activating their anti-gravity muscles before they touched the ground, which required a considerable expenditure of strength (Fig. 4). Even if falls occur, they are more or less directed to avoid self-injury, which makes them easily distinguishable from drop attacks. Sudden knee flexions have been observed in Huntington's chorea [9], but may be distinguished by accompanying choreatic movements. In cataplexy, loss of muscle tone appears only in response to sudden emotional stimuli. Four patients presented with astasia, which is a psychogenic inability to stand without support with preserved function of the lower limbs in the recumbent position. Three patients had vigorous up and down shaking of the body which was generated by rapidly alternating flexion and extension of the knees and - to a lesser degree - of hips and ankles. Arms were either not involved or moved passively, which helps to distinguish this type of tremor from organic variants. Body tremor frequency was in the range of 3-6 Hz in our patients, which contrasts with the faster oscillations of organic orthostatic tremor [12]. Thirty-six patients (97%) showed one or more of the six most common characteristic features: fluctuations, slow motion and hesitation, "psychogenic" ,Romberg test, "walking on ice", sudden buckling and waste of muscle energy. Fourteen patients (37%) and only one of Table 2. Suggestive features of psychogenic dysfunction of stance and gait in 37 patients

these signs, 10 (27%) had two, 5 (14%) and three, 4 (11%) had four and 3 (8%) had five. The only patient who had none of these features was a woman with pseudomyoclonus of the right leg which recurred about every 10 s. Sudden onset with a series of psychogenic seizures, a bizarre tremor of the right hand and spontaneous remission within 2 days confirmed the diagnosis in this patient.

Suggestive features Additional signs suggesting a psychogenic disorder occurred in 73% of our patients (Table 2). We called them suggestive, since differentiation from neurological dysfunction was sometimes not as obvious as in the characteristic features described above. Pseudoataxia refers to an instability of posture and gait which is characterized by demonstrative balancing sometimes with flailing of the arms and bizarre excursions of the trunk while legs are often unaffected (Fig. 5). Patients may perform sudden sidesteps or tumble about. The broad-based gait of neurological ataxia is rare. In psychogenic monoparesis, the affected leg is often dragged behind and may be bizarrely twisted, usually in an equinovarus position. Temporary innervation of the paralysed leg may be observed (Fig. 6). Continuous flexion or extension of the toes may be seen in patients with otherwise normal muscle tone. Psychogenic tremors can often be identified by their unusual distribution, concomitant bizarre posturing of extremities and alleviation by distraction. In contrast to organic tremors their frequency may vary considerably in an individual patient. The distal portions of the lims may be spared and move limply in response to proximal muscle activity. In the absence of these features, however, phenomenological differentiation may prove difficult. Fifty-one percent of patients displayed expressive or demonstrative behaviour (Fig. 7) which may, however, occur likewise in neurological patients with concomitant psychic abnormalities.

Classification into subtypes Motor symptoms (n = 22) Pseudotaxia of the legs of the trunk Sudden sidesteps Flailing of the arms Dragging of the leg Continuous flexion of the toes Continuous extension of the toes Bizarre tremors (hands 7, legs 3, trunk 2, head 1) Expressive behaviour (n = 19) Grasping the leg Mannered posture of hands Suffering or strained facial expresssion Moaning Hyperventilation

It was our clinical impression that psychogenic disorders of stance and gait may be classified into subtypes according to predominant features. The similarity of manifestations was striking in some patients; the overall variability, however, was so large that the clinical use of this approach proved impractical. Four subtypes comprising 14 patients (38%) could be formed, whereas the other 23 patients demonstrated individual manifestations or had various combinations (Table 3).

Factitious gait disorders 6 6 15 8 3

Psychogenic disorders in hospital patients are usually regarded as the result of subconscious conflicts. For comparison we studied a phenomenology of volitionally faked gait disorders in 13 healthy drama students. They were asked to simulate a gait disorder which should be severe

144

5

Fig. 4. Psychogenic buckling, Patient falls forward with sudden flexion of hips and knees and remains in an uneconomic half-flexed posture Fig. 5. Psychogenic pseudoataxic instability of stance and gait with wobbling of the trunk, bizarre balancing and flailing of the arms, which ceases with distraction Fig. 6a-c. Psychogenic monoparesis of the right leg. a Dragging of the twisted leg, grasping the leg; b "paralysed" right leg supports the body during swing phase of the left leg; c innervation of the "paralysed" leg after encouragement

145 Discussion

Fig.7. Psychomotor symptoms of psychogenic gait disorders: suffering facial expression and grasping of the leg Table 3. Classification of psychogenic dysfunction of stance and

gait into characteristic subtypes (37 patients) Slow gait Astasia Pseudotaxia Buckling

6 (16%) 3 (8%) 3 (8%) 2 (6%)

Other types

12a (31%)

Combinations

11 (30%)

a Includes: pseudomyoclonus, rhythmical side-to-side rocking, fixed flexion of hips and knees, generalized tremor, "walking on ice", tripping propulsion with falls, hesitation, monoparesis with dragging of the leg, unilateral limp, bilateral equinovarus posture of the feet, waddling in a squatting position, dragging along (like an exhausted wanderer in the desert) enough to convince the physician of a disease causing disablement. Each student received a written instruction 2 days before evaluation. Video-tapes were recorded and analysed as described above. The small number of investigated subjects does not allow a detailed comparison, but some remarkable differences were noted between patients and volunteers. In contrast to our patients the majority of actors (n = 8) showed disorders with a rather "organic" appearance. Five of the actors had monoparesis of one leg and 3 had limping without relevant paresis as their predominant feature. Fluctuations occurred in 5 subjects, excessive slowness in 2, waste of muscle energy in 2, and buckling in one, whereas other specific symptoms such as hesitation, "psychogenic" Romberg test and the "walking on ice" pattern were not observed. Five subjects showed none of the specific symptoms; only 5 had additional suggestive symptoms as comapred with 73% in the patient group. The average number of specific and suggestive signs per subject was 1.5 in simulated and 4.3 in clinical disorders. In summary, simulated gait disorders appeared less conspicuous and more difficult to diagnose by phenomenology alone than clinical psychogenic gait disturbances. Nevertheless, there was a considerable overlap between the two, which makes clinical distinction difficult in individual cases.

Psychogenic disorders of stance and gait have attracted little scientific attention so far in spite of their frequent occurrence in neurological practice. In a retrospective survey of 60 cases, 32 of which were documented on motion picture or video, Keane [8] found 24 patients with hemiparesis or paraparesis, 23 with ataxia and 9 with trembling, whereas other types of "hysterical" gaits were rare. His description of the clinical phenomenology corresponds well to our findings. The frequency of specific psychogenic motor patterns, however, was not reported. Keane emphasized that a few minutes of gait examination usually lead to the correct diagnosis. Thompson and Sills [17] presented 9 paediatric cases of psychogenic gait dysfunction. Diagnosis was based on discrepancies of symptoms, signs and function, as well as on psychosocial concomitants, whereas specific phenomenological criteria were not applied. Fahn and Williams [4] reported 21 cases of psychogenic dystonia which started in the foot in 10 patients and finally involved one or both lower limbs in 20 patients. Inconsistency over time and incongruity with classical dystonia was observed in 18 patients. Excessive slowness of movement occurred in 5 cases. Gait abnormalities were not analysed in detail. In our study we identified six characteristic criteria which allow a phenomenological diagnosis in over 90% of cases with sufficient certainty at the first evaluation. These features include unusual postures and gait patterns, a striking slowness of locomotion as well as momentary fluctuations. The modified Romberg test with distraction is of particular value. In a small proportion of patients (< 10%) diagnosis is difficult. In our experience, differentiation may by especially intricate from some forms of myoclonus, extrapyramidal hyperkinesia, myasthenia gravis, dyskalaemic paralysis, early polyradiculitis and, last but not least, normal-pressure hydrocephalus. The gait disorder of normal-pressure hydrocephalus is characterized by short stride length, slow speed and postural instability, reduced step height and co-contraction of antagonist muscles [14, 16], thus mimicking some of the above-described features of psychogenic gait dysfunction. Phenomenological diagnosis is supported by additional diagnostic clues. The history may reveal emotional conflicts, a model for the symptom or previous somatizations. Physical examination may show discrepancies such as normal reflexes in a chronically paralysed leg or giveway weakness. It should be noted, however, that obvious organic alterations such as muscle atrophy or joint contractures do not necessarily argue against a psychogenic disorder, as they may represent secondary changes. Psychiatric consultation is advisable to reveal occult psychopathology. Finally, elimination of symptoms by suggestion, placebo or psychotherapy may serve as an ultimate confirmation of the diagnosis. In conclusion, we advocate the phenomenological approach to psychogenic dysfunction of stance and gait, since it is direct, effective, and avoids unnecessary, costly and potentially harmful diagnostic procedures.

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11. Luther JS, McNamara JO, Carwile S, Miller P, Hope V (1982) Pseudoepileptic seizures: methods and video analysis to aid diagnosis. Ann Neurol 12 : 458-462 12. Papa SM, Gershanik OS (1988) Orthostatic tremor: an essential tremor variant? Mov Disord 2:97-108 13. Simopoulos AM, Hildegard H (1969) Progressive hysterical tetraplegia with contractures. A case study. Johns Hopkins Med J 125 : 14-18 14. Solberg Sorensen P, Jansen EC, Gjerris F (1986) Motor disturbance in normal pressure hydrocephalus. Arch Neurol 43 : 3438 15. Strfimpell A (1899) Lehrbuch der speziellen Pathologie und Therapie der inneren Kankheiten, vol 3, 12th edn. Vogel, Leipzig, pp 614-616 16. Sudarski L, Sheldon S (1987) Gait disorder in late-life hydrocephalus. Arch Neurol 263-267 17. Thompson APJ, Sills JA (1988) Diagnosis of functional illness presenting with gait disorder. Arch Dis Child 63 : 148-153 18. Thompson CE (1982) Hysterical paralysis. J Fam Pract 15: 1169-1173

How to identify psychogenic disorders of stance and gait. A video study in 37 patients.

Thirty-seven patients with psychogenic disorders of stance and gait were clinically evaluated, recorded on video, and analysed with regard to clinical...
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