The array of peculiar gaits in these individuals defies easy analysis. An ungainly stance with the head too far forward or the neck extended and arms held in odd positions, a wide-based gait with awkward lurches or feet stomping the floor—each with his own ungraceful style—these are but a few of the patterns that meet the eye. One tries in vain to relate them to a disorder of proprioception, cerebellar deficit, or pyramidal or extrapyramidal disease.
The only plausible explanation that comes to mind is that these variants of gait are based on a change in the natural developmental sequence of cerebral and spinal mechanisms involved in bipedal locomotion, posture, and righting. The acquisition of the developmental refinements of locomotion—such as running, hopping, jumping, dancing, balancing on one foot, kicking a ball are also disrupted or delayed. The rhythmic rocking movements and hand clapping, odd mannerisms, waving of the arms, and other stereotyped patterns mentioned in the chapter on development, make gait even more maladroit. The Lincoln-Oseretsky scale is an attempt to quantitate these maturational delays in the locomotor sphere.
This may take several forms, often dramatic in appearance such as walking on stilts, extreme dystonic postures, or lurching wildly in all directions or collapsing legs, without falling to the ground, actually demonstrating by their gyrations a normal ability to make rapid and appropriate postural adjustments, all nicely summarized by Keane. The hysterical gait disorder may be accompanied by similarly exaggerated movements of the arms, as though to impress the observer with the great effort required to walk and maintain balance. Baik and Lang have emphasized the high frequency of coincident psychogenic movement and gait disorders in their specialty clinic.
Astasia-abasia was a term used to describe a psychogenic gait disorder in which patients, although unable to either stand or walk, display more or less normal use of their legs while in bed and have an otherwise normal neurologic examination and body carriage. When such patients are placed on their feet, they may take a few steps and then become unable to advance their legs; they lurch in all directions and crumple to the floor if not assisted. As noted below, astasia-abasia has causes other than psychogenic and the use of the term has been expanded to describe other forms of complete inability to stand and walk.
Also included in this category are hysterical monoplegias, hemiplegias, or paraplegias. In walking, the patient may hesitate and advance the leg in a grossly ataxic or tremulous manner. Typically, patients with a hysterical paralysis of the leg do not lift the foot from the floor while walking; instead, they tend to drag the leg as a useless member or push it ahead of them as though it were on a skate. In hysterical hemiparesis, the characteristic circumduction seen in bona fide spastic paresis of the leg is absent, as are hemiparetic postures, hyperactive tendon reflexes, and Babinski sign. The hysterical paraplegic cannot very well drag both legs and usually depends on canes or crutches or remains helpless in bed or in a wheelchair; after months or longer of immobilization, the muscles may be flaccid or rigid from shortening, with development of contractures. Leg movements in bed may be unimpaired or the patient may display a Hoover sign (described in Chapter 3), which belies genuine leg weakness. Some of the patients exhibit additional abnormalities of the voice and visual fields, tremors, and asthenic weakness of muscle contraction.