The diagnosis of weakness has been discussed in Chapter 2.

Lower Motor Neuron Weakness: In distal lower motor neuron weakness the most prominent sign is foot drop. Because the more proximal muscles, the hip flexors, are intact, the gait is high-stepping, often with an audible slap as of the foot hits the ground.

With predominantly proximal weakness, because the gluteus medius is involved, the gait becomes waddling, with an abnormal pelvic tilt with each step.

Upper Motor Neuron Weakness: Weakness secondary to central disease results in a circumduction gait. Hip flexion is weak, so the often spastic foot drop cannot be compensated for by raising the leg higher. The quadriceps, on the other hand, is relatively spared, which facilitates knee locking, and the patient can bear weight. Often, in association with the circumduction gait there is flexion of the upper limb across the chest.

Proprioception is tested as described in Chapter 3. Lack of proprioceptive feedback may have a profound effect on gait and when severe can render the patient completely unable to walk. In patients with milder deficits, with each step there is a normal heel strike and then a more pronounced or forcible slap of the sole to the ground. Textbooks often refer to a so-called stamping gait, an attempt to increase sensory feedback, but classic stamping is seldom present.

The Romberg sign is positive. To test for this, the patient is asked to stand with the feet together and the eyes closed. Marked body sway indicates a positive Romberg sign.

Cerebellar signs on examination are described in Chapter 13. Common adjectives used to describe a cerebellar gait include “staggering, reeling, or drunken.” Characteristically, there is a wide-based stance with wide-spread legs, and the patient may stagger from side-to-side. Stride length is slightly shortened. Staggering may be brought out by sudden turning. Cerebellar hemisphere dysfunction produces appendicular clumsiness and ataxia. Vermis dysfunction causes trunk ataxia, and patients with superior vermis lesions, as in alcoholic degeneration, present particularly with gait ataxia.

A mismatch in afferent visual, proprioceptive, and vestibular information leads to the complaint of dizziness or loss of balance. A subjective sensation of rotation or spinning is characteristic of vestibular dysfunction, whereas nonvestibular dizziness may be described as light-headedness, floating, or loss of balance.

The gait of vestibular dysfunction progresses from an occasional stumble, to veering, to frank ataxia. With unilateral vestibular dysfunction the patient veers toward the pathological side.

Extrapyramidal disorders may present with hypokinetic or hyperkinetic movement disorders (see Chapter 13).

Parkinson’s Disease: In Parkinson’s disease there is paucity of movement, and gait abnormalities are the presenting complaint in approximately 15% of these patients. The gait is narrowbased, and stride length is reduced, leading to a shuffle (marche a petit pas). Speed may be increased, leading to the descriptive term “festinating” or hurrying. There is reduced arm swing and a tendency to thoracic kyphosis. The patient is easily displaced backward and may spontaneously take backward steps or even fall (retropulsion). When asked to turn on a dime or about-face, the patient takes many small steps to complete the maneuver. As the disease progresses there is difficulty initiating gait, and the patient may take many small steps on the spot before forward movement ensues (start hesitation). A similar phenomenon may occur when stepping through the portal of a door or attempting to make a sudden turn, when frequent small steps in place without propulsion are seen. When asked to rise from a soft chair, the patient may fall back two or three times before attaining the erect posture.

Varying degrees of Parkinsonian gait are seen in patients with multiple system atrophy in which parkinsonism plays a varying role. In progressive supranuclear palsy, Parkinsonian features and disturbances of ocular motility are seen. Early falling with failure of down gaze is a clue to the diagnosis.

Lower Half Parkinsonism: In lower half parkinsonism, leg movements when walking look to be severely Parkinsonian, but the upper limbs are furiously in movement as if coaxing the patient to walk. This gait is usually caused by subcortical arteriosclerotic dementia (Binswanger’s disease).

Hyperkinetic Movement Disorders: In hyperkinetic disorders the extra movements may interfere with gait, leading to scattered and various intrusions that cause the patient to stagger.

The highest centers for the control of gait are in the frontal lobes, and dysfunction there leads to difficulty with initiation and occasional freezing, with or without multiple steps in place. The patient walks on a narrow base with a markedly shortened stride length. There is hesitation on turning. There is disequilibrium and impaired ongoing locomotion.

At times the prime deficit is one of initiation (ignition failure), when the patient hesitates and may take three or four steps on the spot, with the feet barely clearing the floor. Once underway, however, the stride lengthens and foot clearance is normal.

Rarely, profound breakdown in the control of gait results in an ataxic-like gait. The feet may cross or move in a direction inappropriate to the center of gravity, resulting in a bizarre, uncoordinated gait.

When the cause of frontal gait dysfunction is apparent on investigation, for example, hydrocephalus, the dysfunction is regarded as symptomatic, but in approximately 8% to 10% of patients no obvious cause is found and the label “degenerative” or “idiopathic” is appropriate.

The Cautious Gait: Murray et al (1969) described the cautious gait as follows: “The walking performance of older men gave the impression of a guarded or restrained type of walking in an attempt to obtain maximum stability and security. The walking of older men resembled that of someone walking on a slippery surface. This is regarded as a compensatory adaptation with an appropriate response to real or perceived disequilibrium.”

Fear of Falling: Fear of falling may be exaggerated, but it usually has a rational basis because of prior experience such as a previous fall. The anxiety may be so severe that it could be called a phobia. Such patients, in open spaces, may resort to crawling on hands and knees, and this may
culminate in a wheelchair existence. Fear of falling is associated with increased mortality and may be more frequent in women.