Diagnosis of a walking disorder

Diagnosis of walking and gait disorders is carried out in 2 stages. At the stage of syndromic diagnosis, the features of walking disorders and accompanying clinical signs are identified and analyzed, allowing to draw a conclusion about the leading neurological syndrome. Subsequently, by analyzing the data of additional research methods during the disease, nosological diagnosis is carried out. Motor and sensory disorders characteristic of a particular disease of the nervous system and attempts to compensate for them often form a specific gait, which is a kind of calling card of the disease, allowing to make a diagnosis at a distance. The ability to diagnose a disease by the patient's gait is one of the most important skills of a neurologist.

When observing a patient, it is necessary to focus on how he takes the first step, what is his walking speed, the length and frequency of steps, whether the patient lifts his feet completely off the floor or shuffles, how his walking changes when turning, passing through a narrow opening, overcoming an obstacle, whether he is able to voluntarily change the speed, the height of lifting the legs and other walking parameters. It is necessary to note how the patient gets up from a sitting or lying position, how he sits on a chair, how stable he is in the Romberg pose with open and closed eyes, with his arms down and extended forward, when walking on his toes and heels, tandem walking, when pushing forward, backward or to the side.

To test postural stability, the doctor usually stands behind the patient, warns him of his next actions and asks him to maintain balance by staying in place or taking a step back, after which he quickly pushes him by the shoulders with such force that the patient takes a step back (Tevenard's test). Normally, the patient quickly restores balance by reflexively raising his toes, leaning his body forward or taking one or two quick corrective steps back. In pathology, he has difficulty maintaining balance, takes several small ineffective (counterproductive) steps back (retropulsion) or falls without any attempt to maintain balance (like a sawn tree). Postural stability is usually assessed based on the results of the second attempt (the first is considered a test), but the result of the first attempt may be more informative, since it better correlates with the risk of falls. To identify an apraxic defect, the patient must be asked to imitate rhythmic locomotor movements in a lying or sitting position, draw a number or figure with the toe of the foot, or perform another symbolic action with the foot (for example, kick a ball).

Clinical assessment of balance and gait disorders

Functions	Characteristic
Evaluation of equilibrium (statics)	Getting up from a chair and bed (uprighting synergies). Stability in an upright position with eyes open and closed on a flat and uneven surface, in a normal or special posture, such as extending one arm forward (supportive synergies). Stability in the event of spontaneous or induced imbalance, such as expected or unexpected pushing backwards, forwards, to the side (reactive, rescue and protective synergies)
Gait (locomotion) assessment	Initiation of walking, presence of a starting delay, freezing. Walking pattern (speed, width, height, regularity, symmetry, rhythm of steps, lifting of feet off the floor, support area, coordinated movements of the body and arms). The ability to perform turns while walking (turns with one body, freezing, stamping, etc.). Ability to voluntarily change the pace of walking and step parameters. Tandem walking and other special tests (walking backwards, with closed eyes, overcoming low barriers or steps, heel-knee test, leg movements in sitting and lying positions, trunk movements)

To quantitatively assess gait disorders, the following are used:

• clinical rating scales, such as the GABS (Gait And Balance Scale) proposed by M. Thomas et al. (2004), or the balance and motor activity scale by M. Tinetti (1986);
• simple timed tests, such as the 3-meter test, which involves measuring the time it takes a patient to stand up from a chair, walk 3 m, turn around, return to the chair, and sit down; increased test time (>14 s) has been shown to be associated with an increased risk of falls;
• instrumental methods of gait analysis (e.g. podometry, which evaluates the structure of the step cycle, kinematic analysis of gait, methods of autonomous monitoring of stepping movements); data from instrumental studies of gait disorders should always be analyzed in the context of clinical data.

At the stage of nosological diagnostics, it is necessary to identify, first of all, potentially removable causes, which include intoxication and metabolic disorders (for example, vitamin B deficiency), normotensive hydrocephalus, infections (for example, neurosyphilis). It is important to study the course of the disease. The patient and his relatives should be questioned in detail about the time of the onset of gait disorders, the rate of their progression, the degree of mobility limitation. It is important to take into account that many patients with primary gait disorders complain not of difficulty or uncertainty when walking, but of dizziness or weakness. The patient and his relatives should be asked about the presence of falls and the circumstances in which they occur, fear of falls. It is necessary to clarify the drug history: gait disorders can be aggravated by benzodiazepines and other sedatives, drugs that cause orthostatic arterial hypotension, neuroleptics.

In acute gait and balance disorders, it is necessary to exclude internal organ failure, water-electrolyte imbalance disorders, etc. It is important to analyze accompanying manifestations that may indicate damage to the musculoskeletal, cardiovascular system, sensory organs, peripheral nerves, spinal cord or brain, mental disorders. To exclude orthostatic arterial hypotension, blood pressure should be measured in a lying and standing position. It is necessary not only to identify certain disorders, but also to measure their severity with the nature and severity of the disorders. For example, the presence of pyramidal signs, deep sensitivity disorders, or arthrosis of the hip joints cannot explain a gait with difficulty starting to walk and frequent freezing.

If CNS damage is suspected, neuroimaging is indicated. CT and MRI of the brain can diagnose vascular brain lesions, normotensive hydrocephalus, traumatic brain injury, tumors, and some neurodegenerative diseases. Moderate cerebral atrophy, a thin periventricular strip of leukoaraiosis, or isolated lacunar foci, which are often observed in healthy elderly individuals, should be interpreted with caution. If normotensive hydrocephalus is suspected, a cerebrospinal fluid test is sometimes used: removing 40-50 ml of cerebrospinal fluid can improve walking, which predicts a positive effect of bypass surgery. If spondylogenic myelopathy is suspected, MRI of the cervical spine is necessary. Detection of integrative walking disorders is the basis for studying cognitive functions, especially those reflecting the activity of the frontal lobes, as well as affective functions.

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