ATAXIC GAIT

QUESTIONS AND ANSWERS

Classification of Ataxia

Ataxia encompasses several subtypes based on the neurologic system involved: cerebellar, sensory, vestibular, and mixed. Each subtype presents distinct symptoms. For example, vestibular ataxia often appears associated with nystagmus and vertigo, while sensory ataxia may present with staggering gait patterns, particularly in low-visibility conditions.

Cerebellar Ataxia

Cerebellar ataxia results from dysfunction in the cerebellum. It can affect limb coordination and dynamic balance, leading to what appears as a “drunken” gait. Different cerebellar zones contribute to various functions:

• Medial Zone: Regulates upright stance and balance.
• Intermediate Zone: Modulates limb movement coordination.
• Lateral Zone: Influences locomotion with visual guidance.

What Causes Ataxic Gait?

Ataxia can result from abnormalities in various parts of the nervous system. These include the brain, spinal cord, and peripheral nervous system roots and nerves. The nerves link the central nervous system to muscles, skin, and the external world. Cerebellum impairment often links to a patient’s aberrant gait patterns or clumsy hand or arm movements. Two lateral lobes and a center section make up the cerebellum, a spherical structure linked to the brainstem.

The cerebellar cortex, a continuous layer of nerve cells, covers the outside of the cerebellum. The cortex consists of densely linked neurons that organize geometrically in a very predictable way. The majority of the body’s organs, as well as other sections of the brain, send information to the cerebellar cortex. This information gets transmitted to the cerebellum, which then relays signals to the rest of the brain. These steps allow for precise and coordinated movements.

The Symptoms of Ataxia?

As previously mentioned, ataxia is frequently described as a lack of balance or coordination in bodily motions that do not relate to muscular weakness. When doing voluntary motor tasks including speaking, moving the eyes, eating, or putting on clothing, ataxia symptoms display during the child’s walking with an ataxic gait. Ataxia refers to a symptom of one or more underlying disorders that impact on the neurological system.  It does not appear as a distinct disease in and of itself. A repetitive motor activity like gait can make ataxia symptoms fairly obvious. Symptoms of Parkinson’s disease, leg spasticity, or orthopedic anomalies are different from ataxia in terms of how they affect gait.

Impact of Cerebellar Dysfunction on Gait

Cerebellar dysfunction significantly impacts muscle recruitment and coordination, leading to a distinct form of gait known as ataxic gait. This condition is characterized by a clumsy, irregular, and wide-based walk, often compared to the “drunken gait” observed in individuals under the influence of alcohol. Such gait abnormalities arise from the cerebellum’s inability to effectively process multi-sensory information and perform its role as an “error-correction mechanism.”

Key Features of Ataxic Gait

• Increased Step Width: Patients exhibit a broader stance to maintain balance.
• Reduced Ankle Range of Motion: Limited ankle flexibility further impedes smooth walking.
• Increased Gait Variability: Unpredictable step patterns differentiate cerebellar ataxia from other neurological disturbances.

The primary deficit in ataxic gait is a lack of joint coordination, resulting in abnormal coupling between intra-limb joints and segments of the upper and lower body during walking. This deficit is less obvious during clinical inspection but is critical to understanding the condition.

Diagnosing Ataxia Gait

Common Tests for Diagnosing Ataxia

• Eye Movements: The evaluation of pursuit eye movements involves having the patient follow a moving target, looking for jerky movements characteristic of ataxia. Saccadic movements, which involve shifting gaze between two points, are also examined for accuracy, noting any undershooting or overshooting of the target. Doctors sometimes observe nystagmus, or repetitive uncontrolled eye movements.
• Speech: Patients are assessed for dysarthria, particularly cerebellar dysarthria, which may present as irregular or explosive speech or with scanning dysarthria, where syllables do not flow normally This differentiation is crucial for diagnosis.
• Upper Limbs: Doctors conduct the finger-nose test where the patient extends their arm to touch the examiner’s finger, then their nose, repeating the process. Observations focus on coordination, intention tremor, and the ability to fully extend the arm, as subtle ataxia often appears during extension.
• Lower Limbs: The heel-shin test assesses coordination, requiring the patient to slide their heel down the opposite shin smoothly. Any loss of smooth contact indicates potential ataxia.
• Gait: An ataxic gait is typically broad-based and unsteady. Patients may struggle with tandem walking, where the heel of one foot must touch the toes of the other with each step, highlighting balance difficulties.

By combining these specific tests with broader diagnostic procedures, practitioners can achieve a more accurate diagnosis, paving the way for targeted treatment strategies.

Muscle Recruitment Abnormalities

Recent studies confirm that cerebellar dysfunction affects the timing and magnitude of muscle recruitment in the lower limbs. This results in:

• Irregular Limb Movements: Incorrect foot positioning and abnormal timing during heel strike and push-off phases.
• Abnormal Force Production: Variations in knee and ankle joint kinematics disrupt normal gait cycles.

These issues stem from the cerebellum’s impaired processing, leading to challenges in executing precise and coordinated movements. When doctors understand these mechanisms they can develop targeted interventions to improve motor function in individuals with ataxia.

Alcohol and Ataxia

An unsteady gait can result from issues with various aspects of the neurological system or the body. However, aberrant walking brought on by cerebellar dysfunction generally has recognized characteristics. The term “broadened base” refers to people who walk with an ataxic gait as a result of cerebellar impairment. They frequently stumble and appear slightly intoxicated. Given that alcohol impacts the primary nerve cells in the cerebellum, there appears a similarity between ataxia and intoxication. Although acute alcohol intoxication can result in stumbling, that condition goes away over a very short period.

However, frequent exposure to high alcohol dosages can lead to cerebellar neuron degeneration and chronic ataxia. A significant portion of the cerebellar neurons can get damaged from poisons, protracted convulsions, and oxygen deprivation. Gait issues brought on by disorders in other areas of the neurological system, such as the aberrant gait associated with Parkinson’s disease, normal pressure hydrocephalus, or other types of limb spasticity, are not the same as cerebellar ataxia. Because of muscular or orthopedic problems in the hips, legs, or feet, doctors can identify cerebellar ataxia walking.

How to Quantify Ataxia Gait

While doctors can identify ataxic gait symptoms resulting from cerebellar impairment, it’s crucial to better understand them.

Ataxic gait frequently exhibits widening of the base of support, increased step variability, cadence, tandem gait errors, and poor balance. Ataxia compensations could involve shuffling and taking shorter steps. The abnormalities brought on by ataxia are often measured using temporal and spatial gait measurements. This enables the quantification of the widening of the base of support through the measurement of stride.  Further measurements will determine the overall variability in step-to-step measurements. Doctors use a global score, such as the eGVI, or by examining the step-to-step variability of measurements like step length, stride time, stance time, and swing time.

Core Features Identified by Temporospatial Studies

Current research discloses that a main feature of ataxic gait is increased intrasubject variability of performance. More specifically, cerebellar disorders exhibit increased timing variability, which does not appear in other movement disorders with similar balance deficits and spatial variability. This variability in timing is a hallmark identified by temporospatial studies and offers a deeper understanding of the distinctive nature of cerebellar ataxia.

Doctors can better treat these conditions by identifying them early with better definitions and knowledge of the gait abnormalities brought on by cerebellar ataxia. By recognizing both the spatial and timing variability, healthcare professionals can develop more targeted interventions to address these gait abnormalities effectively.

Clinical Features

About 50% of the population walk with an ataxia gait. Vertigo, tinnitus, alternating hemiparesis, and paresthesias of the fingers, toes, and corners of the mouth all identify additional symptoms. Vision loss or a sudden loss of consciousness for less than a minute are other symptoms.  Brainstem stroke and cardiac arrhythmia are uncommon but can cause a similar gait. Usually, neurological problems are followed by a strong, throbbing occipital headache. Less than one-third of cases include nausea and vomiting. Basilar migraine attacks may occur often in children, but with time, the attacks develop into a pattern of typical migraines. Vertigo and ataxia may occur for the patient during occurrences of typical migraines.

Choosing Medical City Children’s Orthopedics and Spine Specialists

Always consult with your doctor if your child begins to walk differently.  If you come to one of our Medical City Children’s Orthopedics & Spine Specialists offices in Arlington, Dallas, Flower Mound,  Frisco, and McKinney, Texas, our pediatric orthopedic doctors will examine your child and recommend the best treatment option to repair the problem and get your child back playing.

As previously mentioned, our doctors at the Medical City Children’s Orthopedics and Spine Specialists, will examine your child and understand the reasons for an unusual gait.  At that point, the doctor will prepare an individualized treatment plan for your child if he finds the cause of the unusual gait.  After correcting the problem, your child will resume his or her favorite activities. For athletes, it may take up to a year before they may resume their sport.

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Library of Science: Gait Ataxia