How to assess trunk ataxia (cerebellar dysfunction)?

From the Guidelines

Trunk ataxia can be assessed through several clinical tests that evaluate balance and coordination of the trunk muscles, including the sitting test, pull test, gait assessment, Romberg test, and evaluation of rapid alternating movements of the trunk. These assessments help identify trunk ataxia, which typically results from damage to the cerebellum or its connections, particularly the vermis region that coordinates trunk movements 1. The sitting test involves having the patient sit on an examination table with feet unsupported and arms crossed; inability to maintain balance indicates trunk ataxia. Next, perform the pull test by standing behind the seated patient and gently pulling their shoulders backward, observing if they can maintain position or fall backward. For ambulatory patients, assess gait, looking for a wide-based, unsteady walking pattern characteristic of trunk ataxia. The Romberg test is also valuable—have the patient stand with feet together and eyes closed, watching for increased swaying or falling. Finally, evaluate rapid alternating movements of the trunk by asking the patient to quickly rotate their torso from side to side. Some key points to consider when assessing trunk ataxia include:

• Truncal ataxia and titubation (rhythmic and spasmodic nodding or swaying of the head or body) are seen especially, although not exclusively, with disorders that involve the midline cerebellum 1
• Ataxia that is due to peripheral neuropathy is associated with sensory loss, hyporeflexia, and often weakness as well 1
• The time course of illness (eg, acute, recurrent, chronic with or without progression) may indicate or rule out potential etiology 1
• Early detection of trunk ataxia allows for appropriate rehabilitation strategies to improve balance and prevent falls 1. It is also important to note that ataxia may be seen with substance abuse, toxicity, or nutritional deficiencies, for example, as seen with chronic ethanol abuse, methanol toxicity, and heroin use 1. In terms of imaging, MRI of the entire brain without and with IV contrast is the preferred modality for initial assessment for a mass, any process that may result in edema and enhancement, and neurodegenerative disorders 1.

From the Research

Assessment of Trunk Ataxia

To assess trunk ataxia, several methods can be employed, including:

• Quantified measurements of trunk sway during stance and gait tests, which can be useful in evaluating ataxia and monitoring disease progression 2
• Functional trunk training, which may improve upper limb performance and dynamic trunk balance in patients with autosomal recessive hereditary ataxia 3
• Evaluation of trunk-lower limb coordination pattern during gait, which can provide insight into the deficit of coordination between the upper and lower body segments in ataxic patients 4
• Assessment of trunk position sense, which is associated with postural control and can be impaired in ataxic individuals 5
• Use of the Trunk Impairment Scale (TIS), which can predict functional outcomes, including activities of daily living, in patients with acute stroke 6

Methods of Assessment

The following methods can be used to assess trunk ataxia:

• Postural and balance control tests, such as the Sensory Organization Test and the Limits of Stability Test 5
• Gait analysis, including evaluation of trunk-lower limb coordination pattern during gait 4
• Trunk sway measurements, including peak-to-peak measurements of trunk angle and angular velocity 2
• Functional reach tests, such as the Modified Functional Reach Test 3
• Clinical assessment scales, such as the International Cooperative Ataxia Rating Scale and the Trunk Impairment Scale 3, 6

Clinical Implications

Assessment of trunk ataxia can have important clinical implications, including:

• Monitoring disease progression and evaluating the effectiveness of treatment 2
• Identifying patients at risk of falling and developing strategies to prevent falls 2
• Improving upper limb performance and dynamic trunk balance in patients with autosomal recessive hereditary ataxia 3
• Predicting functional outcomes, including activities of daily living, in patients with acute stroke 6