Gait ataxia is said to be one of the most characteristic and sensitive signs of cerebellar damage and is often difficult to characterize because gait patterns can be highly variable (Ilg & Timmerman, 2013). The variability results from the interaction of primary motor deficits in balance control, multijoint coordination & oculomotor dysfunction as well as compensatory strategies and inaccurate postural adjustments. It has been suggested, and clinically this is seen, that a principal feature of gait ataxia is trunk instability (Buckley et al 2018). To compensate for this persons with gait ataxia may increase the width of their base of support, take smaller steps and increase the duration of foot contact to floor, sacrificing the swing phase of locomotion. Therefore they progress forwards with a slower cadence and preferred walking speed (Buckley et al 2018). Gait ataxia is also associated with sensory and vestibular dysfunction. Cassidy et al (2011) found the stigma associated with ‘disordered walking’ seemed to form a significant part of the experience of living with ataxia.
In persons with gait ataxia distinguishing what is the result of the primary pathology and what is secondary due to the compensatory strategies used can be difficult and considerations in the assessment and treatment include:
• Regulation of the relationship between the centre of mass (COM) and base of support (BOS) to minimize fixation strategies
• Attaining and maintaining extensor activity and therefore postural orientation as a basis for feed forward postural stability
• Facilitating the appropriate body segment configuration for the generation of feedforward postural adjustments (early postural adjustments, anticipatory synergy adjustments, preparatory and accompanying anticipatory postural adjustments) and feedback postural adjustments (compensatory postural adjustments)
• Creating an appropriate postural set for treatment and function
• Taking single joint movement patterns to multijoint movement patterns
· Health Condition: A 51-year-old gentleman who had undergone elective surgery 11 years previously for excision of a right vestibular schwannoma. Surgery was complicated by an intraoperative right stroke and he was in coma for ten weeks. He presented with gait ataxia, left sensorimotor impairment, right hearing loss, a right facial weakness with synkinesis and contralateral over-activity and a dysarthria related to the right facial weakness impacting on lip movements as well as reduced respiratory support for speech. There was report of left sided neuropathic pain for which he was on the maximum dose of Pregabalin. Additionally there was a history of bilateral knee pain due to a previous meniscal tear on the left and a torn cartilage on the right, and left shoulder pain.
· Environmental and Personal Factors: He lives with his wife in a house with stairs. He uses a wheelchair for functional mobility but is able to walk short distances with assistance and a walking frame and can manage the stairs using two rails and assistance. Assistance / supervision is also required for transfers, including sit to stand and supine to sit as well as some aspects of self-care, which are carried out in sitting. He attends a gym to weight train and participates in seated boxing. He expressed his main concerns were his standing and walking balance and his goals were to improve this as well as reduce the effort required to walk.
· Assessment: Both the sit to stand (STS) transfer and walking were assessed. To initiate sit to stand he placed his hands on the wheelchair wheel rims and used a compensatory flexion/extension strategy [nose over toes] and ballistic activity to rise into standing. There was the potential to fall during the momentum transfer phase of STS and the strategy resulted in reduced stability in standing. Walking was assessed with his walking frame and usual assistance in both a forwards and backwards direction. There was reduced postural orientation and stability as well as lower limb weakness impacting on single limb stance and progression through stance [on the left greater than on the right]. There was fixation through the upper limbs but he had good upper limb strength to move the frame forwards with the brakes applied. There was a wide BOS with increased latency of postural adjustments as well as inappropriately scaled responses. Intra-limb co-ordination was impaired on the left. However when he looked at his left leg before stepping this allowed him to update internal models / body schema and improved left foot placement resulting in less perturbation to his balance.
A hallmark of the Bobath concept is the interaction between assessment and treatment, with an emphasis on the complex clinical reasoning process enabling a continuously evolving treatment response?base. Within the session the postural transition from standing into sitting was facilitated to gain more information about postural activity and the control of movement as well as to explore key stability / mobility relationships between body segments.
In sitting the upper limbs were placed at 90 degrees on a support to increase trunk extension and a rolled towel was placed under the left ischium to place the right ischium in contact with BOS; this created a more optimal alignment for exploring the shoulder complex in terms of reported shoulder pain and upper limb fixation strategies utilized in walking. This had a positive impact on active trunk extension and the decision to go into supine to assess lower limb alignment and activation was taken. The transition into supine through asymmetrical sitting was facilitated through the left upper limb to maintain a degree of trunk extension.
In supine consideration was given to the creation of an active postural set and environmental modifications were used to align/support the left trunk appropriately as well as both shoulder complexes and the head and neck. A key aspect of treatment intervention in supine was mobilisation of the ribs on the left to reduce arthrogenic stiffness followed by core and lower limb activation and strengthening. The patient was then facilitated from supine into sitting and then into standing and walking. A positive change in motor control performance was seen in terms of more appropriate use of the lower limbs in STS, increased stability in standing and a more automatic gait pattern with improved trunk stability and intra and interlimb co-ordination.
· Reflection ‘In Action’: Within the session consideration was continuously given to the regulation of the relationship between the COM and BOS to optimise postural activation in sitting, supine, standing and walking. Both environmental modifications and therapeutic handling were used to facilitate verticality in both sitting and standing and with improved postural orientation as a basis for feed forward postural control there was greater trunk stability. Facilitating the appropriate active body segment configuration, in particular with regards to a more appropriate alignment of the lower limbs, trunk and left shoulder complex, provided information on the clinical presentation (Vaughan-Graham & Cott 2016) and informed the clinical reasoning as well as a basis for the generation of more appropriate postural adjustments. Facilitation of the postural transitions between standing and sitting, sitting and supine provided key components of the spatial and temporal aspects of the transition to enable experience of movement that was not passive. The creation of optimal sitting at the end of the session facilitated improved biomechanics during the STS transfer and initiation of walking from a more stable stance posture. Transition into steady state walking with increased trunk stability and improved multijoint lower limb movement patterns was achieved.
· Reflection ‘On Action’: From the assessment / treatment intervention the movement diagnosis was determined to be reduced trunk, head & neck orientation and stability; left sensorimotor impairment including sensory ataxia, weakness proximal > distal, sensory disuse and secondary weakness. Secondary problems included a stiff thorax left >right; reduced range of movement at the left glenohumeral joint impacting on left shoulder pain and mal-alignment soft tissues in both lower limbs impacting on knee pain. When considering the patient’s health condition it was surmised that there was evidence of vestibular ataxia on the right correlating with excision of a right vestibular schwannoma and sensory ataxia on the left and neuropathic pain correlating with a possible right thalamic stroke evidenced by initial period of coma.
Working hypotheses generated post assessment/treatment intervention was that:
1. Improved core stability and lower limb strength would improve STS, increase stability in standing and walking and reduce compensatory fixation strategies.
2. Task practice of STS, integrated into a home programme, with optimal foot placement [with a folded towel to improve alignment of the left hip / facilitate heel to floor contact], upper limbs placed on a support at 90 degrees or placed on the arms of the wheelchair / arm chair to facilitate upper trunk alignment, facilitation of antigravity activity around the pelvis/hips with, verbal cues, prior to flexor momentum and momentum transfer phases and forced use of both lower limbs will improve timing and control of STS and result in more stable standing as well as reduce potential falls.
· Suggested quantitative measures to evaluate these two working hypotheses would be the Five Times Sit to Stand Test [FTSTS]; a Berg Balance Scale [BBS]; and the Walking Impairment Scale (WIS).
· Other considerations would be that the high dose of Pregabalin could potentially be contributing to truncal weakness and postural instability and discussion with the GP about an alternative may be useful.
· Additionally an ENT referral would be useful for consideration of a Contralateral Lateral Routing of Signal (CROS) aid, hearing aid technology for people with unilateral hearing [picks up sounds on the on the side of the hearing loss and transmits to the other side; allows detection of sound without turning the head) as this may allow the head to be more orientated to the midline during normal conversation reducing compensatory head turning to the left which may be impacting on cervical spine orientation and trunk stability.
Buckley E, Mazzab C, McNeilla A. (2018) A systematic review of the gait characteristics associated with cerebellar ataxia. Gait and Posture, 60:154-163.
Cassidy E, Reynolds F, Naylor S, De Souza L. (2011) Using interpretative phenomenological analysis to inform physiotherapy practice: an introduction with reference to the lived experience of cerebellar ataxia. Physiotherapy Theory and Practice 27(4):263-77.
Ilg W, Timmann D (2013) Gait ataxia—specific cerebellar influences and their rehabilitation. Movement Disorders 28(11): 1566-1575.?
Vaughan-Graham J, Cott C. (2016) Phronesis: practical wisdom the role of professional practice knowledge in the clinical reasoning of Bobath instructors. J Eval Clin Pract. 23(5):935-948.