Spatax Meeting - Poster Sessions Part 2

This post covers some of the posters shown which I thought warranted a little more detail. There are 4:

Full post index:
Overview: http://hspjourney.blogspot.co.uk/2016/06/international-meeting-on-spastic.html
Papers Day 1: http://hspjourney.blogspot.co.uk/2016/07/spatax-meet-papers-day-1.html
Papers Day 2a: http://hspjourney.blogspot.co.uk/2016/07/spatax-meeting-papers-day-2-part-1.html
Papers Day 2b: http://hspjourney.blogspot.co.uk/2016/08/spatax-meeting-papers-day-2-part-2.html
Papers Day 3: http://hspjourney.blogspot.co.uk/2016/08/spatax-meeting-papers-day-3.html
Posters 1: http://hspjourney.blogspot.co.uk/2016/08/spatax-meeting-poster-sessions-part-1.html
Posters 2: http://hspjourney.blogspot.co.uk/2016/09/spatax-meeting-poster-sessions-part-2.html

Canadian HSP Population
Chrestian et al from Canada reported the Canadian experience of HSP. Their poster presented the analysis of 534 patients, of which 160 had a genetic diagnosis. They found that;

• SPG4 and SPG7 were associated with older age at symptom onset. 
• SPG4 and SPG3A were less associated with learning  difficulties compared with other types.
• SPG11 was strongly associated with progressive cognitive deficits.
• SPG3A was associated with better functional outcome compared with other types
• The strongest predictor for significant disability was abnormal MRI
• SPG4 associated with greater risk of bladder dysfunction
• SPG11 associated with increased pain due to HSP symptoms
• SPG2 associated with increased risk of speech delay
• SPG4 less likely to have motor delay

The poster also reported using the SPATAX-EUROSPA disability stage to assess disability. This scale can be seen here, in part E: https://spatax.files.wordpress.com/2013/09/fichecliniquespatax-eurospa-2011.pdf. The poster is based on this: http://www.neurology.org/content/86/16_Supplement/S43.005

Gait Training for Ataxia

Huisman et al from The Netherlands reported the effects of a five week c-mill training for patients with ataxia. They were testing if the gait in SCA patients and healthy controls can be improved by training on obstacle avoidance and dynamic stability. The patients had ten one hour sessions over 5 weeks, walking on a treadmill with visual cues and obstacles projected onto the belts surface. The difficulty was adjusted to patients capability. The training showed that healthy controls did not improve gait speed but the SCA patients did. 

I had a chat with some about this, who were saying that the patients found the gait training to be very difficult to do, but actually the improvements in gait stayed for some time after the training had finished. This study seems to reinforce the "use it or lose it"approach to muscles, demonstrating that with some hard work it is possible to improve gait.

Wearable Stabiliser for Ataxia

Leonardi et al from Italy reported a small trial using an Equistasi proprioceptive stabiliser. http://www.equistasi.com/en/equistasi/ on people with various types of ataxia who could walk alone or with minimal assistance. The device was worn for 3 weeks and showed improvement in gait without adverse effects. 

It is not clear how the device works, but it appears to generate localised vibrations on the skin which act as a feedback mechanism allowing the brain to modify muscle control. It is not clear how the system is set up to deliver the vibrations. The device is reported elsewhere for use in MS and Parkinsons, and I wonder if there may be applications for HSP.

Gait Patterns in HSP

Casali et al from Italy reported a study of 50 HSP patients, some with genetic diagnoses and others without. They identified 3 distinct gait patterns in patients which correlate robustly with clinical data. The poster showed that many different gait parameters were measured, however the parameters which define the groups are all to do with the range of joint movement in hips, knees and ankles.

Group 1 have a reduced ranges of angular motion for hips, knees and ankles (i.e the joints do not flex much). This group was most affected from a clinical perspective, had the most marked spasticity and walked at the slowest speed.

Group 2 had reduced ankle and knee ranges of angular motion, whereas the range of motion for hips was close to the control values.

Group 3 had an increased hip joint range of angles, with ankle and knee ranges of angular motion, close to the control values. This group was the least affected.

The study is reported as having the potential to help tailor treatments to individual needs.

The study seems to show that the progression of gait begins with increased movement of the hips. the next stage is that the angles of motion of all three joints are reduced, such that hips return to normal and knee and ankles are reduced. The final stage is a reduction (or further reduction?) in all joint ranges.

The poster also showed that progression through the groups leads to reduced walking speed, reduced swing duration, reduced cadence and reduced step length.