Quantifying Muscle Tone in Patients With Brain Injury - a Feasibility Study

Quantifying Muscle Tone in Patients With Brain Injury - a Feasibility Study

This project will determine the feasibility and validity of measuring elbow muscle flexor stiffness in a population of patients with sub-acute severe acquired brain injury using two measurement methods, the portable spasticity assessment device (PSAD) (Movotec, Charlottenlund, Denmark) and an ultrasound measurement called shear wave sonoelastography (SWE).

The purpose of this study is to investigate the feasibility and validity of measuring hypertonia in the elbow flexors of patients with severe acquired brain injury in their sub-acute rehabilitation and collect data to determine the necessary size for a definitive study to determine the clinimetrics of the test methods. The long-term goal is to establish a valid and clinically feasible method for physiotherapists to quantify muscle tone in patients with neurological disorders.

The study hypotheses are:

1. SWE, PSAD and Modified Ashworth Scale (MAS) measurements can be obtained for elbow flexion hypertonia in all patients (no missing data due to test procedure),
2. SWE and PSAD have a moderate to good intra-day intra-tester reliability (ICC two-way mixed effects model with absolute agreement. ICC>0.5, Bland Altman)
3. Passive muscle stiffness measured using the PSAD and SWE have a fair concurrent validity with MAS (Spearmans correlation >0.3)
4. SWE and PSAD are responsive in measuring a reduction of the effect of routine clinical treatment of the hypertonic muscles with botulinum toxin type A (BTX-A) (paired T-test or Wilcoxon test, p>0.05)

The project will include five patients admitted to the clinic for highly specialised neurorehabilitation/TBI. Inclusion criteria for the patients are that they:

1. Fulfil the normal clinical requirements for treatment with BTX-A in at least one of their elbow flexors, (have increased stiffness in at least one of their elbow flexors, MAS greater than 0),
2. Have given the normal informed consent to routine clinical treatment with BTX-A,
3. Have given written informed consent or that proxy consent has been obtained, to participate in the study

Exclusion criteria for patients are that they:

1. Are unable to cooperate with the measurements due to uncontrolled non-voluntary movements
2. Cannot be positioned safely or comfortably for the measurements.