Novel electrical impedance spectroscopy

Novel electrical impedance spectroscopy for neurological disorders

The study is looking for healthy volunteers to participate. Please contact the research team if you are interested and would like to discuss the study in more detail.

Participant information sheet for healthy volunteers (PDF, 818KB)

UK Chief Investigator

Dr James Alix

Research summary

Neurological disorders often cause weakness of various muscles in body. This can be the arms or legs, or muscles around the face like the tongue. Some of these conditions are due to a main problem in the muscle structure, but many are due to problems elsewhere in the body. For example, stroke is a disease of the brain, but it is known that there are changes to muscle after a stroke which may affect recovery.

Assessment of muscle health is therefore important in the diagnosis of neurological diseases and also in monitoring how they change over time. Despite this, the way in which muscle health is assessed is quite variable and often restricted to, for example, painful procedures, or by the clinician asking the patient to move the muscle and then judging the movement.

We have developed a quick, simple, painless way of assessing muscle health using electrical impedance spectroscopy. In this, tiny electrical pulses, that cannot be felt are used to build up an understanding of the structure of the muscle.

We have constructed a new device which we will test on patients with different conditions that affect muscle. We will also test on patients which experts think would benefit from a simple test to evaluate muscle. We will test our technology on healthy volunteers, patients with motor neurone disease (MND), conditions that appear like ND ('mimics'), age-related muscle loss (sarcopenia) and stroke.

We will compare the recordings from the new device against routine ways of assessing these patients. We will also undertake recordings over time to understand how our readings change. We will collect patient feedback on the device and recording procedure.

The study will enable us to understand how well the device works across conditions which could benefit from such technology. This will enable us to plan more detailed studies in the future.

Inclusion / exclusion criteria

Key inclusion criteria

General inclusion criteria to be applied to all work packages:

  • Willing to participate in the study

  • Able to read and understand English (in order to provide informed consent)

  • 18 years or older

Work package/disease specific:

Work package 1 – Healthy volunteers

As per general inclusion criteria.

Work package 2 – MND and its mimics

In addition to the general inclusion criteria:

  • MND patients: under investigation for suspected ALS or fulfilling the possible, probable or definite ALS categories of the Awaji-Shima criteria.

  • MND mimic patients: an established electroclinical diagnosis of CIDP or MMN-CB, a genetic diagnosis of hereditary spastic paraparesis/clinical diagnosis with disease progression in keeping with the condition, muscle disease, benign fasciculations, myeloradiculopathy, myaesthenia gravis.

Work package 3 – Age-related sarcopenia

In addition to the general inclusion criteria:

  • Gait speed <0.8 meters per second.

  • Reduced hand-grip strength.

Work package 4 – Stroke

In addition to the general inclusion criteria:

  • Radiological and clinical evidence of ischaemic or haemorrhagic stroke.

  • Clinical evidence of upper limb or lower limb muscle spasticity (Modified Ashforth Score ≥ 2) in any of the muscle groups amenable to EIS measurement.

Key exclusion criteria

  • Any skin condition with areas of inflammation/infection over potential recording sites.

  • Any co-existing neuromuscular disorder eg peripheral neuropathy, myopathy, myasthenia gravis.

  • Previous stroke.

  • Long term immobilisation (greater than three months).

Current status

Active – recruiting


Royal Hallamshire Hospital, Sheffield

Information about study sites

Contact details

Chief Investigator: Dr James Alix


Study Coordinator: Jennie Maris


Recruitment group(s)

  • Patients with MND

  • Healthy volunteers

  • Patients with diseases that 'mimic' MND

  • Patients with age-related sarcopenia

  • Stroke patients

Recruitment target(s)

175 participants


Medical Research Council, Confidence in Concept Scheme


Sheffield Teaching Hospitals NHS Foundation Trust

Study design

Observational study

Intervention (if applicable)

Not applicable

Phase (if applicable)

Not applicable

Outcome measures

Reliability of impedance measurements from muscle. Test-retest analysis will be undertaken. These will include the intra-class correlation coefficient (reliability) and Bland-Altman analysis (agreement).

Participant information sheet

Participant information sheet for healthy volunteers (PDF, 818KB)