Consultant Clinical Neurophysiologist, Salford Royal Foundation Trust
Honorary Lecturer in Neuroscience, University of Manchester
Honorary Lecturer and PhD student, Liverpool John Moores University
Main research interests
My broad research focus involves investigating the structure and function of small nerve fibres, mainly C-Fibres, in both health and disease (e.g. in small fibre neuropathy). This work involves imaging of C-Fibres (skin and cornea) as well as functional assessments with quantitative sensory testing (using the German Pain Consortium protocol) and microneurography.
I work with the early neuropathy assessment (ENA) group at the University of Manchester. This group has developed a rapid, non-invasive way of quantifying small nerve fibre innervation density using confocal microscopy of the cornea. This has been applied to diabetic small fibre neuropathy as well as many other conditions.
I have also been probing the spinal circuits involved in pain processing in painful and non-painful neuropathy in a translational study with the ENA and in collaboration with colleagues at University College of San Diego.
My work at Liverpool John Moores University focusses on assessing the physiological properties of first order sensory nerves using microneurography. Here activity in single afferent nerves, including large and small nerve fibres, can be recorded to standardised skin stimulations and linked with perception.
My particular interest, and the thrust of current work, relates to a relatively recently discovered C-Fibre, the C-Tactile afferent, which appears to be involved encoding pleasant, affiliative, touch as well as having a significant pain modulatory effect. I am also studying the spinal cord processing of the C-Tactile afferent system in collaboration with Dr Manohar Sharma at the Walton Centre.
- Evaluation of C-Fibre function pre/post cordotomy: an investigation in to role of C-Tactile afferent in affective touch
- Microneurography recording of A-beta and C-Fibres in hairy skin in awake human subjects
- Developing a model to evaluate C-Tactile fibre contribution to allodynia and for testing new topical medications O’Neill F, Marshall A, McGlone F
- Corneal confocal microscopy as a surrogate marker of small fibre neuropathies
- The propane study – an EU funded project assessing of sodium channel phenotype in painful and non-painful neuropathy
- Utility of corneal confocal microscopy in burning mouth syndrome O’Neill F, Marshall A
- Investigating Spinally-Mediated Hyperalgesia in Small Fibre Neuropathy
Kass-Iliyya L, Javed S, Gosal D, Kobylecki C, Marshall A, Petropoulos IN, Ponirakis G, Tavakoli M, Ferdousi M, Chaudhuri KR, Jeziorska M, Malik RA, Silverdale MA. Small fiber neuropathy in Parkinson's disease: A clinical, pathological andcorneal confocal microscopy study. Parkinsonism Relat Disord. 2015 Dec;21(12):1454-60.
Ferdousi M, Azmi S, Petropoulos IN, Fadavi H, Ponirakis G, Marshall A, Tavakoli M, Malik I, Mansoor W, Malik RA. Corneal Confocal Microscopy Detects Small Fibre Neuropathy in Patients with Upper Gastrointestinal Cancer and Nerve Regeneration in Chemotherapy Induced Peripheral Neuropathy. PLoS One. 2015 Oct 2;10(10):e0139394.
Alam U, Asghar O, Petropoulos IN, Jeziorska M, Fadavi H, Ponirakis G, Marshall A, Tavakoli M, Boulton AJ, Efron N, Malik RA. Small Fiber Neuropathy in Patients With Latent Autoimmune Diabetes in Adults. Diabetes Care. 2015 Jul;38(7):e102-3. doi: 10.2337/dc14-2354.
Azmi S, Ferdousi M, Petropoulos IN, Ponirakis G, Alam U, Fadavi H, Asghar O, Marshall A, Atkinson AJ, Jones W, Boulton AJ, Tavakoli M, Jeziorska M, Malik RA. Corneal Confocal Microscopy Identifies Small-Fiber Neuropathy in Subjects With Impaired Glucose Tolerance Who Develop Type 2 Diabetes. Diabetes Care. 2015 Aug;38(8):1502-8.
Ponirakis G, Fadavi H, Petropoulos IN, Azmi S, Ferdousi M, Dabbah MA, Kheyami A, Alam U, Asghar O, Marshall A, Tavakoli M, Al-Ahmar A, Javed S, Jeziorska M, Malik RA. Automated Quantification of Neuropad Improves Its Diagnostic Ability in Patients with Diabetic Neuropathy. J Diabetes Res. 2015;2015:847854.
Chen X, Graham J, Dabbah MA, Petropoulos IN, Ponirakis G, Asghar O, Alam U, Marshall A, Fadavi H, Ferdousi M, Azmi S, Tavakoli M, Efron N, Jeziorska M, Malik RA. Small nerve fiber quantification in the diagnosis of diabetic sensorimotor polyneuropathy: comparing corneal confocal microscopy with intraepidermal nerve fiber density. Diabetes Care. 2015 Jun;38(6):1138-44.
Petropoulos IN, Green P, Chan AW, Alam U, Fadavi H, Marshall A, Asghar O, Efron N, Tavakoli M, Malik RA. Corneal confocal microscopy detects neuropathy in patients with type 1 diabetes without retinopathy or microalbuminuria. PLoS One. 2015 Apr 8;10(4):e0123517.
Petropoulos IN, Ferdousi M, Marshall A, Alam U, Ponirakis G, Azmi S, Fadavi H, Efron N, Tavakoli M, Malik RA. The Inferior Whorl For Detecting Diabetic Peripheral Neuropathy Using Corneal Confocal Microscopy. Invest Ophthalmol Vis Sci. 2015 Apr;56(4):2498-504.
Petropoulos IN, Tavakoli M, Marshall A, Malik RA. Response to comment on Malik. Which test for diagnosing early human diabetic neuropathy? Diabetes 2014;63:2206-2208. Diabetes. 2015 Feb;64(2):e2-3.
Azmi S, Ferdousi M, Petropoulos IN, Ponirakis G, Fadavi H, Tavakoli M, Alam U, Jones W, Marshall A, Jeziorska M, Boulton AJ, Efron N, Malik RA. Corneal confocal microscopy shows an improvement in small-fiber neuropathy in subjects with type 1 diabetes on continuous subcutaneous insulin infusion compared with multiple daily injection. Diabetes Care. 2015 Jan;38(1):e3-4.
Ponirakis G, Petropoulos IN, Fadavi H, Alam U, Asghar O, Marshall A, Tavakoli M, Malik RA. The diagnostic accuracy of Neuropad for assessing large and small fibre diabetic neuropathy. Diabet Med. 2014 Dec;31(12):1673-80.
Pritchard N, Edwards K, Dehghani C, Fadavi H, Jeziorska M, Marshall A, Petropoulos IN, Ponirakis G, Russell AW, Sampson GP, Shahidi AM, Srinivasan S, Tavakoli M, Vagenas D, Malik RA, Efron N. Longitudinal assessment of neuropathy in type 1 diabetes using novel ophthalmic markers (LANDMark): study design and baseline characteristics. Diabetes Res Clin Pract. 2014 May;104(2):248-56
Petropoulos IN, Alam U, Fadavi H, Marshall A, Asghar O, Dabbah MA, Chen X, Graham J, Ponirakis G, Boulton AJ, Tavakoli M, Malik RA. Rapid Automated Diagnosis of Diabetic Peripheral Neuropathy with In Vivo Corneal Confocal Microscopy. Invest Ophthalmol Vis Sci. 2014 Feb 25. pii: iovs.13-13787v1.
Liljencrantz J, Marshall A, Ackerley R, Olausson H. Discriminative and affective touch in human experimental tactile allodynia. Neurosci Lett. 2014 Jan 31;563C:75-79.