Footnotes

• Twitter Rajiv Mohanraj @neuro_manc.

• Contributors RMa and FM researched and wrote the manuscript. RS reported the MR scans and contributed to the manuscript. RR performed EMG studies and contributed to the manuscript. ARV was responsible for initial clinical care of the patient and contributed to the manuscript. RMo continues the care of the patient, contributed to the manuscript and had overall supervision of preparation and revision of the paper.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Consent obtained directly from patient(s).

• Ethics approval Not required, patient consent obtained.

• Data availability statement No data are available.

• Provenance and peer review Not commissioned. Externally peer reviewed by Richard Davenport, Edinburgh, UK.