CRIING

  • Research type

    Research Study

  • Full title

    Investigating Changes in lateralized lacrimation associated with hemicrania continua and associated symptoms using S-methyl-L-thiocitrulline.

  • IRAS ID

    274763

  • Contact name

    Peter J Goadsby

  • Contact email

    peter.goadsby@kcl.ac.uk

  • Sponsor organisation

    King's College London

  • Duration of Study in the UK

    0 years, 8 months, 13 days

  • Research summary

    The International Classification of Headache Disorders (ICHD-III) defines many headache disorders which are uncommon and understanding about their neurobiology is incomplete. Such disorders include hemicrania continua, a rare and continuous headache that is usually accompanied by cranial autonomic symptoms such as lacrimation or nasal congestion.
    Neuronal nitric oxide synthase (nNOS) is highly expressed in the central nervous system and is thought to have crucial roles in synaptic plasticity, long-term depression, pain, memory and blood flow regulation. It is speculated that nNOS dysfunction might be involved in the genesis of some primary headache disorders. The current experimental study will investigate the role of nNOS in hemicrania continua. This will be approached by studying the effect of acute selective nNOS inhibition through S-Methyl-L-thiocitrulline (SMTC) on headache and associated symptoms in participants with this rare primary headache disorder.
    Patients in the database of uncommon headaches will be contacted by their clinical team via email or telephone, given an overview of the study and asked if they would like to participate. The study design consists of a placebo-controlled cross-sectional study of 20 participants. The study will have two visits. In the first the participant will be randomized to receive either placebo (saline) or SMTC. In the second visit they will receive the alternative option that was not given in the first visit, namely saline or SMTC.

  • REC name

    London - South East Research Ethics Committee

  • REC reference

    25/LO/0757

  • Date of REC Opinion

    27 Nov 2025

  • REC opinion

    Further Information Favourable Opinion