Sphenopalatine ganglion volumetry in episodic cluster headache: from symptom laterality to cranial autonomic symptoms.

BACKGROUND: Sphenopalatine ganglion (SPG) is a peripheral structure that plays an important role in cluster headache (CH). Hence, a reliable method to measure the volume of SPG is crucial for studying the peripheral mechanism of CH. Additionally, the association between the clinical profiles and the morphology of the SPG in CH remains undetermined. This study aims to use the manual measurement of SPG volume to investigate its associations with CH, including headache laterality, cranial autonomic symptoms (CASs), presence of restlessness or agitation, and other clinical profiles. METHODS: We prospectively recruited consecutive CH patients at a tertiary medical center between April 2020 and April 2022. A total of eighty side-locked, in-bout, episodic CH patients and 40 non-headache healthy controls received 1.5 T brain MRI focusing on structural neuroimaging of the SPG. The manual measurement process for SPG was under axial and sagittal FIESTA imaging, with reference T2 weight images (sagittal and axial) for localization. The inter-observer agreement of the SPG volume (both sides of the SPG from CH patients and controls) between the two observers was calculated. In CH patients, clinical profiles and the number of CASs (range 0-5) were recorded to analyze their association with SPG volume. RESULTS: The inter-observer agreement between the two raters was excellent for the new SPG volumetry method at 0.88 (95% CI: 0.84-0.90, p < 0.001). The mean [SD] SPG volume was larger in CH patients than in non-headache controls (35.89 [12.94] vs. 26.13 [8.62] µL, p < 0.001). In CH patients, the SPG volume was larger on the pain side than on the non-pain side (38.87 [14.71] vs. 32.91 [12.70] µL, p < 0.001). The number of CASs was positively moderately correlated with the pain-side SPG volume (Pearson r = 0.320, p = 0.004) but not the non-pain side SPG volume (Pearson r = 0.207, p = 0.066). CONCLUSIONS: This proof-of-concept study successfully measured the SPG volume and demonstrated its associations with symptomatology in patients with episodic CH. The direct measurement of SPG provide insights into studies on peripheral mechanism of CH.

2022 Taiwan Guidelines for Preventive Treatment of Migraine.

The Treatment Guideline Subcommittee of the Taiwan Headache Society evaluated the medications currently used for migraine prevention in Taiwan. The subcommittee assessed the results of recently published trials, meta-analyses, and guidelines. After expert panel discussions, the subcommittee reached a consensus on the preventive treatment of migraine in Taiwan, which includes recommendation levels, the strength of evidence, and essential prescription information (i.e., dosage and adverse effects) . The recent introduction of CGRP monoclonal antibodies has had a substantial effect on migraine treatment. Thus, the subcommittee updated the previous version of the treatment guideline published in 2017. Preventive medications for migraines can be divided into the following categories: ß-blockers, anticonvulsants, calcium channel blockers, antidepressants, onabotulinumtoxinA, anti-CGRP monoclonal antibodies, and complementary and alternative medicine. For episodic migraine prevention, propranolol, flunarizine, and topiramate are recommended as the first-line medications. Second-line medications for episodic migraine prevention include valproic acid, amitriptyline, and anti-CGRP monoclonal antibodies. Other treatment options could be used as third-line treatments. For chronic migraine prevention, topiramate, flunarizine, onabotulinumtoxinA, and anti-CGRP monoclonal antibodies are recommended as first-line therapies. Preventive medications for episodic migraine can also be used as second-line treatments for chronic migraine. For menstrual migraines, nonsteroidal anti-inflammatory drugs and triptans can be used for short-term prophylaxis. Indications for starting preventive treatment include a headache frequency of ≥4 days per month, profound disabilities, failure of or contraindication to acute therapies, a complicated migraine with debilitating (e.g., hemiplegic) auras, and migrainous brain infarction. The general principle for oral preventives is to "start low and go slow" while monitoring for adverse events and comorbid conditions. Physicians could consider gradually tapering the medications in patients with sustained improvement over 3 to 6 months in episodic migraine and 6 to 12 months in chronic migraine. Education about not overusing acute medications is also essential for all patients with migraine. Key words: migraine, preventive treatment, evidence-based medicine, guidelines, CGRP monoclonal antibodies, onabotulinumtoxinA, neuromodulation.