Objective To describe a standardized methodology for the performance of peripheral nerve blocks (PNBs) in the treatment of headache disorders. Background PNBs have long been employed in the management of headache disorders, but a wide variety of techniques are utilized in literature reports and clinical practice. Methods The American Headache Society Special Interest Section for PNBs and other Interventional Procedures convened meetings during 2010‐2011 featuring formal discussions and agreements about the procedural details for occipital and trigeminal PNBs. A subcommittee then generated a narrative review detailing the methodology. Results PNB indications may include select primary headache disorders, secondary headache disorders, and cranial neuralgias. Special procedural considerations may be necessary in certain patient populations, including pregnancy, the elderly, anesthetic allergy, prior vasovagal attacks, an open skull defect, antiplatelet/anticoagulant use, and cosmetic concerns. PNBs described include greater occipital, lesser occipital, supratrochlear, supraorbital, and auriculotemporal injections. Technical success of the PNB should result in cutaneous anesthesia. Targeted clinical outcomes depend on the indication, and include relief of an acute headache attack, terminating a headache cycle, and transitioning out of a medication‐overuse pattern. Reinjection frequency is variable, depending on the indications and agents used, and the addition of corticosteroids may be most appropriate when treating cluster headache. Conclusions These recommendations from the American Headache Society Special Interest Section for PNBs and other Interventional Procedures members for PNB methodology in headache disorder treatment are derived from the available literature and expert consensus. With the exception of cluster headache, there is a paucity of evidence, and further research may result in the revision of these recommendations to improve the outcome and safety of these interventions.

Gradual improvement in not uncommon after spinal cord infarction and it may continue long after hospital dismissal. While severe impairment at nadir is the strongest predictor of poor functional outcome, meaningful recovery is also possible in a substantial minority of these patients.

The sphenopalatine ganglion (SPG) has attracted the interest of practitioners treating head and face pain for over a century because of its anatomical connections and role in the trigemino-autonomic reflex. In this review, we discuss the anatomy of the SPG, as well as what is known about its role in the pathophysiology of headache disorders, including cluster headache and migraine. We then address various therapies that target the SPG, including intranasal medication delivery, new SPG blocking catheter devices, neurostimulation, chemical neurolysis, and ablation procedures.

The diagnosis of FCE in life is common at this referral center, accounting for 5.5% of all cases of acute spinal cord infarction seen. Although FCE is a postmortem diagnosis, we propose clinical criteria for FCE in life to better characterize the relatively high number of patients with unexplained ischaemic myelopathy.

Visual snow is a condition where patients see constant, innumerable flickering dots throughout the visual field, similar to "TV static." Though visual snow was originally described in 1995, there were still fewer than 10 cases in the literature prior to 2014. In the last 4 years, this has grown to approximately 200 cases and there has been a concentrated effort to better understand and characterize this condition. It has become apparent that patients who see visual snow frequently have additional visual and non-visual symptoms, and the consistency of these symptoms has led to proposed criteria for visual snow syndrome. When seeing a patient with visual snow, it is important to rule out a possible underlying secondary etiology. Patients with visual snow syndrome frequently have comorbid migraine, but visual snow appears to be a separate entity from persistent migraine aura. The pathophysiology of this syndrome is not clear, but recent neurophysiologic and neuroimaging studies have helped advance our understanding.

Objective To review characteristics and outcomes of all cases of visual snow seen at our institution, with attention to possible triggering events or comorbidities. Methods This is a retrospective case series of patients seen at our tertiary care center from January 1994 to January 2020. Charts were reviewed if they contained the term “visual snow”. Results Of the 449 charts reviewed, 248 patients described seeing visual snow in part or all of their vision. Thirty-eight reported transient visual snow as their typical migraine aura. Of the remaining 210 patients, 89 were reported to have either an inciting event or contributing comorbidity for their visual snow symptoms, including: Post-concussion (n = 15), dramatic change in migraine or aura (n = 14), post-infection (n = 13), hallucinogen persisting perception disorder (n = 10), ocular abnormalities (n = 7), idiopathic intracranial hypertension (n = 4), neoplastic (n = 1), and posterior cortical atrophy (n = 1). Some patients had partial improvement with benzodiazepines (n = 6), lamotrigine (n = 5), topiramate (n = 3) and acetazolamide (n = 3). Presenting characteristics were similar, but patients with visual snow attributed to an inciting event or contributing comorbidity were more likely to have some improvement in their symptoms by last follow-up compared to spontaneous visual snow ( p < .001). Conclusions Though most cases of visual snow are spontaneous, potential secondary causes should be recognized by clinicians. Patients who develop visual snow after an inciting event or related to an underlying comorbidity may have a better prognosis than those in whom it develops spontaneously. In select cases, treatment of the suspected underlying cause may significantly alleviate the otherwise typical intractable visual disturbances associated with visual snow.

Objective Cerebrospinal fluid-venous fistula is an uncommon cause of spontaneous spinal cerebrospinal fluid leak (SSCSFL). We aim to describe the clinical presentation, imaging evaluation, treatment and outcome of SSCSFL secondary to cerebrospinal fluid-venous fistula. Methods A retrospective review was undertaken of SSCSFL cases secondary to cerebrospinal fluid-venous fistula confirmed radiologically or intraoperatively, seen at our institution from January 1994 to March 2019. Cases with undetermined SSCSFL etiology, alternative etiology or unconfirmed fistula were excluded. Results Forty-four of 156 patients met the inclusion criteria (31 women, 13 men). Mean age of symptom onset was 52.6 years (SD 8.7, range 33–71 years). Headache was the presenting symptom in almost all, typically daily (69%), and most often in occipital/suboccipital regions. Headache character was most commonly pressure (38%), followed by throbbing/pulsing (21.4%). Orthostatic headache worsening occurred in 69% and an even greater percentage of patients (88%) reported Valsalva-induced headache exacerbation or precipitation. Headache occurred in isolation to Valsalva maneuvers in 12%. Of 37 patients with documented cerebrospinal fluid opening pressure, 13% were <6 cmH2O; 84%, 7–20 cmH2O; and one, 25 cmH2O. Fistulas were almost exclusively thoracic (95.5%). Only one patient responded definitively to epidural blood patch (EBP). Forty-two patients underwent surgery. Most improved following surgery; 48.7% were completely headache free and 26.8% had at least 50% improvement. Conclusion In our series, cerebrospinal fluid-venous fistula was associated with a greater occurrence of Valsalva-induced headache exacerbation or precipitation than orthostatic headache and did not respond to EBP. Surgery provided significant improvement. Cerebrospinal fluid-venous fistula should be considered early in the differential diagnosis of Valsalva-induced (“cough”) headache.

Conclusions.-When performed in the appropriate setting and with the proper expertise, TPIs seem to have a role in the adjunctive treatment of the most common headache disorders. We hope our effort to characterize the methodology of TPIs by expert opinion in the context of published data motivates the performance of evidence-based and standardized treatment protocols.