Two hundred and forty-eight cases of visual snow: A review of potential inciting events and contributing comorbidities.

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.

Reversible Cerebral Vasoconstriction Syndrome Following Carotid Endarterectomy: A Case Report.

INTRODUCTION: Reversible cerebral vasoconstriction syndrome (RCVS) is a cerebrovascular disorder associated with multifocal intracranial arterial constriction and dilation that occurs spontaneously or as a result of a stimulant. The authors present a case of RCVS in a patient who presented with a new-onset thunderclap headache a day after carotid endarterectomy (CEA). RCVS has been rarely reported after CEA. CASE REPORT: A 65-year-old woman was evaluated for a new-onset thunderclap headache a day after left-sided CEA. Computed tomography (CT) of the head revealed left frontal and parietal subarachnoid hemorrhage (SAH). CT angiography did not show any saccular aneurysms or vessel stenosis. The initial impression was SAH related to reperfusion injury after carotid revascularization. Seven days postoperatively, the patient returned to the hospital with a persistent headache. CT revealed SAH in the vertex of the frontal region bilaterally. Magnetic resonance angiogram (MRA) of the head revealed multifocal stenosis of the intracranial circulation bilaterally. A follow-up MRA 9 weeks postoperatively showed interval improvement of the caliber of the circle of Willis branches and significant improvement of the multifocal stenosis. The patient was diagnosed with RCVS as a result of CEA. CONCLUSION: The authors advise clinicians to consider RCVS as a cause of thunderclap headache or recurrence of a severe headache shortly after CEA-particularly with the presence of a nonaneurysmal convexity SAH.

The Effect of Regional Anesthetic Sphenopalatine Ganglion Block on Self-Reported Pain in Patients With Status Migrainosus.

BACKGROUND: Status migrainosus (SM) is defined as a debilitating migraine attack lasting more than 72 hours in patients previously known to suffer from migraine headache. Typically, these attacks fail to respond to over the counter and abortive medications. The sphenopalatine ganglion (SPG) plays a critical role in propagating both pain and the autonomic symptoms commonly associated with migraines. SPG block via transnasal lidocaine is moderately effective in reducing migraine symptoms, but this approach is often poorly tolerated and the results are inconsistent. We proposed that an SPG block using a suprazygomatic injection approach would be a safe and effective option to abort or alleviate pain and autonomic symptoms of SM. METHODS: Through a retrospective records review, we identified patients with a well-established diagnosis of migraine, based on the International Headache Society criteria. Patients selected for study inclusion were diagnosed with SM, had failed to respond to 2 or more abortive medications, and had received a suprazygomatic SPG block. Patients had also been asked to rate their pain on a 1-10 Likert scale, both before and 30 minutes after the injection. RESULTS: Eighty-eight consecutive patients (20 men and 68 women) received a total of 252 suprazygomatic SPG block procedures in the outpatient headache clinic after traditional medications failed to abort their SM. At 30 minutes following the injections, there was a 67.2% (±26.6%) reduction in pain severity with a median reduction of 5 points (IQR= -6 to -3) on the Likert scale (ranging from 1 to 10). Overall, patients experienced a statistically significant reduction in pain severity (P < .0001). CONCLUSION: The SPG is known to play an integral role in the pathophysiology of facial pain and the trigeminal autonomic cephalalgias, although its exact role in the generation and maintenance of migraine headache remains unclear. Regional anesthetic suprazygomatic SPG block is potentially effective for immediate relief of SM. We believe the procedure is simple to perform and has minimal risk.

Central Hypoventilation: A Rare Complication of Wallenberg Syndrome.

Central alveolar hypoventilation disorders denote conditions resulting from underlying neurologic disorders affecting the sensors, the central controller, or the integration of those signals leading to insufficient ventilation and reduction in partial pressures of oxygen. We report a patient who presented with a left lateral medullary ischemic stroke after aneurysm repair who subsequently developed a rare complication of CAH. Increased awareness of this condition's clinical manifestations is crucial to make an accurate diagnosis and understand its complications and prognosis.

Why do trials for Alzheimer's disease drugs keep failing? A discontinued drug perspective for 2010-2015.

INTRODUCTION: There are dozens of drugs in development for AD with billions of dollars invested. Despite the massive investment in AD drugs and a burgeoning pipeline, there have been more setbacks and failures than treatment successes. Areas covered: The classes of drugs that have failed to date include the monoclonal antibodies, the gamma secretase inhibitors, dimebon, neurochemical enhancers, and one tau drug. Data for these compounds were sought through a PubMed search and a clinicaltrials.gov search. Expert opinion: The obvious question to be posed is: Why are they failing? Is the treatment of symptomatic dementia too late? Are the therapeutic targets incorrect? Are the clinical methodologies imprecise, misleading, or inaccurate? This review summarizes the drugs that have failed during 2010-2015 and offers possible theories as to why they have failed.

Detection of pepsin in mouth swab: correlation with clinical gastroesophageal reflux in preterm infants.

OBJECTIVE: To study the relationship between pepsinogen/pepsin in a mouth swab and clinical gastroesophageal reflux (GER) in preterm infants. METHODS: Preterm infants (birth weight ≤ 2000 g) on full enteral feeds were enrolled. Mouth swabs from cheek and below the tongue were collected one, two and three hours after feeding. An enzymatic assay with substrate fluorescein isothiocyanate-casein was used to detect pepsin A and C activities with further confirmation by western blot. Blinded investigators reviewed the infant's medical record to clinically diagnose GER. RESULTS: A total of 101 premature infants were enrolled. Pepsinogen/pepsin was detected in 45/101 (44.5%) infants in at least one sample. A clinical diagnosis of GER was made in 36/101 (35.6%) infants. Mouth swabs were positive in 26/36 (72%) infants with clinical GER and only 19/65 (29%) infants without GER (p < 0.001). Similarly, the levels of pepsinogen/pepsin A and C were higher in the mouth swabs of infants with clinical GER. CONCLUSION: The detection of pepsinogen/pepsin in a mouth swab correlates with clinical GER in premature infants.