and disability. Stroke is the third leading cause of death and is the major cause of disability in the United States. 1-3 Approximately one half of patients in long-term care facilities require treatment because of strokes.Over one half of strokes are caused bv arteriosclerotic lesions in the cervical carotid artery and are potentially preventable.4-6 Duplex scanning of the carotid artery has evolved as the prime means of discovering strokc-potential carotid artery lesions and provides a rapid, safe, and reliable means of ferreting out such lesions. 1 Prospective randomized clinical trials have shown that safely performed carotid endarterectomy (CEA) can prevent strokes. In the North American Symptomatic Carotid Endarterectomy Trial (NASCET), 24% of patients with carotid artery lesions with greater than 70% diameter reduction who were treated medically had an ipsilateral cerebrovascular accident within 18 months compared to 7% of those patients who underwent CEA .7 Over one half of the strokes occurring in patients in the medical arm of that study were severe or fatal. Two other similar trials, the European Carotid Surgery Trial&dquo; and the Veterans Affairs Cooperative Studies Program Trlal9 for symptomatic carotid endarterectomv showed nearly identical results.The Veterans Affairs Cooperative Study Group 10 for symptomatic carotid artery stenosis found that 9.4% of patients with no symptoms or nonlateralizing symptoms and greater than 50% carotid artery stenosis who were treated medically had ipsilateral strokes during the period of StLidB' compared to 4.5% who had CEA. Transient ischemic attacks occurred in 11.1°lo of those treated medically and the risk of combined neurologic events (stroke plus transient ischemic attack) was 26% for those treated medicaih and 8% for those treated surgically (statistically significant). Although the combined incidence of stroke and death was not significantly different in the medical and surgical patients, it can be surmised that a vascular surgeon with a low perioperative stroke and death rate could prevent strokes in these asymptomatic patients. This is important because approximately 50% of strokes are not preceded by lateralizing events.

We report the first case of Coronavirus Disease 2019 (COVID-19)-associated brain abscess caused by a rare Trichosporon species, T. dohaense . The patient was a known diabetic and had received systemic corticosteroids for the treatment of COVID-19. He underwent craniotomy and evacuation of abscess. The pus aspirate grew a basidiomycetous yeast, morphologically resembling Trichosporon species. The isolate was initially misidentified by VITEK® MS due to lack of mass spectral database of T. dohaense . Accurate identification was achieved by internal transcribed spacer-directed panfungal polymerase chain reaction. The patient had a favorable outcome following surgical intervention and antifungal therapy.

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Hyponatremia is a commonly encountered electrolyte imbalance with varied etiology. Hyponatremia can be broadly classified as hypotonic, isotonic, and hypertonic hyponatremia based on the tonicity of plasma. Hypotonic hypovolemia is further classified as hypovolemic, euvolemic, and hypervolemic hyponatremia based on the volume status. Gastrointestinal fluid and electrolyte losses, secondary to vomiting and diarrhea, is an important predisposition to hypotonic hypovolemic hyponatremia. The renin-angiotensinaldosterone system (RAAS) and antidiuretic hormone (ADH) play a pivotal role in maintaining intravascular volume and serum sodium concentration. Dexamethasone is a potent glucocorticoid with minimal mineralocorticoid activity. It negatively affects the hypothalamic-pituitary-adrenal axis and the reninangiotensin-aldosterone system, particularly with prolonged administration. In the index case, acute severe hypovolemic hyponatremia ensued on the third post-procedure (endovascular embolization of traumatic carotico-cavernous fistula (CCF)) day while the patient was on intravenous dexamethasone. This case underscores that even small fluid and electrolyte imbalance in the setting of dexamethasone therapy may lead to severe hypovolemic hyponatremia, which requires specific therapy.

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