[Two cases of Wernicke´s encephalopathy that developed during total parenteral nutrition in colon cancer patients treated with 5-fluorouracil-based chemotherapy]

Pathophysiology, prevention, and treatment of beriberi after gastric surgery

Beriberi is a nutritional complication of gastric surgery, caused by deficiency of vitamin B₁, or thiamine. Thiamine deficiency leads to impaired glucose metabolism, decreased delivery of oxygen by red blood cells, cardiac dysfunction, failure of neurotransmission, and neuronal death. This review describes the history and pathophysiology of beriberi as well as the relationship between beriberi and nutritional deficiencies after gastric surgery. A literature review of the history and pathophysiology of beriberi and the risk factors for thiamine deficiency, particularly after gastric resection or bariatric surgery, was performed. Recommendations for nutritional follow-up post gastric surgery are based on current national guidelines. Patients may have subclinical thiamine deficiency after upper gastrointestinal surgery, and thus beriberi may be precipitated by acute illness such as sepsis or poor dietary intake. This may occur very soon or many years after gastrectomy or bariatric surgery, even in apparently well-nourished patients. Prompt recognition and administration of supplemental thiamine can decrease morbidity and mortality in patients with beriberi. Dietary education post surgery and long-term follow-up to determine nutritional status, including vitamin and mineral assessment, is recommended for patients who undergo gastric surgery.

The confused oncologic patient: a rational clinical approach

PURPOSE OF REVIEW

The purpose of this review is to provide a practical clinical approach to confusion in the patient with cancer. Confusion in the cancer population has a broader differential diagnosis than in the general medical population. The clinician must consider the usual differential diagnoses as well as causes unique to the cancer patient including direct complications from the cancer and indirect complications related to cancer treatment.

RECENT FINDINGS

In the recent age of precision medicine, the oncologist now utilizes the genomic profile of both the patient and the tumor to provide advanced biologic therapies including targeted anticancer drugs, antiangiogenic agents, and immunotherapy. Such advances carry with them an emerging pattern of neurotoxicity which, although less well described in the literature, is now an important consideration to the clinical approach to confusion in cancer patients.

SUMMARY

Confusion is the most common neurologic complication in cancer and is associated with significant morbidity, mortality, and prolonged hospital stays resulting in increased healthcare costs. Early recognition and treatment of delirium is essential to improve clinical outcomes.

Bilateral Blindness Following Chemoradiation for Locally Advanced Oropharyngeal Carcinoma

Wernicke's encephalopathy is a life-threatening neurologic complication of thiamine deficiency. Though the presentation of symptoms can vary widely, the classical triad is founded on ophthalmoplegia, alteration of mental status, and gait disturbance. We describe a case of Wernicke's encephalopathy in an oncology patient shortly after concurrent 5-fluorouracil, carboplatin, and radiotherapy for locally advanced oropharyngeal cancer, presenting as complete bilateral blindness, ataxia, nystagmus, and confusion. Thiamine was given based on clinical suspicion and rapid improvement of clinical findings occurred. An MRI performed later supported the diagnosis of Wernicke's encephalopathy. A multifactorial etiology of thiamine deficiency from nutritional deficits and neurotoxic effects of chemotherapy are hypothesized.