Even though this patient had prior episodes of WE, there remained diagnostic uncertainty regarding his altered mental status for some time before the nonoral thiamine repletion treatment was implemented. Particularly in this admission, the patient’s mental status frequently waxed and waned and there was the additional confusion of whether a potential psychiatric etiology contributed to some of the elements of his presentation, such as his impulsive self-harm behaviors. This behavior led to recurrent transfers among the Psychiatry Service, Internal Medicine Service, and the ED.
The patient’s presentation did not reflect the classical triad of WE, and while this is consistent with the majority of clinical manifestations, various services were reluctant to attribute his symptoms to WE. Once the threshold of suspicion of thiamine deficiency was lowered and the deficit treated more aggressively, the patient seemed to improve tremendously. Presence of memory problems and confabulation, both of which this patient exhibited, are suggestive of KS and are not expected to recover with treatment, yet for this patient there did seem to be some improvement—though not complete resolution. This is consistent with newer evidence suggesting that some recovery from the deficits seen in KS is possible. 3
Once diagnosed, the treatment objective is the replenishment of thiamine stores and optimization of the metabolic scenario of the body to prevent recurrence. For acute WE symptoms, many regimens call for 250 to 500 mg of IV thiamine supplementation 2 to 3 times daily for 3 to 5 days. High dose IV thiamine (≥ 500 mg daily) has been proposed to be efficacious and free of considerable adverse effects. 12 A study conducted at the University of North Carolina described thiamine prescribing practices in a large academic hospital, analyzing data with the objective of assessing outcomes of ordering high-dose IV thiamine (HDIV, ≥ 200 mg IV twice daily) to patients with encephalopathy. 13 The researchers concluded that HDIV, even though rarely prescribed, was associated with decreased inpatient mortality in bivariable models. However, in multivariable analyses this decrease was found to be clinically insignificant. Our patient benefitted from both IV and IM delivery.
Ideally, after the initial IV thiamine dose, oral administration of thiamine 250 to 1,000 mg is continued until a reduction, if not abstinence, from alcohol use is achieved. 5 Many patients are discharged on an oral maintenance dose of thiamine 100 mg. Oral thiamine is poorly absorbed and less effective in both prophylaxis and treatment of newly diagnosed WE; therefore, it is typically used only after IM or IV replenishment. It remains unclear why this patient required IM thiamine multiple times per day to maintain his mental status, and why he would present with selfinjurious behaviors after missing doses. The patient’s response can be attributed to late-onset defects in oral thiamine absorption at the carrier protein level of the brush border and basolateral membranes of his jejunum; however, an invasive procedure like a jejunal biopsy to establish the definitive etiology was neither necessary nor practical once treatment response was observed. 14 Other possible explanations include rapid thiamine metabolism, poor gastrointestinal absorption and a late-onset deficit in the thiamine diffusion mechanisms, and active transport systems (thiamine utilization depends on active transport in low availability states and passive transport when readily available). The nature of these mechanisms deserves further study. Less data have been reported on the administration and utility of IM thiamine for chronic WE; hence, our case report is one of the first illustrating the role of this method for sustained repletion.