Case Presentation: Our patient is a 42-year-old female with a past medical history notable for bulimia nervosa that presented to the hospital with a several-month history of worsening confusion and disorientation. The patient’s daughter reported that during this time she had occasional nausea, vomiting, poor appetite, and lower extremity weakness. She also reported that the patient was eating very little and drinking large amounts of soft drinks. On physical examination, the vital signs were normal and neurological examination was notable for upper and lower extremity weakness with a decreased light touch in her bilateral lower extremities and areflexia in her legs. The cardiac examination was normal. Investigations revealed a normal CBC, CMP, TSH, UDS, ammonia, normal MRI brain without contrast, and an extraordinarily low level of vitamin B1 (thiamine) of 48 nmol/L and low folate of 1.6mg/mL. A lumbar puncture was performed which was negative for bacterial, viral, or fungal infections and autoimmune encephalitis. An EEG was performed which revealed a moderately reactive posterior dominant rhythm of 6 Hz to 7 Hz observed over the parieto-occipital regions, which did not reveal any epileptiform activity. Our patient was then started on high-dose thiamine and high-dose folate. The patient’s confusion, disorientation, and weakness gradually improved over the next several months with vitamin supplementation, and her sensory and motor impairments resolved.

Discussion: Beriberi is a life-threatening disease caused by a deficiency of thiamin (vitamin B1). It occurs more frequently in developing countries, especially in those regions with limited access to vitamin-enriched foods. It is sub-classified into two types: dry beriberi and wet beriberi. Dry beriberi refers to neurological manifestations, while wet beriberi refers to cardiovascular manifestations. Risk factors include alcoholism, gastric bypass procedures, starvation, malnutrition, and poor diet. Clinical presentation is variable and may include a loss of sensation in the extremities, a loss of strength in the extremities, double vision, memory loss, fatigue, vertigo, and symptoms of heart failure. If a patient is diagnosed with acute thiamine deficiency with cardiovascular or neurologic complications, they must receive IV or PO thiamine three times daily until symptoms resolve or improve. Untreated, beriberi can be fatal. With treatment, symptoms can improve quickly with most patients making a full recovery. Steps must be taken to ensure the appropriate support and care for the patient, ideally in an inter-professional approach including clinicians, nurses, dieticians, community resources, and inpatient or outpatient treatment strategies.

Conclusions: Thiamine deficiencies must be considered in patients with disordered eating and bulimia nervosa presenting with significant neurological deficits. If untreated beriberi can be fatal, however with appropriate vitamin replenishment the prognosis is excellent. An inter-professional team approach is ideal for reducing thiamine deficiency morbidity.