engleski

Wernicke’s encephalopathy associated with total parenteral nutrition after allogeneic stem cell transplantation

Severe side-effects following conditioning chemotherapy in allogeneic stem cell transplantation (allo-SCT) include protracted nausea, vomiting, diarrhea and painful mucositis which can lead to anorexia, malabsorption and consequently malnutrition. Higly reduced caloric intake in allo-SCT recipients often requires use of total parenteral nutrition (TPN). Wernicke's encephalopathy (WE) is a neurological emergency caused by a thiamine (vitamin B1) deficiency. The pathognomonic triad for clinical diagnosis comprises of global confusion, ataxia and ophtalmoplegia and it is most commonly associated with chronic alcoholism in adults. However, non-alcoholic WE has also been described in other conditions, such as prolonged TPN. We report a case of WE occurring in a patient after allo-SCT associated with a prolonged use of TPN. A 18-year old male patient underwent allogeneic allo-SCT for acute myeloid leukemia following myeloablative conditiniong with intravenous busulfan, cyclophosphamide and antithymocite globuline. The patient received 2.1 x108 of bone marrow total nucleated cells from a matched unrelated donor on day 0. GVHD prophylaxis was done with cyclosporine A and methotrexate on days +1, +3, +6, +11. From day +1 our patient had protracted mucositis and nausea which enabled him from eating. For that reason, a commercial TPN was started on day +5 and continuated until day +26. Neutrophil engraftment was achieved on day +22. A bone marrow aspirate taken on day +28 showed normal cellularity and no evidence of disease. On day +42, the patient complained of generalized weakness, gait disturbance, hyperacusia, dysphagia and insomnia. Neurogical examination revealed mild confusion, lower limb and truncal ataxia, bilateral abducens nerve palsy, both vertical and rotatory nystagmus, soft palate palsy and areflexia. Cerebrospinal fluid analysis and cranial CT scans were unremarkable. MRI of the brain showed symmetric high-signal intensities in dorsomedial nuclei of the thalamus, mamillary bodies, inferior colliculi, periaqueductal gray and pontine tegmentu, lesions typical for WE. The patient was therefore immediately treated with thiamine 500 mg/day i.v. His neurological status improved gradually and he received thiamine every day for the next month. He was discharged from the hospital on day +56, with persisting minor neurological signs. He is now 2 years from transplantation, in complete remission, but still with some minor neurological disturbances. Neurological complications often occur in patients undergoing allo-SCT mostly due to infectious, metabolic, immune-mediated causes and use of neurotoxic drugs. However, in patients receiving long-term TPN, WE should also be considered. TPN namely requires high amount of thiamine for the metabolization of carbohydrates. A commercial TPN product used in our case did not include thiamine and we overlooked this possibility. The diagnosis of WE is based on clinical presentation but only 16% of affected patients develop the pathognomonic clinical triad. Measurements of blood thiamine concentrations lack specificity and are not routinely available. Due to selective vulnerability of the midline gray matter areas, MRI plays an important role in the diagnosis of this condition. We conclude that WE should be considered in the differential diagnosis of neurologic disturbances in patients on prolonged TPN after allo-SCT. Intravenous thiamine should be added to TPN in order to prevent this complication.

Wernicke's encephalopathy; stem cell transplantation

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