Background : Non-alcoholic Wernicke's encephalopathy and Korsakoff syndrome are greatly underdiagnosed. There are very few reported cases of neuropsychologically documented non-alcoholic Korsakoff syndrome, and diffusion tensor imaging (DTI) data are scarce.Methods : We report clinical characteristics and neuropsychological as well as radiological findings from three psychiatric patients (one woman and two men) with a history of probable undiagnosed non-alcoholic Wernicke's encephalopathy and subsequent chronic memory problems.Results : All patients had abnormal neuropsychological test results, predominantly in memory. Thus, the neuropsychological findings were compatible with Korsakoff syndrome. However, the neuropsychological findings were not uniform. The impairment of delayed verbal memory of the first patient was evident only when the results of the memory tests were compared to her general cognitive level. In addition, the logical memory test and the verbal working memory test were abnormal, but the word list memory test was normal. The second patient had impaired attention and psychomotor speed in addition to impaired memory. In the third patient, the word list memory test was abnormal, but the logical memory test was normal. All patients had intrusions in the neuropsychological examination. Executive functions were preserved, except for planning and foresight, which were impaired in two patients. Conventional MRI examination was normal. DTI showed reduced fractional anisotropy values in the uncinate fasciculus in two patients, and in the corpus callosum and in the subgenual cingulum in one patient.Conclusions: Non-alcoholic Korsakoff syndrome can have diverse neuropsychological findings. This may partly explain its marked underdiagnosis. Therefore, a strong index of suspicion is needed. The presence of intrusions in the neuropsychological examination supports the diagnosis. Damage in frontotemporal white matter tracts, particularly in the uncinate fasciculus, may be a feature of non-alcoholic Korsakoff syndrome in psychiatric patients.

Thiamine deficiency can lead to Wernicke's encephalopathy (WE), an acute and potentially life-threatening neurological disorder. Even though the main treatment modality for WE consists of thiamine replacement, evidence supporting an optimal dosing strategy and duration is unclear.We present a single-center case series of eleven patients that were admitted with possible WE and treated with high-dose parenteral thiamine.Patients with suspected WE were treated with ≥500 mg intravenous thiamine for a median of 3 days with 73% of patients (eight out of eleven) displaying symptom resolution or improvement after treatment. No significant correlation between symptom resolution and timing of high-dose thiamine initiation (median=92 h) was identified. In patients whose symptoms resolved compared to those whose symptoms did not, there were no differences in patient variables nor adverse effects related to thiamine treatment.High-dose thiamine (≥500 mg) appears safe and efficacious for use in patients with suspected WE.Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.