Non-alcoholic Korsakoff syndrome in psychiatric patients with a history of undiagnosed Wernicke's encephalopathy

Abstract

Wernicke's encephalopathy is often undiagnosed, particularly in non-alcoholics. There are very few reports of non-alcoholic patients diagnosed with Korsakoff syndrome in the absence of a prior diagnosis of Wernicke's encephalopathy and no studies of diffusion tensor imaging in non-alcoholic Korsakoff syndrome. We report on three non-alcoholic psychiatric patients (all women) with long-term non-progressive memory impairment that developed after malnutrition accompanied by at least one of the three Wernicke's encephalopathy manifestations: ocular abnormalities, ataxia or unsteadiness, and an altered mental state or mild memory impairment. In neuropsychological examination, all patients had memory impairment, including intrusions. One patient had mild cerebellar vermis atrophy in MRI taken after the second episode of Wernicke's encephalopathy. The same patient had mild hypometabolism in the lateral cortex of the temporal lobes. Another patient had mild symmetrical atrophy and hypometabolism of the superior frontal lobes. Two patients were examined with diffusion tensor imaging. Reduced fractional anisotropy values were found in the corona radiata in two patients, and the uncinate fasciculus and the inferior longitudinal fasciculus in one patient. Our results suggest that non-alcoholic Korsakoff syndrome is underdiagnosed. Psychiatric patients with long-term memory impairment may have Korsakoff syndrome and, therefore, they should be evaluated for a history of previously undiagnosed Wernicke's encephalopathy.

Korsakoff’s syndrome: a critical review

“…However, in the eleven best documented cases of non-alcoholic KS to date, in whom both MRI and extensive neuropsychological assessment were performed, no marked atrophy in any region or structure was found. 41 , 42 Therefore, we argue that in individual cases, MRI does not enable us to reliably diagnose KS, although an MRI with characteristic lesions in the acute phase of WE ( Figure 3 ) obviously supports a subsequent diagnosis of KS.…”

“…A useful definition of KS might have the following phrasing: “KS is a largely irreversible residual syndrome, caused by severe thiamine deficiency and occurring after incomplete recovery from a Wernicke encephalopathy, predominantly in the context of alcohol abuse and malnutrition, characterized by an abnormal mental state in which episodic memory is affected out of all proportion to other cognitive functions in an otherwise alert and responsive patient, whose psychological make-up may be further distinguished by executive dysfunction, flattened affect, apathy, lack of illness insight, and possibly by fantastic confabulations in the early stage.” In milder forms of KS, especially in non-alcoholic KS, executive dysfunction and other cognitive or behavioral disorders (apart from amnesia) may be absent. 41 , 42 Therefore, it is premature to require the presence of these symptoms in all instances of KS as long as there is no consensus on the severity and duration of the memory disorder required for the diagnosis of KS.…”

Case of non-alcoholic Wernicke’s encephalopathy

“…The presentation is often quite varied7 and often subtle with the classic triad of ophthalmoplaegia, ataxia and confusion only present in a subset of patients. The literature suggests that the degree of suspicion is often low in those who are not alcohol dependent9 and this was true in this case. The lack of clinical correlation or pattern makes it difficult for the physician to make a clinical diagnosis, especially given that they will seldom see a case of non-alcoholic WE in their careers.…”

“…Non-alcoholic WE is easily treated yet often under-diagnosed in the non-alcoholic patient 9. The under diagnosis of WE is considered to be multifactorial.…”

“…Non-alcoholic WE can manifest with atypical symptoms7 and often the clinical suspicion of WE in the non-alcohol-dependent patient is low which may lead to significant under diagnosis 9. Here, we describe a case of WE presenting in a tee-total, obese man.…”