Thiamine Deficiency Neuropathy Research Articles

Clinicopathologic features of folate-deficiency neuropathy.

The clinical significance and characteristics of neuropathy caused by folate deficiency remain to be established. We examined the clinicopathologic features of 18 consecutive patients with neuropathy caused by folate deficiency who presented with low serum folate levels but normal blood thiamine and serum cobalamin levels in the absence of chronic alcoholism. Symptoms were relatively uniform, characterized by slowly progressive polyneuropathy with predominant involvement of the lower extremities, with a tendency to manifest as sensory rather than motor neuropathy and predominant deep rather than superficial sensory loss. The electrophysiologic features were consistent with axonal neuropathy. The histopathologic features of sural nerve biopsy specimens indicated large fiber-predominant axonal loss without segmental demyelination. Although macrocytosis was found in 7 patients, only 3 patients exhibited hemoglobin levels less than 10 g/dL. During the same study period, we found 12 patients who had low blood thiamine levels but normal serum folate and cobalamin levels without chronic alcoholism. Compared with patients who had thiamine-deficiency neuropathy, patients with a folate deficiency showed significantly slower progression (p < 0.01), a tendency to manifest sensory neuropathy (p < 0.05), predominant deep sensory loss (p < 0.01), and preservation of biceps tendon reflexes (p < 0.05). Folate-deficiency neuropathy was characterized by a slowly progressive and sensory-dominant pattern, which was different from thiamine-deficiency neuropathy (i.e., beriberi neuropathy). This study demonstrates the importance of folate deficiency in the differential diagnosis of neuropathy, particularly in countries where folic acid fortification has not yet been practiced.

Alcoholic neuropathy

The concept of alcoholic neuropathy has been obscured because of an often undetected or overestimated influence of thiamine deficiency. We describe clinicopathologic features of alcoholic neuropathy, taking the effect of thiamine status into consideration, and recent progress associated with the pathogenesis. Clinical features of alcoholic neuropathy without thiamine deficiency are characterized by slowly progressive, sensory-dominant symptoms. Superficial sensation is predominantly impaired and painful symptoms are the major complaint. Pathologic features are characterized by small-fiber-predominant axonal loss. In contrast, the clinicopathologic features of alcoholic neuropathy with concomitant thiamine deficiency are variable, constituting a spectrum ranging from a picture of a pure form of alcoholic neuropathy to a presentation of nonalcoholic thiamine-deficiency neuropathy. One possible mediator of the direct neurotoxic effects among the metabolites of ethanol is acetaldehyde. Axonal transport and cytoskeletal properties are impaired by ethanol exposure. Protein kinase A and protein kinase C may also play a role in the pathogenesis, especially in association with painful symptoms. Nutritional deficiency as well as the direct neurotoxic effects of ethanol or its metabolites can cause alcoholic neuropathy. Although clinicopathologic features of the pure form of alcoholic neuropathy are uniform, they show extensive variation when thiamine deficiency is present.

Functional Limitations in Thiamine Deficiency Neuropathy: FIM Score Improvement With Treatment

We studied the functional limitations of the activities of daily living and the effect of treatment on 8 patients with thiamine deficiency neuropathy. Functional activities of daily living were evaluated using the functional independence measure whose scores were obtained before and after high-dose vitamin B1 therapy. In the pretreatment evaluation, the lowest mean score was that of in locomotion (stairs), followed by locomotion (walk-wheelchair), transfers (tub-shower), bathing, dressing the lower body, toileting, transfers (bed-chair-wheelchair), and transfers (toilet), in that order. This tendency was also observed after treatment. The most remarkable therapeutic efficacy was observed in locomotion (walk-wheelchair), followed by transfers (tub-shower), locomotion (stairs), dressing the lower body, and toileting, in that order. Every action reflects the motor ability of the lower extremities. Thiamine deficiency neuropathy should be assessed routinely not only by medical evaluation of clinical symptoms or laboratory studies but also by functional evaluation that reflects each patient's disability.

Postgastrectomy polyneuropathy with thiamine deficiency is identical to beriberi neuropathy

Objective We assessed whether postgastrectomy polyneuropathy associated with thiamine deficiency is clinicopathologically identical to beriberi neuropathy, including a biochemical determination of thiamine status. Methods Clinicopathologic features of 17 patients who had postgastrectomy polyneuropathy with thiamine deficiency were compared with those of 11 patients who had thiamine-deficiency neuropathy caused by dietary imbalance. Results The typical presentation for the two etiologies was as a symmetric sensorimotor polyneuropathy predominantly involving the lower limbs. A variety of clinical features, including neuropathic symptoms, progression, and coexistence of heart failure or Wernicke's encephalopathy, was seen similarly in both conditions. In both groups, the main electrophysiologic findings were those of axonal neuropathy, most prominently in the lower limbs. Sural nerve biopsy specimens also indicated axonal degeneration in both groups. Subperineurial edema was commonly observed. Conclusion This study showed that thiamine-deficiency neuropathies due to gastrectomy and dietary imbalance are identical despite variability in their clinicopathologic features and suggested that thiamine deficiency can be a major cause of postgastrectomy polyneuropathy.

What have we learnt from Graham Frederick Young? Reflections on the mechanism of thallium neurotoxicity

The recent death of the psychopathic poisoner, Graham Frederick Young, prompts the question: has our knowledge of the toxic effects of thallium been increased as a result of his activities? The answer is 'yes' but very little. However, the poisonings led to a re-examination of the topography and pathogenesis of thallium intoxication and the suggestion that there are close similarities with chronic thiamine deficiency neuropathy and arsenical neuropathy. They might be termed chronic energy deprivation neuropathies and are associated with damage to other organs with high energy requirements, namely skin and its appendages, testis and heart. While the exact metabolic 'lesion' in thallium intoxication is not yet known, circumstantial evidence continues to suggest that it may be related to the known interaction of this ion with riboflavin, with consequent effects upon energy generation mechanisms associated with tissue flavoproteins.

Thiamine deficiency neuropathy responds to phenytoin

Thiamine deficiency neuropathy responds to phenytoin

Treatment of Thiamine Deficiency Neuropathy with Phenytoin

Treatment of Thiamine Deficiency Neuropathy with Phenytoin

Thiamine deficiency neuropathy

Despite the fact that thiamine deficiency neuropathy is increasing in incidence in our society, it remains an underdiagnosed disorder. The typical complaints of weakness and burning feet are often regarded as trivial by the attending physician. Electrophysiologic studies are sensitive and often provide supportive evidence to aid in the diagnosis. Since chronic pain therapy is often ineffective, a high index of suspicion should be maintained to help ensure early diagnosis and successful intervention.

Thiamine deficiency neuropathy in rats : K. Kunze and E. Muskat (Giessen, Germany)

Thiamine deficiency has been implicated as a signifccant contributing factor in the development of peripheral neuropathies in chronic alcoholic patients. We hypothezized that thiamine deficiency may lead to an alteration in axonal transport because it has been associated with “dying-back” neuropathies and its importance in neural tissue has been demonstrated with antimetabolites. To test this possibility rats were made thiamine-deficient by feeding a liquid diet lacking thiamine. Control rats were pair-fed a complete liquid diet. The deficiency developed after 3 to 4 weeks and was evidenced by anorexia, weight-loss, and a significant increase in the erythrocyte transketolase activity ratio. Also, the sural nerve conduction velocity was found to be significantly reduced in these animals (18.74 m/s) relative to that of pair-fed control rats (31.99 m/s). In vitro transport experiments utilizing dorsal root ganglia-sciatic nerve preparations indicated that twice as much [35S]methionine-labeled protein accumulated at a ligation by fast transport in the thiamine-deficient rats as in nerves of their pair-fed controls. There was no difference in the level of incorporation of radioactive precursor into the dorsal root ganglia. The increase in transport suggests that thiamine deficiency per se has no detrimental effects on the transport machinery and process, but may indicate extensive regenerative activity in the distal portions of these axons.