Is there a relationship between somatic and autonomic neuropathies in chronic alcoholics?

Toxic and Nutritional Optic Neuropathies—An Updated Mini-Review

Optic neuropathies constitute a group of conditions with various etiologies and might be caused by different factors; we can distinguish the genetic and acquired causes of optic neuropathies. Even though the symptoms are not highly specific, this condition is primarily characterized by unilateral or bilateral vision loss with worsening color detection. The loss may be acute or gradual depending on the causation. In this article, we included a specification of toxic optic neuropathy (TON) mainly triggered by alcohol abuse and also the usage of other substances, including drugs or methanol, as well as intoxication by metals, organic solvents, or carbon dioxide. Nutritional deficiencies, vitamin absorption disorder, and anemia, which usually appear during excessive alcohol intake, and their effect on the etiology of the optic neuropathy have been likewise discussed.

Is gastroparesis that is often detected in patients with alcoholic chronic liver disease a manifestation of an autonomic dysfunction syndrome? A preliminary study

BACKGROUND

the autonomic dysfunction defines the neuropathy of the autonomic nervous system. The prevalence of the gastric dysmotility and its relationship with the autonomic dysfunction in patients with alcohol chronic liver disease is not well known.

METHODS

thirty-six patients with alcohol chronic liver disease and 25 healthy controls were evaluated, in order to detect an autonomic dysfunction through different cardiovascular reflexes and gastric emptying tests.

RESULTS

ninety-four per cent of the patients showed an impaired R index (variations in heart rate during six deep inspirations-expirations per minute) and/or S/S-HR (variations in heart rate when standing from a supine position). Seventy-five per cent of the patients showed gastroparesis (T1/2: gastric half-emptying time was delayed). There was a correlation between the R index and T1/2 (r = -0.49; p < 0.01).

CONCLUSIONS

we suggest that gastroparesis detected in alcoholic chronic liver disease is another clinical manifestation of the autonomic parasympathetic dysfunction.

Alcohol-induced autonomic dysfunction: a systematic review

Purpose

Autonomic dysfunction is a known consequence of chronic and excessive alcohol consumption. The aim of this systematic review was to characterise this phenomenon, describe the frequency at which it occurs and to explore the best management strategies.

Methods

A systematic, computer-based search was conducted using the PubMed database. All studies identified by the search were evaluated independently by at least three authors. For inclusion, studies had to report human subjects consuming ethanol in excess. Case reports and non-original studies were excluded from this review.

Results

A total of 55 studies were included in this review. According to cardiovascular reflex tests, 16–73% of chronic alcohol abusers suffer from autonomic dysfunction. The most commonly occurring symptom is erectile dysfunction, whilst other features such as postural dizziness are rare. The most important risk factor for this condition is total lifetime dose of ethanol, although there is mixed evidence supporting the role of other risk factors. The only management strategy currently explored in the literature is abstinence, which appears to lead to significant improvement in autonomic investigations.

Conclusion

Current literature includes studies of highly heterogeneous populations, consuming differing volumes of alcohol over variable periods of time and utilising a number of different autonomic test batteries and criteria to diagnose autonomic dysfunction. Therefore, further research using homogeneous methods for measuring autonomic dysfunction in the field is needed. Despite this limitation, our review demonstrated that autonomic dysfunction is very common among alcohol abusers.

Alcohol-related peripheral neuropathy: a systematic review and meta-analysis

The primary aim of this systematic review was to establish the prevalence, character, and risk factors of peripheral neuropathy amongst chronic alcohol abusers and to identify the most appropriate management strategies. In this review, possible pathogenetic mechanisms are also discussed. A systematic, computer-based search was conducted using the PubMed database. Data regarding the above parameters were extracted. 87 articles were included in this review, 29 case–control studies, 52 prospective/retrospective cohort studies and 2 randomised control trials, 1 cross sectional study, and 3 population-based studies. The prevalence of peripheral neuropathy amongst chronic alcohol abusers is 46.3% (CI 35.7– 57.3%) when confirmed via nerve conduction studies. Alcohol-related peripheral neuropathy generally presents as a progressive, predominantly sensory axonal length-dependent neuropathy. The most important risk factor for alcohol-related peripheral neuropathy is the total lifetime dose of ethanol, although other risk factors have been identified including genetic, male gender, and type of alcohol consumed. At present, it is unclear what the pathogenetic mechanisms for the development of neuropathy amongst those who chronically abuse alcohol are, and therefore, it is unknown whether it is attributed to the direct toxic effects of ethanol or another currently unidentified factor. There is presently sparse data to support a particular management strategy in alcohol-related peripheral neuropathy, but the limited data available appears to support the use of vitamin supplementation, particularly of B-vitamin regimens inclusive of thiamine.

[Polyneuropathies in intestinal diseases]

Different aspects of polyneuropathies (PN) developed due to the deficit of group B vitamins in intestinal diseases are considered. Neurological disturbances related to intestinal diseases are caused by malabsorption that leads to the deficit of some compounds extremely important for normal cell metabolism, pathological changes of mucous coat of the stomach and intestine and higher sensitivity to the plant protein gluten. Vitamin B12 deficit can lead to a number of neurological disturbances; patients with pernicious anemia most often develop myelopathy and PN. An increase in serum vitamin B1 concentration is identified in 30-80% of patients with alcoholism. However, vitamin B1 deficit is seen also in ulcer disease, chronic gastritis, acute pancreatitis, esophageal metastatic lesions as well as in primary tumors of the stomach and intestine. Demyelinating as well as axonal PN may develop in patients with enteropathy. Gluten intolerance is the most often cause of PN in pathological changes in the intestine Possibilities of clinical and paraclinical diagnosis of these disorders are analyzed.

Alcoholic neuropathy

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

SUMMARY

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.