International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Occupational health

The aim of our long-term studies was to reveal the peculiarities of clinical manifestations of postponed consequences of occupational neurointoxications, mechanisms of their formation and determining the principal diagnostic – criteria of toxical brain disturbances.

Materials and methods 85 patients with chronic mercury intoxication (CHMI) at the age 46,8±6,7 years old and 62 fire fighters taking part in the fire liquidation at the plant “Irkutskcable” in the town of Shelekhov at the age 42,3±5,2 years old were yearly examined at the Clinic of Institute.

An organic brain pathology character was verified using computer electroencephalography (EEG), x-ray computer and magnito-resonance tomography (CT, MRT). Ultrasonic dopplerography (USDG) as well as functional samples displaying the state of brain vessel autoregulation were used to assess cerebral hemodynamics. An experimental psychological study has been performed and process state of lipid peroxidation (LP) as well as antioxidant protection (AOP) based on malone dialdehyde (MDA), lipid hydroperoxide (LHP), diene conjugates (DK), catalase, peroxidase, ascorbinic acid in blood have been studied.

Study results A leading clinical manifestation in a postponed period of occupational neurointoxication was found to be a progressive mildly pronounced encephalopathy (84,9%) in spite of a common opinion, testifying the presense of a “soft” (latent) toxical encephalopathy under contemporary conditions.

Organic psychical disorders with emotional-personal and cognitive disturbances were noted to be as prevailing manifestations of toxical encephalopathy. Diffusive microorganic symptomatics (54,4%) and / or nidus neurological syndromes have also been determined: based on an decreased prevalence of occurrence of epileptiformic (34,5%), vestibular – atactic (31,5%), akinetico-rigid (2,9%) syndromes. EEG alterations testified the disfunction of median brain structures and confirmed the clinically diagnosed epileptic attacks. CT and MRT examinations have shown that a mildly pronounced internal and external hydrocephalia was revealed in 74% of the fire fighters; more considerable alterations were observed in the patients with Cr MJ: encephalopathy signs – 50% of the cases, brainlet subatrophia or atrophia of large hemisphere cortex.

The disorders of cerebral circulation autoregulation have been revealed due to mainly metabolic mechanism. Biochemical studies testified a higher content of underoxidated products of LP (MDA, LHP) in 86,4% of the patients on the background of reduced peroxidase activity and decreased ascorbinic acid content in 41,1% of the cases.

Conclusions Progress of toxical encephalopathy in a postponed period of occupational neurointoxication was induced with the disturbances of cerebral hemodynamics associated with an alterated homeostatic regulation of brain vessels, process activation of lipid peroxidation and failure of antioxidant system. Progradient encephalopathy process is accompanied with the typic electroencephalographic and morphological brain alterations.

Note. Abstracts are published in author's edition

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Last update: 06-Jul-2012 (11:52:05)