ABSTRACT
Mitochondrial myopathies comprise a heterogeneous group of disorders characterized by the presence of ragged red fibres in muscle biopsy. The present study investigates the audiological features in a group of 14 patients in whom diagnosis was histologically confirmed. A complete ENT, neurological and audiological work-up was performed for every patient, including measurement of brainstem auditory evoked potentials (BAEPs). Most patients presented with a varying degree of hearing loss and occasional abnormalities of the latencies and interpeak latencies of the BAEPs, but only the increased latencies of waves I and V have been statistically confirmed. Audiological data suggest non-specific involvement at one or more sites along the auditory pathway.
Subject(s)
Hearing Disorders/etiology , Mitochondrial Myopathies/complications , Adult , Aged , Audiometry, Pure-Tone/methods , Auditory Pathways/pathology , Auditory Threshold/physiology , Biopsy , Cochlea/diagnostic imaging , Cochlea/pathology , Electroencephalography , Electromyography , Evoked Potentials, Auditory, Brain Stem/physiology , Female , Hearing Disorders/diagnosis , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Mitochondrial Myopathies/diagnosis , Muscle, Skeletal/pathology , Severity of Illness Index , Tomography, X-Ray ComputedABSTRACT
BACKGROUND: To evaluate the contribution of leaded gasoline in the presence of abnormal calcifications or cortical atrophy seen in computed tomographies (CT) of the head of occupationally exposed professionals working in the centre of Athens. METHODS: One hundred and twenty-two head CTs from gas station employees and traffic-exposed professionals (taxi and bus drivers) were analyzed for evidence of cortical atrophy or abnormal calcifications. Blood lead level (BLL) of these lead occupationally exposed groups was compared with 37 non-exposed subjects. RESULTS: All three occupationally exposed-to-lead groups had similar blood lead levels compared to the non-exposed group and within the currently accepted norms for lead. No abnormal calcifications were found. Cortical atrophy was more frequently seen in the gas station employees group using univariate and multivariate analysis. In the logistic regression model gas station employment had a stronger impact in developing cortical atrophy [odds ratio of 6.43 (1.46-28.3, 95% CI)] than BLL [odds ratio of 1.4 (1.01-2.05, 95% CI)]. CONCLUSIONS: These results show that employment in gasoline stations may be associated with detectable cortical atrophy in imaging studies and suggest the contribution of a leaded gasoline to its development.
Subject(s)
Air Pollutants, Occupational/adverse effects , Cerebral Cortex/pathology , Gasoline/adverse effects , Occupational Exposure , Adult , Atrophy/chemically induced , Cerebral Cortex/diagnostic imaging , Greece , Humans , Lead/blood , Middle Aged , Multivariate Analysis , Smoking , Tomography, X-Ray ComputedABSTRACT
During the past 10 y, blood lead levels in the population of Athens, Greece, have decreased steadily. This decrease has paralleled the reduction of tetraethyl lead in gasoline and the introduction of unleaded fuel. Blood lead levels and other parameters were studied in 42 gas-station employees, 47 taxi drivers, 47 bus drivers, and 36 controls, all of whom worked in Athens. The blood lead levels did not differ significantly among the four groups (5.64+/-1.7 microg/dl, 5.96+/-1.7 microg/dl, 5.88+/-1.3 microg/dl, and 5.76+/-1.7 microg/dl, respectively). Glutamic-oxaloacetic transaminase (i.e., aspartate aminotransferase) and glutamic-pyruvic transaminase (i.e., alanine aminotransferase) were elevated in gas-station employees, and the former was elevated in taxi drivers. Gas-station employees who smoked had higher blood lead levels than their nonsmoking counterparts. The absence of any difference in the blood lead levels of individuals for whom physical examinations were either normal or abnormal suggests that either lead was not the cause of increased blood lead levels or that its contribution may have been important in the past.
