Possible influence of styloid process length on isolated vertigo of unknown aetiology.

OBJECTIVE: Eagle syndrome or styloid process syndrome is a clinical condition of complex aetiology. Since, as a consequence of vascular compression,due to the length of the styloid process and its nearness to the internal carotid artery,it can lead to vertigo. Vertigo may be the only symptom of stylocarotid syndrome and it is extremely challenging diagnose.To the best of our knowledge, this is the first study that measures the lengths of styloid process on the Croatian population's,and possible influence of styloid process length on isolated vertigo of unknown aetiology. METHODS: This study included 829 subjects who were divided into two groups.The first group was the control group, consisting of 800 subjects.The second group, study group, consisted of 29 subjects who suffered from the vertigo of unknown aetiology. RESULTS: The statistically significant difference between the study and the control group was observed in the length of the styloid process, and in the closest distance of the styloid process from the carotid artery. CONCLUSIONS: The prolonged styloid process and its close association with the internal carotid artery may affect vertigo of unknown aetiology and should be clinically and radiographically investigated in cases of unexplained vertigo as an isolated and only symptom within stylocarotid syndrome.

Accident severity levels and traffic signs interactions in state roads: a seemingly unrelated regression model in unbalanced panel data approach.

This study intended to investigate the interactions between accident severity levels and traffic signs in state roads located in Croatia, and explore the correlation within accident severity levels and heterogeneity attributed to unobserved factors. The data from 410 state roads between 2012 and 2016 were collected from Traffic Accident Database System maintained by the Republic of Croatia Ministry of the Interior. To address the correlation and heterogeneity, a seemingly unrelated regression (SUR) model in unbalanced panel data approach was proposed, in which the seemingly unrelated model addressed the correlation of residuals, while the panel data model accommodated the heterogeneity due to unobserved factors. By comparing the pooled, fixed-effects and random-effects SUR models, the random-effects SUR model showed priority to the other two. Results revealed that (1) low visibility and the number of invalid traffic signs per km increased the accident rate of material damage, death or injured; (2) average speed limit exhibited a high accident rate of death or injured; (3) the number of mandatory signs was more likely to reduce the accident rate of material damage, while the number of warning signs was significant for accident rate of death or injured.

Identifying the safety factors over traffic signs in state roads using a panel quantile regression approach.

OBJECTIVE: This study intended to investigate the interactions between accident rate and traffic signs on state roads located in Croatia and accommodate the heterogeneity attributed to unobserved factors. Data from 130 state roads between 2012 and 2016 were collected from Traffic Accident Database System maintained by the Republic of Croatia's Ministry of the Interior. METHODS: To address the heterogeneity, a panel quantile regression model was proposed, in which a quantile regression model offers a more complete view and a highly comprehensive analysis of the relationship between accident rate and traffic signs, and the panel data model accommodates the heterogeneity attributed to unobserved factors. RESULTS: Results revealed that (1) low visibility of material damage (MD) and death or injury (DI) increased the accident rate; (2) the number of mandatory signs and the number of warning signs were more likely to reduce the accident rate; (3) the average speed limit and the number of invalid traffic signs per kilometer exhibited a high accident rate. CONCLUSIONS: To our knowledge, this study is the first attempt to analyze the interactions between accident consequences and traffic signs by employing a panel quantile regression model; by including visibility, the present study demonstrates that low visibility causes a relatively higher risk of MD and DI. It is noteworthy that average speed limit positively corresponds with accident rate; the number of mandatory signs and the number of warning signs are more likely to reduce the accident rate; and the number of invalid traffic signs per kilometer is significant for the accident rate; thus, regular maintenance should be performed for a safer roadway environment.