Received: 5 April 2019
Accepted: 29 November 2019
First Online: 19 December 2019
Ethics approval and consent to participate
: The aim and procedures of the study were explained to every participant and all participants provided informed written consent to participate in the study. The study was approved by the ethical committee of department of Neurology, Faculty of medicine, Cairo University, on October 20, 2014, but Cairo University does not provide approval reference number.
: Not applicable.
: The authors declare that the research was conducted in absence of any commercial relationships that could be constructed as a potential competing interest.