Received: 3 September 2019
Accepted: 14 February 2020
First Online: 28 February 2020
Ethics approval and consent to participate
: This work was approved by the ethical committee at the National Center for Neurological Science, Khartoum, Sudan reference number 2009-02-09. The ethical approval certificate is attached. All the authors approved the participation of the manuscript. Consent was taken from all participants; a sample of the consent form in Arabic is attached.
: Not applicable.
: The authors declare that they have no competing interests.