After receiving treatment in a hospital in Spain then, Nanjappa flew back to his home in Bangalore. The shooter was diagnosed with Bell's palsy (a form of facial paralysis).
But the 38-year-old did not give up. He made a recovery in about one-and-half months' time and was back in training. He had to put in extra hours to return to top form.
In three months' time, October 2013, he shot for a silver in the Men's 50-metre Free Pistol at the 6th Asian Air Gun Championship in Tehran.
Dr Arpan Bhattacharyya of Manipal Hospital in Bangalore is said to be the main force behind Nanjappa's treatment.
Three months before the paralytic attack (April 2013), Nanjappa had won his first ISSF World Cup medal - a bronze in Changwon (South Korea).
"I was initially worried as the eye is the most crucial organ for a shooter. But then, I read up about it and realised that it was a condition that would last a maximum of six months," Nanjappa had told "The Hindu" in October last year.
The newspaper's report said that though Nanjappa was not affected by partial paralysis (on the right side), he has to use eye drops frequently due to dry eye syndrome.
Nanjappa, who started shooting in 1999, inspired by his national-level shooter father PN Papanna, took a break in 2003 and headed to Canada.
He worked as a software engineer in Canada before returning to India in 2009 and picking up the competition gun again.
Congragulation Mr. prakash nanjappa What a comeback after partial facial paralysis
Congragulation Mr. prakash nanjappa What a comeback after partial facial paralysis— The KingMaker (@karthikeyane7) July 26, 2014
"I didn't have time for shooting then (in Canada). Again, it was correspondence from my father that inspired me to get back to the sport. I returned, quit (my) software job and started practising again," Nanjappa told the newspaper.
Nanjappa, who is supported by Olympic Gold Quest (OGQ), describes him as a "dedicated, disciplined and working hard" to win laurels for India.
OGQ is confident that with the right kind of support he will be able to achieve his aim of winning a medal for India at the 2016 Rio Olympics, they said.
OGQ's mission is to support athletes in winning Olympic gold medals. OGQ has short-listed six individual disciplines shooting, athletics, boxing, wrestling, archery and badminton as the ones in which Indian athletes have the strongest potential to win Olympic medals.
Team OGQ has legends such as Geet Sethi, Prakash Padukone, Viswanathan Anand, Leander Paes among others.
Nanjappa is an inspiration to many. Next big destination for him is Rio de Janeiro - 2016 Olympics.