New Delhi, Dec 9 (IANS): Former union minister Jaswant Singh, who was hospitalised with a severe head injury four months ago, continues to be in coma and is showing no sign of improvement, doctors said Tuesday.

"His (Jaswant Singh) condition is still the same. He continues to be in coma. All the treatment processes remain the same with a team of doctors observing him closely every day," a senior doctor at the Army Hospital (Research and Referral) told IANS here.

"The team of doctors consists of neurosurgeons and critical care specialists. Every effort is being made to revive Jaswant Singh," he added.

According to the doctor, Jaswant Singh is being given total parenteral nutrition (TPN) which delivers nutrients intravenously when a patient is unable to eat on his/her own.

The 76-year-old leader was admitted to the hospital Aug 8 in a critical condition after his family found him lying on the floor of his house in an unconscious state.

In the past several leaders across the globe have also slipped into coma. Former Israeli prime minister Ariel Sharon was in coma for eight long years before dying in Jan 2014.

Some Indian leaders include former union minister Priya Ranjan Dasmunsi, who slipped into coma in 2008 after suffering a heart stroke. Former president K.R. Narayanan and first Indian prime minister Jawaharlal Nehru died after being in the condition for a few days.

Former Karnataka chief minister Veerendra Patil was another leader who died after being in coma for two days.