Gramsci wrote the Prison Notebooks during an eleven-year physical death-agony

Evidence

It is therefore not surprising that Gramsci’s letters from prison reveal a sense of isolation that was more than simply a physical one—but compounded terribly both by political preoccupations and by anxiety about Julia. Increasingly, Gramsci was forced back into himself. Much of the time, particularly towards the end of his stay in Turi, he was too ill even to read or write. Hunchbacked, sickly, having suffered at least three major breakdowns of his health even when he was free and able to enjoy medical attention and maintain a special diet, his years in prison were literally an eleven-year death-agony. — Antonio Gramsci, Selections from the Prison Notebooks, 236