So I’m hoping someone can answer me, because I am so confused over this. I have thinking about it for days now. (I’m in a rabbit hole and can’t get out) In the Netflix Documentary Roman Empire (S3E2) it said and showed Caligula falling ill and into a coma from something called “brain fever.” It went on to say he was in this coma for 3 MONTHS!!!!???? and and then suddenly woke up from this illness.. Immediately I’m like, wait, what did they just say? Did I hear that right? REWIND! Umm? A coma? Is this not a documentary? No it’s gotta be, its historians and professors telling the story. Have IVs been around 2000 years? Of course not! 😂 <<<(this is me trying to make sense of it) ...so bears all the questions...How do you eat in a coma? How do you drink? How do you relieve yourself? They had IVs back then? No, don’t be stupid!(3 months in a coma 2000 years ago and surviving just seemed like something so “dumb” to say, that I noticed it immediately) (I’m very surprised no one else has asked this question, except for one person I could find, but it was no help) Then the googling ensues, and there isn’t much I could find to be honest. However lots of sources also said he was in a coma. So it is, in fact, apparently what record we have but HOW???? Google also says “brain fever” was probably something like meningitis or encephalitis. So here it is, days after trying to understand, I come to reddit. I’m sick of google searching and not getting anything satisfying? Any History buffs able to clear things up for me? How did Caligula survive a 3 month coma???? What am I missing here?
In addition to the answers given in the thread that Ludkey linked, it's worth taking a look at the actual sources. When a story like this seems so bizarre, it may be that something is being misreported.
And it is misreported. No ancient source mentions a coma. No ancient source mentions a period of three months. No ancient source mentions headaches.
The sources for Gaius' illness are Philo, Embassy to Gaius 14-21 (ca. 40 CE); Suetonius, Gaius 14.2 (ca. 100 CE); and Dio Cassius 59.8.1-2 (3rd century).
It's clear the illness was severe, and perhaps life-threatening, and that it lasted long enough for news to propagate around the empire, that is to say on the order of a month or perhaps more. But beyond that, what they describe is vague. There are no descriptions of symptoms.
Philo. In the 8th month of Gaius' reign, in early autumn, a serious disease struck him. (The 8th month of his reign ought to have been October-November 37, mid-to-late autumn, so Philo's timeline is a bit wobbly.) The illness arose because he had changed his behaviour from relative modesty, while Tiberius was alive, into a lifestyle of sumptuousness and gluttony. While he was ill people put on a show of mournful faces, and when news came of his illness abating, they were on tenterhooks for the latest news. When it was announced he was fully recovered, they went back to their normal cheerfulness.
Suetonius. A few months after the beginning of his reign, Gaius fell ill, and courtiers put on a big show of making ridiculous vows if his life should be spared.
Dio Cassius. Gaius became sick, but didn't die, and instead caused the death of Tiberius' grandson on suspicion of trying to profit from Gaius' illness.
Suetonius and Dio aren't great sources, but Philo actually met Gaius and was writing before the end of his reign. Together they make a reasonably coherent story (maybe setting aside Suetonius' Dio's lurid story about Tiberius' grandson).
For a take on the evidence and what people have thought about it, I suggest Anthony Barrett's biography Caligula (1989, repr. 2001), the opening pages of chapter 5. He sums up some 20th century speculations about the nature of the disease: encephalitis lethargica, a.k.a. sleeping sickness (Sandison, 1958); hyperthyroidism (Katz, 1972); something affecting the central nervous system (Massaro and Montgomery, 1978); or a particular form of epilepsy (Benediktson, 1989). You may also have read an earlier version of these conjectures in Robert Graves' novel I, Claudius (1934), which also casts the illness as transformative, causing delusional insanity.
These conjectures are based mostly on the supposition that there was a change in Gaius' character before and after the illness -- Suetonius and Dio seem to regard it as a turning point in his career, and Philo draws a causal link to Gaius' lifestyle -- in conjunction with Suetonius' testimony that as a young man Gaius suffered from "falling sickness" (comitialis morbus, Gaius 50), and sometimes had faint spells where he was unable to walk or collect his thoughts. The falling sickness in his youth is worth taking seriously, but we don't know if it was connected to the illness in 37, and the notion of a change in Gaius' character is barely more than speculation.
Sandison's suggestion of encephalitis lethargica (article link; a.k.a. epidemic encephalitis, a.k.a. sleeping sickness) seems to be the one that has taken hold in popular accounts. That's probably because it's the only one that appeared in a medical journal (obviously historians can't be trusted!). That isn't to say it's incompetent: Sandison shows mastery of the ancient sources, of how unreliable they are, and of the secondary literature.
Anyway Sandison's guess is, I reckon, where the notion of a coma came from. You'll find it widely reported that Gaius suffered from headaches before going into his supposed coma: as I mentioned, that isn't mentioned in any ancient source. It must be entirely based on the supposition that he had encephalitis.
If you compare the specificity of the suggestion with the vagueness of the sources, the only responsible conclusion is that we don't have anywhere remotely near enough information to infer any symptoms at all, let alone to diagnose a very rare illness.
I just paused the episode to Google this very thing. I am so thankful that you exist. I was over her imagining how bad he would stink because no bed pans. Then I imagined him in a diaper. And then I was like...how he food? Then I imagined them pouring water down his throat to keep him alive and thought that can't be right omfg this show is a lie.