Brain Fever

A Forgotten Trope. In fiction, Brain Fever is a sudden, acute febrile illness brought on by mental shock or stress. It is often severe and may cause raving delirium or insanity. Meningitis and encephalitis, literal inflammations of the brain, have also been referred to as "brain fever," and fictional cases of Brain Fever may exhibit the same symptoms.

A popular plot device in the nineteenth century, Brain Fever isn't used much anymore because, well, diseases don't work that way.

Film

 * Played completely straight in Brand Upon The Brain. Mind you, Guy Maddin plays straight a lot of tropes that nobody else uses now—or ever.
 * In Metropolis, Freder collapses with a fever when he thinks Maria has betrayed him.
 * Played straight in The Tai Chi Master. This happens to Jet Li's character after.
 * In Therese, the title character becomes ill for two weeks after her oldest and favorite sister leaves to become a nun.
 * In Soap Dish, Elisabeth's Shue's character, Lori Craven, plays a destitute deaf-mute who is revealed to have Brain Fever during a live telecast of The Sun Also Sets.
 * Joe Versus the Volcano. Joe suffers from a terminal "brain cloud".

Literature
""After a long talk with the harbor-master, Captain Leclere left Naples greatly disturbed in mind. In twenty-four hours he was attacked by a fever, and died three days afterwards.""
 * In A Little Princess, Sara's father dies of brain fever after going bankrupt.
 * In Agatha Christie's The Murder On The Links, a man collapses with a fever, which Hercule Poirot attributes to a shock on top of ongoing mental strain.
 * Later Christie novels reflect the fact that Science Marches On. For instance, in The Big Four Hastings suggests that an insensible man is suffering from brain fever, to which a doctor character responds, "Invention of novelists!"
 * Victor Frankenstein from Frankenstein had two bouts.
 * The character Phillip Ammon suffers from Brain Fever after Elnora disappears from the swamp in A Girl Of The Limberlost.
 * Happens a lot in Georgette Heyer's period romance novels.
 * Appears in several Sherlock Holmes stories, including "The Copper Beeches," in which a girl's father pesters her about her inheritance until she gets brain-fever; and "The Adventure of the Naval Treaty," in which a man is ill for nine weeks after a treaty is stolen from under his nose. There's also "The Crooked Man", where the dead man's wife is rendered insensible for testimony by the same effect.
 * Dracula had Jonathan Harker suffer from brain fever when Mina finally found him after he somehow escaped the vampire's clutches.
 * In Wuthering Heights, Cathy (the first one) is very ill with brain fever, caused by a confrontation between herself, Edgar, and Heathcliff, during the first two months of her pregnancy. She never entirely regains her health, and dies two hours after the baby is born.
 * When The Count of Monte Cristo opens, Captain Leclere has died of brain fever, leaving Edmond Dantès in command of his vessel.


 * In Maurice, the titular character came "nearer to brain fever than he supposed" due to being worried about the state of his relationship with Clive while they were separated and... being too sentimental in their love letters. They meet up, decide to only write facts in said letters, and he recovers.
 * In the Conan the Barbarian story "A Witch Shall Be Born", Valerius acts feverishly, babbling, thrashing, and giving Ivga a hard time quieting him. While he was wounded, it explicitly says that his mental torment was worse.
 * In Crime and Punishment, Raskolnikov suffers a fever that becomes much worse after he goes through with his plan to commit murder, and Pulcheria Alexandrovna develops brain fever after.
 * In La Dame Aux Camelias, Armand is already ill from grief after Marguerite's death, and develops a full-blown brain fever after seeing her body exhumed. In his case, the doctor declares it a fortunate occurrence: the physical illness will drive out the strong emotion, and prevent Armand from going mad with grief.
 * In Foundations Triumph by David Brin, Brain fever is used by name and common among certain groups.
 * In The Turn of the Screw, Flora becomes seriously ill and delirious after her governess accuses her of conspiring with ghosts.
 * In Eragon, the first book in The Inheritance Cycle, the titular character and his mentor, Brom enter the city of Teirm under the aliases of Evan and Neal. Brom plays the role of the slighty senile uncle and Eragon comments to a guard that he had a bit too much sun and now has a touch of the brain fever. After they are safely inside the city, Brom comments "A touch of brain fever?" and Eragon replies that he couldn't let him have all the fun.

Live Action TV
Believe it or not, this is not a Forgotten Trope in Southeast Asia, where many a Korean Drama or Taiwanese Series has the hero/heroine collapsing due to stress, overwork, or convenience, and ends up being cared for by their significant other, often with comfort food and a cold compress across the eyes.
 * Boys Before Flowers: This happens several times with Jeun Di, especially when she worked multiple jobs.
 * Can You Hear My Heart: Dong Joo frequently would collapse with a fever as a consequence of his fall when he was eight years old. Luckily, Woo Ri was there to nurse him.
 * Devil Beside You: Qi Yue gets to do the cold compress thing on Ahmon's brow.
 * Hana Yori Dango: This happens twice between Tsukushi and Tsukasa, once in an elevator and once in a blizzard.
 * Mars: It gave Qi Luo an excuse to take care of Chen Ling all night long.
 * Personal Taste: Park Gae In gets fevers when she is on her period, leading Jeon Jin Ho to procure painkillers and rub her tummy all night long.
 * Shining Inheritance: Go Eun Song helps an hurt old lady on the street; once her fever is down, it turns out the woman is the CEO of a giant food conglomerate.
 * You Are Beautiful: Hwang Tae Young took care of Go Mi Nam when she developed a fever after getting wet.

Video Games

 * Subverted in Tales of the Abyss, when Luke's mother falls ill after his sudden disappearance. Tear feels terrible, since she was the cause of Luke's vanishing, but Luke tells her that his mother has always been sickly - the stress of his disappearance might have made her worse, but it certainly wasn't the only cause of her illness.

Western Animation

 * In a Pinky and The Brain short, the duo went to live with a group of Amish farmers for some reason, and at one point Brain explains Pinky's antics as the results of "the Brain Fever".
 * In Avatar: The Last Airbender, Zuko spirals into an illness immediately after he frees Appa at the pinnacle last few episodes of the 2nd season, the explanation being that his inner turmoil had caused his body to react in a sickly fashion.

Real Life

 * Just like being cold, stress and mental shock can't make you sick, but they make getting sick much easier.
 * Some drugs, including cocaine, can induce hyperthermia when overdosed. In the 19th century, administering cocaine to patients suffering from emotional stress might actually have induced the febrile state which this trope blames on mental causes alone.
 * You'll find "brain fever" mentioned in most 19th century medical textbooks, so it wasn't "invented by novelists" as Christie's character says above. (Conan Doyle used it frequently, and he was a doctor in Real Life.) Any use before 1930 or so is more likely to be a case of Science Marches On than a sign of ignorance on the part of the author.
 * Shock could also be a reasonable explanation for some of the fictional reports, combined with PTSD and a stress-weakened immune system.