Daniel Sánchez-Tejerina San José

Especialista en Neurología. Aquí, opiniones personales pero también clínica e investigación en enfermedades neuromusculares H.U. Vall d’Hebron y VHIR.

[Pablo García Casado @pgcasado]

El fútbol, los padres, el paso del tiempo. Otra maravilla de @eballester https://t.co/1nrXeJlXOs

[Elias @iam_elias1]

ChatGPT diagnosed 40 million people with a disease that was invented as a joke.

Not a real disease. Not a misunderstood disease. A completely fictional condition with a fake name, fake papers, and fake statistics.

And it told patients to see a specialist.

The disease is called Bixonimania. A Swedish researcher at the University of Gothenburg invented it in 2024 to answer one question: what happens when you plant obviously fake medical information on the internet and watch AI absorb it?

She deliberately chose the name bixonimania because it sounded ridiculous — bixon is a nonsense word, and mania is a psychiatric term that no legitimate eye condition would ever use. She uploaded two papers to a preprint server. Both were obviously fraudulent. AI-generated images of patients with dark circles gave the fake research a veneer of plausibility.

Then she waited.

She did not have to wait long.

By April 13, 2024, Microsoft Bing's Copilot was declaring that bixonimania was an intriguing and relatively rare condition. On the same day, Google's Gemini was informing users that bixonimania was caused by excessive blue light exposure and advising them to visit an ophthalmologist. Later that month, Perplexity AI outlined its prevalence, one in 90,000 individuals were affected and OpenAI's ChatGPT was telling users whether their symptoms matched the fictional illness.

One in 90,000. A precise statistic. For a disease that does not exist.

Every red flag was visible. The name was absurd. The papers were crude. The condition made no scientific sense. None of the AI systems flagged any of it.

They read the fake papers. They absorbed the fake statistics. They presented both to patients with clinical authority and zero hesitation.

Then it got worse.

Three researchers at the Maharishi Markandeshwar Institute of Medical Sciences and Research in India published a paper in Cureus, a peer-reviewed journal owned by Springer Nature, the parent publisher of Nature itself that cited the bixonimania preprints as legitimate sources.

A real peer-reviewed paper. In a Springer Nature journal. Citing a fictional disease as established medical fact. Passing editorial review. Entering the permanent scientific record.

It was only retracted after the hoax became public.

Nature published a full investigation of the experiment. Alex Ruani, a health-misinformation researcher at University College London, called it a masterclass in how misinformation operates.

Here is the scale of what this means.

More than 40 million people turn to ChatGPT every day for health information, according to OpenAI's own analysis. ECRI, a US patient-safety nonprofit has named chatbot misuse the number-one health technology hazard of 2026. ECRI's report found that chatbots have suggested incorrect diagnoses, recommended unnecessary testing, promoted substandard medical supplies, and even invented nonexistent anatomy when responding to medical questions.

Number one. Out of every health technology hazard that exists in 2026.

An April 2026 study published in BMJ Open found that nearly half of the answers provided by leading AI chatbots to common health questions contain misleading or problematic information.

Nearly half. Of all health answers. From the tools 40 million people use every day.

Here is the line from the researcher that cuts through everything.

The Bixonimania case is striking precisely because it was engineered to be so obviously fake. The real question it raises is: what is passing through the same systems that is not nearly so easy to spot?

The experiment used a ridiculous name. Fraudulent papers. Visible red flags at every level.

It was designed to be caught.

It was not caught.

The AI that told patients about Bixonimania is the same AI they asked about their chest pain, their medication, their child's symptoms, and their cancer screening schedule.

40 million people. Every day.

And nobody is telling them that nearly half of what comes back may be wrong.

Source: Osmanovic Thunström · University of Gothenburg · Nature · April 2026 ·

Link in the (comments)

[Ruben Hume @rubenhume]

Amazonia has a new logo, and it’s a masterpiece. The letters were extracted from satellite images of the river itself

[Julio Rodríguez, PhD | Genética Clínica @bitacorabeagle]

El @NEJM ha publicado un glosario ilustrado de términos médicos y biológicos, de acceso gratuito, con imágenes chulísimas y muy explicativas para utilizar en presentaciones, artículos o RRSS
https://t.co/8OlvNjjDrF

[RTVE @rtve]

Frente a los derechos humanos, el silencio no es una opción. Paz y justicia para Palestina.

https://t.co/puZwqrZD76

[IFCN and its Clinical Neurophysiology journals @ClinicalNeuroph]

[CANVAS: Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome] Berciano et al.: "CANVAS seems to be a unique syndrome with selective sparing of Ia fibers sub-serving spindle afferents, with greater vulnerability of dorsal root ganglion (DRG) neurons innervating the skin rather than muscle-afferents DRG neurons." https://t.co/26Elrh5Sng

[Neurology Today @NeurologyToday]

Inebilizumab improves myasthenia gravis severity and reduces steroid dependency. Phase 3 trial shows significant improvement, with response magnitude increasing over time. Read more online! #AANAM25 @YaleMed @AANMember

https://t.co/uKVEUTyRvG

[Leandro Carranza @leocarranza99]

Cuando te pregunten por qué Stephen Curry es el mejor tirador de todos los tiempos, mostrales esta foto de Ezra Shaw y contales que ese lanzamiento entró.

[Rafael Bravo @rafabravo]

Corticoides: La reducción progresiva es innecesaria cuando la duración del tratamiento ha sido <3-4 semanas, independientemente de la dosis.
https://t.co/vn0Fz5kIC5

[Alberto Edjogo-Owono @albertoowono]

7 partidos
7 victorias
Equipo más goleador
Eliminando a las 3 favoritas (Alemania, Francia e Inglaterra)
Alegría y fútbol ofensivo
Goles decisivos de la unidad B
Más merecido, imposible.
España 🇪🇸 levanta la cuarta.

Titanes

[Teledeporte @teledeporte]

😢 EL FÚTBOL ES LA H*****

Mikel Merino ha marcado el gol de la locura española y ha tenido el detalle de celebrarlo igual que el tanto que anotó su padre hace 33 años en el mismo estadio

𝙇𝙊𝙎 𝙈𝙀𝙍𝙄𝙉𝙊 𝙃𝘼𝙉 𝘾𝙊𝙉𝙌𝙐𝙄𝙎𝙏𝘼𝘿𝙊 𝙎𝙏𝙐𝙏𝙏𝙂𝘼𝙍𝙏

#EuroRTVE #EURO2024 https://t.co/NvRQggzzd2

[K. Creek @sgrstk]

A fact is information minus emotion. An opinion is information plus experience. Ignorance is an opinion lacking information. And, stupidity is an opinion that ignores a fact.

[Julen Berrueta @idazten]

Ha muerto Bernard Hill a los 79 años. Protagonizó una de las escenas más icónicas de quienes vivimos obsesionados con El Señor de los Anillos.

«Cabalgad hasta la desolación y el fin del mundo»

[Pedro Torrijos @Pedro_Torrijos]

¿Sabíais que en Madrid hubo una piscina en una isla EN MEDIO DEL MANZANARES?
Se llegaba por un puentecito y la piscina tenía playa, zonas deportivas y un precioso edificio racionalista.

Pero solo duró 20 años.

En #LaBrasaTorrijos del 2 de mayo, "La Isla".
🧵⤵️

[ؘ @archivemileyc]

any Miley Cyrus cover is better than the original song

— a Thread ✨

[Sem Signals @semsignals]

Yo me bajo en Atocha.

[literland @literlandweb1]

“– ¿Por qué si uno sabe nadar flota sin moverse y cuando no sabe se hunde?
– El miedo pesa, hijo”.
"La partida", Miguel Delibes

[literland @literlandweb1]

Marcel Proust decía que cuando uno extraña un lugar lo que realmente añora es la época que corresponde a ese lugar; no se extraña un sitio, sino un momento.

[Neurologia H12O @Neurodoce]

Hoy hemos celebrado el 50 aniversario de nuestro Servicio de Neurología.
Un gran día para recordar a los que están y a los que faltan. Todos ellos partícipes de un proyecto que mantiene su impulso como el primer día.
Gracias!😍

[Nacho Carretero @NachoCarretero]

Israel no es Israel. La israelí es una sociedad compleja. Contiene ciudadanos contrarios a la ocupación de territorios, sobre todo entre la izquierda laica abundante en ciudades como Tel Aviv o Haifa, que defiende la solución de dos Estados y piden el fin del bloqueo a Gaza.