Loading
What changed between revision 1 and revision 2, compared over the article's markdown source with its frontmatter — so a change to status, evidence or reversibility shows up as the edit it is.
Older · revision 1
Import· initial corpus import, not an edit
Initial import of content/head-transplant.md — the filesystem corpus, unchanged. Not an edit.
12.7 kB
Revision 1
Revision 2
lines 7–15 → 7–146 unchanged lines not shown
categories: ["bodies"]categories: ["bodies"]tags: ["transplantation", "spinal cord", "neurosurgery", "medical ethics", "identity", "fringe science"]tags: ["transplantation", "spinal cord", "neurosurgery", "medical ethics", "identity", "fringe science"]summary: "The proposed transfer of a living human head onto a donor body, blocked chiefly by the inability to reconnect a severed spinal cord and rejected by mainstream neurosurgery."summary: "The proposed transfer of a living human head onto a donor body, blocked chiefly by the inability to reconnect a severed spinal cord and rejected by mainstream neurosurgery."updated: "2026-07-27"updated: "2026-08-23"humanEvidence: "No human attempt has been made; living-subject work stops at Demikhov's 1950s dogs and White's 1970 rhesus monkeys, whose cords were never joined, and the 2017 human procedure was a rehearsal on two cadavers."humanEvidence: "No human attempt has been made; living-subject work stops at Demikhov's 1950s dogs and White's 1970 rhesus monkeys, whose cords were never joined, and the 2017 human procedure was a rehearsal on two cadavers."issues: ["The spinal-cord-injury population figure in the closing section is unsourced.", "The 2023 whole-eye transplant at NYU Langone needs a source."]------ ```infobox```infoboxlines 41–49 → 40–4825 unchanged lines not shown
In 2013 the Italian neurosurgeon Sergio Canavero published an outline for a human procedure, which he called HEAVEN, with an associated protocol for spinal cord fusion he called GEMINI.[^canavero2013] Its elements were a very sharp blade to sever the cord with minimal crush injury, deep hypothermia to extend the brain's tolerance of interrupted perfusion, immediate application of polyethylene glycol as a fusogen to promote membrane fusion between cut axons, and a period of spinal cord stimulation and immobilisation during recovery.In 2013 the Italian neurosurgeon Sergio Canavero published an outline for a human procedure, which he called HEAVEN, with an associated protocol for spinal cord fusion he called GEMINI.[^canavero2013] Its elements were a very sharp blade to sever the cord with minimal crush injury, deep hypothermia to extend the brain's tolerance of interrupted perfusion, immediate application of polyethylene glycol as a fusogen to promote membrane fusion between cut axons, and a period of spinal cord stimulation and immobilisation during recovery. Canavero announced a Russian volunteer with spinal muscular atrophy, who later withdrew. He collaborated with Xiaoping Ren at Harbin Medical University, and in 2017 the pair announced what press coverage described as the first human head transplant. It was a rehearsal on two cadavers: the vessels, cord and tissues of two deceased donors were joined over many hours. Nothing was restored to life, and no functional claim could be tested. Reports of recovery after cord transection and polyethylene glycol treatment in rodents have come almost entirely from the same collaboration and have not been independently replicated.Canavero announced a Russian volunteer with spinal muscular atrophy, who later withdrew. He collaborated with Xiaoping Ren at Harbin Medical University, and in November 2017 Canavero announced at a press conference in Vienna what press coverage described as the first human head transplant.[^brodwin2017] It was a rehearsal on two cadavers: the vessels, cord and tissues of two deceased donors were joined over a procedure Canavero said lasted eighteen hours. Nothing was restored to life, and no functional claim could be tested. Reports of recovery after cord transection and polyethylene glycol treatment in rodents have come almost entirely from the same collaboration and have not been independently replicated. No head transplant has ever been performed on a living human being. The reaction from neuroscience and neurosurgery was uniformly negative. The bioethicist Arthur Caplan described the programme as unsupported by science; leaders of professional neurosurgical bodies stated they would not wish the outcome on any patient; spinal cord researchers, including some who had worked with White, characterised the fusion claims as unfounded. In 2024 a promotional concept video for a robotic head-transplant system circulated widely under the name BrainBridge; it was an animation produced outside any research institution and presented no experimental work at all.The reaction from neuroscience and neurosurgery was uniformly negative. The bioethicist Arthur Caplan described the programme as unsupported by science; neurosurgeons interviewed at the time said the spinal-fusion claims were not credible and that the science had not been done.[^brodwin2017] In 2024 a promotional concept video for a robotic head-transplant system circulated widely under the name BrainBridge; *MIT Technology Review* reported that it was an animation made by a science communicator, that no company of that name was incorporated anywhere, and that it presented no experimental work at all.[^regalado2024] > [!caution] What was reported and what was done> [!caution] What was reported and what was done> The 2017 announcement is a case study in how a procedural rehearsal becomes a claimed achievement. Joining tissues between two cadavers demonstrates that the anatomy can be dissected and sutured. It says nothing about circulation, consciousness, immune tolerance or neurological function, which are the entire content of the proposal.> The 2017 announcement is a case study in how a procedural rehearsal becomes a claimed achievement. Joining tissues between two cadavers demonstrates that the anatomy can be dissected and sutured. It says nothing about circulation, consciousness, immune tolerance or neurological function, which are the entire content of the proposal.lines 54–60 → 53–594 unchanged lines not shown
Restoring function would require far more than membrane fusion. Millions of axons would have to reconnect, each to a target of the appropriate class, in a topographically correct arrangement, and the resulting circuit would have to be usable by a brain whose motor map was built for a different body. Polyethylene glycol can fuse the membranes of adjacent cut axons in laboratory preparations; it does not perform routing.Restoring function would require far more than membrane fusion. Millions of axons would have to reconnect, each to a target of the appropriate class, in a topographically correct arrangement, and the resulting circuit would have to be usable by a brain whose motor map was built for a different body. Polyethylene glycol can fuse the membranes of adjacent cut axons in laboratory preparations; it does not perform routing. The scale of the difficulty was underlined by a 2023 transplant at NYU Langone in which a patient received a partial face transplant that included an entire eye. The globe survived with perfused retina, which was itself a first. Vision was not restored, because the optic nerve is a central tract and could not be reconnected — a single nerve, under ideal circumstances, with the world's attention on it. Restoring sight after optic nerve loss currently requires bypassing the nerve altogether, which is what a cortical visual prosthesis attempts and why the devices in [[retinal-implant]] exist.The scale of the difficulty was underlined by a 2023 transplant at NYU Langone in which a patient received a partial face transplant that included an entire eye. The globe survived with perfused retina, which was itself a first.[^ceradini2024] Vision was not restored, because the optic nerve is a central tract and could not be reconnected — a single nerve, under ideal circumstances, with the world's attention on it. Restoring sight after optic nerve loss currently requires bypassing the nerve altogether, which is what a cortical visual prosthesis attempts and why the devices in [[retinal-implant]] exist. ## Other barriers## Other barriers lines 74–80 → 73–7913 unchanged lines not shown
## Where the idea stands## Where the idea stands Head transplantation occupies a peculiar position: it is not disproved, merely dependent on a prerequisite that nobody can supply. If complete spinal cord transection became repairable, the achievement would transform the treatment of the hundreds of thousands of people living with spinal cord injury, and that population — not head transplant candidates — is where such a technique would be used first and where its success would be measured.Head transplantation occupies a peculiar position: it is not disproved, merely dependent on a prerequisite that nobody can supply. If complete spinal cord transection became repairable, the achievement would transform the treatment of the more than 15 million people estimated to be living with spinal cord injury worldwide,[^who2024] and that population — not head transplant candidates — is where such a technique would be used first and where its success would be measured. The motivations offered for the procedure are better served by other approaches. Spinal muscular atrophy, the condition of the volunteer who was announced and then withdrew, now has approved gene therapies of the kind described in [[somatic-gene-therapy]], which arrived within a few years of the head transplant proposal and changed the prognosis for the disease it was meant to address. For other degenerative conditions the realistic paths remain gene and cell therapy and assistive technology, including [[brain-computer-interface]] control of external devices and [[exoskeleton|powered exoskeletons]]. For the ambition of escaping a failing body altogether, the relevant articles are [[cryonics]], [[whole-brain-emulation]], [[mind-uploading]] and [[neuroprosthetics]], each of which faces its own unsolved problems but none of which requires reconnecting a spinal cord this year.The motivations offered for the procedure are better served by other approaches. Spinal muscular atrophy, the condition of the volunteer who was announced and then withdrew, now has approved gene therapies of the kind described in [[somatic-gene-therapy]], which arrived within a few years of the head transplant proposal and changed the prognosis for the disease it was meant to address. For other degenerative conditions the realistic paths remain gene and cell therapy and assistive technology, including [[brain-computer-interface]] control of external devices and [[exoskeleton|powered exoskeletons]]. For the ambition of escaping a failing body altogether, the relevant articles are [[cryonics]], [[whole-brain-emulation]], [[mind-uploading]] and [[neuroprosthetics]], each of which faces its own unsolved problems but none of which requires reconnecting a spinal cord this year. lines 94–97 → 93–10013 unchanged lines not shown
[^white1971]: `paper` White, R. J. et al. "Cephalic exchange transplantation in the monkey." *Surgery*, 1971. {The spinal cords were never joined, so the animals were quadriplegic and ventilated, and survival was hours to a few days.}[^white1971]: `paper` White, R. J. et al. "Cephalic exchange transplantation in the monkey." *Surgery*, 1971. {The spinal cords were never joined, so the animals were quadriplegic and ventilated, and survival was hours to a few days.}[^canavero2013]: `paper` Canavero, S. "HEAVEN: The head anastomosis venture Project outline for the first human head transplantation with spinal linkage (GEMINI)." *Surgical Neurology International*, 2013. {A protocol proposal rather than a report of experiments; it presents no new data of its own.}[^canavero2013]: `paper` Canavero, S. "HEAVEN: The head anastomosis venture Project outline for the first human head transplantation with spinal linkage (GEMINI)." *Surgical Neurology International*, 2013. {A protocol proposal rather than a report of experiments; it presents no new data of its own.}[^silver2004]: `paper` Silver, J. and Miller, J. H. "Regeneration beyond the glial scar." *Nature Reviews Neuroscience*, 2004.[^silver2004]: `paper` Silver, J. and Miller, J. H. "Regeneration beyond the glial scar." *Nature Reviews Neuroscience*, 2004.[^brodwin2017]: `news` Brodwin, E. "Surgeon claims he's completed the first human head transplant." *Business Insider* (republished by ScienceAlert), 18 November 2017. {Reports the Vienna announcement of the cadaver rehearsal and the assessments of neurosurgeons who found the spinal-fusion claims not credible; no supporting documentation accompanied the claim.}[^regalado2024]: `news` Regalado, A. "That viral video showing a head transplant is a fake. But it might be real someday." *MIT Technology Review*, 23 May 2024. {Reports that the BrainBridge video was an animation by the science communicator Hashem Al-Ghaili and that no company of that name was incorporated.}[^ceradini2024]: `paper` Ceradini, D. J. et al. "Combined Whole Eye and Face Transplant: Microsurgical Strategy and 1-Year Clinical Course." *JAMA*, 2024. {The one-year report of a single case: the transplanted globe remained perfused with photoreceptor responses on electroretinography, and no vision was restored.}[^who2024]: `report` World Health Organization. "Spinal cord injury." Fact sheet, 2024. {Estimates 15.4 million people living with spinal cord injury globally as of 2021.} removed, struck through added, underlinedLine numbers count the serialised markdown of each revision, frontmatter included.
91 lines are the same in both revisions, and 61 of them are not shown. Neither revision here is necessarily the current article — read Head transplantation for the text this wiki stands behind today.