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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: "2026-10-30"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 27–33 → 26–3211 unchanged lines not shown
}}`````` **Head transplantation** is the proposed surgical transfer of a living head onto a body from a different individual, so that the recipient's brain is supplied by a new circulatory and musculoskeletal system. The procedure is more accurately called a body transplant, since the person who would survive is the one attached to the head. No human attempt has been made. The obstacle that makes it implausible is not surgical technique but the fact that a completely severed spinal cord cannot be repaired, and every proposal for performing the operation depends on solving that problem first.**Head transplantation** is the proposed surgical transfer of a living head onto a body from a different individual, so that the recipient's brain is supplied by a new circulatory and musculoskeletal system. The procedure is more accurately called a body transplant, since the person who would survive is the one attached to the head. No human attempt has been made. What makes it implausible is the spinal cord rather than surgical technique: a completely severed cord cannot be repaired, and every proposal for performing the operation depends on solving that problem first. ## Animal precedents## Animal precedents lines 35–49 → 34–481 unchanged line not shown
In the 1950s Vladimir Demikhov, a Soviet surgeon who did foundational work on cardiac and pulmonary transplantation, created dogs bearing a second head and forelimbs grafted onto the neck of an adult host. The grafted heads were conscious and could lap fluid. The animals survived days, dying of rejection.In the 1950s Vladimir Demikhov, a Soviet surgeon who did foundational work on cardiac and pulmonary transplantation, created dogs bearing a second head and forelimbs grafted onto the neck of an adult host. The grafted heads were conscious and could lap fluid. The animals survived days, dying of rejection. Robert White, a neurosurgeon at Case Western Reserve University, performed the most technically advanced version in 1970, transferring the head of one rhesus monkey onto the body of another with vascular anastomosis and hypothermic protection. The transplanted head regained consciousness, tracked with its eyes, and responded to stimuli; the animals survived for periods reported as hours to a few days before succumbing to rejection or complications.[^white1971] Crucially, White made no attempt to join the spinal cords. The animals were quadriplegic and ventilated, and White himself described the result as a demonstration that the brain could be maintained on a foreign circulation, not as a functional transplant.Robert White, a neurosurgeon at Case Western Reserve University, performed the most technically advanced version in 1970, transferring the head of one rhesus monkey onto the body of another with vascular anastomosis and hypothermic protection. The transplanted head regained consciousness, tracked with its eyes, and responded to stimuli; the animals survived for periods reported as hours to a few days before succumbing to rejection or complications.[^white1971] White made no attempt to join the spinal cords. The animals were quadriplegic and ventilated, and White himself described the result as a demonstration that the brain could be maintained on a foreign circulation, not as a functional transplant. ## The modern proposal## The modern proposal 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 [[face-and-hand-transplantation|partial face transplant]] that included an entire eye. The globe survived with perfused retina, which was itself a first.[^ceradini2024] The surgeons joined the donor optic nerve to the recipient's, and the retina still responded to light, but at one year the patient had no light perception in the transplanted eye.[^ceradini2024] The optic nerve is a central tract, and joining it did not restore sight even though it was a single nerve, handled 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|cortical visual prosthesis]] attempts and why the devices in [[retinal-implant]] exist. ## Other barriers## Other barriers lines 70–80 → 69–799 unchanged lines not shown
Even granting technical success, the procedure raises questions the surgical literature does not usually face. The resulting person would carry another individual's genome in every cell below the neck, including the gametes, so any children conceived would be genetically the donor's. Legal identity, in most systems, would follow the head, but no statute anywhere addresses the case. The psychological consequences of waking in an unfamiliar body are unknown; limb transplant recipients have occasionally requested removal of a functioning graft, and a whole body is not comparable.Even granting technical success, the procedure raises questions the surgical literature does not usually face. The resulting person would carry another individual's genome in every cell below the neck, including the gametes, so any children conceived would be genetically the donor's. Legal identity, in most systems, would follow the head, but no statute anywhere addresses the case. The psychological consequences of waking in an unfamiliar body are unknown; limb transplant recipients have occasionally requested removal of a functioning graft, and a whole body is not comparable. The philosophical question is thinner than it looks. Almost every theory of personal identity locates the person with the brain, so a head transplant is a body transplant and the identity puzzle is mild compared with the cases discussed in [[personal-identity-and-continuity]] and [[teleportation-problem]]. The serious ethical objection is not metaphysical but clinical: performing an irreversible operation whose central step has never worked in any animal, on a patient who is typically disabled rather than dying, and whose realistic outcome is death or a state worse than the one they began in. Appeals to [[morphological-freedom]] do not settle this, since a right to modify one's own body is generally held to presuppose that the modification is technically possible and the consent adequately informed.The philosophical question is thinner than it looks. Almost every theory of personal identity locates the person with the brain, so a head transplant is a body transplant and the identity puzzle is mild compared with the cases discussed in [[personal-identity-and-continuity]] and [[teleportation-problem]]. The serious ethical objection is clinical rather than metaphysical: performing an irreversible operation whose central step has never worked in any animal, on a patient who is typically disabled rather than dying, and whose realistic outcome is death or a state worse than the one they began in. Appeals to [[morphological-freedom]] do not settle this, since a right to modify one's own body is generally held to presuppose that the modification is technically possible and the consent adequately informed. ## 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, rather than 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.
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