Phantom pain

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Classification according to ICD-10
G54.6 Phantom pain
G.54.7 Phantom limb without pain
ICD-10 online (WHO version 2019)

Under phantom pain means a pain sensation in an amputated limb (even a body part such as the appendix may be affected), which is of a phantom limb is distinguished or phantom sensation is in the still the feeling that the limb is still completely or partially present, and is moving even without this being perceived as pain. Must also be the butt pain is deferred, the just is not a perception of pain in the amputated area, but in the remaining stump, but can occur simultaneously with a phantom pain.

Forms, occurrences, symptoms

Between 50 and 80% of patients with amputations have sensations in areas corresponding to the amputated limb and the majority of these sensations are painful in nature. Phantom sensations can also occur after the removal of parts of the body that are not limbs, for example after a mastectomy, tooth extraction (phantom tooth pain) or after the extirpation of an eye (phantom eye syndrome). The missing limb is often perceived as being shorter and can make it feel like it is in a painful or twisted position. The pain may also be burning or felt as cold or warmth or other discomfort such as tingling, itching, or bruising. Occasionally, the pain can be aggravated by stress , anxiety , weather changes. Phantom pain is usually intermittent . The frequency and severity of the seizures usually decrease over time.

The phenomenon of phantom pain was first described by Ambroise Paré in 1552 . The word phantom limb was first used in 1871 by the American doctor Silas Weir Mitchell , the term phantom pain ("douleur fantôme") was first used in 1894 by the French doctor Jacques-Pierre-Louis-Séverin Abbatucci.

Clinical picture

Although not all phantom limbs are painful, patients sometimes feel as though they are gesticulating, feeling itchy and twitching, or even trying to grab or pick up things. Ramachandran and Blakeslee, for example, describe that in some patients the imagined limbs are no longer what they should be. For example, one patient reported that her phantom arm was about "15 cm too short".

Some people with phantom limbs feel that their missing limb gestures while they talk - but whether they feel the weight of the phantom limb while they are gesticulating is unclear. If one assumes, however, that the hands and arms have their representations in the motor cortex and in the language centers, this finding is not particularly surprising. Some patients describe that their phantom limb behaves as if it is still there and feels that way, while others find that it begins to develop a life of its own and no longer obeys their commands.

“I put a coffee cup in front of John and asked him to reach for it [with his phantom limb]. When he said he was going to put out his arm, I pushed the cup away.
"Ouch!" He shouted. “Don't do that!”
“What's wrong?”
“Don't do that,” he repeated. “I had my fingers around the handle of the mug when you pulled it away. It really hurts! ”
Wait a minute. I wrest a real cup from phantom fingers and the victim screams ouch! The fingers were an illusion, but the pain was real - in fact, it was so severe that I dared not repeat the experiment. "

- Ramachandran, Phantoms in the Brain. P. 43.

Neurological basics

The fact that the representation of the face in the cortical homunculus is next to the representation of the hand and arm is crucial in explaining the causes of the phantom limb and phantom pain.

Until not so long ago, the current theory of the cause of phantom limbs and phantom pain assumed that the severed nerve endings were irritated (so-called “neuromas”). After a limb amputation, the amputated limb remains in the conscious body scheme. If a limb is amputated, many of the severed nerve tracts now end at the remaining stump. These nerve endings can become inflamed and it was believed that they would send abnormal signals to the brain. It was also thought that such functionally nonsensical signals would now be interpreted by the brain as pain.

Therapies based on this theory have consistently failed. In extreme cases, the surgeons even amputated a second time and shortened the stump in the hope of removing the inflamed nerve endings and at least temporarily relieving the patient of the phantom pain. Instead, however, the phantom pain intensified, and many patients now suffered both from the original phantom limb as well as from the newly created phantom stump, which now developed its own pain pattern. In some cases, surgeons even cut the sensory nerve pathways leading to the spinal cord and, in very severe cases, even removed the part of the thalamus that receives the sensory signals from the body.

In the early 1990s, Tim Pons at the National Institutes of Health (NIH) demonstrated that the brain can reorganize itself when sensory input fails. When he heard about these findings, VS Ramachandran began to suspect that phantom sensations could be based on a kind of “cross-wiring” in the somatosensory cortex, which is located in the postcentral gyrus , and which picks up the corresponding signals from the extremities and the rest of the body. Signals from the left half of the body are picked up by the right brain hemisphere and vice versa. The input from the extremities reaches the somatosensory cortex in the normal way and is processed within the representation provided for this in the somatosensory homunculus. The input from the hand is next to the input from the arm, the input from the foot is next to the input from the leg and so on. A strange thing is that the input from the face is next to that from the hand.

Ramachandran now made the following assumption: If someone has lost his right hand in an accident, for example, he may feel a phantom limb because the signal input that normally originates from this hand and is routed into the left somatosensory cortex ceases. The areas of the somatosensory cortex adjacent to the hand (or the arm and face) could now take over this now signalless region (“remap”). Ramachandran et al. Initially demonstrated this “remapping” by showing how even caressing different parts of the face of such patients led to the feeling that different parts of the now missing limb were being touched. With the help of magnetencephalographic (MEG) examinations, through which the brain activity in humans can be made visible, Ramachandran was able to show the reorganization within the somatosensory cortex.

Not all scientists support the thesis that phantom pain is caused by incorrect adjustments in the cortex. Pain researchers such as Tamar Makin (Oxford) and Marshall Devor (Hebrew University, Jerusalem) postulated that phantom pain is mainly caused by faulty stimuli from the peripheral nervous system. In 2013, Marshall Devor in Israel and researchers in Albania carried out experiments in which they were able to reduce or completely eliminate phantom pain by injecting local anesthetics into the spinal canal, more precisely into the liquor space (intrathecally) and into the spinal ganglion . These results supported the theory that phantom pain is primarily caused by the peripheral nervous system in a "bottom-up" process.

Pain etiology

However, it is not entirely clear how the actual pain arises. It is most likely that there will now be conflict situations between the old and the new pattern within the reorganized cortical representation of the affected limb, be it that search signals emanate from the old pattern that remain sensory and proprioceptive without an answer, so that the cortical representation of the amputated limb in an attempt to compensate for this amplifies the intensity of its signals, which then eventually leads to pain sensations. The psychologist Ronald Melzack put forward this theory based on the conception of a cortical neuromatrix and neurosignature, which is quite similar to Ramachandran's theory, which assumes a remapping conflict that is still unclear in the details as the cause of pain. The resolution of this conflict then also removes the pain.

treatment

Some treatments use drugs such as B. Antidepressants are used. The spinal cord stimulation may be effective in phantom pain. The spinal cord is electrically stimulated by electrodes placed close to the spinal cord, so that the nerve impulses sent to the brain are superimposed or prevented. Depending on whether the low-frequency or high-frequency spinal cord stimulation is used, the amputee feels tingling in the phantom limb instead of the pain or the pain disappears.

Analgesia by spinal cord stimulation , physiotherapy , acupuncture , hypnosis and biofeedback can also be used in the treatment of phantom pain, but are often of little use. Pain can also be combated by the patient's distraction and preoccupation with or focusing on other things. A stump massage occasionally brings relief.

In operations that can be planned, the subsequent occurrence of phantom pain can be favorably influenced by suitable preoperative pain management. This is done through effective pain control through analgesics and neuroleptics . The brain seems to implement the preoperative sensory patterns here.

A newer treatment for phantom pain is mirror therapy . It was developed by Ramachandran and others. With the help of artificial visual feedback, the patient can "move" the phantom limb and thus release it from the imagined painful position. In some patients, such repeated training has led to long-term improvement, and in a very unusual case even to a complete elimination of the phantom sensation extending between the hand and shoulder (so that the phantom hand finally “hung” directly from the shoulder).

In the meantime, virtual reality technology is also being used to address the discomfort associated with phantom limb syndrome. Researchers at the University of Manchester have shown that phantom pain can be relieved by connecting the person's real limb to an interface through which they can watch two limbs move in a computer-generated simulation. This works on a similar basis as mirror therapy in that the somatosensory cortex is also “tricked” here, except that the illusion is stronger here.

See also

literature

  • PW Halligan, A. Berger: Phantoms in brain. In: Brit. med. J. 319, (1999), pp. 587-588.
  • PW Halligan: Phantom limbs: The body in mind. In: Cogn. Neuropsychiatry. 7 (3), (2002), pp. 251-268.
  • J. Halbert, M. Crotty, ID Cameron: Evidence of the optimal management of acute and chronic phantom pain: a systematic review. In: Clin. J. Pain. 18 (2), (2002), pp. 84-92, PMID 11882771 .
  • R. Melzack: Phantom limbs. In: Sci. Amer. Apr 1992, pp. 120-126.
  • SW Mitchell: Phantom limbs. In: Lippincott's Mag Popular Literature & Science. 8 (1871), pp. 563-569.
  • TP Pons, PE Garraghty, AK Ommaya et al .: Massive cortical reorganization after sensory deafferentation in adult macaques. In: Science. 252 (5014), (1991), pp. 1857-1860.
  • VS Ramachandran, DC Rogers-Ramachandran, M. Stewart: Perceptual correlates of massive cortical reorganization. In: Science. 258 (5085), (1992), pp. 1159-1160. ( online PDF; 513 kB)
  • VS Rachamandran: Behavioral and magnetoencephalographic correlates of plasticity in the adult human brain. In: Proc. natl. Acad. Sci. 90 (1993), pp. 10413-10420. ( online PDF; 2.2 MB)
  • VS Rachamandran, DC Rogers-Rachamandran, S. Cobb: Touching the phantom. In: Nature. 377: 489-490 (1995).
  • VS Rachamandran, DC Rogers-Rachamandran: Synaesthesia in phantom limbs induced with mirrors. In: Proc. roy. Soc. Lond. 263 (1369), (1996), pp. 377-386. (on-line)
  • VS Rachamandran, S. Blakeslee: Phantoms in the Brain. Probing the Mysteries of the Human Mind. William Morrow & Co, 1998, ISBN 0-688-15247-3 .
  • VS Rachamandran, W. Hirstein: The perception of phantom limbs: The DO Hebb lecture. In: Brain. 9 (121), (1998), pp. 1603-1630. ( online PDF; 6.3 MB)
  • ES Saadah, R. Melzack: Phantom limb experiences in congenital limb-deficient adults. In: Cortex. 30 (3), (1994), pp. 479-485.
  • Sherman RA, Sherman CJ, Parker L.: Chronic phantom and stump pain among American veterans: results of surgery. In: Pain. 18, (1984), pp. 83-95.
  • TT Yang, CC Gallen, VS Rachamandran et al: Noninvasive detection of cerebral plasticity in adult human somatosensory cortex. In: Neuroreport. 5 (6), (1994), pp. 701-704.

Web links

Wiktionary: Phantom pain  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ L. Nikolajsen, TS Jensen: Phantom limb. In: SB McMahon, Patrick D. Wall (Eds.): Wall & Melzack's Textbook of Pain. 5th edition. Elsevier, 2006, p. 961ff.
  2. ↑ Ambroise Paré, La maniere de traicter les playes faictes tant par hacquebutes que par fleches: et les accidentz d'icelles, comme fractures et caries des os, gangrene et mortification: auec les pourtraictz des instrumentz necessaires pour leur curation. Et la methode de curer les combustions principalement faictes pa la pouldre à canon, Paris 1552. See G. Keil, So-called first description of phantom pain by Ambroise Paré, in: progress of medicine 108 (1990), h. 4, 62-66.
  3. ↑ Zürcher, Urs, “When it hurts where there's nothing left. Aspects of a body history of phantom pain «, in: Historische Anthropologie 13 (2005), issue 1, pp. 61–90.
  4. ^ Walter Siegenthaler : Clinical Pathophysiology. Georg Thieme Verlag, Stuttgart 1970, chap. Pain and pain disorders. Phantom Pain, p. 899.
  5. ↑ Epoch Times website, July 16,2014
  6. ↑ Peripheral nervous system origin of phantom limb pain, Pain, Vol. 155, Issue 7, pages 1384-1391 [1]
  7. ↑ 3D system 'moves' phantom limbs BBC News, November 14, 2006, accessed January 22, 2008.