Phantom Limb Syndromes
Introduction
Most people who have had amputation would have experienced a phantom limb; it is a sensation that the limb is actually present, and in some cases there is a feeling of pain. There is a lot of empirical evidence to suggest changes in cortical topography following amputation. “With the advent of non-invasive imaging techniques such as MEG (magneto encephalogram) and functional MRI, topographical reorganization can also be demonstrated in humans, so that it is now possible to track perceptual changes and changes in cortical topography, in individual patients.”
A feature of the human brain is the multiplicity of specialized areas, which can be organized into distinctive maps. This, along with other theories, gives credence to the fact that once neural connections have been laid down in foetal life, no new connections can be made. However, experiences in previous decades in regards to amputations have highlighted the need to revisit this theory. This phrase was first introduced by Silas Weir Mitchell, who also provided for the first time a clear clinical description. This syndrome has been known since antiquity, and consequently, there are associated folklores. Since the first description by Mitchell, there has been a lot of curiosity surrounding the disease, but very little experiments were done to find out more.
Phenomenology of Phantom Limb
clinical findings. It is experienced by almost 90 to 98% of people immediately after the loss of a limb. It is likely that the incidence may be higher after traumatic injury or in case of pre-existing painful condition. It is relatively less prevalent in childhood because the body hadn’t got time to consolidate. Such sensations begin soon afterwards – as soon as the anesthetic wears off, and the patient is conscious – but it may be delayed by a few weeks in some patients. In most of the cases, Phantoms, is present initially for a few days or even weeks, before gradually fading away. In a small percentage of patients, such phantoms persist for years to decades. Some patients are able to recall the phantoms at will even after their disappearance. Though they have been mostly reported after amputation of limbs, there have been cases in contexts of breast and parts of face, or even internal viscera. It has been reported that the phantom often presents a “habitual posture”, a posture they have been used to. When it fades from conscious, it usually fades completely. However, in about 50% of cases, particularly of upper arms, it fades gradually until just the sensation of palm is left. It has been suggested that this phenomenon of telescoping occurs because the representation of the map in the somatosensory maps changes gradually. However, this fails to occur, whenever there exists a preexisting peripheral nerve lesion of that limb. Quite interestingly, such Phantoms have been reported in individual with congenitally missing limbs. In such cases, patients experiences very vivid Phantoms that gesticulated during conversation.
Typical symptoms include sensation of; (a) shooting, stabbing, piercing, or burning pain; (b) pleasure; (c) an article of clothing or jewelry; (d) the limb still being attached and functionally normal; and (e) numbness, tickling or cramping. The diagnosis is made on clinical history as there is no diagnostic treatment.
factors enhancing phantoms. They are usually more vivid and last longer after traumatic limb loss or after amputation as a result of pre-existing painful limb lesion. Such phantoms are less when the amputation is a result of a planned surgery. This could be because of greater attention paid to the mutilated or painful limb before the surgery. Such Phantoms are also pronounced when the patient is suffering from stump pathology such as, scarring and neuromas. This influences both the vividness and the duration of the sensation. Also, it has been reported the sensations have been revived following application of mechanical or electrical stimulation. Further, it has been observed that activities such as rest and distraction can help alleviate the severity of pain. It is very common observation that “voluntary movement, intense concentration, and contraction of stump muscles can enhance the Phantom experience. On the other hand, emotional shock can aggravate it.
Other general risk factors include, preamputation pain, a blood clot in the stub, preamputation infection, previous damage to the spinal cord or perhpheral nerves that supplied the affected limb, and type of anesthesia used during the amputation.
movement of phantom and emergence of repressed memories. A lot of patients have claimed that they have been able to generate movement of Phantom voluntarily. Examples of such movements include reaching out to grab something, making a fist, and moving the fingers individually. Completely voluntary movements have also been reported.
Another interesting aspect of the Phantoms is the reemergence of long-lost memories. There have been examples where people have reported the sensation of clenching spam of the phantom hand with the sensation of nails digging in. It usually takes several minutes to hours voluntarily unclench the phantom. The one possible reason is that “when motor commands are sent from the premotor and motor cortex to clench the hand, they are normally damped by error feedback from proprioception. If a limb is missing, however, such damping is not possible.”
Experimental Findings
plasticity in the somatosensory system. There have been some early reports implicating the changing cortical and thalamic representation following amputations. Further experiments confirmed that such changes occurred due to unmasking of ordinary silent synapses. It is a known fact that the complete somatotopic map exists in the cortex of the primates. In an experiment in which a finger of the monkey was amputated, it was reported that the corresponding to that digit started responding when the adjacent finger was stimulated. The use of magnetoencephalogram (MEG) has made it possible for fine localization of several centimeters.
Treatment Modalities
According to , treatment of phantom pain in the limbs is rather difficult. It is usually determined on the basis of the level of pain. Treatments may be combined based on patients’ level of pain. Possible options with regards to treatment include (a) heat application; (b) biofeedback in order to reduce muscle tension; (c) relaxation techniques; (d) massage of the amputated area; (e) surgical removal of the scar tissue entangling a nerve; (f) physical therapy; (g) TENS (transcutaneous electrical nerve stimulation) of the stump; (h) Neurostimulation techniques for example stimulation of the spinal cord or of the deep brain; and (i) medications such as pain-relieves, neuroleptics, anticonvulsants, anti-depressants, beta-blockers, and sodium channel blockers.
Anosognosia
Introduction
According to , patients of such neurological disorders are “partially or completely unaware of the deficits caused by their disease.” It is a very common neurodegenerative disease, and is particularly common in frontotemporal dementia. It has significant impact on quality and function parameters of patients with neurodegenerative diseases and their caregivers. There has been relative lack of formal studies in non-Alzheimer’s related dementias. Also, there have been a few studies that have tried to systematically identify the role of specific cognitive impairment in the pathogenesis of anosognosia. Consequently, the underlying mechanism is poorly understood. Factors playing important role include episodic memory. Although frontal lobe systems are critical for self-awareness, the most relevant frontal lobe functions are yet to be identified. “Motivation required to engage in self-monitoring and emotional activation making errors as significant are often-overlooked aspects of performance monitoring that may underlie anosognosia in some patients.”
Clinical presentation
Anosognosia can be described as reducedion of awareness of the deficits, as well as signs and symptoms of an illness. It is not just denial but a neurological deficit. It is commonly seen along with psychotic diseases such as schizophrenia, and is “also seen in those who have suffered from right brain hemisphere lesions due to stroke, dementia, and traumatic brain injury. In some studies, it has been found that people with schizophrenia also suffer from brain hemispheric asymmetry in the anterioinferior temporal lobe and it is this asymmetry correlates to this lack of awareness.”
An important aspect to remember is that anosognosia is a neurological disorder and is beyond patient’s control. It is characterized by following signs and symptoms:
- A severe and persistent absence of insight
- Erroneous beliefs, such as they are not sick that are fixed and don’t change upon confrontation with the person, with overwhelming contrary evidence, and
- Illogical explanations when attempt to explain the evidence.
Treatment Modalities
It is because of this that Anosognosia is relatively the most troubling symptom of severe mental illness. The major reason being that it prevents a person from getting the help they need. The most appropriate approach is to rely on the doctor. The recommended approach includes: (a) to actively listen to the patient; (b) showing empathy; (c) showing agreement with the patient; and (d) fostering partnership with the patient.
The critical thing to remember is that one cannot talk someone out of delusion. However, it is very critical to listen to such persons. The crux of the treatment plan is to get the patient to realize the need for treatment in their own way, instead of forcing on them. This therapy called the Motivational Enhancement Therapy and motivational interventions have been found to be more effective than the psychoeducation approaches.
In Context of Alzheimer’s disease
According to , the unawareness of deficit in Alzheimer’s disease has been reported in the clinical descriptions at the later stages of the diseases. It is described as an “impaired ability to recognize the presence or appreciate the severity of deficits in sensory, perceptual, motor, affective, or cognitive functioning.” The concept of unwareness has described in many ways. It can be measured as the “discrepancy between the patient’s self-report and the report of a natural caregiver or the clinical rating of a healthcare professional.”
In Context of Stroke
Anosognosia, also called the “denial illness”, in 58% of right hemisphere stroke patients denied having hemiplegia, and even refused to admit any weakness in their left arm. This belief of theirs remains despite the manifestation of paralysis. Some patients also show bizarre attitude towards their paralyzed limb at the same time not denying it. The most common attitudes are dislike/hatred of the paralyzed limb (misoplegia) and nonbelonging. The latter means they refuse to believe that the limb belongs to them, and consider it to be somebody else’s. The state is relatively short live, lasting for a few days after stroke.
The underlying pathology is quite confusing. However, most of the researchers agree that these have to be a combination of hemiplegia with other symptoms of brain damage due to stroke. Such symptoms could be, but not limited to; sensory loss; inattention; intellectual confusion etc. But, there is not general agreement between the studies. The Anosognosia for hemiplegia (AHP) is not a necessary consequence of myocardial infaction (MI). However, it is psychologically interesting as it show the importance of ability to voluntary movements to a balanced sense of our personality. It shows that patients are reluctant to accept absence of voluntary movements. A part of it can be explained by failure of attention. Another related phenomenon is somatoparaphrenia (delusional belief about the body).
Conclusion
In conclusion, anosognosia is not caused by damage to one particular area. “Rather a person’s awareness of illness involves a brain network that includes the prefrontal cortex, cingulate, superior and inferior parietal areas, and temporal cortex and the connections between these areas. Damage to any combination of these areas can produce anosognosia, but damage to the prefrontal and parietal areas together make anosognosia especially likely.”
Bibliography
Antoine, C., Antoine, P., Guermonprez, P., & Frigard, B. (2004). Awareness of deficits and anosognosia in Alzheimer's disease. Encephale, 570 - 577. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/15738860
Haggard, P. (n.d.). Control of human action. Retrieved from Department of Psychology, UCL: http://www.psychol.ucl.ac.uk/patrick.haggard/c567/c5678.html
Ramachandran, V. S., & Hirstein, W. (1998). The perception of phantom limbs. Brain, 1603 - 1630. Retrieved from http://brain.oxfordjournals.org/content/121/9/1603.full.pdf
Rosen, H. J. (2011). Anosognosia in neurodegenerative disease. Neurocase, 231 -241. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/21667396
Scheinberg, D. (n.d.). Phantom Limb Syndrome. Retrieved from NYU Langone Medical Center: http://www.med.nyu.edu/content?ChunkIID=96857
Tracy, N. (2012, Oct 12). Handling Anosognosia – Neurological Inability to Recognize Your Mental Illness. Retrieved from Healthy Place: http://www.healthyplace.com/blogs/breakingbipolar/2012/10/handling-anosognosia-neurological-inability-recognize-mental-illness/
WebMD. (2013, Mar 03). Pain Management Health Center. Retrieved from WebMD: http://www.webmd.com/pain-management/guide/phantom-limb-pain
Wootton , T. (2012, Aug 30). Anosognosia: How Conjecture Becomes Medical “Fact”. Retrieved from Psychology Today: http://www.psychologytoday.com/blog/bipolar-advantage/201208/anosognosia-how-conjecture-becomes-medical-fact
