| Dejerine-Roussy Syndrome | |
|---|---|
| Classification and external resources | |
| ICD-9 | 338.0 |
| DiseasesDB | 13002 |
| MeSH | D013786 |
Dejerine–Roussy syndrome or thalamic pain syndrome is a condition developed after a thalamic stroke, a stroke causing damage to the thalamus.[1][2] Ischemic strokes and Hemorrhagic strokes can cause lesioning in the thalamus. The lesions, usually present in one hemisphere of the brain, most often cause an initial lack of sensation and tingling in the opposite side of the body. Weeks to months later, numbness can develop into severe and chronic pain that is not proportional to an environmental stimulus, called dysaesthesia or allodynia.[1] As initial stroke symptoms: numbness and tingling, dissipate, an imbalance in sensation causes these later syndromes, characterizing Dejerine–Roussy syndrome. Although some treatments exist, they are often expensive, chemically-based, invasive, and only treat patients for some time before they need more treatment, called "refractory treatment."[2]
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Dejerine–Roussy syndrome has also been referred to as: "Posterior Thalamic Syndrome", "Retrolenticular Syndrome", "Thalamic Hyperesthetic Anesthesia", "Thalamic Pain Syndrome", "Thalamic Syndrome", "Central Pain Syndrome", and "Central Post-Stroke Syndrome".[2][3][4] This condition is not associated with "Roussy-Levy Syndrome" or Dejerine-Sottas disease, both of which are genetic disorders.[5][6][7]
In 1906, Joseph Jules Dejerine and Gustave Roussy provided descriptions of central post-stroke pain (CPSP) in their paper entitled: "Le syndrome thalamique". The name Dejerine–Roussy syndrome was coined after their deaths. The syndrome included "…severe, persistent, paroxysmal, often intolerable, pains on the hemiplegic side, not yielding to any analgesic treatment".[2]
In 1911, it was found that that the patients often developed pain and hypersensitivity to stimuli during recovery of function. And thus is was thought that the pain associated after stroke was part of the stroke and lesion repair process occurring in the brain.[8] It is now accepted that Dejerine–Roussy syndrome is a condition developed due to lesions interfering with the sensory process, which triggered the start of pharmaceutical and stimulation treatment research. The last 50 years have been filled with refractory treatment research. As of the early 2000's, longer treatments lasting months to years have been explored in the continued search for permanent removal of abnormal pain.[8][2]
Dejerine–Roussy syndrome is most commonly preceded by numbness in the affected side. In these cases, numbness is replaced by burning and tingling sensations, widely varying in degree of severity across all cases.[9] The majority of those reported are cases in which the symptoms are severe and debilitating.[8] Burning and tingling can also be accompanied by hypersensitivity, usually in the form of dysaesthesia or allodynia. Less commonly, some patients develop severe ongoing pain with little or no stimuli.[10]
Allodynia refers to hypersensitivity to sensations associated with a stimulus that would normally not cause pain.[1][11][12] For example, there is a patient who experiences unrelenting pain when a breeze touches his skin. Most patients experiencing allodynia, experience pain with touch and pressure, however some can be hypersensitive to temperature.[8]
Dysaesthesia is defined as pain due to thalamic lesioning. This form of neuropathic pain can be any combination of itching, tingling, burning, or searing experienced spontaneously or from stimuli.[12]
Allodynia and dysaesthesia replace numbness between one week and a few months after a thalamic stroke. In general, once the development of pain has stopped, the type and severity of pain will be unchanging and if untreated, persist throughout life. Consequentially, many will undergo some form of pain treatment and adjust to their new lives as best they can.[8]
Pain associated with Dejerine–Roussy syndrome is sometimes coupled with anosognosia or somatoparaphrenia which causes a patient having undergone a right-parietal, or right-sided stroke to deny any paralysis of the left side when indeed there is, or deny the paralyzed limb(s) belong to them.[1] Although debatable, these symptoms are rare and considered part of a "thalamic phenomenon", and are not normally considered a characteristic of Dejerine–Roussy syndrome.[8]
Although there are many contributing factors and risks associated with strokes, there are very few associated with Dejerine–Roussy syndrome and thalamic lesions specifically. In general, strokes damage one hemisphere of the brain, which can include the thalamus. The thalamus is generally believed to relay sensory information between a variety of subcortical areas and the cerebral cortex.[11] It is known that sensory information from environmental stimuli travels to the thalamus for processing and then to the somatosensory cortex for interpretation. The final product of this communication is the ability to see, hear or feel something as interpreted by the brain. Dejerine-Roussy syndrome most often compromises tactile sensation. Therefore, the damage in the thalamus causes miscommunication between the afferent pathway and the cortex of the brain, changing what or how one feels.[2] The change could be an incorrect sensation experienced, or inappropriate amplification or dulling of a sensation. Because the brain is considered plastic and each individual's brain is different, it is almost impossible to know how a sensation will be changed without brain mapping and individual consultation.
Recently, magnetic resonance imaging has been utilized to correlate lesion size and location with area affected and severity of condition. Although preliminary, these findings hold promise for an objective way to understand and treat patients with Dejerine–Roussy syndrome.[13]
The imbalance in sensation characterized by Dejerine–Roussy syndrome can be argued through a model addressing a system of inputs and outputs that the brain must constantly process throughout life, suggesting latent plasticity. The right and left hemispheres of the brain both play important roles in the sensory input and output.[1] When a stroke damages one hemisphere, it is proposed that the other hemisphere will cope with the discrepancies in a specific manner. The left hemisphere tends to "gloss over" discrepancies from inputs, eliciting either denial or rationalization defense mechanisms in order to stabilize said discrepancy. In contrast, the right hemisphere does the opposite, and will focus on the discrepancy, and motivate action to be taken to restore equilibrium. Therefore, damage to the left hemisphere can cause both an indifference to pain and hypersensitivity to pain (dysaesthesia or alloydnia), while damage to the right hemisphere can cause denial as a defense mechanism (anosognosia and somatoparaphrenia).
The insular cortex, part of the cerebral cortex, is responsible for self-sensation, including the degree of pain perceived by the body, and for self-awareness and defense mechanisms. The insular cortex is often lesioned by a stroke. Particularly, the posterior insula has been mapped to correlate to pain experienced by an individual. In addition, is has been proven that the posterior insula receives a substantial amount of the inputs of the brain, and can be treated with visual, kinesthetic, and auditory inputs.
Individuals with emerging Dejerine–Roussy syndrome usually report they are experiencing unusual pain or sensitivity, and should visit a post-stroke rehabilitation center immediately. Stroke rehabilitation clinics are located worldwide and specialize in diagnosis, prognosis, and treatment of conditions associated post-stroke.[8]
Due to the uniqueness of each case, a close clinician-patient relationship is vital in diagnosis and treatment. Stroke rehabilitation clinic staff debriefs the patient, then reviews information from the initial stroke to determine the location of brain lesioning.[8] Some may attempt to correlate lesions with the type and severity of pain in order to prescribe the best treatment option[13] and coping strategies. Hypersensitivity in conjunction with lesions within the thalamus allow for the diagnosis of Dejerine–Roussy syndrome.[2] A typical stroke rehabilitation clinic may have between 10 and 15 Dejerine–Roussy patients at a time, each with differing symptoms from each other. Cases diagnosed and treated are primarily moderate to severe cases of Dejerine Roussy syndrome, and mild cases usually go undiagnosed.[12]
Many chemical medications have been used for a broad range of neuropathic pain including Dejerine–Roussy syndrome. Symptoms are generally not treatable with ordinary analgesics.[14] Traditional chemicals include opiates and anti-depressants. Newer pharmaceuticals include anti-convulsants and Kampo medicine. Pain treatments are most commonly administered via oral medication or periodic injections. Topical In addition, physical therapy has traditionally been used alongside a medication regimen. More recently, electrical stimulation of the brain and spinal cord and caloric stimulation have been explored as treatments.
The most common treatment plans involve a schedule of physical therapy with a medication regimen. Because the pain is mostly unchanging after development, many patients test different medications and eventually choose the regimen that best adapts to their lifestyle, the most common of which are orally and intravenously administered.[8]
Expensive and invasive, the above treatments are not guaranteed to work, and are not meeting the needs of patients. There is a need for a new, less expensive, less invasive form of treatment, one of which is postulated below.
Of the millions experiencing strokes worldwide, over 30,000 in the United States alone have developed some form of Dejerine–Roussy syndrome.[1] 8% of all stroke patients will experience central pain syndrome, with 5% experiencing moderate to severe pain. The risk of developing Dejerine–Roussy syndrome is higher in older stroke patients, about 11% of stroke patients over the age of 80.[2]
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