Thalamic syndrome is an unusual neurological condition that occurs as a result of a stroke. It affects the thalamus of the brain. The condition most often occurs in older people. 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 and months later, numbness can develop into severe and chronic pain.
Definition
The thalamus is a part of the midbrain that acts as a relay of sensations, such as touch, pain, and temperature, carried by various parts of the spinal cord. Having received these sensations, the thalamus integrates them and transfers them to the corresponding part of the cerebral cortex. Bleeding or blood clot in blood vessels can lead to stroke, which is the main cause of thalamic syndrome. People with irregular heart rhythms, high blood pressure, and high cholesterol are at risk of developing this condition.
History
In 1906, Joseph Jules Degerin and Gustave Russi presented a description of central post-stroke pain (CPB) in an article entitled "Talamic syndrome." The name of Dejerine's syndrome - Russi was coined after their death. It included "strong, persistent, paroxysmal, often unbearable pains on the hemiplegic side, not amenable to any analgesic treatment."
In 1911, it was found that patients often develop pain and hypersensitivity to irritants during restoration of function. It was believed that the pain associated with a stroke is part of it. It is now accepted that thalamic syndrome is a condition that has developed due to damage that interferes with the sensory process. This triggered the start of pharmaceutical research and stimulation research. The last 50 years have been filled with refractory surveys. As of the beginning of the 2000s, longer procedures, lasting from months to years, were investigated in a constant search for removal of abnormal pain.
Signs
Signs and symptoms of thalamic syndrome can range from numbness and tingling to loss of sensitivity or hypersensitivity to external stimuli, involuntary movements and paralysis. Severe and prolonged pain may also appear. Persons suffering from a stroke and reporting pain or abnormal sensations are evaluated to confirm the diagnosis. The cause of the pain is established through the elimination process. To exclude the presence of tumors or blockages of blood vessels, tomographic studies of the brain may additionally be required.
The prognosis of thalamic pain syndrome depends on the severity of the stroke. Often, lifelong management of pain through medication may be necessary.
Development risk
The following are some of the risk factors for thalamic pain:
- High blood pressure (hypertension).
- Increased blood cholesterol (hypercholesterolemia).
- Elderly age.
- Blood coagulation disorders.
- Irregular heart rhythm.
It is important to note that the risk factor increases the chances of developing the condition. Some of them are more important than others. The absence of a risk factor does not mean that a person will not acquire the syndrome.
Causes and pathophysiology
Although there are many factors and risks associated with strokes, very few of them are associated with thalamic Dejerine-Russi syndrome. In general, strokes damage one hemisphere of the brain, which may include the thalamus. Sensory information from environmental stimuli enters it for processing. Then into the somatosensory cortex for interpretation. The end product of this is the ability to see, hear or feel. Thalamic syndrome after a stroke most often affects tactile sensations. Therefore, damage to the thalamus causes a disruption in the interaction between the afferent pathway and the cerebral cortex, changing what or how a person feels. Change can be a wrong sensation, its amplification or dulling.
Symptoms
Signs and symptoms associated with thalamic syndrome may be as follows:
- Severe pain in the limbs (it can be constant).
- The reaction can be exaggerated: even a pin prick can cause severe pain.
- Superficial touch, emotional stress, and a sharp change in air temperature can cause severe pain.
- Weakness or paralysis of affected limbs.
- Loss of sense of position: inability to determine the position of a limb or the development of the illusion that it does not exist when the eyes are closed.
- Abnormal involuntary movements.
How is diagnosed
Diagnosis of thalamic syndrome is carried out using the following methods:
- A thorough physical examination and assessment of the symptoms of the victim.
- Assessment of medical history.
- A thorough neurological examination.
- Eliminate other causes of pain by using imaging techniques.
- Computed tomography of the head and neck.
- MRI of the brain.
- Angiogram of the brain.
How is it treated?
Treatment for thalamic syndrome is aimed at relieving pain. For this, the following measures may be considered:
- The use of opioids. Despite their effectiveness, relief lasts from 4 to 24 hours. In addition, they pose a high risk for the development of addiction.
- Tricyclic antidepressants and selective serotonin reuptake inhibitors. They are effective for a short time.
- The use of anticonvulsants.
- Local anesthesia is relevant.
- Stimulation of the thalamus and spinal cord through implantation of electrodes.
Thalamic syndrome, as a rule, is not treated with commonly available painkillers. A cure for pain is usually required for the rest of your life.
Epidemiology
Of the millions of people who have had a stroke worldwide, more than 30,000 have acquired some form of Dejerine-Russi syndrome. 8% of all patients experience central pain, 5% - moderate pain. The risk of developing the syndrome is higher in elderly patients with stroke. About 11% of stroke patients are older than 80 years.