Trunk alternating syndromes are a group of he alth conditions that are caused by damage to the brainstem. The clinical picture of these units is variable, it is determined by exactly in which part of the central nervous system the pathology appeared. One of the constant features of truncated alternating syndromes is that cranial nerves are paralyzed on the side of the defect, while paresis or paralysis develops on the opposite side.
Trunk alternating syndromesappear as a result of unilateral damage to the brainstem, and their symptoms depend on where the damage occurred. The brain stem is one part of the brain. It consists of the midbrain, the bridge and the medulla (some authors also include the interbrain in the brainstem). The brainstem is a very important structure, because it is where the centers that control basic life activities, such as, for example, breathing or the work of the heart, are located. This part of the brain also houses the pituitary gland (one of the basic glands in the endocrine system) and the structures that control the course of metabolism. The examples mentioned are only some of the numerous functions of the brain stem. It is worth adding that it is here that the numerous nuclei of the cranial nerves are located. In addition, nerve pathways run through the brainstem and are responsible for transmitting signals to and from the cortex and the spinal cord. Injuries to the brainstem can have various consequences - the most serious of possible outcomes is the death of the patient. In the brainstem, however, the damage may be relatively minor and closely located. In such cases, patients may develop the so-called trunk alternating syndrome. Due to the fact that the symptoms of truncated alternating syndromes vary depending on the location of the lesion, there are several types of these diseases.
Stem alternating syndromes: causes
The most common causes of truncated alternating syndromes are the processes of ischemia of the nervous tissue and the associated strokes in specific parts of the brain. Diseases from this group may also have a different background - in the etiology of alternating trunk syndromes the following are also important:
- tumors of the central nervous system
- multiple sclerosis
- processesinflammatory processes in the brain
Stem alternating bands: types
Patients experience two types of ailments when it occurs. Symptoms of paralysis of (one or more) cranial nerves are noted on the damaged side. On the side opposite to the existing damage, paralysis (sometimes paresis) occurs, which may be accompanied by sensory disturbances. The clinical picture of truncated alternating syndromes depends on the exact location of the damage to the nervous system.
When the defect is present in the midbrain, Benedict's syndrome may develop, which results from damage to the red nucleus. In the course of the individual, the oculomotor nerve (III) is paralyzed on the side of the lesion and the hemiplegia is contralateral. These ailments are accompanied by involuntary movements in the form of tremors, chorea and athetosis.
Another example of a syndrome that occurs as a result of damage to the midbrain is Nothnagel's syndrome, in which the oculomotor nerve (III) is paralyzed on the side of the damage and the contralateral incoherence of the limbs occurs. in the bridge, Millard-Gubler syndrome may develop. It is associated with the palsy of the facial nerve on the same side as the defect in the pons and with the contralateral hemiparesis.
Another example of a truncated alternating syndrome that is associated with bridge tissue damage is Foville's syndrome. In its course, the abduction and facial nerves are paralyzed on the same side as the damage and the opposite hemiparesis. Another symptom of Foville's syndrome is the inability to look in the direction where the damage occurred. A third location where the onset of damage may result in truncated alternating syndromes is the medulla medulla. Defects in this area of the brain result in the appearance of the most symptomatic truncated alternating syndromes. An example of an entity in this category is Wallenberg's syndrome, in which the trigeminal, glossopharyngeal and vagus nerves are paralyzed. Patients on the side of the lesion have Horner's syndrome, nystagmus, as well as tremors and hearing disorders. On the side opposite to the defect, there are split sensory disorders and paresis.
Trunk alternating syndromes: prognosis and treatment
In the case of the most common cause of truncated alternating syndromes, i.e. ischemic processes, thedefects are usually permanent. Only rehabilitation can help patients in such a situation. In the case of other etiological factors of stem alternating syndromes, such as oncological diseases or inflammatory processes, curing the patient of them - as long as these units do not leave permanent defects - may lead to the disappearance of the patient's ailments.