Shay-Dreijer syndrome is a separate form of multisystem atrophy, characterized by pronounced autonomic disorders with a predominance of orthostatic hypotension. Along with vegetative manifestations, symptoms of parkinsonism, urinary incontinence, cerebellar syndrome are observed. Diagnosis is carried out on the basis of clinical data, taking into account the data of cerebral MRI / CT, the results of an orthostatic test, a Minor test. Treatment includes measures to increase blood pressure in an upright position of the body, taking corticosteroids, antiparkinsonian pharmaceuticals, neuroprotectors.
General information
Shay-Dreijer syndrome is one of three variants of MSA (multiple systemic atrophy), including strionigral degeneration and olivopontocerebellar atrophy. The syndrome is named after American neurologists Milton Shay and Glen Dreijer, who described in 1960 cases of the disease, which is a combination of autonomic dysfunction, cerebellar ataxia and Parkinsonism. Since orthostatic hypotension is the predominant symptom at the initial stage, the syndrome is found in the literature on neurology under the synonymous name “idiopathic orthostatic hypotension”. Shay-Dreijer syndrome is observed mainly after 50 years. Among this age group, the prevalence is 1%. Men get sick more often than women.
Causes
The etiology remains unknown. The genetic determinacy of the disease is assumed. There are known family cases with an autosomal dominant type of inheritance. The occurrence of the syndrome as a paraneoplastic process in the amygdala tumor is described. Some researchers point to the similarity of morphological changes accompanying the syndrome and observed in chronic metal poisoning. Only the cause of orthostatic hypotension is relatively clear – the dysfunction of the sympathetic NS (nervous system), which normally provides compensatory vascular reactions.
Pathogenesis
The mechanism of development of progressive degenerative encephalomyelopathy, which is the morphological substrate of the disease, has not been studied. The pathological process affects the neurons of the central autonomic structures, peripheral autonomic ganglia, extends to the cortical-spinal, cortical-nuclear, cerebellar pathways, subcortical nodes. Normally, the transition to an upright position is accompanied by an increase in vascular tone, increased heart rate, which allows you to prevent a drop in blood pressure. The defeat of the sympathetic division of the NS causes the absence of this compensatory mechanism. As a result, when taking an upright position, there is a sharp decrease in blood pressure, a decrease in blood flow to the brain, diffuse ischemia of which causes syncope (fainting).
Due to the degeneration of nerve fibers of the conducting cerebellar tracts, coordination disorders develop. Pathological changes in subcortical ganglia provoke symptoms of parkinsonism. The pathogenesis of the latter is unclear, but clearly differs from that of Parkinson’s disease, since conventional antiparkinsonian drugs are ineffective in the treatment of Shay-Dreijer syndrome. Morphologically, neuronal death and gliosis are observed. The process symmetrically extends to the black substance, caudate nucleus, olives, conducting tracts, cerebellum, vagus nerve nuclei, Clark’s columns located in the spinal cord, peripheral autonomic nodes.
Symptoms
In the prodromal period, there may be a decrease in libido, impotence, dysuric phenomena, poor heat tolerance due to reduced sweating. The onset of the disease is characterized by complaints of increased fatigue, unstable gait, dizziness, frequent episodes of darkening in the eyes, pre-fainting states. The severity of orthostatic disorders quickly worsens, the time of syncope occurrence from the moment of transition to the vertical state decreases to several minutes, and subsequently lasts less than a minute. Trying to compensate for orthostatic hemodynamic disorders, prolong their stay in an upright state, patients walk without unbending their knees, bending their head and bending their torso forward (skater pose). In severe cases, fainting occurs in a sitting position in bed.
Extrapyramidal disorders occur several months after the manifestation of orthostatic disorders, sometimes simultaneously with them. A detailed picture of Parkinsonism is observed in 60% of cases. Bradykinesia, hypomimia, muscle rigidity, monotony of voice, fine-pitched tremor of the distal extremities are characteristic. Most patients have bladder atony, which causes frequent urge to urinate, enuresis, urinary incontinence. Possible weakness of the urethral and anal sphincters. Anhidrosis (lack of sweating) is typical, leading to significant dryness of the skin. Cerebellar ataxia (unsteadiness of walking, adiadochokinesis, intentional trembling) it is detected in 40% of cases, it is difficult to determine against the background of extrapyramidal disorders. In 20% of patients, the syndrome proceeds with corticobulbar disorders, leading to the appearance of a sucking reflex, dysphagia.
Complications
Hemodynamic disorders of the orthostatic type lead to frequent fainting with a fall. As a result of falls, injuries occur (bruises, fractures, concussion of the brain). Episodes of transient ischemia of cerebral structures cause a decrease in memory and intelligence, mental disorders. Severe orthostatic disorders make patients bed sick, which is fraught with the development of congestive pneumonia, bedsores. In old age, Shai-Dreijer syndrome is often complicated by ischemic stroke, leading to persistent paresis, changes in the psycho-emotional and cognitive spheres. These complications aggravate the course of the disease, cause disability of the patient.
Diagnostics
Diagnostic difficulties are associated with poor awareness of neurologists about the existence of this pathology, the similarity of the clinical picture with Parkinson’s disease. In many cases, the syndrome is initially diagnosed as Parkinsonism, and only the ineffectiveness of standard antiparkinsonian therapy makes it necessary to continue the diagnostic search. The basis of the diagnosis is:
- Collecting anamnesis. It allows you to exclude the effects of toxic factors, determine the age and nature of the manifestation of symptoms.
- Neurological examination. It determines bradykinesia, slowness of movements, postural tremor, plastic rigidity of muscles, the phenomenon of “gear wheel”, shakiness of walking, nystagmus, adiadochokinesis. Sometimes there is an asymmetry of the pupils, partial Gorner syndrome.
- Orthostatic test. In a horizontal position, blood pressure is approaching normal. In the standing position, both systolic and diastolic pressure decreases, the drop exceeds 30 mmHg. In severe cases, systolic pressure drops to 50-40 mmHg.
- Neuroimaging. In the initial stage of the disease, changes in CT, MRI of the brain are not detected. Subsequently, atrophic changes are noted in the subcortical ganglia, brain stem, cerebellum. The results obtained do not have independent significance, should be interpreted in accordance with clinical data.
- A Minor sample. The iodine-starch test is used to assess sweating. The absence of darkening of the skin area covered with iodine solution after applying starch to it indicates anhidrosis.
- Electromyography of sphincters (rectal, urethral) reveals signs of denervation in the form of delayed action potentials.
Shai-Dreijer syndrome should be differentiated from Parkinson’s disease, postencephalitic and vascular parkinsonism, degenerative diseases of the central nervous system (Farah’s disease, Alzheimer’s disease, neuroacanthocytosis). Sometimes it is necessary to exclude occlusion of the carotid artery. A distinctive feature of the disease is early orthostatic disorders. With Parkinsonism, Parkinson’s disease, autonomic dysfunction manifests itself much later, less pronounced. Parkinsonian changes due to encephalitis are accompanied by hyperhidrosis, hypersalivation. In differentiation with other degenerative pathology of the central nervous system, anamnesis, the course of the disease, and MRI data are important.
Treatment
Etiopathogenetic therapy of Shay-Dreijer syndrome has not been developed. Symptomatic treatment is carried out aimed at reducing the severity of hemodynamic disorders, Parkinsonian symptoms. Complex therapy has four main components:
- Reduction of orthostatic disorders. To slow down the pressure drop in an upright position, tight bandaging of the lower extremities and abdomen is recommended. A diet with a high salt content is prescribed. Fluoride-containing corticosteroids (triamcinolone, dexamethasone) are used in pharmacotherapy. Adrenomimetics are effective against orthostatic hypotension, but increase pressure in the horizontal state.
- Antiparkinsonian treatment. The disease in most cases is resistant to dopas-containing drugs. Despite this, L-Dopa pharmaceuticals are used at the initial stage, since early initiation of therapy in a number of patients gives a positive effect. The lack of response to therapy serves as an indication for the appointment of trihexyphenidyl.
- Neuroprotective therapy. It is carried out to maintain the metabolism of neurons, slow down the processes of degeneration and atrophy. Nootropics, antioxidants, and neurometabolites are used.
- Kinesiotherapy. It is aimed at maintaining the patient’s motor activity, preventing hypostatic pneumonia. The exercise program is selected by the kinesiologist individually. In severe orthostatic disorders, the patient performs exercises in a supine position.
Prognosis and prevention
Shay-Dreijer syndrome is characterized by a fairly rapid progression. The gradual aggravation of orthostatic disorders leads to the loss of the ability to move independently. The average life expectancy after diagnosis is 7-8 years. In some cases, the process is stabilized, lasting 3-5 years. The lack of clear ideas about the etiopathogenesis of pathology excludes the possibility of developing effective preventive measures.