Vascular parkinsonism is a decrease in the number, amplitude and speed of voluntary movements against the background of muscle rigidity, etiopathogenetically associated with the presence of cerebrovascular pathology. It is clinically manifested by slowness, shuffling gait, postural instability, hypomimia of the face, a tendency to depression. The vascular genesis of the disease is established on the basis of data from the ultrasound of intra- and extracranial vessels, cerebral neuroimaging. Treatment is predominantly conservative, consisting of basic (vascular) and symptomatic (antiparkinsonian) therapy.
ICD 10
G21.4
General information
For the first time, the assumption of the presence of a vascular factor among other causes of damage to the substantia nigra was expressed in 1894 by the French neurologist Brissaud. In 1929, the American physician M. Critchley presented the first detailed description of atherosclerotic parkinsonism. Vascular parkinsonism (VP) refers to rare forms of secondary parkinsonism and, according to various data, accounts for 2-15% of all its cases. Pathology is diagnosed in 11% of patients who have suffered an ischemic stroke, in 14% of cases of subcortical DEP. The average age of patients varies in the range of 40-90 years.
Causes
The main etiological factor in the development of VP is the lesion of subcortical ganglia caused by cerebrovascular disorders. The latter may have an acute (stroke, lacunar infarction) and chronic (chronic cerebral ischemia) course. The disease often occurs due to pathological changes occurring in the cerebral arteries against the background of chronic arterial hypertension. Taking into account the caliber of the affected vessels , two main groups of etiofactors are distinguished:
- Lesion of the small cerebral arteries. Common pathology of arterioles and small arteries is observed in hypertensive encephalopathy, arteriosclerosis, vascular amyloidosis, SLE, antiphospholipid syndrome. The defeat of the penetrating vessels supplying the deep cerebral divisions is accompanied by chronic diffuse ischemia, transient episodes of more pronounced ischemia (incomplete infarcts), provoking pathological changes in subcortical nodes.
- Damage to medium and large arteries. It is less common. It is caused by thromboembolism of the branches of the middle cerebral artery, cerebral atherosclerosis, the presence of arteriovenous malformation, angiopathy in nodular periarteritis, cerebral vasculitis. Vascular parkinsonism is a consequence of ischemic or hemorrhagic stroke in the basal nuclei.
Pathogenesis
Pathological changes in the small cerebral arteries potentiate diffuse hypoperfusion of tissues. Increased permeability of the walls of the affected vessels causes perivascular edema, deposition of hemosiderin, plasma proteins leaving the vascular bed. The result of chronic ischemia and vascular permeability is the death of subcortical structural elements. The dead areas are insufficiently replaced by astrocytes, which causes spongiosis — pathological sponginess of the white matter.
The defeat of large branches and trunk of the middle cerebral artery (vascular stenosis, occlusion, thinning of the wall) provokes the occurrence of a stroke with the formation of a vast area of necrosis of subcortical elements. Thus, the vascular factor leads to the death of dopamine-producing neurons, dopamine dysmetabolism, damage to dopamine receptors. The predominance of acetylcholine activating effects on the inhibitory motility of the caudate nucleus leads to hypokinesia, parkinsonism develops.
Classification
Vascular parkinsonism has a variable clinical picture, can be combined with other neurological symptoms associated with hemodynamic changes, secondary degenerative processes. These factors cause certain diagnostic difficulties. To understand the variety of clinical symptoms helps to identify the characteristic features of the course of the joint venture. In accordance with this criterion , there are three options:
- Acute/subacute. A sudden or rapidly developing manifestation of symptoms is characteristic. Subsequently, there is a stabilization of the course, a certain regression of symptoms is possible.
- Stepwise progressive. The clinic unfolds gradually. The period of progression alternates with stabilization and partial regression of manifestations.
- Steadily progressing. It is observed most rarely. Typically, there is a continuous increase in the severity of symptoms, there are no stabilization periods. A similar course is typical for primary degenerative diseases of the central nervous system, which makes it difficult to conduct differential diagnosis.
The features of the course of the disease correlate significantly with the nature of cerebrovascular pathology. Understanding the etiology of the occurrence of VP is crucial for adequate planning of therapeutic measures. In this regard , it is advisable to allocate the following two forms:
- Post-stroke. It is observed with lesions of the cerebral arteries of medium / large caliber. Parkinsonism develops for 6-12 months after a stroke. Subacute or acute course is characteristic. Akinetic-rigid syndrome can have a unilateral character. Neuroimaging research methods reveal a localized contralateral stroke zone.
- Without a stroke. It is typical for lesions of small intracerebral arteries. Parkinsonism has a subacute debut, progresses stepwise, less often — steadily. Akinetic-rigid symptoms are bilateral in nature. Neuroimaging detects diffuse changes in subcortical structures, lacunar foci in the shell and pale ball.
Symptoms
In typical cases, there is a bilateral subacute development of symptoms. Hypokinesia, muscle rigidity prevail in the lower extremities. Patients complain of stiffness, difficulty walking, “sticking of the feet to the floor.” The gait is slow, shuffling, with small steps. Typical slowness, lack of gestures, impoverishment of facial expressions. Postural instability appears early — discoordination, which makes it difficult to hold the body in a certain position and when changing position. Muscle rigidity leads to a constant semi-bent position of the limbs.
In some cases, the disease manifests itself with the appearance of mild parkinsonian signs: isolated oligobradykinesia (within the lower extremities), one moderately pronounced symptom of Parkinsonism, several mild manifestations. The symptoms of the initial stage in total do not reach the criteria defining true parkinsonism, similar to the debut of a number of degenerative diseases, the clinic of age-related subcortical changes. It is possible to suspect a joint venture in such cases as the symptoms progress.
Vascular Parkinsonism proceeds without violations of the sense of smell (anosmia). The resting tremor that characterizes Parkinson’s disease is detected only in 4% of cases of VP. Concomitant symptoms depend on the localization and prevalence of vascular lesion. Pyramidal disorders, cerebellar ataxia, masking parkinsonism in the onset of the disease are more often observed. Tonic disorders, myoclonia, pseudobulbar syndrome, symptoms of focal lesion of higher nervous functions (aphasia, amnesia, apraxia), frontal syndrome are possible. Typically progressive intellectual decline.
Complications
Previously, the formation of postural disorders significantly complicates the patient’s independent movements, dangerous falls, traumatizing the patient. The situation is aggravated in the presence of cerebellar and pyramidal disorders. Limitation of motor activity is complicated by the formation of joint contractures. The personality changes accompanying Parkinsonism (narrowing of the circle of interests, isolation, low mood background) contribute to the occurrence of depression. Progressive cognitive disorders lead to dementia. The patient loses the possibility of self-service, requires constant care. Pseudobulbar paralysis is dangerous by aspiration of food with the development of aspiration pneumonia.
Diagnostics
To diagnose vascular parkinsonism to a neurologist allows the presence of clinical criteria of akinetic-rigid syndrome, confirmed by instrumental studies of cerebrovascular disease, the identification of a causal relationship between them. Since the vascular genesis of pathology causes polymorphism of clinical manifestations, it is advisable to establish a diagnosis of VP if Parkinsonism is the dominant syndrome. The main diagnostic measures include:
- Neurological examination. Confirms oligobradykinesia with predominant lesion of the lower extremities, plastic muscle tone, postural instability. Parkinsonism is combined with other neurological disorders. Cognitive testing determines the slowness of thinking to varying degrees, memory loss, difficulty concentrating.
- Ultrasound of cerebral vessels. Ultrasound of the vessels of the head and neck makes it possible to assess the state of cerebral circulation, diagnose cerebrovascular pathology. During the study, vascular stenosis, thromboembolism, diffuse changes in arterial walls can be detected. The absence of hemodynamic disorders makes it possible to exclude the vascular genesis of the disease, but their presence is not an unambiguous confirmation of the joint venture.
- Magnetic nuclear resonance. MRI of the brain reveals a vascular lesion of the structures responsible for parkinsonism. The morphological substrate of post-stroke VP is subcortical foci in the basin of the middle and anterior cerebral arteries. The stroke-free form is characterized by a diffuse nature of the lesion, the presence of multiple lacunar foci. Brain CT data are less informative and are used when magnetic resonance imaging is not possible.
An important place in the diagnostic search is occupied by differential diagnosis. Elderly patients are particularly difficult, since they often have vascular disorders and age-related degeneration of the basal ganglia. To differentiate vascular Parkinsonism from Parkinson’s disease, the features of the course, the absence of postural tremor, olfactory disorders, the presence of pyramidal, cerebellar concomitant symptoms allow. Significant difficulties are presented by the differential diagnosis of vascular pathology from degenerative lesions of the central nervous system (multisystem atrophy, dementia with Lewy bodies, corticobasal degeneration). It is possible to reliably exclude the primary degenerative genesis of subcortical disorders only on the basis of pathomorphological analysis data.
Treatment
VP therapy requires a comprehensive approach aimed at the underlying etiopathogenetic factor and the main clinical manifestations of the disease. Normalization of cerebral hemodynamics, prevention of the occurrence of ONMC is essential. In most cases, conservative treatment is used, including:
- Basic therapy. It is aimed at the vascular mechanism of the disease development, prevents further damage to brain tissues. Correction of blood pressure, antiplatelet, antiatherogenic therapy is carried out. A high risk of cardiogenic embolism is an indication for the appointment of anticoagulants.
- Symptomatic treatment. Parkinsonism is an indication for dopaminergic therapy, carried out primarily with levodopa drugs. The course of trial levodopatherapy is carried out in the maximum daily dosage for 1-3 months, it is effective in 22-50% of patients. The action of levodopa is potentiated by amantadines. In the absence of an effect, therapy with dopamine receptor agonists, MAO inhibitors is prescribed. Neuroprotective, nootropic, and antidepressant therapy are carried out in parallel.
- Surgical treatment is reduced to stereotactic operations. The most common pallidotomy is partial destruction of the pale globe. Intervention can be effective with limited lesions. Multi-focal processes, as well as extranigral parkinsonism, which is not associated with the pathology of the substantia nigra, do not respond well to neurosurgical treatment.
Prognosis and prevention
The effectiveness of VP treatment depends on the etiology of cerebrovascular disorders, localization and extent of the lesion. It is possible to compensate for the manifestations of parkinsonism in patients with a positive response to levodopa therapy. Localization of the lesion in the striar and thalamic regions causes parkinsonism resistant to dopamine therapy, which has a more serious prognosis.
Primary prevention of VP includes the exclusion of factors leading to pathological changes in the vessels of the brain (smoking, atherogenic nutrition, weight gain), adequate correction of arterial hypertension, timely therapy of cardiovascular diseases. Secondary prevention consists in maintaining full-fledged cerebral hemodynamics, prevention of acute disorders of cerebral blood flow. Patients under the supervision of a therapist or cardiologist should carry out constant monitoring of blood pressure. Regular courses of vascular therapy are recommended.