Parkinson's disease: diagnosis
Last reviewed: 23.04.2024
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In the absence of an alternative diagnosis, the diagnosis of Parkinson's disease is possible in the presence of at least three of its four main manifestations: tremor of tranquility, rigidity (increased muscle resistance in the entire volume of passive movement in this or that limb joint), often as a "cogwheel", bradykinesia and postural instability. Often, weakened facial expressions (masklike face), micrography, violation of fine coordination of movements, bent (flexor) posture, the phenomenon of "hardening", which is characterized by a sudden blockade of motion and often provoked by fright at the appearance of a sudden stimulus.
[Differential diagnosis of Parkinson's disease
Parkinson's disease should be differentiated from other diseases that cause Parkinson's syndrome, including drug parksonism, progressive supranuclear palsy, multisystem atrophy (striatigral degeneration, Shia-Draiger syndrome), diffuse Levy disease, corticobasal degeneration. Each patient with Parkinson's disease should first of all find out whether he takes drugs blocking dopamine receptors, including antipsychotics (for example, chlorpromazine and haloperidol), drugs for the treatment of nausea and weakened gastric motility (eg, prochlorperazine or metoclopramide). Reserpine can also cause Parkinsonism.
About other diseases should be first of all to think in the case when the patient does not have a classical tremor of rest. With progressive paradynamic paralysis (PNP), postural reflexes usually suffer early, which is manifested by frequent unexplained falls. Progressing nuclear palsy should also be suspected when the arbitrary saccade is violated, especially in the vertical plane, and also in cases where rigidity in the neck and trunk is expressed to a much greater extent than in the extremities. Striato-nigral degeneration and Shay-Dryger syndrome are clinical variants of the same disease - multisystem atrophy (MSA) , which is characterized by specific pathomorphological changes, but can manifest itself in various clinical syndromes. Although some patients with multisitem atrophy have a resting tremor, frequent presence of spasticity in the lower extremities, extensor stop signs, orthostatic hypotension and sometimes ataxia, distinguishes them from patients with Parkinson's disease. Corticobasal degeneration is often manifested by apraxia and the phenomenon of "foreign limb", which is characterized by the fact that the arm (less often the leg) spontaneously takes unusual postures and makes involuntary movements. The disease of diffuse Levi bodies is usually characterized by dementia with a tendency to visual hallucinations, but sometimes it is manifested by parkinsonism, which is resistant to levodopa preparations. The complete absence of resting tremor often indicates that the patient does not have Parkinson's disease, but one of the above diseases. A more reliable diagnostic sign of Parkinson's disease is the high efficacy of dopaminergic agents.
Although symptomatic therapy is effective in the early stages of Parkinson's disease, it does not affect the process of neuronal death of a black substance that continues steadily and leads to the progression of the disease. As the progression of Parkinson's disease occurs, late complications, which are largely provoked by the therapy itself. These include drug dyskinesia and the phenomenon of "on-off", characterized by rapid fluctuations between the state of immobility due to increased symptoms of parkinsonism and a more mobile condition, usually accompanied by dyskinesia. There are three main types of dyskinesia, of which the most common is dyskinesia "peak dose". These movements usually have a choreoathetoid character, are aggravated by excitement, but rarely cause the patient significant anxiety. Another type of dyskinesia - biphasic dyskinesia - at the beginning and end of the next dose of dopaminergic. Biphasic dyskinesias to a much greater degree cause the patient discomfort than dyskinesia "peak dose", and usually have a ballistic or dystonic character. Often they are more severe in the afternoon. The third type of dyskinesia - dyskinesia of the "turn-off" period - occurs against the background of the depletion of the action of the next dose and the increase in symptoms of parkinsonism, usually they are represented by a painful reduction of the lower extremities.