Читать книгу Pathy's Principles and Practice of Geriatric Medicine - Группа авторов - Страница 164

A mild increase in muscle tone, usually associated with a concomitant decrease of muscle bulk and strength, is reported with ageing. In this regard, it should be noticed that mild extrapyramidal signs such as axial bradykinesia, rigidity, resting tremor, and postural instability are common amongst community‐dwelling older individuals even if they do not configure a definite PD.⁵⁶ To achieve the diagnosis of PD, specific criteria have to be satisfied.⁵⁷ The diagnosis of PD is based on a three‐step process. First, parkinsonism is defined by the presence of bradykinesia (e.g. slowness of movement) in combination with tremor and/or rigidity. If the criteria are not met (step 1), prodromal or non‐clinical parkinsonism could be considered (in addition to other non‐parkinsonian tremulous conditions, such as essential or dystonic tremor). Once parkinsonism is diagnosed, it should be determined whether this condition is attributable to idiopathic PD: when absolute exclusion criteria (e.g. brain lesions, drug‐induced parkinsonism, etc.) (step 2) are absent and supportive clinical features (e.g. olfactory loss, sleep disturbances, and other non‐motor symptoms) are present (step 3).⁵⁸ Hence, the presence of isolated tremor, rigidity, or simple slowness of movement is not sufficient to configure the diagnosis of PD per se. More importantly, senile tremor constitutes one of the commonest movement disorders, reaching a prevalence of ~10% in subjects by age 90.⁵⁹ This so‐called ageing‐related tremor emerges in midlife and increases with ageing. The exact nature of this tremor remains unclear, configuring a wide spectrum of disorders that encompasses essential tremor (e.g. idiopathic), dystonic tremor (e.g. tremor associated with dystonia in any body region), and also PD, being associated both with increasing cognitive impairment and mortality.⁵⁸