Neue Erkenntnisse zur Pathophysiologie der Apraxien durch funktionelle Bildgebung

Abstract

Apraxias are disorders of motor cognition that cannot be explained by basic sensorimotor deficits or aphasia. The relatively high frequency of apraxia (approximately half of all patients with left-hemispheric stroke suffer from apraxia during the acute phase) as well as its prognostic value for determining the outcome of rehabilitative therapy clearly convey the necessity of more comprehensive research into the pathophysiology of apraxia in order to develop new therapeutic strategies. In recent years, functional imaging (PET and fMRI) has helped to provide important new insights into the pathophysiology of ideomotor apraxia (defective movement plan) and ideational apraxia (defective action concept). In this review, the neural bases for the clinically observed dissociations between the imitation of abstract and symbolic movements (as in ideomotor apraxia) and for the object-trigger system (which is disturbed in ideational apraxia) will be exemplified. Furthermore, we will recapitulate recent studies that provide evidence for the complementary functions of the right and left parietal cortices in the spatial and temporal organization of complex, object-related actions. The particular importance of the left parietal cortex for motor cognition is further supported by studies examining the integration of spatial and temporal movement information during the generation of a movement plan as well as by the generation of such movement plans in the left parietal cortex independent from the hand that executes the movement.

Diagnosis and treatment of upper limb apraxia

“…Here, the focus is on therapeutic interventions that have been examined in randomized controlled trials (RCTs) and thus can be recommended based on strong evidence-based criteria. Note that we do not restrict our review to these evidence-based therapies for apraxia, but also describe further published therapeutic approaches [ 10 ], as these might have implications for the development of new therapeutic strategies for upper limb apraxia [ 72 ].…”

Diagnostik und Therapie der Gliedmaßenapraxie

“…Darüber hinaus werden aber auch Therapieansätze vorgestellt, die auf Modellen zur Pathophysiologie der Apraxie basieren. Auch wenn hier oftmals noch keine randomisierten, kontrollierten Studien vorliegen und daher zum jetzigen Zeitpunkt diese experimentellen Therapieansätze nicht empfohlen werden können [31], sind diese Ideen für die Entwicklung neuer Strategien bei der Therapie der Gliedmaßenapraxie relevant [32]. wurden, stand bei der Entwicklung anderer Tests der Einsatz im Rahmen von wissenschaftlichen Studien im Vordergrund.…”