医学院神经解剖学教案小脑损伤

神经解剖学选修课教程4-1-2 小脑损伤lesions of the cerebellum,Review1: Three functional divisions of the cerebellum: spinocerebellum(paleocerebellum) cerebrocerebellum(neocerebellum) vestibulocerebellum(archicerebel-lum),spinocerebellum(paleocerebellum): important in controlling the posture and movement of the trunk and limbs cerebrocerebellum(neocerebellum): participates in the planning of movemnet vestibulocerebellum(archicerebellum): helps us to maintain balance and control head and eye movement,Review2: Connections and functions of the functional divisions,Spinocerebellar pathways(1),Spinocerebellar pathways(2),Spinocerebellar pathways(3),Cerebrocere-bellar pathway,Vestibulocere-bellar pathway,Clinical Correlations,Damage to the cerebellum produces neurological signs on the same side as the lesion,Knowledge of the anatomy of the descending projection system is crucial for understanding why cerebellar damage typically produces ipsilateral motor signs.This is because both the cerebellar efferent projections are crossed as well as the descending pathways, which are the targets of cerebellar action. The combined decussations result in a system of connections that is “doubly crossed”.,Damage to cerebellar input from the spinal cord also produces ipsilateral signs because the principal spinocerebellar pathways, the dorsalspinocerebellar and cuneocerebellar tracts, ascend ipsilaterally. Thus, whether damage occurs to either cerebellar inputs or outputs, or to the cerebellum itself, neurological signs are present on the ipsilateral side.,Signs and syndromes of cerebellar lesions,There three classic neurological signs of cerebellar damage: Ataxia is inaccuracy in the speed, force, and distance of movement. Nystagmus is a rhythmic involuntary oscillation of the eyes. Tremor is involuntary oscillation of the limbs or trunk.,The flocculonodular lobe syndrome(caudal vermis syndrome) consists of the inability to maintain the upright posture due to truncal dystaxia. Nystagmus may also be present.This syndrome occurs most commonly with tumor of the vermis,The cerebellar hemisphere syndrome consists of dystaxia and hypoton