The cerebrum plays a role in most neural functions, so that focal lesions may cause many different neurological syndromes. A focal lesion of the cerebrum often causes sensory or motor abnormalities of the other side of the body, because many of these pathways cross to the contralateral side in the central nervous system. Vision, somatosensation, and motor control of the limbs, in particular, are usually mostly or entirely crossed functions of the cerebrum, so that a lesion of one cerebral hemisphere often causes visual, somatosensory, or upper motor neuron abnormalities on the contralateral side.
A few cognitive functions are also usually performed by one side of the cerebrum. For example, the left cerebral hemisphere performs most language functions in most people, so that left cerebral hemisphere lesions may cause language dysfunction. Diffuse dysfunction of the cerebrum, particularly the cerebral cortex, may cause abnormalities of the higher neural functions with or without also involving the lower neural functions. For example, a common syndrome of diffuse cerebral cortical dysfunction called delirium often involves abnormal arousal, attention, orientation, and other higher neural functions while usually sparing basic sensory, motor, and autonomic functions.
Next:
Introduction to Neurology 