Physiology and Localization of Gait The bipedal gait is complex and depends on action of almost all parts of the nervous system. Gait is initiated in different ways depending on the purpose of the movement, whether intentional or reflexive. Gait…
Localization of Coordination Control and Deficits Coordination is a prominent part of the examination. Whereas coordination is typically considered to be a test of cerebellar function, coordination deficits can be produced by a wide range of lesions. Coordination depends on…
Sensory Systems Localization Two pathways, the dorsal columns and the spinothalamic tract, carry sensory information from the periphery to the brain, and they carry two distinct sets of information. Dorsal Columns The dorsal columns pathway is responsible for fine touch…
Motor System Localization Identification and description of motor deficits is critical for the understanding of neurologic localization. The assessment of the presence of weakness and other motor deficits provides an excellent basis for approaching the localization of brain lesions. Elements…
Cranial nerves are discussed elsewhere in this text. This chapter identifies some other commonly seen syndromes involving the brainstem and cranial nerves. Lesions affecting one cranial nerve solely or predominantly are discussed under the respective nerve; brainstem lesions producing cranial…
As in every aspect of the neurologic examination, the mental status examination can help to localize a lesion in the nervous system. It can also provide crucial information about the extent and severity of the patient’s deficits. The most important…
Neuromuscular Transmission Defects Neuromuscular transmission defects present with weakness and fatigability. The tendency to fatigue early and the absence of sensory symptoms are clues to these disorders. These defects are due to impaired synaptic transmission, either from impaired acetylcholine (ACh)…
Approach to Diagnosis Neuromuscular disorders have specific clinical findings, as discussed here, but part of the task of neuromuscular localization is ruling out a lesion of the spinal cord or brain. Central disorders producing peripheral manifestations usually affect systems other…
Spinal Cord Anatomy and Localization Localizing a lesion to a specific location within the cord is key to diagnosis. The differential diagnosis is narrowed by deciding exactly how the cord is affected through the following signs: ■ Corticospinal tract deficits…
Brainstem Dysfunction Midbrain Isolated cranial nerve (CN) III or CN IV palsy is rarely due to a midbrain lesion, despite the location of the nuclei. Midbrain lesions can produce partial or complete palsies of these cranial nerves plus hemiparesis from…