lokalisationssignaler

Lokalisationssignaler, or localization signs, are clinical signs that help localize the site of a neurological lesion by matching observed deficits to an anatomical structure or level within the nervous system. They are a fundamental part of the neurological examination and are used to guide diagnostic thinking. They differ from non-localizing signs, which do not point to a single site, and from diffuse signs that suggest widespread pathology.

Localization signs can be organized by anatomical level. Supratentorial and cortical signs include focal motor or sensory deficits that map to specific cortical areas, aphasia when dominant hemisphere language areas are affected, and neglect with parietal involvement. Brainstem signs arise from cranial nerve palsies or long-tract findings that localize to specific nuclei or pathways within the brainstem, often with crossing or pattern-specific deficits. Spinal cord signs include a defined sensory level, dissociated sensory loss, and motor abnormalities with upper motor neuron features below the lesion, sometimes with sphincter disturbances. Peripheral nerve signs are distributed along a nerve or nerve root, presenting as focal weakness, sensory loss in a dermatomal or perineural pattern, and reduced or absent reflexes. Myopathic and neuromuscular junction signs, by contrast, localize to muscle or the neuromuscular transmission apparatus.

In practice, lokalisationssignaler must be interpreted in the context of the whole examination, as multiple lesions or atypical presentations can blur localization. Imaging and laboratory tests are typically used to confirm or refine the localization suggested by clinical signs.