Neurological Examination - Interpretation

Interpretation

The results of the examination are taken together to anatomically identify the lesion. This may be diffuse (e.g. neuromuscular diseases, encephalopathy) or highly specific (e.g. abnormal sensation in one dermatome due to compression of a specific spinal nerve by a tumor deposit).

General principles

• Looking for side to side symmetry: one side of the body serves as a control for the other. Determining if there is focal asymmetry.
• Determining if the process involves the peripheral nervous system (PNS), central nervous system (CNS) or both. Considering if the finding (or findings) can be explained by a single lesion or whether it requires a multifocal process.
• Establishing the lesion's location. If the process involves the CNS, clarifying if it is cortical, subcortical, or multifocal. If subcortical, clarifying if it is white matter, basal ganglia, brain stem or spinal cord. If the process involves the PNS then determining if it localizes to the nerve root, plexus, peripheral nerve, neuromuscular junction, muscle or if it is multifocal.

A differential diagnosis may then be constructed that takes into account the patient's background (e.g. previous cancer, autoimmune diathesis) and present findings to include the most likely causes. Examinations are aimed at ruling out the most clinically significant causes (even if relatively rare, e.g. brain tumor in a patient with subtle word finding abnormalities but no increased intracranial pressure) and ruling in the most likely causes.