Findings Helpful for Localizations within the Nervous System | |
| SIGNS | |
|---|---|
| Cerebrum | Abnormal mental status or cognitive impairment |
| Seizures | |
| Unilateral weaknessa and sensory abnormalities including head and limbs | |
| Visual field abnormalities | |
| Movement abnormalities (e.g., diffuse incoordination, tremor, chorea) | |
| Brainstem | Isolated cranial nerve abnormalities (single or multiple) |
| “Crossed” weaknessa and sensory abnormalities of head and limbs, e.g., weakness of right face and left arm and leg | |
| Spinal cord | Back pain or tenderness |
| Weaknessa and sensory abnormalities sparing the head | |
| Mixed upper and lower motor neuron findings | |
| Sensory level | |
| Sphincter dysfunction | |
| Spinal roots | Radiating limb pain |
| Weaknessb or sensory abnormalities following root distribution (see Figs. 183-1. The Cutaneous Fields of Peripheral Nerves and 183-2. Distribution of the Sensory Spinal Roots on the Surface of the Body (Dermatomes)) | |
| Loss of reflexes | |
| Peripheral nerve | Mid or distal limb pain |
| Weaknessb or sensory abnormalities following nerve distribution (see Figs. 183-1. The Cutaneous Fields of Peripheral Nerves and 183-2. Distribution of the Sensory Spinal Roots on the Surface of the Body (Dermatomes)) | |
| “Stocking or glove” distribution of sensory loss | |
| Loss of reflexes | |
| Neuromuscular junction | Bilateral weakness including face (ptosis, diplopia, dysphagia) and proximal limbs |
| Increasing weakness with exertion | |
| Sparing of sensation | |
| Muscle | Bilateral proximal or distal weakness |
| Sparing of sensation | |
a Weakness along with other abnormalities having an “upper motor neuron” pattern, i.e., spasticity, weakness of extensors > flexors in the upper extremity and flexors > extensors in the lower extremity, and hyperreflexia.
b Weakness along with other abnormalities having a “lower motor neuron” pattern, i.e., flaccidity and hyporeflexia.