Classification and anatomy of the sensory system

1. Big picture

The sensory system is one of the most important systems for neurological localization. In the exam, the key is not only to list sensory modalities, but to know which pathway carries which sensation, where the pathway crosses, and what lesion pattern results when one pathway is damaged.

The central idea:

Pain and temperature = spinothalamic pathway Vibration, joint position and discriminative sensations = dorsal column-medial lemniscus pathway Unconscious proprioception = spinocerebellar pathway

This explains many classic neurological patterns: syringomyelia, tabes dorsalis, Brown-Séquard syndrome, brainstem alternating sensory loss, thalamic sensory loss, and cortical sensory disturbances.