By the end of this presentation, you will be able to:

  • Findings on contralateral side:
  • Diagram: Show crossed vs. uncrossed pathways.

    • | Tract | Origin | Decussation | Function | Lesion Effect | | :--- | :--- | :--- | :--- | :--- | | Lateral Corticospinal | Motor cortex (area4) | Medulla (90%) | Fine, skilled movement | Ipsilateral UMN signs | | Anterior Corticospinal | Motor cortex | Spinal segment | Proximal muscles | Minimal (redundant) | | Rubrospinal | Red nucleus | Midbrain | Flexor tone | Minimal in humans | | Vestibulospinal | Vestibular nuclei | None | Extensor tone | Ipsilateral hypotonia | | Reticulospinal | Reticular formation | Mixed | Posture, locomotion | Autonomic dysfunction | | Tectospinal | Superior colliculus | Midbrain | Head/eye reflexes | Impaired orienting |

    | Tract | Funiculus | Sensation | Decussation | Destination | | :--- | :--- | :--- | :--- | :--- | | Fasciculus gracilis (DCML – lower) | Posterior | Vibration, fine touch | Medulla | Thalamus | | Fasciculus cuneatus (DCML – upper) | Posterior | Vibration, fine touch | Medulla | Thalamus | | Lateral Spinothalamic | Lateral | Pain, temperature | Spinal cord | Thalamus | | Anterior Spinothalamic | Anterior | Crude touch | Spinal cord | Thalamus | | Posterior Spinocerebellar | Lateral (peripheral) | Unconscious proprio | None (ipsilateral) | Cerebellum |

    Title: Dorsal Column (Fine Touch & Vibration) Content:

  • Key Clinical: Damage causes loss of vibration sense and fine touch on the same side below the lesion (if lesion is below medulla).

    • Title: Conclusion Content: