Bilateral ventral pons
Signs & Symptoms
|Both||Weakness – upper and lower extremity||Quadriplegia: bilateral cortical spinal tracts|
|Both||Weakness – face – entire side||Bilateral corticobulbar tracts|
|Neither||Lateral gaze weakness||Bilateral fascicles of CN VI|
|Neither||Dysarthria||Bilateral corticobulbar tracts|
Bilateral ventral pons lesions (iscemic or hemorrhagic) may result in this deefferented state, with preserved consciousness and sensation, but paralysis of all movements except vertical gaze and eyelid opening.
- Quadriplegia due to bilateral corticospinal tract involvement
- Aphonia due to corticobulbar tract involvement to lower cranial nerve nuclei
- Occasionally, impairment of horizontal eye movements due to bilateral involvement of the fasciclesof cranial nerve
- Reticular formation is spared, so the patient is typically fully awake. The supranuclear ocular motor pathways lie dorsally, so that vertical eye movements and blinking are intact.