PBL - Weak Hand And Drooping Eyelid Flashcards
Where would pain be felt if a Pancoast tumour encases the C8 nerve root, and what would happen to the muscles in that area?
Medial two digits of the hand would be painful
The intrinsic muscles of the hand would atrophy
Describe the pain that would be felt if a tumour interferes with the T1 nerve root?
Pain which radiates down the medial aspect of the arm and forearm, stopping at the wrist
If there is a disruption to the sympathetic nerves of the eye, what symptoms occur?
Ptosis Miosis Hemi-facial anhidrosis Loss of head and neck sympathetic tone Enophthalmos
Describe the sympathetic pathway to the eye.
First order neuronal fibres
Second order neuronal fibres (pre ganglionic)
Third order neuronal fibres (postganglaionic)
Describe when first-order neuronal fibres arise and end in sympathetic innervation of the eye
Arise from poster-lateral hypothalamus
Descend through brainstem until termination at C8-T2
Describe when second-order neuronal fibres arise and end in sympathetic innervation of the eye
Exit through T1 root, travelling close to lung apex through sympathetic chain and cervical-thoracic ganglion
Terminate in superior cervical ganglion
Describe when third-order neuronal fibres arise and end in sympathetic innervation of the eye
Exit ganglion forming plexus around carotid internal. Ascending into cavernous sinus
Runs to eye via CN4and CN51
What does the sympathetic innervation of the eye supply do?
Supplies iris dilator muscles
Supplies smooth muscle of upper and lower lid
Which fibres of the face cause sweating and tone to occur?
Vasomotor and sweat gland fibres
- form plexus around external carotid artery
Which order of neuronal fibres are affected by a pancoast tumour to cause horners syndrome?
Second order neuronal fibres
- called a second order neuronal lesion
Are pancoast tumours the only thing that can cause horners syndrome?
No - if any of the orders of neuronal fibres are affected in any way, the syndrome can appear
Why does enopthalmos occur?
Loss of sympathetic supply to the eye causes narrowing of the palpebral fissure, causing the ILLUSION of enopthalmos
How can upper limb swelling and discolouration be caused by a pancoast tumour?
Tumour growth in the lung apex can completely or partially compress the subclavian vein
What problems in the upper limb can be caused by a pancoast tumour - and why?
Upper limb swelling and discolouration Loss of vascular tone (loss of sympathetic innervation) Oedema (failure of venous drainage) Tenderness Erythema Warmth
Which anatomical structures allow the formation of three compartments within the thoracic inlet?
Insertion of the anterior and middle scalene muscle on the posterior scalene muscle (on second rib)