Horner's Syndrome and Pancoast Tumours Flashcards
What is Horner’s syndrome?
A triad of three unilateral symptoms: ptosis, anhidrosis and miosis
What is ptosis?
Drooping of the upper eyelid
What is anhidrosis?
absence of sweating
What is miosis?
Constricted pupil
In Horner’s syndrome there may also be enophthalmos. What is enophthalmos?
Posterior displacement of the eye
Describe the sympathetic nervous supply to the eye
Originates in the hypothalamus and descends via the brainstem to terminate in the ciliospinal centre (C8-T1)
A preganglionic fibre then exits then T1 root and travels close to the lung apex through the sympathetic chain and stellate ganglion to terminate in the superior cervical ganglion
the post ganglionic neuron then forms a plexus around the internal carotid artery and ascends into the cavernous sinus where it enters the orbit via the ophthalmic division of the trigeminal nerve
What structures in the eye does the ophthalmic division of the trigeminal nerve innervate?
Iris dilatory muscles
Smooth muscle fibres of the upper and lower lid
How do the nerve fibres which provide sympathetic innervation to the eye, affect the sweat glands?
These fibres follow the external carotid artery to supply the sweat glands of the ipsilateral side of the face
Horner’s syndrome can result from a lesion at any point in the neuronal pathway of the sympathetic innervation to the eye. T/F?
true
What is a Pancoast tumour?
A tumour which exists on the superior sulcus of the lung and has destructive lesions of the thoracic outlet
What are the most common tumour types of Pancoast tumours?
Squamous cell carcinomas or adenocarcinomas
Why is the location of a Pancoast tumour significant?
Because the local inflammatory effects of the tumour puts pressure on the surrounding nerves and blood vessels (i.e. stellate ganglion, brachial plexus, superior vena cava)
If a Pancoast tumour invades the brachial plexus, what symptoms will occur?
Shoulder pain
Weakness
Paraesthesia
Pancoast tumours can result in Horner’s syndrome. Why is this?
Horner’s syndrome can result from compression of the T1 sympathetic nerve root which can occur with Pancoast tumours
How can Pancoast tumours result in erythema, oedema and a decrease venous return resulting in dyspnoea?
By compressing the superior vena cava if the Pancoast tumour is located in the right lung
What imaging techniques are used to diagnose Pancoast tumours?
CT
CXR
How are Pancoast tumours treated?
This depends on the types of tumour involved and its effect on surrounding structures
surgery is used to remove the tumour
Often chemotherapy or radiotherapy is required pre-surgery to shrink the tumour
From which nerve roots does the brachial plexus arise?
C5-T1
Which spinal nerves combine to form the superior trunk of the brachial plexus?
C5/6
Which spinal nerves combine to form the inferior trunk of the brachial plexus?
C8/T1
Which spinal nerve(s) form the middle trunk of the brachial plexus?
C7
Which cord of the brachial plexus do the anterior branches of the superior and middle trunks form?
Lateral cord
The three posterior branches of the superior, middle and inferior trunks of the brachial plexus form which cord?
Posterior cord
Which branch of the brachial plexus forms the medial cord?
Anterior branch of the inferior trunk
A branch from the lateral cord and medial cord combine to form which terminal nerve branch of the brachial plexus?
Median nerve
From which cord of the brachial plexus do the axillary and radial nerves form?
Posterior cord
From which cord of the brachial plexus does the musculatocutaneous nerve form?
Lateral cord
From which cord of the brachial plexus does the ulnar nerve form?
Medial cord
From which cord of the brachial plexus do the medial pectoral, medial cutaneous nerve of the arm and medial cutaneous nerve of the forearm arise?
Medial cord
From which cord of the brachial plexus do the upper sub scapular, thoracodrosal and lower sub scapular nerve arise?
Posterior cord
From which cord of the brachial plexus does the lateral pectoral nerve arise?
Lateral cord
From which trunk of the brachial plexus do the supra scapular and subclavius nerve arise?
Superior trunk
From which nerve roots does the dorsal scapular nerve arise?
C5/6/7
Why are biopsies particularly useful in the diagnosis of Pancoast tumours?
To determine the cell type of the cancer involved
What diagnostic tests can be used to check for metastasis of Pancoast Tumours?
CT or mRU of the brain
Mediastinoscopy (determine spread to the mediastinum)
What factors worsen the prognosis of a Pancoast tumour?
Presence of Horner syndrome
mediastinal lymph involvement
Incomplete surgical removal of the tumour
