Diseases of Autonomic Nervous System I Autonomic Nervous System II Nervous System Physiology I This video will cover the following topics: 1. Diseases of Sympathetic Nervous System 2. Horner Syndrome- Pathophysiology, Etiology, Clinical features 3. Raynaud Phenomenon- Pathophysiology, Clinical features 4. Diseases of the Parasympathetic Nervous System 5. Argyll Robertson Pupil- Pathophysiology, Clinical features 6. Adie tonic Pupil- Pathophysiology, Clinical features You can also watch the same topic on HM Learnings Youtube channel. You can also follow HM Learnings on facebook, instagram and twitter for daily updates

3. Diseases of Sympathetic Nervous System
• Horner Syndrome
• Raynaud Phenomenon

4. Horner Syndrome
• Injury of the sympathetic tract heading towards the face.
Pathophysiology
• Injury of the sympathetic-face innervation along their course will
cause horner syndrome.
• Therefore, any injury either to the higher input centres to sympathetic
outflow (brainstem/ reticulospinal tract) or to the preganglionic
neuron or to the postganglionic neuron or to the cervical ganglion or
to the carotid artery (pericarotid plexus) will lead to manifestation of
the clinical features of horner syndrome.

6. • Sympathetic nervous system innervates the following structures in the
face:
1. Superior tarsal muscle (Muller muscle)
2. Inferior tarsal muscle
3. Orbitalis
4. Dilator pupillae
5. Sweat glands
6. Blood vessels

7. Aetiology
1. Malignancy of cervical lymph nodes that passes on to cervical
sympathetic chain.
2. Pancoast tumour of lungs
3. multiple myeloma
4. syringomyelia
5. traction of cervical rib
6. Injury to carotid artery

8. Clinical Features
1. Ptosis- drooping of upper eyelid due to paralysis of muller muscle
2. Miosis- constriction of pupil due to paralysis of dilator pupillae
3. Anhydrosis- impaired sweat secretion in one half of the face
4. Blushing/ flushing of same half of face due to loss of sympathetic
vasoconstrictor effect

9. Raynaud Phenomenon
• Vasospastic disease due to the hyperactivity of vasoconstrictor
sympathetic fibers affecting digital arteries of fingers, toes, tip of nose,
ears and penis.
• Bilateral disorder
• precipitated by cold and smoking.

10. Clinical Features
Triphasic change in colour of skin of digits-
A. Pallor (pale), cold and numb skin due to vasospasm.
B. Cyanosis (blue skin) and intense pain due to reduced blood flow.
C. Rubor (redness and swelling) due to recovery of blood flow.

11. Diseases of Parasympathetic Nervous System
• Argyll Robertson Pupil
• Adie tonic pupil

12. Argyll Robertson Pupil
• Injury to the Pretectal nucleus of midbrain.
• Aetiology- neurosyphilis
Pathophysiology
• Accommodation reaction is a triple response reaction which involves
pupillary constriction, convergence of visual axis and contraction of
ciliary muscle to increase the curvature of lens.
• As this reaction doesn’t involve pretectal nucleus, it will be present in
argyll Robertson pupil
• Under normal conditions, pretectal nucleus is inhibitory to Edinger
Westphal nucleus and thus inhibits it to cause pupil constriction.

13. • When light falls on eyes, this inhibition will be lost and EWN can
cause the pupil constriction by oculomotor nerve. This enables the
pupil to respond to light which is called as pupillary light reflex.
• But when there is injury to pretectal nucleus, even under normal
conditions, the pupil remains constricted as pretectal inhibition is lost.
• Thus pupillary light reflex i.e. the ability of pupil to respond to light is
lost in argyll roberston pupil

15. Pupillary reaction

16. Clinical Features
1. Accommodation reaction with pupillary response is present
2. Pupillary light reflex is absent
3. Constricted pupil (miosis)

17. Adie tonic pupil
• Suppression of parasympathetic ocular function
Clinical Features
1. delayed accommodation
2. diminished or absent light reflex
3. delayed pupil dilation in darkness