The document discusses the peripheral nervous system (PNS) which is divided into the somatic and autonomic nervous systems. The somatic system includes spinal nerves and cranial nerves which innervate skeletal muscles. The autonomic system regulates functions of internal organs. Some common neuropathies that can affect the PNS are discussed such as carpal tunnel syndrome, ulnar neuropathy, and polyneuropathies including Guillain-Barré syndrome. Plexopathies like brachial plexopathy and lumbosacral plexopathy are also summarized.

2.  Part of nervous system outside CNS
 Nerves from brain and spinal cord
PNS is divided into :
1.Somatic
2.Autonomous

3.  Nerves from cns to skeletal muscles
1.spinal nerve
a. 8 pairs of cevical nerves
b. 12 pairs of thoracic nerves
c. 5 pairs of lumbar nerves
d. 5 pairs of sacral nerves
e. 1 pair of coccygeal nerves
Attached to spinal cord by 2 roots -
dorsal and ventral root s

4. 2. cranial nerves
 Cell bodies in brain
 12 pairs
olfactory , optic , occulomotor , trochlear
, trigeminal , abducens , facial
, vestibulocochlear , glossopharyngeal
, vagus , spinal accessory , hypoglossal
nerves

5.  Supply all tissues other than skeletal muscles
 ANS is divided into –
1.sympathetic consisting of thoracic and
lumbar ganglia
2.parasympethetic consisting of
III,VII,IX,X cranial nerves and 2, 3,4 sacral
segments of the spinal nerves

6.  Lesions/diseases affecting neve roots –
radiculopathy
 Lesions/diseases affecting nerve plexus-
plexopathy
 Lesions/diseases affecting individual nerves-
neuropathy

7.  It can be of
a. focal affecting a single nerve –
mononeuropathy
b.multifocal affecting several nerves –
mononeuropathy multiplex
c.generalised - polyneuropathy

8. I. ENTRAPMENT NEUROPATHY
 Due to compression/or entrapment of single
nerve
 Pathology – presure damages myelin
sheath,axons and cause slowing of conduction
 eg.
median nerve – carpel tunnnel syndrome
ulnar nerve at elbow
radial nerve compression
common peroneal nerve compression
lateraL cutaneous nerve of thigh compression

9. NERVE MUSCLE AREA OF SENSORY
WEAKNESS LOSS
MEDIAN NERVE LAT PALM
(CARPEL ABDUCTOR POLLICIS &THUMB,INDEX
TUNNEL SYN.) BREVIS MIDDLE ,LAT HALF OF
4TH FINGER
MEDIAL PALM,LITTLE
ULNAR (AT ALL SMALL HAND USCLES AND MEDIAL HALF
ELBOW) EXCLUDING APB OF 4TH FINGER
RADIAL SUPINATOR DORSUM OF THUMB
WRIST & FINGER
EXTENSORS
COMMON DORSIFLEXION AND DORSUM OF FOOT
PERONEAL EVERSION OF FOOT – FOOT
DROP
LATERAL LATERAL BORDER OF
CUTANEOUS NIL THE THIGH
NERVE OF
THIGH

10. II. TRIGEMINAL NEUROPATHY
 Unilateral facial sensory loss
 Associated with scleroderma,sjogren syndrome
 Reactivation of varicella virus in trigeminal
ganglion causes herpes zoster

11. III. FACIAL NERVE PALSY
 Also called bell’s palsy
 Causes – lesion within facial canal or maybe
due to reactivation of latent herpes simplex
virus 1 infection
 Symptoms – pain around ears
unilateral facial weakness
deviation of angle of mouth

12. IV. HEMIFACIAL SPASM
 Seen after middle age
 Intermittent twitching around one eye
spreading ipsilaterally to other parts of facial
muscles
 Spasms exacerbated by talking,eating or stress
 Cause – an aberrant arterial loop irritating the
nerve just outside the pons

13.  Involvement of several isolated nerves
 Nerves involved are widely seperated leading
to asymmetrical pattern
 Clinical pattern resemble polyneuropathy
 Due to involvement of vasa nervosum or
malignant infiltration of nerves
 causes ; acute –
DM, vasculitis,diphtheria,lymes
disease,cryoglobinemia
chronic –
DM,leprosy,paraprotinaemia,HIV,sarcoidosis

14.  Simultaneous involvement of many peripheral
nerves
 Symmetric and distal loss of functions
 Distal lower limbs are involved first and later
the distal upper limbs
 Glove and stocking sensory loss

15. I . GUILLAIN-BARRE SYNDROME
 Syndrome of acute paralysis
 In 70%of patients within 1-4 weeks after
respiratory infection or diarrhoea
 Pathology – CMI responses directed at myelin
proteins of spinal roots and nerves
- due to mimicry between epitopes in micro
organisms and gangliosides
 Release of cytokines block nerve conduction

16. Clinical features include
 Distal paraesthesia & limb pain
 Rapidly ascending muscle weakness
 Facial and bulbar weakness
 Ultimately respiratory weakness

17. II . CHRONIC POLYNEUROPATHY
 Most frequent
 Two types
- chronic demyelinating polyneuropathy –
hereditary and immune mediated
-chronic axonal polyneuropathy

18. I . BRACHIAL PLEXOPTHY
 Trauma to the brachial plexus
 Causes- infiltration from breat or apical lung
tumour
-anatomical abnormalities
 According to site:-
-upper plexus (root- C5/6)
-lower plexus (root – C8/T1)
-thoracic outlet syndrome (root – C8/T1)

19. SITE ROOT AFFECTED SENSORY LOSS
MUSCLES
UPPER PLEXUS BICEPS,DELTOID
C5/6 ,SPINATI,RHOM PATCH OVER
(erb-duchenne BOIDS,BRACHIO DELTOID
syndrome) RADIAALIS
LOWER PLEXUS ALL SMALL
C8/T1 HAND ULNAR BORDER
(dejerine-klumpke MUSCLES,ULNA HAND/FOREAR
syndrome) RWRIEST M
FLEXORS
THORACIC ULNAR BORDER
OUTLET C8/T1 SMALL HAND HAND/FOREAR
SYNDROME MUSCLES,ULNA M/UPPERARM
R FOREARM

20. II . LUMBOSACRAL PLEXOPATHY
 Causes –
neoplastic infiltration
compression by retroperitoneal haematomas in
patients with coagulopathy
 Presents with painful wasting of quadriceps
with weakness of knee extension and
adduction, absent knee jerk

21.  Causes : -
- compression at or near spinal exit foramen
by prolapsed intervertebral disc
-degenerative spinal disease
-infiltration by spinal and paraspinal tumour
masses

22. Clinical features
 Muscle weakness
 Muscle wasting
 Dermatomal sensory loss
 Pain in the muscles whose motor roots are
involved

23. Thank you