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
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
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