This document provides an overview of peripheral neuropathy, including: 1) It defines peripheral neuropathy and outlines the anatomy of the peripheral nervous system. 2) It classifies peripheral neuropathies based on anatomy, nerve fiber diameter, and pathological basis. 3) It discusses the key differences between axonopathies and myelinopathies, including typical symptoms and prognosis.

1. APPROACH TO
PERIPHERAL
NEUROPATHY
Speaker: Dr. Ritwik Ghosal MBBS(HONS) MRCP-1(UK)
MD( MEDICINE PGT)

2. Introduction
• Peripheral neuropathy is the term for damage to nerves of the
peripheral nervous system, which may be caused either by
diseases of the nerve or from the side-effects of systemic
illness.

3. • HUMAN NS-----CNS
• -----PNS
• EACH NEURON has 3 parts
• SOMA
• DENDRITES
• AXON

4. -Anterior horn cell
-Motor neuron
-Ventral root
-Dorsal root ganglion
-Dorsal root
-Plexus
-Peripheral nerve
-Axon
-Myelin sheath
-Neuromuscular
junction
-Muscle

5. Basis of classification of PN
Anatomy
Nerve fibre diameter
Pathological basis

6. Classification( anatomical)
1) Mononeuropathy
2) Plexopathy- brachial, lumbar, sacral
3) Radiculopathy- cervical, thoracic, lumbosacral
4) Multiple mononeuropathy( mononeuropathy multiplex)
5) Polyneuropathy- symmetrical/ asymmetrical
6) polyradiculoneuropathy

7. Role of nerve fibres in
peripheralneuropathy

10. #1. Where is the lesion?
#2. What is the etiology?
#3. What is the treatment?
The 3 questions of clinical neurology…
www.ama-assn.org/ ama/pub/category/7172.html

11. Key pointerfor Axonopathies
• By far the majority of the toxic, metabolic and endocrine
causes
The pathologic changes usually begin in the far distal
parts of the largest & longest nerves & advance along the
affected fibers towards their nerve cell bodies ( dying
back neuropathy)
for this reason muscles of feet & legs are affected
earlier & more severely than those of hands & forearm.
Symmetric distribution of weakness

12. Key pointerMyelinopathies
Clues: hypertrophic nerves on exam
global areflexia
weakness without wasting
motor >> sensory deficit.

13. Key difference
Axonopathy
1. Distal symmetrical
lower limb weakness.
2. Atrophy characteristics
3. Poor prognosis.
Myelinopathy
1. Weakness of proximal
limb & facial muscles
before or at the same
time as distal parts.
2. Atrophy usually absent.
3. Better prognosis than
axonopathies.

15. Copyright ©2002 BMJ Publishing Group Ltd.
Hughes, R. A C BMJ 2002;324:466-469
Using nerve conduction studies in polyneuropathy
http://www.neuroanatomy.wisc.edu/SClinic/Weakness/Weakness.htm
= Slow!
= Low!
= Slow!

16. 7 Questions?
1) Systems (Fibers) involved?
2) Distribution?
3) Nature of sensory involvement?
4) Evidence of UMN involvement?
5) Temporal involvement?
6) Evidence for hereditary neuropathy?
7) Associated medical conditions?

17. Peripheral neuropathy by
clinical courseAcute onset (days to 4 weeks) Guillain-Barré syndrome
Acute intermittent porphyria
Critical illness polyneuropathy
Thallium toxicity
Subacute onset (4-8 weeks) Toxins or medications
Nutritional deficiency
Metabolic abnormality
Paraneoplastic syndrome
CIDP
Chronic course (>8 weeks) Hereditary motor and sensory neuropathy
(HMSN)
Inherited sensory neuropathy
CIDP
Relapsing/remitting course Guillain-Barré syndrome
CIDP
HIV/AIDS
Toxin (intermittent exposure)
Porphyria

18. Personal history
1. Associated medical illness? : DM, Hypothyroidism,
connective tissue disease, cancer
2. Drug history?
3. High risk occupation? : HIV

20. Amyloid
neuropathy

21. Loss of function
“negative symptoms”
Disturbed function
“positive symptoms”
Motor nerves Weakness
Atrophy
Walking difficulties
Muscle cramp
Fasciculation
Myokymia
Tremor
When do we suspect motor nerve involvement?

22. www.neuro.wustl.edu/neuromuscular/pics/people/patients/Hands/handatrophymnd3.jpg

23. Polyneuropathy with
predominantly motor
manifestation
1) GBS
2) Lead intoxication
3) Acute motor axonal neuropathy
4) Multifocal motor neuropathy
5) CIDP
6) Hereditary motor sensory neuropathies( CMT)
7) Neuropathy with osteosclerotic myeloma

24. PNP with UL>LL motor
involvement
1) Lead neuropathy
2) Porphyria
3) Familial amyloid neuropathy t-2
4) Tangier disease
5) Multifocal motor neuropathy

25. -Metabolic
-Toxic or drug
-Nutritional
deficiency
Polyneuropat
hy caused by

26. Loss of function
“negative symptoms”
Disordered function
“positive symptoms”
Sensory
“Large Fiber”
↓ Vibration
↓ Proprioception
Hyporeflexia
Sensory ataxia
Paresthesias ( 60%
in acquired & 17% in
inherited PN)
Sensory
“Small Fiber”
↓ Pain
↓ Temperature
Hyperalgesia
Allodynia
TWWhen do we suspect sensory neuropathy

28. Pattern of sensory loss
POLY
NEUROPAT
HY
Symmetrical,distal,legs>arms
Can even progress to face
SEVERE
AXONAL
NEUROPAT
HY
ESCUTCHEON pattern of sensory
loss over abdomen and thorax
SENSORY
GANGLION
OPATHY
Sensory loss of trunk,scalp,face due
to simultaneous damage of
proximal&distal part of sensory
nerve

29. Small-fiber neuropathies
1) DM & IGT
2) Amyloid neuropathy
3) HIV-associated distal sensory neuropathy
4) Fabry disease
5) Tangier disease
6) Sjogren syndrome
7) Cryptogenic small fiber neuropathy

30. Asymmetric proprioceptive
sensory loss without weakness
Consider causes of sensory neuronopathy( ganglionopathy)
i. Paraneoplastic
ii. Sjogren syndrome
iii. Toxic- cisplatin& other chemotherapeutics
iv. HIV related
v. Vitamin B6 toxicity

31. Loss of function
“- symptoms”
Disturbed function
“+ symptoms”
Autonomic nerves ↓ Sweating
Hypotension
Urinary retention
Impotence
Vascular color changes
↑ Sweating
Hypertension
The When do we suspect autonomic involvement

32. Salient pointer
• Orthostatic hypotension, fainting spells, heat intolerance or
any bladder, bowel, or sexual dysfunction.
• Orthostatic fall in BP without an appropriate increase in heart
rate.
• These features in absence of diabetes should alert
the clinician to the possibility of amyloid
polyneuropathy.

33. NP with autonomic system
involvement
A. Acute-
i. acute panautonomic neuropathy( idiopathic,
paraneoplastic)
ii. GBS
iii. Porphyria
iv. Toxic
B.Chronic-
i. DM
ii. Amyloid neuropathy
iii. Paraneoplastic sensory neuropathy
iv. HIV related
v. Hereditary sensory & autonomic neuropathy

34. Clues from general survey?
• Pulse & BP- orthostatic hypotension without tachycardia: AIN
hypertension : CKD
• Respiration- GBS
• Anaemia- Vitamin B12 deficiency, CKD
• Goitre- Hypothyroidism
• Skin & skeletal changes- DM, Leprosy , Amyloid, Connective
tissue diseases.

35. Clue from general survey
VASCULITIS PURPURA,LIVEDORETICU
LARIS
CRYOGLOBULINEMI
A
PURPURA
FABRY’S DISEASE ANGIOKERATOMAS
LEPROSY SKIN
HYPERPIGMENTATION
OSTEOSCLEROTIC
MYELOMA-POEMS
HYPERPIGMENTATION
VARIEGATE
PORPHYRIA
BULLOUS LESIONS

37. REFSUM’S DISEASE ICTHYOSIS
ARSENIC/THALLIUM
INTOXICATION
MEE’S LINES
THALLIUM
POISONING
ALOPECIA
GIANT AXONAL
NEURPATHY
CURLED HAIR

39. NERVE THICKENING in NPthy
• LEPROSY
• DIABETES
• AMYLOIDOSIS
• NEUROFIBROMATOSIS
• REFSUM’S DISEASE
• DEJERINE SOTTAS DISEASE
• ROUSSY LEVY SYNDROME

41. Where do we get deformity?
• Pressure sores
• Amputations of toe
• Burns
• Pes cavus
• High arch palate
• Claw foot & hand

43. CMT deformities

44. Multiple mononeuropathy
A. Axonal injury
I. Vasculitis ( systemic , nonsystemic)
II. Diabetes melitus
III. Sarcoidosis
IV. Hansen disease
V. HIV-1 infection
B.Demyelination
I. Multifocal motor neuropathy
II. Lewis- sumner syndrome
III. Multiple compression neuropathy (DM, hypothyroid)
IV. Hereditary neuropathy with liability to pressure palsies

45. Multiple
mononeuropathy
with vasculitis

46. NP with facial nerve
involvement
1) GBS
2) HIV-1
3) Sarcoidosis
4) CIDP
5) Lyme disease
6) Tangier disease
7) Gelsolin familial amyloid neuropathy ( finnish)

48. Investigations
Complete haemogram including MCV
FBS, TSH, Creatinine
Urinalysis
 HIV-1, HBsAg, Anti HCV , CMV Titer
ANF, P-ANCA, Rheumatoid factor, ESR
SPEP
CSF study – GBS, Infective causes
ECG with valsalva, CXR
Electrodiagnostic study
Nerve biopsy

50. Indications for nerve biopsy
Essential in
i. Vasculitis
ii. Amyloidosis
iii. Sarcoidosis
iv. Hansen disease
v. Giant axonal neuropathy
vi. Tumour infiltration
Supportive in
i. CMT T-1 & 3
ii. CIDP
iii. Paraneoplastic neuropathy

53. Treatment
• General
• Subtype specific
• Diabetes mellitus
• Renal insufficiency
• Hypothyroidism
• Vitamin B12 deficiency
• Systemic vasculitis

55. Treatment
• Preventative and palliative
• Weight reduction
• Assiduous foot care
• Good shoes
• Ankle-foot orthoses as needed
•Several organizations provide support