Download Peripheral Nerve Diseases

Peripheral Nerve Diseases
Prof. Dr. Ece AYDOĞ
Physical Medicine and Rehabilitation
Learning objectives:
be able to define parts of peripheral nervous system
be able to describe injuries in the peripheral nervous
system (neuropraxia, aksonotmezis, nörotmezis,)
be able to describe clinical signs of peripheral
neuropathy (somatic and autonomic)
be able to classify peripheral neuropathy according to
the causes
5.5 be able to describe diagnosis, pharmacological and
nonpharmacological treatment approaches for peripheral
neuropathy.
Peripheral Nervous System
(PNS)
The function of the PNS is to carry impulses to
and from to central nervous system
These impulses regulate motor, sensory and
automotic activities
The peripheral nervous system is comprised of
structures which lie outside the pial membrane
of the brainstem and spinal cord and can be
divided into cranial, spinal and autonomic
componenets.
The structure of the NERVE
CELL and AXON
Peripheral Nervous System
Structure of a Peripheral Nerve
􀁻 Endoneurium – loose
connective tissue that
surrounds axons
􀁻 Perineurium – coarse
connective tissue that
bundles fibers into
fascicles
􀁻 Epineurium – tough
fibrous sheath around
a nerve
PNS in the Nervous System
Receptor Classification by
Stimulus Type
􀁻 Mechanoreceptors – respond to touch,
pressure, vibration, stretch, and itch
􀁻 Thermoreceptors – sensitive to changes in
temperature
􀁻 Photoreceptors – respond to light energy (e.g.,
retina)
􀁻 Chemoreceptors – respond to chemicals (e.g.,
smell, taste, changes in blood chemistry)
􀁻 Nociceptors – sensitive to pain causing stimuli
The somatic system consists of
– 12 pairs of cranial nerves
– 31 pairs of spinal nerves:
8 cervical (C1-C8)
12 thoracic (T1-T12)
5 Lumbar (L1-L5)
5 Sacral (S1-S5)
1 Coccygeal (C0)
Spinal Nerves: Roots
􀁻 Each spinal nerve connects to the spinal
cord via two medial roots
􀁻 Ventral roots arise from the anterior
horn and contain motor (efferent) fibers
􀁻 Dorsal roots arise from sensory neurons
in the dorsal root ganglion and contain
sensory (afferent) fibers
Nerve Plexuses
All ventral rami except T2-T12 form interlacing
nerve networks called plexuses
Plexuses are found in the cervical,
brachial, lumbar, and sacral regions
Each resulting branch of a plexus
contains fibers from several spinal nerves
Each muscle receives a nerve supply from more
than one spinal nerve
Damage to one spinal segment cannot
completely paralyze a muscle
Brachial Plexus
Formed by C5-C8 and T1 (C4 and T2 may also
contribute to this plexus)
It gives rise to the nerves that innervate the
upper limb
Lumbar Plexus
Arises from L1-L4 and
innervates the thigh,
abdominal wall, and psoas
muscle
The major nerves are the
Femoral nerves for
anterior thigh muscles
Obturator nerves for
adductors muscles
Sacral Plexus
Arises from L4-S4 and
serves the buttock, lower
limb, pelvic structures, and
the perineum (pudendal
nerve)
The major nerve is the
sciatic, the longest and
thickest nerve of the body
– tibial
– common fibular
(peroneal)
Dermatomes
A dermatome is the area
of skin innervated by the
cutaneous branches of a
single spinal nerve
All spinal nerves except
C1 participate in
dermatomes
Pathologies of peripheral nerves
Nerves (Seddon and Sunderland
Classification)
Neurapraxia
Axonotmesis
Neurotmesis
Total conduction failure
(neurapraxia)
No function
Recovers spontaneously over days or
weeks (when the cause is resolved)
Results of spontaneous recovery are
almost always good
Neurapraxia
Epineurium
Perineurium
Endoneurium
Axon
Interruption of axons
(axonotmesis)
No function
New axon grows from cell body
(spontaneously)
Axonotmesis
Nerve may regenerate from injured
location away from the cell body
Regeneration: 1 mm per day (approx. 1
inch per month)
Results of spontaneous recovery are
good to moderate depending on
distance
Axonotmesis
Epineurium
Perineurium
Endoneurium
Axon
Type 2
Neurotmesis
Type 3
Type 4
Type 5
Interruption of nerve trunk
(neurotmesis)
No function
Does not regenerate spontaneously
Irreversible, grafting is required
Axonotmesis
Epineurium
Perineurium
Endoneurium
Type 2
Neurotmesis
Type 3
Type 4
Type 5
Axon
Peripheral Neuropathy
Mode of Onset
Acute
Subacute
Chronic
Peripheral Neuropathy
Acute: (A few days-4 weeks)
– Guillain-Barre Syndrome (GBS)
–
–
–
–
–
–
Traumatic
Vasculitis
Herpes Zoster
Diphtheria
Porphyria
Toxic (Thallium)
Peripheral Neuropathy
Sub-acute: (Devolop over weeks)
Symmetric..Sensory-motor
Toxic
Nutritional (Alcohol)
Paraneoplastic (Sensory neuronopathy)
Asymmetric...Motor-sensory
Vasculitis
Diabetic amyotrophy
Peripheral Neuropathy
Chronic:(Devolop over months,
years)
1-Acquired
–
–
–
–
–
Diabetic distal sensory neuropathy
Leprosy
Autoimmune neuropathies
Para-Neoplastic
Others ( uremia….)
Peripheral Neuropathy
2-Hereditary
– HMSN ( Charcot-Marie-Tooth )
– Refsum’s disease
– Hypertrophic polyneuropathy (DejerineSottas disease)
Causes
1. Nutritional, metabolic and toxic neuropathies;
the most common causes are diabetes mellitus and
alcoholism
Vitamin deficiencies,
Renal failure,
Chronic liver disease,
Drugs (e.g. vincristine),
Heavy metals,
Toxins (e.g. diptheria),
Chemicals (e.g. Hexane, glue)
Diabetes - distal symmetric, autonomic and focal or
multifocal asymmetric presentations
2-Inflammatory neuropathies
Infectious - shingles (VZV), leprosy
Vasculitic - polyarteritis, SLE
Guillain-Barré
Chronic inflammatory demyelinating
polyradiculopathy
3. Hereditary neuropathies
Hereditary sensory, motor and autonomic
neuropathies
Leukodystrophies
Porphyria
4. Miscellaneous neuropathies
Amyloid
Paraneoplastic
Compression
Mononeuropathies
Median nerve- Carpal tunnel Syndrome
Ulnar nerve-Cubital tunnel syndrome
Radial nerve- Spiral oluk tuzak
Posterior interosseous
neuropathy
Toracicus longus nerve-Serratus anterior
Winging scapula
Common Peroneal nerve-Fibula head
Lateral femoral cutaneous nerve-Meralgia paresthetica
Tibial nerve-Tarsal tunnel syndrome
Plexopathies
Brachial plexus-Erb palsy, Klumpke palsy,
Personage-Turner syndrome (idiopathic
brachial neuritis)
Lumbosacral plexus
Polyneuropathies
Diabetic neuropathies
Polyneuropathy (Sensory loss and distal
weakness)
Autonomic neuropathy (Postural
hypotension, impotence, nocturnal
diarrhoea)
Mononeuropathy (Diabetic amytrophy)
Polyneuropathies
Guillain-Barre Syndrome (GBS):
Acute inflammatory demyelination
polyradiculopathy
Peripheral Neuropathy
Symptomatology-Motor
Weakness:
– Lower motor-neuron type
hypotonia & hyporeflexia
fasiculation
wasting (chronic)
distal distribution
Peripheral Neuropathy
Symptomatology-Motor
Wasting & Deformities:
Chronic > 3 months duration
Kypho-scoliosis
Pes cavus – Clawing of hands & feet
Hereditary Motor-Sensory Neuropathy
Peripheral Neuropathy
Symptomatology-Sensory
Sensory Changes:
 Hyposthesia
Parastheasia
Dysthesia
Allodynia
Hyperalgesia
Peripheral Neuropathy
Symptomatology-Sensory
Distribution of sensory changes:
gloves & stocking
root or nerve distribution
Peripheral Neuropathy
Symptomatology-Autonomic
Autonomic manifestations:
Anhydrosis
Postural Hypotension
Bladder Atonia…incontinence
Gut Atonia….diarrhea
Sexual dysfunction
History
–
–
–
–
–
–
–
–
–
–
Time course (acute, subacute, chronic, episodic)
Negative: numbness
Postive: tingling, pain
Weakness and loss of function
Balance
Postural dizziness
DM
Medication
Social, toxins, diet
Family history
Examination/Evaluation
Observation of skin color, integrity, temperature
Presence of pressure points or ulceration
Strength testing
ROM/flexibility testing
Neurological testing
Reflexes
Sensation
Proprioception
Balance/coordination
Foot wear assessment
Diagnosis
A strong clinical suspicion will suffice to
make a clinical diagnosis. To support the
diagnosis some investigatios are
necessary these include:
Electromyography
Nerve biopsy
Nerve conduction studies
Magnetic resonance imaging
Computed tomography
Special Investigation
Nerve conduction studies
– Motor conduction velocity
– Sensory conduction velocity
Demyelination:
Marked slowing of conduction velocity (30% at least
reduced) with progressive reduction of amplitude.
Axonal change:
Reduced amplitude or absence of response to stimulation
with mild slowing of conduction velocity
Localized compression of nerve:
Slowing conduction in region of block e.g. Over the elbow
when ulnar nerve is compressed there.
Special Investigation
Electromyography (EMG)
A fine needle is inserted into the muscle and the
recorded activity displayed on an oscilloscope.
Primarily of value in muscle disease but can also
give indirect evidence of a neropathic process.
If chronic denervation has occured, reinnervation may be present with long duration
high amplitude motor unit potentials.
Special Investigation
Nerve biopsy
In neuropathies of uncertain cause, light
and electron microscopy examination
occasionally help diagnosis.
The sural nerve is usually chosen for
biopsy.
Treatment
Non pharmacological
Patient education
Maintaining optional weight
Avoiding exposure to toxins
Eating a balanced diet
Correcting nutritional deficiencies
Avoiding alchohol consumption
Exercise
Quitting smoking
Pharmacological
First line treatments
– Antidepressants (i.e., tricyclic antidepressants and dual
reuptake inhibitors of both serotonin and norepinephrine)
– Calcium channel α2-δ ligands (i.e., gabapentin and
pregabalin)
– Topical lidocaine
Second-line treatments
- Opioid analgesics and tramadol
Third-line treatments
-Antiepileptic and antidepressant medications, mexiletine, N
methyl-d-aspartate receptor antagonists, and topical
capsaicin
Physical Therapy and Rehabilitation
Aerobic conditioning
Progressive flexibility/stretching exercises
Progressive strengthening exercises
Balance/coordination
Gait training
Alternative
Monochromatic infrared
Vibrating insoles
Tai chi
Aerobic Conditioning
Flexibility Exercises
Assessment from trunk to feet
Goal is to normalize muscle length to allow
for normal mechanics with movement
Strengthening Exercises
Initial focus is on core, hip, knee, and
ankle strengthening
Progress into functional activities
Balance Exercises
Adaptive Devices
• Prophylactic measures (eg. pressure
sores)
• Orthotics
• Assistive devices
• Walking aids
• Wheelchairs
• Environmental modifications
Surgical Options
• Tendon transfers, releases
• Procedures for pain relief (eg. ablation,
implants)
• Joint stabilization
• Nerve repair, grafts