2. neuropathies

Neuropathies

Neuropathies1Dr. RS Mehta, BPKIHS

What is NeuropathyNeuropathy is a disorder resulting from injury to the peripheral nerves the motor, sensory and autonomic nerves. The main function of the peripheral nervous system is to connect thecentral nervous system (CNS) to the limbs and organs.Unlike the CNS, the PNS is not protected by theboneof spine and skull, or by theblood brain barrier, leaving it exposed to toxinsand mechanical injuries.

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Review Basic Concept of Nerves3Dr. RS Mehta, BPKIHS

SynapsesFigure 11.17


Reflex ArcFigure 13.14

Receptor1234Sensory neuronIntegration center5EffectorMotor neuron

StimulusSkin

Spinal cord (in cross-section)Interneuron


Structure of a NerveFigure 13.3b


Regeneration of Nerve FibersFigure 13.4


Cranial Nerve X: VagusFigure X from Table 13.2


Spinal NervesFigure 13.6


Brachial PlexusFigure 13.9a


After the PNS is damaged!The deterioration of the peripheral nerves disrupts the bodys ability to communicate with its muscles, organs and tissues.Neuropathy is like the bodys wiring system going haywire, causing unusual or unpleasant irritations including tingling, burning, itchiness, dizziness and many many more!If ignored, as this is done often these symptoms can lead to numbness at one extreme to unremitting pain at the other. It can come and go, slowly progress over many years or become severe and debilitating.


Neuropathy a rare illness ???Often it is misdiagnosed or thought of merely as a side effect of another disease such as diabetes or cancer or even kidney failure. It can occur at any age however it is more common among older adults. 12Dr. RS Mehta, BPKIHS

Neuropathy= pathological processes damaging a nerve or nerves.

The mechanisms of damage may be:- Demyelination e.g. GB Syndrome Axonal degeneration: e.g. Toxic neuropathies Compression: Causes segmental demyelination e.g. Entrapment N.4. Vasculopathy (infarction): e.g. DM5. Infiltration: e.g. leprosy, sarcoidosis. 13Dr. RS Mehta, BPKIHS

Types of NeuropathyNeuropathies may affect just one nerve,- a condition called mononeuropathy, or several nerves called polyneuropathy.

The peripheral nervous system is part of the nervous system that includes nerves in the face, arms, legs, torso, and some nerves in the skull. In fact, all the nerves which are not located in the central nervous system (which includes the brain and the spinal cord) are peripheral nerves.


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There are four types of neuropathy:


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A number of conditions can lead to damage of the autonomic nerves and these possible causes are similar to those for peripheral neuropathies. The most common cause is diabetes.Other causes include:AlcoholismAmyloidosis- abnormal protein buildup in organsAutoimmune diseasesTumorsMultiple system atrophySurgical or traumatic injury to nervesCertain medications, (including chemotherapy drugs and anticholinergics)Parkinsons disease and HIV/AIDS

Autonomic Neuropathy (AN)16Dr. RS Mehta, BPKIHS

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More than 100 types of peripheral neuropathy have been identified, each with its own characteristic set of symptoms, pattern of development, and prognosis.Peripheral Neuropathy (PN)

Dr. RS Mehta, BPKIHS17

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Peripheral Neuropathies18Dr. RS Mehta, BPKIHS

Peripheral nerve diseases: 1- Mononeuropathies 2- Multiple mononeuropathies (mononeuritis multiplex) 3- Polyneuropathies19Dr. RS Mehta, BPKIHS

Mononeuropathies20Dr. RS Mehta, BPKIHS

Mononeuropathies 1- Acute : sustained pressure e.g. tourniquet 2- Chronic: entrapment Causes according to site of compression 1- Carpal tunnel Median N 2- Cubital tunnel Ulnar N 3- Spiral groove of humerus Radial N 4- Inguinal ligament Lateral cutaneous of thigh 5- Neck of fibula Common peroneal N 6- Flexor retinaculum (tarsal tunnel) Post tibial


Figure 13.9cBrachial Plexus: Distribution of Nerves


Lumbar Plexus

Figure 13.10


Sacral PlexusFigure 13.11


Mononeuritis multiplex Causes 1- leprosy (commonest) 2- DM 3- vasculitis 4- sarcoidosis 5- amyloidosis 6- malignancy 7- neurofibromatosis 8- HIV infection 9- Idiopathic multifocal motor neuropathy 25Dr. RS Mehta, BPKIHS

Poly neuropathies Causes: 1- Metab & endocrine: - DM - Uraemia - Chronic liver failure - Hypothyroidism - Acromegaly - Amyloidosis


2- Toxic neuropathies: - Alcohol - Drugs ( INH, phenytoin, vincristine) - Heavy metals (lead, arsenic, Hg) - Organic solvents (acryl amide, organophos)


3- Infective: - Leprosy - Diphtheria - HIV - H. zoster28Dr. RS Mehta, BPKIHS





4.Inflammatory: - Guillian Barre syndrome. - Chronic demyelinating polyneuropathy - Idiopathic chronic sensorimotor neuropathy - Connective tissue diseases - Sarcoidosis33Dr. RS Mehta, BPKIHS

5- Vitamin deficiency: - B12 - B1 - B6 - Folate - Nicotinic acid - Vit E


6- Neuropathy associated with malignant disease 7- Neuropathy associated with critically ill pts35Dr. RS Mehta, BPKIHS

Modalities of polyneuropathies: - Sensory - Motor - Mixed - Autonomic36Dr. RS Mehta, BPKIHS

C/F of Polyneuropathies1- Sensory dysfn: numbness, paraesthesiae, hyperaesthesia & pain starting distally and ascending proximally in gloves & stockings with impaired perception of pain, touch, temp vibration & position sense.

2- Motor dysfn: flaccid weakness most marked distally.

3- tendon reflexes: depressed or absent.


4- Autonomic neuropathy: gastro paresis, gustatory sweating, noct. diarrhoea, over flow incontinence, failure of erection, resting tachycardia

Causes: - DM - GB - Acute intermittent porphyria - Amyloidosis - Drugs38Dr. RS Mehta, BPKIHS

Investigations: guided by sympt & signs The cause of polyneuropathy is suggested by the history including the onset, FH, PMH, DH, and predominant clinical manifestations. - CBC & ESR - Renal profile & liver biochemistry - Blood glucose & thyroid fns.- Plasma electrophoresis - Urinary levels of heavy metals. - CSF - CXR


- Serum lipids, lipo proteins, cry proteins - Vitamins assay - Genetics - Search for cause e.g. radiology, immaging, stools for occult blood, endoscopy, mamography - Nerve conduction studies - EMG - Nerve biopsy.40Dr. RS Mehta, BPKIHS

Tests to evaluate neuropathyElectrodiagnositic TestsNerve Conduction Studies - evaluates how the nerves transmit electrical stimuli.Electromyography (EMG) measures the electrical activity of muscles in response to nerve stimulation.

Skin Biopsy Small Fiber Neuropathy cannot be diagnosed with EMG and nerve conduction studies that only measure the large fibers.


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Diabetes Autoimmunity Infections Nutritional Deficiencies Toxins Hereditary Conditions Certain Cancer and Cancer Treatments42Other Investigations: Dr. RS Mehta, BPKIHS

Neuropathies associated with metab and endocrine disorders

Diabetes mellitus (occur singly or in combin) - Symmetric sensory or mixed polyn - Asymmetric motor radiculopathy ( diabetic amyotrophy) - Mononeuritis or mononeuritis multiplex - Autonomic43Dr. RS Mehta, BPKIHS

Toxic neuropathies - Alcoholic polyn - Distal sensorimotor polyn frequently accomp by painful cramps, muscle tenderness and painful paraesthesia in legs - Autonomic - May respond to B1 - Recurs or progress with alcohol intake - Similar distal sensorimotor polyn occurs in beri beri (thiamine def)44Dr. RS Mehta, BPKIHS

Vitamin deficiency - Def states occur in malnutrition - preventable - potentially reversible if treated early 1- B12 def - Distal sensory polyn - Absent ankle jerk - Extensor planter - Optic neuropathy - Intellectual dysfn45Dr. RS Mehta, BPKIHS

2- Thiamine def ( beri beri) - polyn - cardiac failure- nystagmus, ophthalmoplegia, ataxia, amnesia, confusion, coma - Parental B1 for Rx 3- Pyridoxine def (B6) - Mainly sensory - More common in slow acetylaters on INH. - 10mg per day 46Dr. RS Mehta, BPKIHS

Infective neuropathies 1- Leprosy - peripheral nerves are thickened - In LL leads to gloves & stockings sensory loss - Multiple mononeuropathy 2- Diphtheric neuropathy (demyelinating) - Loss of accomodation in 2-4 W - polyn in 4-6 W


3- AIDS neuropathy - Chronic symmetric sensorimotor polyn - progressive polyradiculopathy or radiculomyelopathy ? CMV - Seropositive Pts may also develop demyeelinating polyradiculopathy and mononeuritis multiplex48Dr. RS Mehta, BPKIHS

Inflammatory polyneuropathies 1- Acute post infective polyn - 1-4/52 following resp tract infection, ( in 25% of cases, more severe & residual deficit), surgery & immunization - Demyelination of the spinal roots & periph N has probably immunological basis. - Patient presents with distal weakness and numbness ascending over days to involve the face, resp muscles & bulbar muscles. - Patient may C/O back pain. 49Dr. RS Mehta, BPKIHS

- Treatment: - supportive ( ABC, nursing, physioth) - mechanical ventilation if resp paralysis occur. - Monitor resp with vital capacity. - Plasmapheresis & IV Ig if given early - Use of steriod is controversial. - complete recovery occur in 80% in 3-6 M - mortality 4% & 3% relapse. - remainder left with disability.50Dr. RS Mehta, BPKIHS

Predominantly motor neuropathy 1- GB 2- Ca neuropath 3- Charcot Marie tooth disease (peroneal muscular atrophy 4- lead poisoning51Dr. RS Mehta, BPKIHS

Management of neuropathies 1- In 1/3 treatable cause: - toxins & offending drugs removed - Deficiencies & metab abn corrected - inflammatory causes by immunosuppression 2- In 1/3 there is identifiable cause but no TR as in hereditary 3- In 1/3 no specific cause-- Physiotherapy & occupational therapy52Dr. RS Mehta, BPKIHS

RxDrugs: Gabapentin, Amitriptyline etc. In addition to these medications there are ointments and creams used by patients. Oxycodone, Hydrocodone and as well as other opiates are often prescribed for neuropathy pain.Patients have described getting relief from acupuncture, reflexology and others.53Dr. RS Mehta, BPKIHS

Types of Neuropathy: Summary Autonomic NeuropathyCancer-Related NeuropathiesCompressive NeuropathiesDiabetic NeuropathyDrug-Induced and Toxic NeuropathyG.I. and Nutrition-Related NeuropathiesHereditary NeuropathiesImmune-Mediated NeuropathieInfectious Diseases and NeuropathyNeuropathic PainChemotherapy Induced Neuropathy


Neuropathy Treatment55Dr. RS Mehta, BPKIHS

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Thank you56Dr. RS Mehta, BPKIHS


Simplified diagram of lumbosacral plexus. Contribution of L1 root is not shown. Lumbosacral trunk or cord is shown. 58Dr. RS Mehta, BPKIHS

Origin, course, and distribution of sciatic nerve 59Dr. RS Mehta, BPKIHS

Components12 pair of Cranial nerves31 pair of Spinal nervesSympathetic trunksGangliaSplanchnic nerves60Dr. RS Mehta, BPKIHS

PainTouchPressureTemperatureVibrationPositionWhat exactly is the deficit SensorySpinothalamic Posterior Column


What exactly is the deficit Motor

Ulnar nerve supplies:Hypothenar muscles 3,4 LumbricalsAll interossiAdductor Pollicus

Test:Abd D Minimi

Claw Hand

Card Test

Book Test

Anatomy Based Tests62Dr. RS Mehta, BPKIHS

What is the effect of the loss wasting, residual paralysis, deformity, contractures, sores

Restoring: Dorsi-flexion of wrist in Erbs Palsy. Wrist extensors have been isolated and tested will now be powered by suturing Pronator Teres insertion to them. 63Dr. RS Mehta, BPKIHS

2. neuropathies

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