Peripheral Neuropathies

Dr Sarah Dawson, 31st July 2014

Aims

• Define neuropathy

• Describe different neuropathies and identify common disease patterns

• List a differential diagnosis for each type of neuropathy

What is neuropathy?

Peripheral neuropathy (PN) is damage or disease affecting nerves• may impair sensation,

movement, gland or organ function, or other aspects of health, depending on the type of nerve affected.

Classification

• Mononeuropathy

• Mononeuritis multiplex

• Polyneuropathy

• Autonomic neuropathy

• Neuritis

Name that neuropathy

Mononeuropathies• Affects one nerve

• Direct injury to a nerve, ischemia, or inflammation.

• likely that the cause is a physical compression, localized trauma or infection

• e.g. carpal tunnel, cubital tunnel

• "pins-and-needles" sensation of one's "foot falling asleep"

Mononeuritis multiplex• Simultaneous or sequential involvement of individual noncontiguous

nerves,

• either partially or completely,

• evolving over days to years

• asymmetric

• Typically presenting with acute or subacute loss of sensory and motor function of individual nerves

• May also cause pain

• deep, aching pain

• worse at night

• frequently in the lower back, hip, or leg

• In diabetes typically encountered as acute, unilateral, severe thigh pain followed by anterior muscle weakness and loss of knee reflex.

Causes• Diabetes Mellitus

• Vasculitides

• polyarteritis nodosa,

• Wegener's granulomatosis,

• Churg–Strauss syndrome

• Immune-mediated disease

• Rheumatoid

• SLE

• Infections

• leprosy

• lyme disease

• HIV

• sarcoidosis, amyloidosis

• cryoglobulinemia

• chemicals, e.g trichloroethylene and dapsone

• Jellyfish (rare)

Back to…name that neuropathy

Patterns of disease in diabetes

Polyneuropathy

•Affects many nerve cells

in various parts of the

body

•Symmetrical

•Progresses slowly

•Caused by processes

affecting the whole body

Disease Patterns

• D istalaxonopathy e.g. diabetes, impaired glucose tolerance, alcohol• the cell bodies of neurons remain intact• axons are affected in proportion to their length. • symptoms occur first and most severely in the feet.

• Myelinopathy aka Demyelinating disease e.g. Gullain Barre Syndrome• myelin sheath around axons is damaged• affects the ability of the axons to conduct electrical impulses

• Neuronopathy affects the cell bodies of neurones directly• motor neurones (e.g. motor neurone disease)• sensory neurones (sensory neuronopathy e.g. Herpes Zoster or dorsal root ganglionopathy).

Other causes axonopathy

• Metabolic disturbance- diabetes

• Renal failure

• Connective tissue disease

• Toxins eg alcohol

• Malnutrition/ Vitamin deficiencies

• Infections e.g. Lyme disease

• Drugs (especially chemo)

AllopurinolAmiodarone

Ara-CCarboplatin

CisplatinColchicine

Danosine (ddl)Dapsone

DisulfiramDocetaxel

Etoposide (VP-16)EthambutolEtoposideGentamin

GoldIndomethacin

IsoniazidLithium

L-tryptophancontaminant

MercuryMetronidazole

MisonidazoleNitrofurantoinNitrous Oxide

PaclitaxelPerhexilenePhenytoinPyridoxine

SulfapyridineStatins

Stavudine (d4T)Streptokinase

SuraminTacrolimus

ThalidomideTNF-alpha antagonistsTumor Necrosis Factor

VincristineZalcitabine (ddC)

Zimeldine

Autonomic neuropathy• Most commonly in latter stages DM

• Symptoms

• Urinary-incontinence or retention

• GI tract: dysphagia, abdominal pain, nausea, vomiting, malabsorption, fecal incontinence, gastroparesis, diarrhoea, constipation

• CVS disturbances of heart rate orthostatic hypotension, inadequate increase of heart rate on exertion

• Resp impairments in the signals associated with regulation of breathing and gas exchange (central sleep apnea, hypopnea, bradypnea).[5]

Also hypoglycemia unawareness, genital impotence, sweat disturbances

Last chance to name that neuropathy!

Neuritis

inflammation of a nerve (mononeuritis)

or

the peripheral nervous system (polyneuritis)

Causes• Physical injury-bad shoes

• Infection

• Herpes simplex

• Shingles

• Leprosy

• Lyme disease

• Chemical injury

• Radiation

• Underlying conditions causing

localised neuritis

• Diphtheria

• Localised injury

• Diabetes

• Underlying conditions causing

polyneuritis

• Beriberi (vit B1deficiency)

• Vitamin B12 deficiency

• Vitamin B6 excess

• Metabolic diseases -DM

• Celiac disease

• Herpes zoster

• Hypothyroidism

• Porphyria

• Infections, bacterial or viral

• Autoimmune disease, especially MS

+ Guillain- Barre syndrome

• Cancer

• Alcoholism

Summary• Neuropathy has several

different patterns

• Early identification of pattern helps target diagnosis, which in turn influences management

• Diabetes may present with many different disease patterns

• Causes are diverse from metabolic processes, infection, nutritional deficits, autoimmune disease, drugs, toxins and more

Thank you