We searched the Cochrane Library (January, 1990 to October, 2003), OVID MEDLINE (January, 1990 to October, 2003), OVID Excerpta Medica (EMBASE: January, 1990 to October, 2003), and OVID Current Contents (January, 2002 to October, 2003). The search included reports of research in human beings only, and all languages. The search terms selected were “peripheral neuropathy”, “polyneuropathy”, and “guideline”. We then limited the search using the terms “epidemiology”, “diagnosis”, “nerve conduction
SeminarPeripheral neuropathy
Section snippets
Epidemiology
The overall prevalence of the condition is about 2400 (2·4%) per 100 000 population, but in people older than 55 years, the prevalence rises to about 8000 (8%) per 100 000.1 Since these figures do not include traumatic peripheral nerve injuries, the total burden of peripheral neuropathy on society is even greater. Although traumatic nerve injuries are important, they are not covered in this review since their diagnosis and management are highly specialised. Comprehensive coverage of peripheral
Diagnosis
The clinical manifestations of peripheral neuropathy vary widely. Presenting features encompass varying combinations of altered sensation, pain, muscle weakness, or atrophy, and autonomic symptoms. Accurate diagnosis rests on the skill with which clinical symptoms, signs, and electrodiagnostic study findings can be woven together. In accordance with this diagnostic approach, patients whose history and clinical examination suggest the presence of a peripheral neuropathy should have confirmation
Mononeuropathy
The term mononeuropathy implies a focal lesion of a single peripheral nerve. The usual causes are trauma, focal compression, and entrapment. The most common mononeuropathy is carpal tunnel syndrome caused by entrapment of the median nerve in the carpal tunnel.16, 17, 18, 19 Ulnar neuropathy due to compression of the nerve at or near the elbow is the second most common mononeuropathy.20, 21 Electrodiagnostic studies are indispensable in the accurate diagnosis of mononeuropathies. They serve to
Mononeuropathy multiplex
Mononeuropathy multiplex describes the involvement of multiple separate noncontiguous peripheral nerves either simultaneously or serially. The pattern of nerve involvement is random, multifocal, and frequently evolves quickly. In some cases, the neuropathy might progress to a point at which individual nerve lesions summate, resulting in confluent and symmetric deficits that can mimic a distal symmetrical polyneuropathy. Attention to the pattern of early symptoms is important in correct
Polyneuropathy
The most common variety of polyneuropathy is distal symmetrical polyneuropathy.15, 43 In this setting, nerve fibres are believed to be affected in a length–dependent way; length in this context meaning distance from the parent nerve cell body (either the dorsal root ganglion sensory neuron or the anterior horn motor neuron). Thus, toes and soles of the feet are affected first. This pattern of neuropathy is associated with several acquired systemic diseases, metabolic disorders, and exogenous
Subclassification of polyneuropathies
Separating polyneuropathies into acute and chronic forms is very helpful for refining the diagnosis and treatment.
Chronic demyelinating polyneuropathy
This is the easiest category to define since the causes are limited (panel 1). Demyelinating polyneuropathies are either genetically determined or acquired. Electro-diagnostic features are helpful in making this distinction because uniform symmetrical slowing of nerve conduction usually indicates a genetically determined neuropathy, whereas multifocal slowing and conduction block are indicative of acquired demyelinating neuropathies.
Most genetically determined demyelinating polyneuropathies are
Chronic axonal polyneuropathy
This is the most common variety of polyneuropathy and has many possible causes. The commonest cause is diabetes mellitus, which should be foremost in the differential diagnosis. However, a range of systemic diseases and metabolic disorders such as nutritional deficiencies, chronic renal failure, and malignant diseases as well as exogenous intoxications from medications, alcohol abuse, or chemical agents can result in this pattern of neuropathy (Table 1, Table 2).
Laboratory investigations of peripheral neuropathy
The cause of most peripheral neuropathies is evident when the information obtained from the medical history, neurological examination, and electrodiagnostic studies is combined with simple screening laboratory tests (panel 2). All patients with a peripheral neuropathy should have a complete blood count, erythrocyte sedimentation rate or C-reactive protein, comprehensive metabolic panel (fasting blood glucose, renal function, liver function), thyroid function tests, urinalysis, serum B-12 and
Role of nerve biopsy in evaluation of neuropathies
Nerve biopsy is most useful in documentation of inflammatory disorders such as vasculitis, sarcoidosis, CIDP, infectious diseases such as leprosy, or infiltrative disorders such as amyloidosis or tumour.24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34 The procedure is best reserved for patients in whom the diagnosis cannot be obtained by other means. Nerve biopsies should always be processed in experienced laboratories with the capability to do teased fibre preparations, semi-thin plastic sections,
Treatment
Treatment of peripheral neuropathy is divided into those that are specific for the subtype of neuropathy, and those that are useful for neuropathies in general. Medical causes such as diabetes mellitus, renal insufficiency, hypothyroidism, vitamin B-12 deficiency, or systemic vasculitis need specific and active treatment. Immune-mediated neuropathies such as Guillain-Barré syndrome or CIDP respond to specific treatments. If treated appropriately, many patients with dysimmune neuropathies have a
Search strategy and selection criteria
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