Diagnosis and Management of Peripheral Nerve Disorders

DIAGNOSIS AND MANAGEMENT OF PERIPHERAL NERVE DISORDERS Edited by Jerry R. Mendell, John T. Kissel and David R. Cornblath 2000. New York: Oxford University Press Price £130. pp. 718. ISBN 0195133013 This is another excellent text in the Contemporary Neurology series. It follows on from Disorders of the Peripheral Nerves (2nd edition) and, whereas the latter focused on particular neuropathies, this updated publication, as its title suggests, is more encompassing. The contributors and editors are to be congratulated on producing a comprehensive and up‐to‐date textbook which is eminently readable. The text is interspersed with informative tables, good quality clinical and histological photographs and exceptionally clear line drawings and illustrations. A few words on the structure and some aspects of the contents of the book, which is divided into two parts: Part 1 (141 pages of text) covers clinical assessment and various laboratory tests used to investigate a neuropathy. When outlining neurophysiology and autonomic function tests, informative clinical case studies are discussed, and perhaps more cases could have been presented as they clearly delineate the helpfulness and limitations of these tests. The chapter on ‘Peripheral Nerve and Skin Biopsies’ has high quality pathological photographs and again utilises well chosen clinical cases. It emphasises the fact that a nerve biopsy is to be carried out to answer specific questions relating to the neuropathy and is not to be used as a screening test. The choice of nerve to be biopsied and the processing of the tissue are discussed and raise important issues—although the sural nerve is the commonest to be biopsied, it is not necessarily the one that will yield the most information, particularly if the neuropathy is patchy. Once the tissue is removed, where should it be processed and analysed? Ideally, this should be in a laboratory with experience in dealing with nerve biopsies. Herein lies a problem not only in the US, but also in the UK. Should nerve biopsy material be dealt with only in recognized units with standard processing and staining protocols to try and ensure that the maximum information is obtained about the neuropathy being investigated? The use of skin biopsy in the investigation of a peripheral neuropathy is an emerging technique but still in its infancy—reflected in the fact that only three pages are dedicated to this topic and half of this is taken up by colourful confocal micrographs. Future textbooks will have more page space for this technique even though its role may be confined to investigating painful and non‐painful small fibre neuropathies, and perhaps as a way of prospectively monitoring treatments for diabetic and HIV neuropathies, for example. There is an excellent review of the relatively recent development on the use of autoantibody testing. Of the various anti‐ganglioside antibodies, some are relatively non‐specific (e.g. anti‐GM1 in Guillain–Barré syndrome and multifocal motor neuropathy), with others carrying a high specificity (anti‐GQ1b in Miller‐Fisher syndrome and anti‐Hu antibodies in paraneoplastic subacute sensory neuronopathy/encephalitis syndrome). Other ‘anti‐nerve’ antibodies are being discovered (e.g. anti‐sulfatide antibodies) but do not as yet fit with a specific neuropathy phenotype. In an era when we are lured to over‐investigate patients by requesting batteries of blood tests, the author makes an important point when he states that ‘rarely will an antibody test in isolation provide a specific diagnosis’. Part 2 is the heart of the book (535 pages of text) and consists of 23 chapters covering various aspects of peripheral neuropathies ranging from Guillain–Barré syndrome to Fabry’s disease. As in Part 1, several chapters have included illustrative case studies. The layout in all the sections is clear and reader‐friendly. The use of tables to summarize the key clinical, investigative and treatment features is consistent and very helpful. The referencing is comprehensive. Special effort has been made to include a greater number of illustrations than one might normally encounter in a book of this type and, in addition to being informative (e.g. in the section on entrapment neuropathies), they add colour. The only drawback is that the use of reprinted black and white clinical photographs, albeit infrequent, is made to look very outdated—but is a small price to pay. The immune/inflammatory neuropathies, Guillain‐Barré syndrome, multifocal motor neuropathy with conduction block and chronic inflammatory demyelinating polyradiculoneuropathy (GBS, MMN and CIDP) are comprehensively covered. The use of intravenous immunoglobulin as the first line treatment of these disorders is outlined and recommended, and it would have been of interest to have had some comments on the cost and safety issues (prion protein transmission) linked to this treatment and also on the issue of the possible requirement of the patient’s (or next of kin’s) written consent before treatment, given safety concerns and that IvIg is not licensed for use in CIDP and MMN. The lack of clinical trial evidence means that the discussion on longer term immunosuppressive treatments for CIDP and neuropathies associated with monoclonal gammopathies for example, is as in older texts, confined to listing potential regimens, but without being able to recommend one specific protocol. The newer gene abnormalities associated with the various Charcot–Marie–Tooth (CMT) neuropathies have given rise to a new classification. It is now CMT Types 1A–D, CMT Types 2A–D, Dejerine–Sottas disease (severe variant of CMT1 rather than the older nomenclature of HMSN III), CMT Types 4A–C and X‐linked CMT. Other neuropathies ‐HMSN V (+ spastic paraplegia), HMSN VI (+ optic atrophy) and HMSN VII (+ retinitis pigmentosa) await linkage studies before they are added to the new CMT neuropathy classification. The classification of the Hereditary Sensory and Autonomic Neuropathies remains unchanged (HSAN Types I–VI), but the advances in the understanding of the molecular basis of these disorders (various neurotrophins and their tyrosine kinase receptors) means this will be shortlived. Likewise, great advances have been made in the understanding of familial amyloid polyneuropathies (FAP) with most being caused by mutations in the transthyretin gene (FAP I and FAP II). As this protein is produced in the liver, this potentially lethal condition can be treated by liver transplantation. Two new proteins cause the other rarer types of FAP: apolipoprotein A‐1 (FAP III) and gelsolin (FAP IV). Other areas are slower to change, but the chapters on neuropathies related to infection (HIV, leprosy), vitamin deficiencies, connective tissue diseases and porphyria are comprehensive and well structured. Diabetic neuropathy still has its multiple pathogenic possibilities (both metabolic and vascular), which have spawned various therapies but sadly none have come through strict clinical trials. A newer approach has been to look at altered neurotrophic factors (nerve growth factor and insulin‐like growth factors), but very recently the Phase III trial of recombinant human nerve growth factor was discontinued due to lack of effect. Hopefully, other neurotrophic agents will emerge. Diagnosis and Management of Peripheral Nerve Disorders is a definite must for the neurology departmental library to be accessed by all members of the team. It will happily be placed next to larger tomes such as the two volume Peripheral Neuropathy (Dyck et al.), providing for the time being the most up‐to‐date text on peripheral neuropathies. It will be well used.