Clinical utility of peripheral nerve biopsy

Peripheral Neuropathy

Peripheral neuropathy is a commonly encountered disorder in clinical practice. In light of an aging population and the diabetes and obesity pandemic, the prevalence of peripheral neuropathy is increasing, posing a significant public health concern. This article provides a diagnostic framework for neuropathies and summarizes treatment options.

Pediatric Nerve Biopsy Diagnostic and Treatment Utility in Tertiary Care Referral

BACKGROUND

Pediatric neuropathies are both unique and similar to their adult counterparts, with genetic varieties thought to be more common. The objective of this work was to assess the utility of nerve biopsy in children at a tertiary referral center in light of availability of current genetic testing.

METHODS

We retrospectively reviewed the clinical, nerve biopsy, and genetic testing findings of 316 pediatric (age ≤18 years) patients.

RESULTS

Median age at diagnosis was 9.8 years (4 days to 18 years). Nerve biopsy was nontargeted in 198 (182 whole sural, seven superficial peroneal, and nine other), targeted in 21 (14 fascicular sciatic and seven brachial plexus), and unknown in 97 cases. Prebiopsy localizations and diagnoses were diverse, most commonly with length-dependent localizations (n = 150). Median follow-up was 6 months (0 to 480 months). A distinctive histopathologic diagnosis was made in 106 cases (33%), including inflammatory or immune (n = 30), neoplastic (n = 19), hereditary (n = 41), vasculitis (n = 10), and other (n = 6). Nerve biopsy confirmed the suspected diagnosis in 91 (29%) individuals and changed or refined the initial diagnosis in 182 (58%). Treatment modifications as a result of biopsy occurred in 80 (25%) cases; 59 (19% of the entire cohort) with clinical improvements noted, most commonly by immunotherapy (n = 30). Low diagnostic yield occurred in "hypotonic infants" without nerve conduction abnormalities. Pain at the biopsy site beyond 1 month was rare (n = 3; 1%). Forty-four patients underwent genetic testing. Among demyelinating varieties, mutations were identified in five of 11 (46%) cases compared with only six of 33 (18%) cases of axonal varieties.

CONCLUSION

Pediatric nerve biopsy provides diagnostic information that frequently alters treatment recommendations. Furthermore, it leads to clinical improvements, especially in inflammatory immune neuropathies. For suspected inherited varieties, genetic testing has the highest diagnostic yield in demyelinating phenotypes.

Clinical approach to peripheral neuropathy: anatomic localization and diagnostic testing

PURPOSE OF REVIEW

This article provides a clinical approach to peripheral neuropathy based on anatomic localization and diagnostic testing.

RECENT FINDINGS

Advances have been made in the evaluation of small fiber neuropathy and in the known genetic causes of neuropathy.

SUMMARY

History and physical examination remain the most useful tools for evaluating peripheral neuropathy. Characterization of a neuropathy aids in limiting the differential diagnosis and includes consideration of temporal profile (tempo of onset and duration), heredity, and anatomic classification. Anatomic classification involves (1) fiber type (motor versus sensory, large versus small, somatic versus autonomic), (2) portion of fiber affected (axon versus myelin), and (3) gross distribution of nerves affected (eg, length-dependent, length-independent, multifocal). Diagnostic testing may include serologic and CSF evaluation, electrodiagnosis, skin biopsy, quantitative sensory testing, autonomic testing, nerve biopsy, confocal corneal microscopy, and laser Doppler imager flare.

Painful peripheral neuropathies

BACKGROUND AND OBJECTIVES

Painful neuropathies are common and often difficult to treat. The objective of this report was to review the subject to facilitate diagnosis and pain relief.

CONTENTS

The classification, causes, type of fibers involved, manifestations, diagnosis, adjuvant tests, questionnaires used in the diagnosis, and treatment are described.

CONCLUSIONS

The subject is very broad and involves several causes and treatments that often should be combined to obtain adequate pain control.

Les neuropathies périphériques : orientations et moyens diagnostiques

PURPOSES

Neuropathies are defined as dysfunction of peripheral nerves, which may show motor, sensory and autonomic symptoms. Although most neuropathies are symmetric, it is important to distinguish a polyneuropathy from a mononeuropathy, a multiple mononeuropathy or a polyradiculoneuropathy. Electrophysiological procedures are helpful in determining the pathological process which may be either an axonopathy, a myelinopathy or a neuronopathy.

MAIN POINTS

Major progresses have been made in the ten past years in the management and diagnostic approaches of peripheral neuropathy. The history and the physical examination are the first steps to the evaluation of patients with peripheral neuropathy. Electrodiagnostic studies and then laboratory tests are the next step in the diagnostic procedures of peripheral neuropathies. These will lead to a proper identification of the cause of neuropathy, allowing to develop a specific treatment for the patient. However, even after a careful work-up of a patient with neuropathy, 25 to 40% of patients with polyneuropathies remain undiagnosed.

PERSPECTIVES

Further development are focused in better understanding the pathogenesis and molecular mechanisms of peripheral nerve diseases in order to provide a specific and adequate treatment for each neuropathy.