Ultrasound scanning in the diagnosis of peripheral neuropathies.

Nerve ultrasound scanning has become a valuable diagnostic tool in the routine workup of peripheral nerve disorders, effectively complementing conventional electrodiagnostic studies. The most relevant sonographic features are nerve size and structural integrity. Several peripheral neuropathies show characteristic and distinct patterns of nerve enlargement, allowing their early and accurate identification, and reducing test-burden and diagnostic delay for patients. In mononeuropathies such as carpal tunnel syndrome and ulnar neuropathy at the elbow, nerve enlargement develops only at specific sites of entrapment, while in polyneuropathy the nerve enlargement may be multifocal, regional or even diffuse. Nerve ultrasound scanning can reliably identify chronic inflammatory neuropathies, even when extensive electrodiagnostic studies fail, and it should therefore be embedded in routine diagnostic workup of peripheral neuropathies. In this paper we describe a potential diagnostic strategy to achieve this.

Nerve ultrasound for diagnosing chronic inflammatory neuropathy: A multicenter validation study.

OBJECTIVE: To validate the diagnostic accuracy of a previously described short sonographic protocol to identify chronic inflammatory neuropathy (CIN), including chronic inflammatory demyelinating polyneuropathy (CIDP), Lewis Sumner syndrome, and multifocal motor neuropathy (MMN), and to determine the added value of nerve ultrasound to detect treatment-responsive patients compared to nerve conduction studies (NCS) in a prospective multicenter study. METHODS: We included 100 consecutive patients clinically suspected of CIN in 3 centers. The study protocol consisted of neurologic examination, laboratory tests, NCS, and nerve ultrasound. We validated a short sonographic protocol (median nerve at forearm, upper arm, and C5 nerve root) and determined its diagnostic accuracy using the European Federation of Neurological Societies/Peripheral Nerve Society criteria of CIDP/MMN (reference standard). In addition, to determine the added value of nerve ultrasound in detecting treatment-responsive patients, we used previously published diagnostic criteria based on clinical, NCS, and sonographic findings and treatment response (alternative reference standard). RESULTS: Sensitivity and specificity of the sonographic protocol for CIN according to the reference standard were 87.4% and 67.3%, respectively. Sensitivity and specificity of this protocol according to the alternative reference standard were 84.6% and 72.8%, respectively, and of NCS 76.1% and 93.4%. With addition of nerve ultrasound, 44 diagnoses of CIN were established compared to 33 diagnoses with NCS alone. CONCLUSIONS: A short sonographic protocol shows high diagnostic accuracy for detecting CIN. Nerve ultrasound is able to detect up to 25% more patients who respond to treatment. CLASSIFICATION OF EVIDENCE: This multicenter study provides Class IV evidence that nerve ultrasound improves diagnosis of CIN.

Nerve ultrasound improves detection of treatment-responsive chronic inflammatory neuropathies.

OBJECTIVE: To examine the diagnostic accuracy of nerve ultrasound in a prospective cohort of consecutive patients with a clinical suspicion of chronic inflammatory neuropathies, including chronic inflammatory demyelinating polyneuropathy, Lewis-Sumner syndrome, and multifocal motor neuropathy, and to determine the added value in the detection of treatment-responsive patients. METHODS: Between February 2015 and July 2018, we included 100 consecutive incident patients with a clinical suspicion of chronic inflammatory neuropathy. All patients underwent nerve ultrasound, extensive standardized nerve conduction studies (NCS), and other relevant diagnostic investigations. We evaluated treatment response using predefined criteria. A diagnosis of chronic inflammatory neuropathy was established when NCS were abnormal (fulfilling criteria of demyelination of the European Federation of Neurological Societies/Peripheral Nerve Society) or when the degree of nerve enlargement detected by sonography was compatible with chronic inflammatory neuropathy and there was response to treatment. RESULTS: A diagnosis of chronic inflammatory neuropathy was established in 38 patients. Sensitivity and specificity of nerve ultrasound and NCS were 97.4% and 69.4% and 78.9% and 93.5%, respectively. The added value of nerve ultrasound in detection of treatment-responsive chronic inflammatory neuropathy was 21.1% compared to NCS alone. CONCLUSIONS: Nerve ultrasound and NCS are complementary techniques with superior sensitivity in the former and specificity in the latter. Addition of nerve ultrasound significantly improves the detection of chronic inflammatory neuropathies. Therefore, it deserves a prominent place in the diagnostic workup of chronic inflammatory neuropathies. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that nerve ultrasound is an accurate diagnostic tool to detect chronic inflammatory neuropathies.

La belle indifférence revisited: a case report on progressive supranuclear palsy misdiagnosed as conversion disorder.

BACKGROUND: Since the advent of computed tomography and magnetic resonance imaging scans, neurological disorders have less often been falsely labeled as conversion disorder (CD). However, misdiagnosis of a neurological disorder as CD still occurs, especially in cases with insidious onset. Misinterpretation of la belle indifférence may contribute to such misdiagnosis. Here, we describe a case of progressive supranuclear palsy/Richardson's syndrome (PSPS) misdiagnosed as a case of CD. CASE: A 62-year-old woman consulted two different neurologists in 2012 because of falling spells since 2009 and was diagnosed with CD. She was referred to the Clinical Center of Excellence for Body, Mind, and Health for treatment of CD. After neurological examination, blood tests, and psychiatric examination, in which la belle indifférence and a history of incest were found, CD was confirmed. However, despite treatment for CD, the patient's physical symptoms deteriorated over a year. After repeated physical and psychiatric examinations, neurocognitive assessment, and consultation with a third neurologist because of suspicion of neurological disease, the patient was diagnosed with PSPS. CONCLUSION: La belle indifférence may be a psychological sign in the context of CD, but it may also be an expression of lack of mimic due to Parkinsonism or of eye movement disorder in the context of neurological illness. A diagnosis of CD should not be considered definitive if no improvement occurs in terms of physical, mental, and cognitive symptoms despite appropriate therapy. In case of deterioration, neurological reexamination and reinterpretation of la belle indifférence should be considered.