David R. Del Toro

Evidence-based guideline: Treatment of painful diabetic neuropathy: Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation

Objective: To develop a scientifically sound and clinically relevant evidence-based guideline for the treatment of painful diabetic neuropathy (PDN). Methods: We performed a systematic review of the literature from 1960 to August 2008 and classified the studies according to the American Academy of Neurology classification of evidence scheme for a therapeutic article, and recommendations were linked to the strength of the evidence. The basic question asked was: “What is the efficacy of a given treatment (pharmacologic: anticonvulsants, antidepressants, opioids, others; and nonpharmacologic: electrical stimulation, magnetic field treatment, low-intensity laser treatment, Reiki massage, others) to reduce pain and improve physical function and quality of life (QOL) in patients with PDN?” Results and Recommendations: Pregabalin is established as effective and should be offered for relief of PDN (Level A). Venlafaxine, duloxetine, amitriptyline, gabapentin, valproate, opioids (morphine sulfate, tramadol, and oxycodone controlled-release), and capsaicin are probably effective and should be considered for treatment of PDN (Level B). Other treatments have less robust evidence or the evidence is negative. Effective treatments for PDN are available, but many have side effects that limit their usefulness, and few studies have sufficient information on treatment effects on function and QOL.

Evidence-based Guideline: Treatment of Painful Diabetic Neuropathy

To develop a scientifically sound and clinically relevant evidence‐based guideline for the treatment of painful diabetic neuropathy (PDN).

EVIDENCE-BASED GUIDELINE: TREATMENT OF PAINFUL DIABETIC NEUROPATHY-REPORT OF THE AMERICAN ASSOCIATION OF NEUROMUSCULAR AND ELECTRODIAGNOSTIC MEDICINE, THE AMERICAN ACADEMY OF NEUROLOGY, AND THE AMERICAN ACADEMY OF PHYSICAL MEDICINE & REHABILITATION

The objective of this report was to develop a scientifically sound and clinically relevant evidence‐based guideline for the treatment of painful diabetic neuropathy (PDN). The basic question that was asked was: “What is the efficacy of a given treatment (pharmacological: anticonvulsants, antidepressants, opioids, others; non‐pharmacological: electrical stimulation, magnetic field treatment, low‐intensity laser treatment, Reiki massage, others) to reduce pain and improve physical function and quality of life (QOL) in patients with PDN?” A systematic review of literature from 1960 to August 2008 was performed, and studies were classified according to the American Academy of Neurology classification of evidence scheme for a therapeutic article. Recommendations were linked to the strength of the evidence. The results indicate that pregabalin is established as effective and should be offered for relief of PDN (Level A). Venlafaxine, duloxetine, amitriptyline, gabapentin, valproate, opioids (morphine sulfate, tramadol, and oxycodone controlled‐release), and capsaicin are probably effective and should be considered for treatment of PDN (Level B). Other treatments have less robust evidence, or the evidence is negative. Effective treatments for PDN are available, but many have side effects that limit their usefulness. Few studies have sufficient information on their effects on function and QOL. Muscle Nerve, 2011.

Evidence-based guideline: Treatment of painful diabetic neuropathy. Report of the American Academy of Neurology, the American Association of Neuromuscular and Electrodiagnostic Medicine, and the American Academy of Physical Medicine and Rehabilitation

To develop a scientifically sound and clinically relevant evidence‐based guideline for the treatment of painful diabetic neuropathy (PDN).

Abductor hallucis false motor points: Electrophysiologic mapping and cadaveric dissection

False motor points (FMPs) can occur in intrinsic foot or hand muscles, causing spuriously prolonged distal motor latencies by misrepresenting the compound muscle action potential (CMAP) onset. We investigated the motor point (MP) and possible FMPs in abductor hallucis (AH) by three methods: (1) electrophysiologic mapping of the CMAP with a grid of approximately 29 G1 sites over AH (n = 20), including commonly used MPs just anterior to (Ant‐MP) and posterior to (Post‐MP) the navicular tuberosity; (2) electrophysiologic mapping with direct percutaneous threshold stimulation of AH (same grid as above); and (3) cadaveric dissection (n = 4). We found AH FMPs in 19 of 20 feet (2.7 FMPs/foot) which resulted in prolongation of the CMAP onset latency by 0.5–2.3 ms. Post‐MP had a significantly lower mean threshold stimulus intensity than all other grid sites, including the FMPs. The anatomic MP of AH was consistently found just inferior and posterior to the navicular tuberosity. This study demonstrates that AH FMPs: (1) can be identified in virtually all feet; (2) do not correspond to the true MP (i.e., Post‐MP); and (3) are likely due to superimposed compound action potentials from nearby muscles or nerves.

Electrodiagnostic reference values for upper and lower limb nerve conduction studies in adult populations.

Introduction: To address the need for greater standardization within the field of electrodiagnostic medicine, the Normative Data Task Force (NDTF) was formed to identify nerve conduction studies (NCS) in the literature, evaluate them using consensus‐based methodological criteria derived by the NDTF, and identify those suitable as a resource for NCS metrics. Methods: A comprehensive literature search was conducted of published peer‐reviewed scientific articles for 11 routinely performed sensory and motor NCS from 1990 to 2012. Results: Over 7,500 articles were found. After review using consensus‐based methodological criteria, only 1 study each met all quality criteria for 10 nerves. Conclusion: The NDTF selected only those studies that met all quality criteria and were considered suitable as a clinical resource for NCS metrics. The literature is, however, limited and these findings should be confirmed by larger, multicenter collaborative efforts. Muscle Nerve 54: 371–377, 2016

Establishing high‐quality reference values for nerve conduction studies: A report from the normative data task force of the American Association Of Neuromuscular & Electrodiagnostic Medicine

Introduction: There are not uniform standards for nerve conduction testing across the United States. The objective of this study is to present a set of methodologically sound criteria to evaluate the literature for the purpose of identifying high‐quality normative nerve conduction studies (NCS) suitable for widespread use. Methods: The Normative Data Task Force (NDTF) was formed to review published studies on methodological issues related to NCS. A set of criteria was then developed to evaluate the literature. These criteria and their rationale are described. Results: We identified 7 key issues that reflect high quality in NCS. For each issue, specific review criteria were developed. Conclusion: Rigorous criteria enable identification of high‐quality studies dealing with nerve conduction reference values. This represents the first step toward the overarching goal of recommending NCS techniques and reference values for electrodiagnostic medicine. Muscle Nerve 54: 366–370, 2016

Amputee Subject Testing Protocol, Results, and Analysis of a Powered Transtibial Prosthetic Device

A powered ankle-foot prothesis and its control system were previously designed and built. To evaluate this prosthesis, amputee subject testing was performed. The testing results are analyzed and compared between the powered prosthesis, passive prosthesis, and able-bodied gait. Qualitative comparison showed the prosthesis achieved the design objectives. During stance phase, active ankle moment was generated in the powered prosthesis before push-off to help the amputee walk more naturally. During swing phase, the powered prosthesis was able to move to natural position to achieve foot clearance. However, the prosthesis is slightly under powered compared with the able-bodied ankle.

Generator sources for the early and late ulnar hypothenar premotor potentials: Short segment electrophysiologic studies and cadaveric dissection☆

OBJECTIVE Determine the generator sources for the ulnar hypothenar premotor potentials (PMPs). DESIGN Observational. SETTING EMG laboratory. SUBJECTS Ten asymptomatic adult volunteers, three cadaver hands. MAIN OUTCOME MEASURE Far-field versus near-field characteristics of recorded PMPs as determined by bipolar and referential recording electrode montages. A possible anatomic basis for any observed differences between ulnar PMPs and previously studied median PMPs were explored through cadaveric dissection. RESULTS An early PMP (E-PMP) had a latency that varied with changes in the position of G1 only. A late PMP (L-PMP was seen only when G1 and G2 were on different volumes (palm vs fifth digit, or second digit vs fifth digit); its latency did not vary significantly with changes in the position of G1 and G2. CONCLUSIONS (1) E-PMP is a near-field potential generated by the ulnar nerve passing near the G1 electrode. (2) L-PMP represents a far-field potential generated by the ulnar digital nerves as they traverse from the hand volume containing G1 to the finger volume containing G2. (3) Greater L-PMP-to-CMAP separation in the median than in the ulnar nerve was explained by cadaveric dissection, which revealed that the motor branch (responsible for the trailing CMAP) is longer in the median nerve than in the ulnar nerve relative to each nerves corresponding digital sensory branch (responsible for the preceding L-PMP). (4) The PMP that is typically recorded with G1 at the hypothenar motor point and G2 on the fifth digit most likely represents E-PMP. (5) Any proposed diagnostic use of the ulnar PMPs must take into consideration these generator sources.

Guiding Treatment for Foot Pain

In the electrodiagnostic (EDX) approach of the patient who presents with foot pain, numbness, and/or tingling, it is important to consider a broad differential diagnosis of both neuropathic and nonneuropathic conditions, including focal and systemic causes. This article assists the electromyographer in the selection and utilization of the most appropriate EDX studies for evaluation. The EDX findings and impression can then help guide potential treatment options for the patient with foot pain and other symptoms. Moreover, this discussion demonstrates the added value that EDX evaluation of the foot provides to the comprehensive assessment of foot pain.