Mononeuropathies in pregnancy.

While signs and symptoms of peripheral neuropathy may appear to be similar among all patients, further evaluation both at the bedside and beyond demonstrate distinct differences in the pattern of certain neuropathies. A working knowledge of these differences and of the available tools to distinguish them is quite useful to the clinician. This chapter provides an overview of the distinction among various neuropathy profiles. Focal neuropathies may occur from compression or from entrapment. Neurologic examination aids in anatomic localization, which further refines and directs electrodiagnostic and ultrasound testing. Subsequent therapeutic approaches vary depending on the location of the focal neuropathy. Focal neuropathy may occur outside of pregnancy but the outcome is more predictable in this situation.

Ultrasound in EMG-Guided Biopsies: A Prospective, Randomized Pilot Trial.

INTRODUCTION: At our institution, core muscle biopsies are performed on muscles selected using electromyography (EMG). Ultrasound (US) guidance is not used routinely. The aim of this study was to determine if US guidance of EMG selected muscles would increase the diagnostic yield of the biopsy as compared to the current practice standards. METHODS: Two trained physicians performed 40 randomized biopsies (US guided or traditional approach). The amount of tissue obtained in each biopsy was recorded (volume and mass), along with the final pathologic diagnosis in each case and incidence of complications. RESULTS: Forty patients were studied. Sixteen muscle biopsies were done with US guidance; 50% had a definitive diagnosis, and 38% did not. In the non-US guidance group, 58% had a definitive diagnosis, and 33% did not. CONCLUSIONS: US did not provide any additive advantage when used to guide biopsy in a muscle previously selected for biopsy with EMG. Muscle Nerve 54: 786-788, 2016.

Peripheral neuropathies in pregnancy.

PURPOSE OF REVIEW: This article provides an overview of the most common peripheral neuropathic disorders in pregnancy with a focus on clinical recognition, diagnosis, and treatment. RECENT FINDINGS: The literature on this topic consists primarily of case reports, case series, and retrospective reviews. Recent work, particularly in carpal tunnel syndrome, brachial neuritis, and inherited neuropathies in pregnancy, has added to our knowledge of this field. Awareness of diabetic polyneuropathy with associated autonomic dysfunction in pregnancy has grown as the incidence of diabetes mellitus increases in women of childbearing age. SUMMARY: Women may develop mononeuropathy, plexopathy, radiculopathy, or polyneuropathy during pregnancy or postpartum. Pregnancy often influences consideration of etiology, treatment, and prognosis. In women of childbearing age with known acquired or genetic neuromuscular disorders, pregnancy should be anticipated and appropriate counseling provided. An interdisciplinary approach with other medical specialties is often necessary.

Neurology and diving.

Diving exposes a person to the combined effects of increased ambient pressure and immersion. The reduction in pressure when surfacing can precipitate decompression sickness (DCS), caused by bubble formation within tissues due to inert gas supersaturation. Arterial gas embolism (AGE) can also occur due to pulmonary barotrauma as a result of breath holding during ascent or gas trapping due to disease, causing lung hyperexpansion, rupture and direct entry of alveolar gas into the blood. Bubble disease due to either DCS or AGE is collectively known as decompression illness. Tissue and intravascular bubbles can induce a cascade of events resulting in CNS injury. Manifestations of decompression illness can vary in severity, from mild (paresthesias, joint pains, fatigue) to severe (vertigo, hearing loss, paraplegia, quadriplegia). Particularly as these conditions are uncommon, early recognition is essential to provide appropriate management, consisting of first aid oxygen, targeted fluid resuscitation and hyperbaric oxygen, which is the definitive treatment. Less common neurologic conditions that do not require hyperbaric oxygen include rupture of a labyrinthine window due to inadequate equalization of middle ear pressure during descent, which can precipitate vertigo and hearing loss. Sinus and middle ear overpressurization during ascent can compress the trigeminal and facial nerves respectively, causing temporary facial hypesthesia and lower motor neuron facial weakness. Some conditions preclude safe diving, such as seizure disorders, since a convulsion underwater is likely to be fatal. Preventive measures to reduce neurologic complications of diving include exclusion of individuals with specific medical conditions and safe diving procedures, particularly related to descent and ascent.

Neuromuscular disorders in pregnancy.

Preexisting and coincident neuromuscular disorders in pregnancy are challenging for clinicians because of the heterogeneity of disease and the limited data in the literature. Many questions arise regarding the effect of disease on the pregnancy, delivery, and newborn in addition to the effect of pregnancy on the course of disease. Each disorder has particular considerations and possible complications. An interdisciplinary team of physicians is essential. This article discusses the most recent literature on neuromuscular disorders in pregnancy including acquired root, plexus, and peripheral nerve lesions; acquired and inherited neuropathies and myopathies; disorders of the neuromuscular junction; and motor neuron diseases.

Carbon monoxide, skeletal muscle oxidative stress, and mitochondrial biogenesis in humans.

Given that the physiology of heme oxygenase-1 (HO-1) encompasses mitochondrial biogenesis, we tested the hypothesis that the HO-1 product, carbon monoxide (CO), activates mitochondrial biogenesis in skeletal muscle and enhances maximal oxygen uptake (Vo(2max)) in humans. In 10 healthy subjects, we biopsied the vastus lateralis and performed Vo(2max) tests followed by blinded randomization to air or CO breathing (1 h/day at 100 parts/million for 5 days), a contralateral muscle biopsy on day 5, and repeat Vo(2max) testing on day 8. Six independent subjects underwent CO breathing and two muscle biopsies without exercise testing. Molecular studies were performed by real-time RT-PCR, Western blot analysis, and immunochemistry. After Vo(2max) testing plus CO breathing, significant increases were found in mRNA levels for nuclear respiratory factor-1, peroxisome proliferator-activated receptor-gamma coactivator-1alpha, mitochondrial transcription factor-A (Tfam), and DNA polymerase gamma (Polgamma) with no change in mitochondrial DNA (mtDNA) copy number or Vo(2max). Levels of myosin heavy chain I and nuclear-encoded HO-1, superoxide dismutase-2, citrate synthase, mitofusin-1 and -2, and mitochondrial-encoded cytochrome oxidase subunit-I (COX-I) and ATPase-6 proteins increased significantly. None of these responses were reproduced by Vo(2max) testing alone, whereas CO alone increased Tfam and Polgamma mRNA, and COX-I, ATPase-6, mitofusin-2, HO-1, and superoxide dismutase protein. These findings provide evidence linking the HO/CO response involved in mitochondrial biogenesis in rodents to skeletal muscle in humans through a set of responses involving regulation of the mtDNA transcriptosome and mitochondrial fusion proteins autonomously of changes in exercise capacity.

Spinal accessory nerve lesions.

The spinal accessory nerve, primarily a motor nerve, innervates the sternocleidomastoid and trapezius muscles. Proximally, lesions can occur intracranially at the skull base or just outside the jugular foramen producing ipsilateral weakness of trapezius and sternocleidomastoid muscles; or distally, in the posterior neck triangle causing trapezius muscle weakness.

Neurologic injuries from scuba diving.

Interest in scuba (self-contained underwater breathing apparatus) diving increased in the 1970s, and undersea diving continues to be a popular sport early in the 21st century, with approximately 3 million certified divers in the United States. The Divers Alert Network (DAN), an institution created in 1981 by the Commerce Department, National Oceanic and Atmospheric Administration, has collected diving injury data for US and Canadian divers since 1987 that can be studied to suggest the epidemiologic characteristics of diving. This article examines neurologic injuries resulting from scuba diving.

Neurologic injuries from scuba diving.

Interest in scuba (self-contained underwater breathing apparatus) diving increased in the 1970s, and undersea diving continues to be a popular sport early in the 21st century, with approximately 3 million certified divers in the United States. The Divers Alert Network (DAN), an institution created in 1981 by the Commerce Department, National Oceanic and Atmospheric Administration, has collected diving injury data for US and Canadian divers since 1987 that can be studied to suggest the epidemiologic characteristics of diving. This article examines neurologic injuries resulting from scuba diving.

Peripheral neuropathy in pregnancy.

Peripheral neuropathy, mononeuropathy and polyneuropathy, are not common in pregnancy. When complaints occur, however, even if minor, they can be bothersome to the pregnant woman. Peripheral nerve function may threaten the mother and fetus in various ways during gestation. Quick recognition and treatment efforts should therefore be the clinician's goal. This article reviews peripheral neuropathy in pregnancy.

Subacute combined degeneration due to copper deficiency.

There is growing clinical evidence supporting a connection between copper deficiency and subacute combined degeneration. While nearly half of patients with copper deficiency myelopathy exhibit MRI abnormalities, signal changes are often ill-defined in distribution. We report a patient with sensory ataxia and spastic paraplegia from copper deficiency whose MRI demonstrates abnormal signal restricted to the dorsal and lateral columns, providing clear radiological support of an association between hypocupremia and combined system degeneration.