A simple and objective marker for stress.

Objective: To examine the association between pressure pain sensitivity (PPS) at sternum and various well established physiological stress measures among opera singers during a performance as a measure for transitional stress, and resting values in out-clinic patients as a measure for persistent stress.

Methods: Changes in PPS on the index finger and sternum, middle blood pressure (MAP), heart rate (HR), pressure-rate-product (PRP) and salivary cortisol (SCO) were recorded in 26 opera solo singers during a performance. Resting PPS, HR, MAP, PRP and presence of a noxious withdrawal reflex (NWR) were recorded in 181 out-clinic patients.

Multifocal motor neuropathy with conduction block: slow but not benign.

Objective: To describe a patient with multifocal motor neuropathy with conduction block who had annual clinical and physiological examinations for 18 years but declined treatment for personal reasons.

Design: Case report.

Setting: Collaboration between 2 academic tertiary care hospitals.

Electrophysiologic techniques in critical illness-associated weakness.

Neuromuscular disorders are increasingly recognized in the critically ill but conventional electrodiagnostic techniques often provide non-specific results or are hampered by local conditions that prevent adequate disease classification. Muscle fiber inexcitability is a common phenomenon in critical illness myopathy possibly secondary to disordered sodium channel fast inactivation and associated with loss of myosin staining. Direct muscle stimulation techniques, measuring evoked response amplitudes and comparison of nerve and muscle stimulated responses, are recognized methods of demonstrating this phenomenon.

RAGE modulates peripheral nerve regeneration via recruitment of both inflammatory and axonal outgrowth pathways.

Axotomy of peripheral nerve stimulates events in multiple cell types that initiate a limited inflammatory response to axonal degeneration and simultaneous outgrowth of neurites into the distal segments after injury. We found that pharmacological blockade of RAGE impaired peripheral nerve regeneration in mice subjected to RAGE blockade and acute crush of the sciatic nerve. As our studies revealed that RAGE was expressed in axons and in infiltrating mononuclear phagocytes upon injury, we tested the role of RAGE in these distinct cell types on nerve regeneration.

Antagonism of RAGE suppresses peripheral nerve regeneration.

Axotomy of peripheral nerve triggers events that coordinate a limited inflammatory response to axonal degeneration and initiation of neurite outgrowth. Inflammatory and neurite outgrowth-promoting roles for the receptor for advanced glycation end products (RAGE) have been suggested, so we tested its role in peripheral nerve regeneration. Analysis of immunohistochemical localization of RAGE by confocal microscopy revealed that RAGE was expressed in axons and infiltrating mononuclear phagocytes upon unilateral sciatic nerve crush in mice.

Motor Unit Estimate Number in the Anterior Tibial Muscle: Normative Data versus Findings in Critically Ill Patients in Intensive Care Units.

Objectives: To determine the number of motor units (MUNEs) in the anterior tibial muscle of normal subjects for comparison with those of severely paretic or paralytic muscles of critically ill patients in intensive care units.

Results: The mean MUNE for 24 normal subjects (194 +/- 5; mean +/- standard deviation) was similar to that of the 22 patients with critical illness (184 +/- 10). However, both the mean amplitude of the evoked compound muscle action potential (CMAP) and of the single motor unit action potential (S-MUAP) among patients were approximately one third of those in normal subjects.

Congenital Guillain-Barré syndrome associated with maternal inflammatory bowel disease is responsive to intravenous immunoglobulin.

A 34-week floppy preterm infant born to a mother with acute ulcerative colitis presented with a progressive reduction in spontaneous limb movements, severe generalized hypotonia, areflexia, autonomic dysfunction and respiratory failure. Electromyography revealed pronounced denervation activity and markedly slow nerve conduction velocity (3 m/s) with evidence of conduction block. These findings indicated demyelination with additional axonal features.

Inclusion body myositis mimicking motor neuron disease.

Objective: To describe the clinical and electrophysiologic features of patients with inclusion body myositis that was misinterpreted as motor neuron disease.

Patients And Methods: We retrospectively retrieved the medical records of 70 patients with a pathologic diagnosis of inclusion body myositis. From this group, we selected those who had been first diagnosed as having motor neuron disease or amyotrophic lateral sclerosis.

Electrophysiologic studies in critical illness associated weakness: myopathy or neuropathy--a reappraisal.

Objective: Unexplained weakness in critically ill patients is recognized with increasing frequency. However, it is debated whether the condition is a peripheral neuropathy or a myopathy. Diagnostic difficulties can arise from multiple sources that are not generally a factor in other neuromuscular conditions.

Diagnostic value of electrophysiological tests in patients with sciatica.

Objectives: To assess the diagnostic value of electrophysiological tests in patients with sciatica.

Materials And Methods: The diagnostic value of electrophysiological tests were evaluated in 25 patients with monoradicular sciatica. The electrophysiological study included dermatomal somatosensory evoked potentials, electromyography, F-wave latencies, H-reflexes and motor and sensory nerve conduction determinations.

EMG evidence of myopathy and the occurrence of titin autoantibodies in patients with myasthenia gravis.

We studied 65 patients with myasthenia gravis (MG). Clinical, neurophysiological, immunological, and histological findings suggested the coexistence of a presumed autoimmune myopathy. The clinical features were persistent pyridostigmine-resistant weakness and atrophy of striated muscles.

Acute and chronic neuropathies: new aspects of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, an overview and an update.

During the last 15 years new information about clinical, electrophysiological, immunological and histopathological features of acute and chronic inflammatory neuropathies have emerged. Thus, the Guillain-Barré syndrome (GBS) is no longer considered a simple entity. Subtypes of the disorder besides the typical predominant motor manifestation, are recognized, i.

The role of quantitative electromyography in inclusion body myositis.

Objective And Methods: Inclusion body myositis is said to have both myopathic and neurogenic features on electrophysiological tests. Twenty one studies from 20 patients with biopsy defined inclusion body myosis, 13 of whom had quantitative electromyography (qEMG), were reviewed to determine if this technique added diagnostic specificity (one patient had both needle EMG and a later study with qEMG before muscle biopsy).

Results: Excessive numbers of polyphasic motor unit potentials (MUPs) (> 12% per muscle) were seen in 11 of the 13 patients.

Lymphoproliferative disorders and motor neuron disease: an update.

We studied 26 patients with both motor neuron disease and lymphoproliferative disease (LPD). Twenty-three patients had definite or probable upper motor neuron signs; none had electrophysiologic evidence of motor neuropathy. LPD syndromes comprised Waldenström's macroglobulinemia, multiple myeloma, chronic lymphocytic leukemia, follicular cell lymphoma, and Hodgkin's disease.

Motor neuron disease, lymphoproliferative disease, and bone marrow biopsy.

Some have suggested that nonfamilial motor neuron disease (MND) may be autoimmune, and the neurological disorder may benefit from immunotherapy. There have been reports of over 30 cases of lymphoproliferative disease (lymphoma, multiple myeloma, Waldenström's macroglobulinemia) with MND, and these patients might he offered immunosuppressive therapy. Bone marrow examination might increase the sensitivity of the diagnostic workup for lymphoma and other lymphoproliferative disorders.

Diabetic peripheral neuropathy: a clinicopathologic and immunohistochemical analysis of sural nerve biopsies.

We performed quantitative immunohistochemical studies of sural nerve biopsy specimens from 20 patients to determine whether endoneurial and epineurial lymphocytic infiltration occurs in diabetic nerves. The diabetic nerves contained a mean of 129 CD3+ cells per tissue section compared to 19 cells in patients with chronic neuropathy matched for the histologic severity of disease, and 0-5 cells in normal control nerves. The T-cell infiltrates in the diabetic nerves were predominantly of the CD8+ cell type.

Anti-MAG and anti-SGPG antibodies in neuropathy.

We compared the binding of human antibodies from patients with neuropathy to the myelin-associated glycoprotein (MAG), to its cross-reactive glycolipid sulfoglucuronyl paragloboside (SGPG), and to sections of peripheral nerve. Titers were correlated with the clinical presentation and results of electrophysiological and pathological studies. Most patients had a predominantly sensory or sensorimotor demyelinating neuropathy and highly elevated antibodies to both MAG and SGPG, but 2 had highly elevated antibodies to MAG alone, and 1 to SGPG alone.

Sensory pathophysiology in chronic acquired demyelinating neuropathy.

Pathophysiological changes in sensory fibres in chronic acquired demyelinating neuropathy (CADP) are poorly understood, and it is not known to what extent sensory loss may be due to axonal loss or to conduction block. Motor and sensory nerve condition were studied in 18 patients with CADP to delineate abnormalities in the compound sensory action potential (CSAP) recorded proximally along the limb. To distinguish small CSAPs from noise, near-nerve needle electrodes and electronic averaging were used.