Aging of phrenic nerve conduction in the elderly

Imai, Tomihiro; H, Yuasa; Kato, Yasuo; Matsumoto, Hiroyuki

doi:10.1016/j.clinph.2005.08.003

Cited by 16 publications

(19 citation statements)

References 15 publications

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“…Our finding that phrenic nerve stimulation just above the clavicles is better than higher up in the neck (e.g., at the upper level of the thyroid cartilage),5, 7, 8 is in concordance with several previous studies 3, 6, 9, 12. However, in contrast to all previous studies that used stimulation at the posterior border of the SCM muscle, we found that changing the stimulation site to a slightly more medial position, between the clavicular and sternal heads of the SCM muscle (Fig.…”

Section: Discussionsupporting

confidence: 93%

“…In the first 5 subjects, different stimulation positions along both SCM muscles were attempted. As stimulation in the supraclavicular fossa, just above the clavicles, gave the best results,3, 6, 11 the optimal (medial–lateral) position at that level was explored in the remaining volunteers. For CMAP recording the active electrode (G1) was fixed 5 cm above the xiphoid process, and the reference electrode (G2) 16 cm from G1, on the chest margin ipsilateral to the stimulated phrenic nerve (Fig.…”

Section: Methodsmentioning

confidence: 99%

“…Phrenic nerve conduction studies have been used for a number of years in the evaluation of patients with respiratory failure and suspected neuromuscular disorders 2, 8, 12. Although several approaches to phrenic nerve stimulation have been described, stimulation at the posterior border of the sternocleidomastoid (SCM) muscle, both at the level of the upper margin of the thyroid cartilage5, 7, 8 and in the supraclavicular fossa just above the clavicle,3, 6, 9, 11 occasionally results in difficulties in obtaining a well‐formed and reproducible supramaximal compound motor action potential (CMAP). Furthermore, using these stimulation sites, concomitant brachial plexus stimulation has also often proven to be a problem 3, 5, 7–9…”

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confidence: 99%

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Phrenic nerve conduction studies: Technical aspects and normative data

Resman-Gaspersc

Podnar

2007

Muscle and Nerve

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In our clinical work we have occasionally encountered difficulties (e.g., no response, concomitant brachial plexus stimulation) in performing phrenic nerve conduction studies. The aim of this study was to overcome these difficulties and obtain our own set of normative data. In 29 healthy volunteers (15 men), aged 21-65 years, phrenic nerve conduction studies were performed using bipolar surface stimulation electrodes and a standard recording montage. Stimulation just above the clavicle, between the sternal and clavicular heads of the sternocleidomastoid muscles, elicited responses at the lowest stimulation strength, without concomitant brachial plexus stimulation. M-wave amplitude and duration changed with respiration, whereas latency and area did not. The normative limit for M-wave latency was 8.0 ms (upper), for amplitude it was 0.46/0.33 mV (lower: inspiration/expiration), and for area it was 4.4 mVms (lower). We suggest a slight modification of the generally used position for phrenic nerve stimulation, and the use of M-wave latency and area (unaffected by the respiratory cycle) in future phrenic nerve conduction studies. Phrenic nerve conduction studies have been used for a number of years in the evaluation of patients with respiratory failure and suspected neuromuscular disorders. 2,8,12 Although several approaches to phrenic nerve stimulation have been described, stimulation at the posterior border of the sternocleidomastoid (SCM) muscle, both at the level of the upper margin of the thyroid cartilage 5,7,8 and in the supraclavicular fossa just above the clavicle, 3,6,9,11 occasionally results in difficulties in obtaining a well-formed and reproducible supramaximal compound motor action potential (CMAP). Furthermore, using these stimulation sites, concomitant brachial plexus stimulation has also often proven to be a problem. 3,5,[7][8][9] In addition, as only limited information has been published on the stimulation strength needed to record maximal amplitude phrenic nerve CMAPs, 3 excessive electrical currents might be used unnecessarily in these studies, particularly in patients with phrenic nerve abnormalities.The aims of the present study were to: (1) determine a better position for phrenic nerve stimulation; (2) define the stimulation strength needed to obtain supramaximal CMAPs in healthy volunteers; (3) calculate normative data for all nerve conduction parameters measured by modern electromyography (EMG) systems; and (4) compare changes in CMAP parameters during respiration. METHODSThe study group consisted of 29 healthy volunteers (15 men), 21-65 years old (median, 33 years), with no respiratory or neuromuscular disorders. Subjects' data were as follows: height, 160 -192 cm (mean, 174 cm); sternum length, 16 -27 cm (mean, 22 cm); neck circumference, 31-45 cm (mean, 36 cm); chest circumference, 73-119 cm (mean, 90 cm); weight, 49 -105 kg (mean, 69 kg); and body mass index (BMI), 18 -33 kg/m 2 (mean, 23 kg/m 2 ). The subjects were recruited mainly from hospital personnel, and were minimally ...

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Section: Discussionsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Phrenic nerve conduction studies: Technical aspects and normative data

Resman-Gaspersc

Podnar

2007

Muscle and Nerve

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“…Phrenic nerve stimulation is simple and well tolerated, and it can be performed with surface stimulating and recording electrodes even in infants (24) and the elderly (20). The amplitude of the motor response depends on the number of excitable motor units in the diaphragm (37), but it is also affected by other factors, such as the respiratory cycle (24).…”

Section: Discussionmentioning

confidence: 99%

“…The control subjects had no neurological or respiratory dysfunction. Their ages ranged from 35 to 70 years (mean age 60), with approximately equal numbers of subjects in each decade (20).…”

Section: Subjects and Protocolmentioning

confidence: 99%

Respiratory Insufficiency with Preserved Diaphragmatic Function in Amyotrophic Lateral Sclerosis

et al. 2014

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Objective We performed a longitudinal study to elucidate the correlation between respiratory insufficiency and respiratory biomarkers, including diaphragmatic compound muscle action potential (DCMAP), at the initiation of noninvasive ventilation (NIV) in patients with amyotrophic lateral sclerosis (ALS). Methods The patients were assessed at least every six months. Additional assessments were performed at the start of respiratory therapy when the patients met the criteria for the initiation of NIV. Each assessment consisted of a full neurological examination, a phrenic nerve conduction study, respiratory function tests, and nocturnal pulsed oximetry. Patients We enrolled 43 patients with either definite or probable ALS as defined by the revised El Escorial criteria. Results The patients were divided into two groups according to the timing of the initiation of respiratory therapy. Seventeen patients (group A) met the criteria for NIV initiation when their DCMAP remained normal. Twenty-six patients (group B) met the criteria when their DCMAP decreased below normal limits. Although respiratory function parameters were significantly worse in group B compared with group A at NIV initiation, more than 80% of the patients in both groups developed nocturnal desaturation during sleep. Conclusion DCMAP is not always a reliable indicator for determining the optimal timing for NIV initiation during the progression of respiratory insufficiency in ALS. Physicians should be aware of the risk of respiratory insufficiency during sleep in patients with ALS.

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