Reduction in the appearance of facial hyperpigmentation after use of moisturizers with a combination of topical niacinamide and N-acetyl glucosamine: results of a randomized, double-blind, vehicle-controlled trial.

BACKGROUND: Topical niacinamide and N-acetyl glucosamine (NAG) each individually inhibit epidermal pigmentation in cell culture. In small clinical studies, niacinamide-containing and NAG-containing formulations reduced the appearance of hyperpigmentation. OBJECTIVES: To assess the effect of a combination of niacinamide and NAG in a topical moisturizing formulation on irregular facial pigmentation, including specific detection of changes in colour features associated with melanin. METHODS: This was a 10-week, double-blind, vehicle-controlled, full-face, parallel-group clinical study conducted in women aged 40-60 years. After a 2-week washout period, subjects used a daily regimen of either a morning sun protection factor (SPF) 15 sunscreen moisturizing lotion and evening moisturizing cream each containing 4% niacinamide + 2% NAG (test formulation; n = 101) or the SPF 15 lotion and cream vehicles (vehicle control; n = 101). Product-induced changes in apparent pigmentation were assessed by capturing digital photographic images of the women after 0, 4, 6 and 8 weeks of product use and evaluating the images by algorithm-based computer image analysis for coloured spot area fraction, by expert visual grading, and by chromophore-specific image analysis based on noncontact SIAscopy for melanin spot area fraction and melanin chromophore evenness. RESULTS: By all four measures, the niacinamide + NAG formulation regimen was significantly (P < 0.05) more effective than the vehicle control formulation regimen in reducing the detectable area of facial spots and the appearance of pigmentation. CONCLUSIONS: A formulation containing the combination of niacinamide + NAG reduced the appearance of irregular pigmentation including hypermelaninization, providing an effect beyond that achieved with SPF 15 sunscreen.

Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin.

The palmitoyl pentapeptide palmitoyl-lysine-threonine-threonine-lysine-serine (pal-KTTKS) is a synthetic material that was designed as a topical agent to stimulate collagen production and thus provide a skin anti-wrinkle benefit. To determine if pal-KTTKS is effective, the clinical study reported here was conducted. Caucasian female subjects (n = 93, aged 35-55) participated in a 12-week, double-blind, placebo-controlled, split-face, left-right randomized clinical study assessing two topical products: moisturizer control product vs. the same moisturizer product containing 3 ppm pal-KTTKS. Pal-KTTKS was well tolerated by the skin and provided significant improvement vs. placebo control for reduction in wrinkles/fine lines by both quantitative technical and expert grader image analysis. In self-assessments, subjects also reported significant fine line/wrinkle improvements and noted directional effects for other facial improvement parameters.

Back pain as a secondary disability in persons with lower limb amputations.

OBJECTIVE: To evaluate the frequency, duration, intensity, and interference of back pain in a sample of persons with lower limb amputations. DESIGN: Retrospective, cross-sectional survey. SETTING: Community-based survey from clinical databases. PARTICIPANTS: Participants who were 6 or more months post lower limb amputation (n = 255). INTERVENTION: An amputation pain survey that included several standardized pain measures. MAIN OUTCOME MEASURES: Frequency, duration, intensity, and interference of back pain. RESULTS: Of the participants who completed the survey (return rate, 56%), 52% reported experiencing persistent, bothersome back pain. Of these, 43% reported average back pain intensity in the mild range (1-4 on 0-10 rating scale) and 25% reported pain of moderate intensity (5-6 on 0-10 scale). Most respondents with back pain rated the interference of their pain on function as none to minimal. However, nearly 25% of those with back pain described it as frequent, of severe intensity (>or=7 on 0-10 scale), and as severely interfering with daily activities including social, recreational, family, and work activities. CONCLUSIONS: Back pain may be surprisingly common in persons with lower limb amputations, and, for some who experience it, may greatly interfere with function.

Optimizing the number of tests for carpal tunnel syndrome.

The combined sensory index (CSI), the sum of three latency differences, median-ulnar across the palm (palmdiff), median-ulnar to the ring finger (ringdiff), and median-radial to the thumb (thumbdiff), has higher sensitivity and reliability for carpal tunnel syndrome than individual tests. The objective in this study was to develop an approach that minimizes testing but maximizes accuracy. We retrospectively studied 300 hands. There were endpoints for individual tests that confidently predicted the CSI; for ranges between these endpoints, further testing was required. These ranges were: palmdiff 0-0.3 ms; ringdiff 0.1-0.4 ms; and thumbdiff 0.2-0.7 ms. One may use a strategy in which more tests are performed when results are in these ranges. This approach can allow accurate diagnosis with fewer tests when values are extreme, yet uses the greater diagnostic power of more tests when values are midrange.

Increased threshold sural amplitude after upper limb isometric contraction in complete paraplegics.

OBJECTIVE: To determine whether the enhancement of threshold sural sensory nerve action potentials (SNAPs) occurred in patients with spinal cord injury after upper limb isometric contraction. DESIGN: This prospective study, in which ten paraplegic patients with spinal cord injury were recruited from the Harris County community and served as his/her own control, was performed in the electromyography laboratory at Harris County Hospital District Quentin Mease Hospital. The baseline SNAP was established using ten threshold, signal-averaged stimuli to the sural nerve. With the same stimulus strength, the SNAP was recorded while the subjects' arms were pulled apart against a force gauge at 50% and 100% maximum force. Responses were recorded every 4 min until the values returned to baseline. RESULTS: Results showed an increase in the SNAP amplitude after 50% and 100% maximum force. The mean preexercise SNAP amplitude was 4.0 +/- 0.6 (SE) microV. At 50% force, the SNAP amplitude was 7.57 +/- 1.2 microV; at 100% force, it was 7.29 +/- 1.2 microV. The post hoc analysis of the data revealed P = 0.009 and P = 0.01 for 50% and 100% maximum force, respectively. CONCLUSIONS: The threshold SNAP of the sural nerve was enhanced after isometric exercise in paraplegic patients with spinal cord injury.

Lumbosacral plexopathy in pelvic trauma.

We reviewed the electrophysiologic data and the etiology of lumbosacral plexopathy in 22 consecutive patients with pelvic trauma referred for electromyography (EMG). Most (68%) patients had sacral fractures or sacroiliac joint separation, 14% had acetabular fractures, and 9% had femoral fractures. Lumbosacral plexopathy was significantly more common (P = 0.0026) among patients with sacral fractures (incidence of 2.03%) than among the entire population of patients with pelvic and acetabular fractures (overall incidence 0. 7%). Patients with acetabular and femoral fractures may have suffered injury to multiple proximal nerves originating from the plexus rather than injury to the plexus, as confirmed by magnetic resonance imaging (MRI) neurogram in select cases.

Test-retest reliability of combined sensory index: implications for diagnosing carpal tunnel syndrome.

When compared to single nerve conduction tests, the combined sensory index (CSI) has been shown previously to have superior sensitivity and specificity for diagnosing carpal tunnel syndrome. The CSI is the sum of (1) median-ulnar ring finger antidromic latency difference at 14 cm (ring-diff); (2) median-radial thumb antidromic latency difference at 10 cm (thumb-diff); and (3) median-ulnar midpalmar orthodromic latency difference at 8 cm (palm-diff). To evaluate the reliability of single nerve conduction tests (ring-diff, thumb-diff, and palm-diff) vs. a combined summary variable (CSI), we conducted a prospective study during which the same investigator performed test and retest sessions on one hand of 32 subjects. Results showed that the CSI had the highest test-retest reliability (Spearman rho = 0.95), when compared with ring-diff, thumb-diff, and palm-diff (Spearman rho = 0.67, 0.75, and 0.74, respectively). Therefore, we propose the use of the CSI as not only an accurate but also a reliable method for diagnosing carpal tunnel syndrome.

Chronic phantom sensations, phantom pain, residual limb pain, and other regional pain after lower limb amputation.

OBJECTIVES: To determine the characteristics of phantom limb sensation, phantom limb pain, and residual limb pain, and to evaluate pain-related disability associated with phantom limb pain. DESIGN: Retrospective, cross-sectional survey. Six or more months after lower limb amputation, participants (n = 255) completed an amputation pain questionnaire that included several standardized pain measures. SETTING: Community-based survey from clinical databases. PARTICIPANTS: A community-based sample of persons with lower limb amputations. MAIN OUTCOME MEASURES: Frequency, duration, intensity, and quality of phantom limb and residual limb pain, and pain-related disability as measured by the Chronic Pain Grade. RESULTS: Of the respondents, 79% reported phantom limb sensations, 72% reported phantom limb pain, and 74% reported residual limb pain. Many described their phantom limb and residual limb pain as episodic and not particularly bothersome. Most participants with phantom limb pain were classified into the two low pain-related disability categories: grade I, low disability/low pain intensity (47%) or grade II, low disability/high pain intensity (28%). Many participants reported having pain in other anatomic locations, including the back (52%). CONCLUSIONS: Phantom limb and residual limb pain are common after a lower limb amputation. For most, the pain is episodic and not particularly disabling. However, for a notable subset, the pain may be quite disabling. Pain after amputation should be viewed from a broad perspective that considers other anatomic sites as well as the impact of pain on functioning.

Traumatic injury to peripheral nerves.

This article reviews the epidemiology and classification of traumatic peripheral nerve injuries, the effects of these injuries on nerve and muscle, and how electrodiagnosis is used to help classify the injury. Mechanisms of recovery are also reviewed. Motor and sensory nerve conduction studies, needle electromyography, and other electrophysiological methods are particularly useful for localizing peripheral nerve injuries, detecting and quantifying the degree of axon loss, and contributing toward treatment decisions as well as prognostication.

Role of neurophysiologic evaluation in diagnosis.

The electrodiagnostic evaluation assesses the integrity of the lower-motor-neuron unit (i.e., peripheral nerves, neuromuscular junction, and muscle). Sensory- and motor-nerve conduction studies measure compound action potentials from nerve or muscle and are useful for assessing possible axon loss and/or demyelination. Needle electromyography measures electrical activity directly from muscle and provides information about the integrity of the motor unit; it can be used to detect loss of axons (denervation) as well as reinnervation. The electrodiagnostic examination is a useful tool for first detecting abnormalities and then distinguishing problems that affect the peripheral nervous system. In evaluating the patient with extremity trauma, it can differentiate neurapraxia from axonal transection and can be helpful in following the clinical course. In patients with complex physical findings, it is a useful adjunct that can help discriminate motor neuron disease from polyneuropathy or myeloradiculopathy due to spondylosis.

Somatosensory evoked potential monitoring during closed humeral nailing: a preliminary report.

OBJECTIVES: To assess the role of intraoperative somatosensory evoked potential (SSEP) monitoring of the radial and median nerves in preventing iatrogenic nerve injury during closed, locked intramedullary (IM) nailing of the humerus. DESIGN: Prospective clinical study. SETTING: Pacific Northwest Level One trauma center and Southern California military medical center. PATIENTS: Thirteen patients with indications for surgical stabilization of fractures of the humeral diaphysis and either unknown neurologic status of the affected limb or anticipated difficult reduction maneuvers due to fracture complexity or displacement. INTERVENTION: Closed, antegrade or retrograde locked IM nailing of the humerus was attempted while intraoperative monitoring of the radial and median nerves with SSEP was performed. MAIN OUTCOME MEASUREMENTS: Intraoperative radial and median nerve SSEP changes during closed fracture manipulation, guide rod insertion, reaming, and humeral nail placement. RESULTS: Baseline recordings were obtained in twelve of thirteen patients for both the radial and median nerves. An absence of radial nerve signal in one patient with a closed head injury prompted an open procedure, revealing entrapment of the radial nerve in the fracture. Intraoperative SSEP changes were observed in two of the twelve remaining patients during fracture manipulation and distal interlocking. The signal amplitude returned after discontinuation of manipulation and traction, and alteration of the interlocking maneuver. No neurologic deficits were noted in these two patients. CONCLUSIONS: Intraoperative radial nerve SSEP monitoring appears to reliably reflect the status of the radial nerve in those patients with a humerus fracture. In three of eleven patients, intraoperative signal changes prompted a change in surgical plan. In no patient did there appear to be evidence of iatrogenic nerve injury.

Electrodiagnostic evaluation of traumatic nerve injuries.

This article reviews the techniques of motor and sensory nerve conduction studies and needle electromyography methods, which are particularly useful for localizing nerve injuries in upper extremity and hand trauma. Included are details of methods for detecting and quantifying the degree of axon loss and for using this information to make treatment decisions and predict outcomes. The epidemiology and classification of traumatic peripheral nerve injuries, the effects of these injuries on nerve and muscle, and the means by which electrodiagnosis is used to help classify the injury are described. An overview of recovery mechanisms also is presented.

Somatosensory potentials, CSF creatine kinase BB activity, and awakening after cardiac arrest.

OBJECTIVE: To examine the utility of somatosensory evoked potential (SEP) peaks and CSF creatine kinase BB isoenzyme activity (CKBB) in predicting nonawakening from coma due to cardiac arrest. BACKGROUND: Accurate predictors of neurologic outcome in patients comatose after cardiac arrest are needed to improve medical decision making. METHODS: A total of 72 comatose patients had bilateral median SEPs, and of these, 52 had CSF and CKBB. Awakening was defined as following commands or having comprehensible speech. Both short (N1) and long (N3) latency SEP peaks were analyzed. Nonparametric analyses were used. RESULTS: For patients who had both tests, CKBB > or = 205 U/L predicted nonawakening with a sensitivity of 49% and a specificity of 100%. Bilateral absence of the N1 peak predicted nonawakening with a sensitivity of 53% and a specificity of 100%. Using CKBB > or = 205 U/L, bilaterally absent SEP N1 peaks, or both predicted nonawakening with a sensitivity of 69% and a specificity of 100%. Using CKBB > or = 205 U/L, bilaterally absent N1 peaks, bilateral N3 > or = 176 msec or absent, or some combination predicted nonawakening with a sensitivity of 78% and a specificity of 100%. CONCLUSION: The combination of an absent N1 peak and elevated CKBB performs better than either alone in predicting nonawakening after cardiac arrest. Prolonged or absent N3 latency may increase sensitivity. These results should be interpreted with caution given the small number of patients and the possibility of a self-fulfilling prophecy.

Serum positive botulism with neuropathic features.

A 32-year-old man presented with multiple cranial neuropathies and his serum was positive for botulism type B. However, serial electrodiagnostic studies were consistent with a primarily neuropathic process, such as Fisher syndrome, rather than a neuromuscular junction disorder. Electrodiagnostic study findings in patients with presumed neuromuscular junction disorders may mimic findings suggestive of a neuropathic process, or the bioassay for botulism may be falsely positive in patients with Fisher Syndrome.

Comparison of speech-evoked v tone-evoked P300 response: implications for predicting outcomes in patients with traumatic brain injury.

The P300 response is a cognitive event-related potential recorded over the scalp. The tone-evoked P300 response has been used to predict outcomes of patients with brain injury. However, it may lead to false predictions because some normal people have a very small tone-evoked P300 response. It is hypothesized that speech may generate a more robust P300 response than tones. A voice-generator prototype was designed for this study. The rare speech signal was the word "mommy" in a female voice. The common signal was a 1000-Hz tone. Twenty-two normal adults (11 males, 11 females; age range, 18-60 yr) were tested for both speech-evoked and tone-evoked P300 responses. Speech-evoked P300 responses had significantly larger amplitudes (mean, 12.1 microV) than the tone-evoked responses (mean, 5.9 microV; P < 0.0001). Six subjects with brain injury were also tested using the same protocol: two subjects with severe brain injury showed no response to either stimulus. Both died within 1 wk after the testing. Although two subjects with moderate brain injury could not complete the testing because of agitated behavior, two other subjects with mild traumatic brain injury showed a larger speech-evoked than tone-evoked P300 response. The speech-evoked P300 response may be promising in predicting outcomes of patients with brain injury.

Laryngeal electromyographic findings in Charcot-Marie-Tooth disease type II.

Charcot-Marie-Tooth disease is a hereditary motor and sensory neuropathy that exhibits progressive muscular atrophy in the limbs, beginning with the lower extremities. It is now understood to be a heterogeneous group of disorders that can be differentiated both clinically and genetically. In Charcot-Marie-Tooth disease type II C, axonal neuropathy, diaphragm weakness, and vocal cord paralysis are described within kindreds. We used laryngeal electromyography to study a patient with this disorder. This technique has potential in the diagnosis of Charcot-Marie-Tooth disease type II.

Idiopathic bilateral vocal fold weakness.

OBJECTIVE: To describe an unrecognized clinical entity, idiopathic bilateral vocal fold weakness, and propose recommendations regarding the diagnosis and management of these cases. STUDY DESIGN: Retrospective, nonrandomized case study. METHODS: All cases of bilateral vocal fold weakness evaluated at the University of Washington Voice Disorders Clinic between 1991 to 1998 were reviewed. RESULTS: Four patients with bilateral laryngeal weakness were determined to have idiopathic bilateral vocal fold paresis following exhaustive workups, including videostroboscopy, bilateral laryngeal electromyography (EMG), neurological consultation, and other pertinent studies. CONCLUSIONS: Performing bilateral laryngeal EMG is an essential aspect of the workup of any laryngeal weakness case, particularly if the etiology is unknown on presentation. Idiopathic bilateral vocal fold weakness is an underrecognized but real clinical diagnosis that will become more familiar with the increasing utilization of laryngeal EMG in clinical situations.

Effect of isometric contraction on threshold somatosensory evoked potentials.

We previously described the augmentation of sensory nerve action potential amplitudes after near and remote isometric muscle contraction. In this study, we wished to determine if the sensory cortex was involved in this process. In this prospective, intrinsically controlled study, we studied threshold somatosensory evoked potentials in 12 normal subjects with stimulation of the median nerve at 5.1 Hz. The subjects were tested during the following conditions: baseline, 25%, and 75% maximum isometric abductor digiti minimi contraction for 4 min. Each of these conditions was recorded before, during, and 4 min and 8 min after contraction. Results showed that at 25% contraction, there was a significant temporal increase in N9 amplitude (2.1-2.6 microV; P = 0.05, analysis of variance, repeated measures) and a decrease in N20 amplitude with 75% contraction (1.9-1.6 microV; P = 0.03, analysis of variance, repeated measure). No significant changes were noted in the spinal cord or brainstem recordings. In conclusion, it appears that augmentation of the brachial plexus peripheral nervous system recording occurs concurrently with central inhibitory gating. The possibility of peripheral nervous system adaptability will be discussed.

Strategies for analyzing nerve conduction data: superiority of a summary index over single tests.

We compared three strategies for diagnosing carpal tunnel syndrome: using a single test; requiring one, two, or three of three tests to be abnormal; or utilizing a single summary variable incorporating data from three tests. Sixty-five hands of subjects without clinical carpal tunnel syndrome (CTS) were compared with 66 hands with clinical CTS. Three latency differences were measured: median-ulnar (8 cm) midpalmar orthodromic (palmdiff); median-ulnar ring finger (14 cm) antidromic (ringdiff); and median-radial thumb (10 cm) antidromic (thumbdiff). The combined sensory index (CSI) was the sum of these three differences. Sensitivity for the tests was palmdiff 69.7%, ringdiff 74.2%, thumbdiff 75.8%, and CSI 83.1%. Specificity was 95.4-96.9%. Requiring one, two, or three of three tests to be abnormal yielded sensitivities of 84.8%, 74.2%, or 56.1%, respectively, but specificities of 92.3%, 98.5%, and 100%, respectively. We conclude that a combined index improves diagnostic classification over use of single test results.