Optimal Effect of Phenol Block in the Sciatic Nerve of Rats: Standardization of Minimized Dosage and Duration of Application.

The phenol nerve block has been widely used in clinical practice for spasticity reduction, but the correlation between the dosage of phenol and its effectiveness has seldom been discussed. The objective was to determine the optimal duration of phenol in contact with the nervous tissue and to investigate the dose-response relationship of 5% aqueous phenol solution by percutaneous nerve block in rats. Group I (n = 8) received sciatic nerve block by bathing the nerves in phenol solution, and group II (n = 40) by injecting phenol percutaneously. Group IIa to IId received different volumes (0.80, 0.16, 0.08 and 0.04 ml) and group IIe received normal saline. Compound muscle action potential (CMAP) was measured pre-injection and at 90 and 270 sec after injection and after surgical exposure of the nerves. The duration of CMAP reduced by 10%, 25%, 50%, 75% and 100% after phenol injection was also recorded. The mean latency for the evoked response to subside in direct phenol application (group I) and percutaneous nerve block (group IIa) were 73.5 ± 5.9 and 62.4 ± 7.6 sec, respectively. There was no statistical difference for the time periods in the blocking effect elicited by phenol solution between these two methods. Ninety sec was set as the optimal duration for phenol to produce complete conduction blockage. Higher volume of phenol produced more significant blocking effect at 90 and 270 sec after injection. Percutaneous injection with 0.16 ml of phenol solution had the same blocking effect as 0.8 ml. The continuous injection model for percutaneous phenol block indeed used significantly more phenol than actually needed. Clinically, the progressive injection model can be used to minimize injection volume.

Relative and absolute reliabilities of the myotonometric measurements of hemiparetic arms in patients with stroke.

OBJECTIVE: To investigate the relative and absolute reliabilities of the myotonometer. DESIGN: Psychometric study. SETTING: Three medical centers. PARTICIPANTS: Patients with stroke (N=61). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Muscle tone, elasticity, and stiffness of relaxed affected deltoid, triceps brachii, biceps brachii, extensor digitorum, flexor carpi radialis, and flexor carpi ulnaris were measured twice, 30 minutes apart, using the myotonometer. Intraclass correlation coefficient, a relative reliability index, was calculated for 3 muscular properties and for each muscle to examine the degree of consistency and agreement between the 2 test sessions. Absolute reliability indices, including the SEM, smallest real difference, and Bland-Altman limits of agreement, were used to quantify measurement errors and check systematic biases of the 2 test sessions. RESULTS: The intraclass correlation coefficients were .83 to .95 for muscle tone, elasticity, and stiffness of all muscle groups. The SEM and the smallest real difference of muscle tone, elasticity, and stiffness of the biceps were the smallest among the 6 muscles tested. The Bland-Altman analyses showed no systematic bias between most of the repeated measurements. Compared with other muscles, biceps had narrower limits-of-agreement ranges, indicating that the myotonometric measurements of the biceps had higher stability and less variation over time. CONCLUSIONS: The myotonometer reliably measures muscular properties, with good relative and absolute reliabilities. These findings are useful for clinicians and researchers to assess muscle properties reliably and determine whether a real change has occurred in groups and on individual levels of patients with stroke.

Effectiveness of the end-range mobilization and scapular mobilization approach in a subgroup of subjects with frozen shoulder syndrome: a randomized control trial.

Treatment strategies targeting abnormal shoulder kinematics may prevent pathology or if the pathology develops, shorten its duration. We examined the effectiveness of the end-range mobilization/scapular mobilization treatment approach (EMSMTA) in a subgroup of subjects with frozen shoulder syndrome (FSS). Based on the kinematics criteria from a prediction method, 34 subjects with FSS were recruited. Eleven subjects were assigned to the control group, and 23 subjects who met the criteria were randomly assigned to the criteria-control group with a standardized physical therapy program or to the EMSMTA group. Subjects attended treatment sessions twice a week for 8 weeks. Range of motion (ROM), disability score, and shoulder complex kinematics were obtained at the beginning, 4 weeks, and 8 weeks. Subjects in the EMSMTA group experienced greater improvement in outcomes compared with the criteria-control group at 4 weeks (mean difference=0.2 of normalized hand-behind-back reach) and 8 weeks (mean difference=22.4 degrees humeral external rotation, 0.31 of normalized hand-behind-back reach, 7.5 disability, 5 degrees tipping and 0.32 rhythm ratio). Similar improvements were found between the EMSMTA group and control group. The EMSMTA was more effective than a standardized physical therapy program in a subgroup of subjects who fit the criteria from a prediction method.

Conduction and morphological changes in wrist nerves immediately after bilateral sanding exercises in hemiparetic subjects.

OBJECTIVE: To investigate the immediate effects of bilateral upper-extremity sanding exercises on conduction and morphologic characteristics of the median and ulnar nerves at the wrist in hemiparetic subjects and control subjects. DESIGN: Case control study using a pretest-post-test design. SETTING: Inpatient rehabilitation department affiliated with a teaching hospital. PATIENTS (OR PARTICIPANTS): Thirty hemiparetic subjects and 21 matched control subjects who met our inclusion criteria and had no history of diseases that may have predisposed them to peripheral neuropathies were recruited for this study. METHODS: Bilateral nerve conduction tests and ultrasonographic evaluations were performed on each subject before and immediately after a 30-minute bilateral sanding exercise with a frequency of 5 repetitions per minute. MAIN OUTCOME MEASUREMENTS: The effects of exercises on bilateral median and ulnar wrist nerves were assessed with the use of sensory and motor nerve conduction velocity tests and by width/thickness ratios in ultrasonographic evaluations. RESULTS: In the hemiparesis group, the pre-exercise amplitude of the motor component for the median and ulnar nerves were respectively lower than the corresponding values in the control group (P < .05), whereas the pre-exercise amplitude and velocity of the sensory component were lower than the corresponding values in the control group (P < .01). After the exercise, the assessments for the affected side showed reductions in the conduction velocity of the sensory component and an increase in the width/thickness ratio for the median nerve (P < .05). CONCLUSIONS: The median and ulnar nerves at the wrist in hemiparetic subjects before sanding exercises showed different conduction characteristics compared with control subjects. Their affected side also demonstrated significant conduction and morphologic changes after the exercises. These subclinical findings may be attributed to different mechanisms such as overuse, spasticity, and demyelinating changes. Prevention of these subclinical changes is recommended to enhance exercise safety in hemiparetic patients.

Electrophysiologic evidence of spinal accessory neuropathy in patients with cervical myofascial pain syndrome.

OBJECTIVE: To evaluate whether or not spinal accessory neuropathy exists in patients with cervical myofascial pain syndrome (MFPS). DESIGN: Prospective study. SETTING: A neurophysiologic laboratory in a university hospital. PARTICIPANTS: Patients with cervical MFPS (n=25) and healthy controls (n=20). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We performed nerve conduction studies (NCSs) in bilateral spinal accessory nerves, and electromyography and stimulated single-fiber electromyography in the trapezius muscles of all patients and controls. Parameters including nerve conduction velocities (NCVs), amplitudes and areas of compound muscle action potentials (CMAPs), and mean consecutive differences (MCDs) in single-fiber electromyography were measured, analyzed, and compared with the disease durations of the patients. RESULTS: Spinal accessory NCSs showed normative NCVs but with prominently reduced CMAP amplitude in the patients with cervical MFPS, which is recognized as an axonal neuropathy of the spinal accessory nerves. Electromyography showed prominent evidence of denervation and reinnervation patterns in 48% of the MFPS patients. The abnormal MCDs in single-fiber electromyography indicated a synaptic delay of motor endplates in the motor units, and may signify evolving instability of neuromuscular transmission in the spinal accessory nerves innervating trapezius muscles of the patients. CONCLUSIONS: This study demonstrates electrophysiologic evidence of neuroaxonal degeneration and neuromuscular transmission disorder in a significant proportion of patients with cervical MFPS. We suggest that spinal accessory neuropathy may be associated with cervical MFPS.

Quantification of the Trömner signs: a sensitive marker for cervical spondylotic myelopathy.

The Trömner sign is commonly used as a clinical neurological examination for upper motor neuron lesions above the fifth or sixth cervical segments of the spinal cord. This study aims to assess and quantify the Trömner signs utilizing electrophysiological test, and correlate to the severity of cord compression in cervical spondylotic myelopathy (CSM). We enlisted 46 CSM patients, and 30 healthy persons as controls. Manual Trömner and Hoffmann signs were tested in all subjects. By using a self-designed instrument, we performed electrophysiological assessments for the Trömner signs in patients and controls. Parameters of conduction latencies and amplitude of muscle action potentials were measured and compared with the cord compression ratios in CSM patients. The results showed a greater diagnostic sensitivity for the quantified Trömner signs in comparison to those of manual Trömner signs and Hoffmann signs. We found a positive correlation between the amplitude of muscle action potentials obtained in the Trömner signs and the cord compression ratios in the patients with CSM. In conclusion, the Trömner signs can be measured by electrophysiological assessments. We demonstrate a new quantification method for an established neurological sign. Not only is Trömner sign a highly sensitive test in clinical neurological examination, the electrophysiological assessment of this sign can also serve as an objective marker for evaluation of the severity of cervical cord compression.

Early-onset stroke in a patient with nasopharyngeal cancer associated with protein C deficiency.

We report a 47-year-old male stroke patient with nasopharyngeal cancer (NPC) and protein C deficiency. The patient was diagnosed with NPC and received a complete course of radiotherapy. Infarction stroke occurred 28 months after radiotherapy and magnetic resonance imaging of the brain confirmed the diagnosis. Carotid duplex sonography showed 50-79% stenosis in his left internal carotid artery. Coagulation profiles indicated protein C deficiency. After medical treatment and rehabilitation, the patient regained the ability to walk and he could perform most of his daily activities. Radiotherapy-induced carotid stenosis is an exacerbating feature of stroke in patients with protein C deficiency. We suggest early carotid duplex sonography and survey of the coagulation profile to prevent a stroke in patients with NPC.

Secondary motions of the shoulder during arm elevation in patients with shoulder tightness.

An analysis of secondary shoulder motions (humeral rotation, humeral head anterior/posterior translation, scapular tipping, and scapular upward/downward rotation) in subjects with anterior/posterior shoulder tightness provides the opportunity to examine the role of tightness as a means of affecting shoulder motions. Subjects with shoulder tightness (anterior, n=12; posterior, n=12) elevated their arms in the scapular plane. Three replicated movements were performed to the maximum motions. Kinematics data were collected by FASTRAK 3D electromagnetic system. To determine if a significant difference of the secondary motions existed between anterior/posterior shoulder tightness, two-factor mixed ANOVA models with the repeated factor of elevation angle (five elevation angles) and the independent factor of group were calculated. The relationships between the self-reported functional scores (Flexilevel Scale of Shoulder Function, FLEX-SF) and abnormal shoulder kinematics were assessed. For humeral head anterior/posterior translation, the subjects with posterior tightness demonstrated anterior humeral head translation (10mm, p=0.019) compared to subjects with anterior tightness. The subjects with anterior tightness demonstrated less posterior tipping (2.2 degrees , p=0.045) compared to subjects with posterior tightness. The humeral anterior translation had moderate relationships with FLEX-SF scores (r=-0.535) in subjects with posterior tightness. The scapular tipping had moderate relationships with FLEX-SF scores (r=0.432) in subjects with anterior tightness. In conclusion, the secondary motions were different between subjects with anterior and posterior shoulder tightness. During arm elevation, less scapular posterior tipping and less posterior humeral head translation in subjects with anterior and posterior shoulder tightness, respectively, are significantly related to self-reported functional disability in these subjects.

Quantification of shoulder tightness and associated shoulder kinematics and functional deficits in patients with stiff shoulders.

Measurement of anterior/posterior shoulder tightness, humeral external/internal rotation range of motion (ROM), scapular upward rotation/tipping ROM, and functional limitations were made in 46 patients with unilateral stiff shoulders (SSs) using a clinical measurement (shoulder tightness), a three-dimensional electromagnetic tracking device (shoulder ROM), and self-reports of function. Patients with SSs in their dominant shoulder demonstrated statistically greater posterior shoulder tightness compared to nondominant shoulder. Control dominant shoulders demonstrated decreased internal ROM as compared with control nondominant shoulders (p=0.021). In SSs, significant relationships were found between humeral internal rotation ROM and posterior shoulder tightness (R=0.49, p<0.0005), humeral external rotation ROM and anterior shoulder tightness (R=0.59, p=0.0002), scapular tipping and anterior shoulder tightness (R=0.57, p=0.004). Specifically, in patients with dominant SSs, posterior shoulder tightness and functional limitation were related (R=0.56, p=0.002). In patients with dominant involved shoulders, emphasise on posterior tightness stretch may improve functional ability directly. In addition to stretching program in patients with SSs, internal rotation ROM of control dominant shoulder is also important to consider in the rehabilitation of patients with SSs.

Effects of task instructions and target location on reaching kinematics in people with and without cerebrovascular accident: a study of the less-affected limb.

OBJECTIVE: We investigated how verbal instructions and target location interacted to influence reaching movement of the less-affected limb in participants with and without unilateral cerebrovascular accidents (CVAs). METHOD: Using a counterbalanced repeated-measures design, 26 people with CVA and 24 age-matched healthy people performed the reaching tasks under 4 conditions formed by the crossing of verbal instructions (speed and accuracy emphasis) and target locations (ipsilateral and contralateral to the performing hand). RESULTS: In the control groups, speeded instructions and ipsilateral reaches elicited significantly more preprogrammed movements than did accuracy instruction and contralateral reaches, respectively. Similar patterns of performance in response to task constraints were found in the CVA groups except for movement initiation in the right CVA group. CONCLUSION: Instruction and locations interacted to constrain reaching movements in both control and CVA groups. The combination of speeded instruction and ipsilateral reach may optimize movement performance of the less-affected limb in stroke patients.

Increased carrying angle is a risk factor for nontraumatic ulnar neuropathy at the elbow.

UNLABELLED: The literature suggests a possible relationship between carrying angle and nontrauma-related ulnar neuropathy. To confirm that relationship, we asked whether carrying angle is a risk factor in patients with nontrauma-related ulnar neuropathy. We measured the carrying angles of the elbow in 36 patients with a clinically and electrophysiologically confirmed diagnosis of nontraumatic ulnar neuropathy at the elbow and in 50 healthy control subjects. Correlation analysis was performed between carrying angles and parameters of nerve conduction studies, including nerve conduction velocities and amplitudes of muscle and nerve action potentials. The mean carrying angle was greater in the patients than in the control subjects. Females had a greater carrying angle than males. We observed an inverse relationship between carrying angles and motor nerve conduction velocities at cross-elbow segments of the ulnar nerves and with sensory nerve conduction velocities of the distal ulnar nerves. An increased carrying angle of the elbow appears to be an independent risk factor of nontrauma-related ulnar neuropathy. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Evidence of neuroaxonal degeneration in myofascial pain syndrome: a study of neuromuscular jitter by axonal microstimulation.

The mechanism of myofascial pain syndrome (MPS) is unclear. Previous reports pointed out that pathogenesis of either referred pain or local twitch response in trigger point of MPS is related to the nerve degeneration and disintegration of motor and sensory nerves in spinal cord. The purpose of the present study is to investigate the evidence of neuromuscular transmission disorders in trigger point muscles of patients with MPS by using stimulated single-fiber electromyography (SFEMG) examination. Twenty-three patients with neck MPS and 16 age-matched controls attended for the present study. The jitter or mean consecutive difference (MCD) was calculated as the mean of the absolute differences for 30 consecutive interpotential intervals between stimuli and single-fiber potentials in trapezius and levator scapulae muscles. The relationship between the MCD values and the disease duration was measured. The results showed significantly increased MCDs in trapezius and levator scapulae muscles in MPS patients. MCD values measured in the trigger point muscles were found to be positively correlated with the disease duration. The present study with axonal microstimulation and SFEMG demonstrates a prominent evidence of neuroaxonal degeneration and neuromuscular transmission disorders in the trigger point muscles of MPS patients. The mechanism of MPS is possibly implicated with the degeneration of motor neurons.

Reorganization of the cortico-spinal pathway in patients with chronic complete thoracic spinal cord injury: a study of motor evoked potentials.

OBJECTIVE: To evaluate the change in motor evoked potential parameters following transcranial magnetic stimulation in patients with chronic complete thoracic cord injury. DESIGN: A cross-sectional study. SUBJECTS: Eighteen patients with chronic complete thoracic cord injury and 18 age- and sex-matched healthy controls were included in the study. The mean post-injury duration was 13.0 (standard deviation (SD) 6.0) years. METHODS: The latency, amplitude, central conduction time and peripheral conduction time of motor evoked potentials from bilateral abductor pollicis brevis and first dorsal interosseous muscles following transcranial magnetic stimulation were measured and compared between the patients and healthy controls. The predicting variables for central conduction time, including age, sex, height, illness duration and job activity, were analysed using a simple correlation and stepwise multiple regression model. RESULTS: The patients with complete thoracic cord injury had longer central conduction time recording of the dominant hand in both abductor pollicis brevis and first dorsal interosseous muscles. The difference in latency approached significance between the patients and controls. There was no statistical difference in amplitude between them. Regression analysis demonstrated that patients who were older, less physically active and with longer illness duration showed prolonged central conduction time. CONCLUSION: The central conduction time in the dominant hand of chronic complete thoracic cord injury is prolonged. This study revealed motor reorganization of the central nervous system in complete thoracic cord injury. Decreased physical activity and prolonged illness may cause these changes.

Shoulder kinematic features using arm elevation and rotation tests for classifying patients with frozen shoulder syndrome who respond to physical therapy.

Physical therapy is an intervention commonly used in the treatment of subjects with frozen shoulder symptoms, with limited proven effect. The purpose of this study was to identify the kinematic features of patients with frozen shoulder who are more likely to respond to physical therapy. Thirty-four subjects presenting frozen shoulder syndrome were studied to determine altered shoulder kinematics and functional disability. Subjects received the same standardized treatment with passive mobilization/stretching techniques, physical modalities (i.e. ultrasound, shortwave diathermy and/or electrotherapy) and active exercises twice a week for 3 months. Initially, subjects were asked to perform full active motion in 3 tests: abduction in the scapular plane, hand-to-neck and hand-to-scapula. During the test, shoulder kinematics were measured using a 3-D electromagnetic motion-capturing system. In the initial and follow-up sessions, the self-reported Flexilevel Scale of Shoulder Function (FLEX-SF) was used to determine functional disability from symptoms. Improvement with treatment was determined using percent change in FLEX-SF scores over three months of treatment [(final score-initial score)/initial score x 100, >20% improvement and < = 20% nonimprovement]. Shoulder kinematics were first analysed for univariate accuracy in predicting improvement and then combined into a multivariate prediction method. A prediction method with two variables (scapular tipping >8.4 degrees during arm elevation, and external rotation >38.9 degrees during hand to neck) were identified. The presence of these two variables (positive likelihood ratio=15.71) increased the probability of improvement with treatment from 41% to 92%. It appears that shoulder kinematics may predict improvement in subjects with frozen shoulder syndrome. Prospective validation of the proposed prediction method is warranted.

Mobilization techniques in subjects with frozen shoulder syndrome: randomized multiple-treatment trial.

BACKGROUND AND PURPOSE: The purpose of this study was to compare the use of 3 mobilization techniques--end-range mobilization (ERM), mid-range mobilization (MRM), and mobilization with movement (MWM)--in the management of subjects with frozen shoulder syndrome (FSS). SUBJECTS: Twenty-eight subjects with FSS were recruited. METHODS: A multiple-treatment trial on 2 groups (A-B-A-C and A-C-A-B, where A=MRM, B=ERM, and C=MWM) was carried out. The duration of each treatment was 3 weeks, for a total of 12 weeks. Outcome measures included the functional score and shoulder kinematics. RESULTS: Overall, subjects in both groups improved over the 12 weeks. Statistically significant improvements were found in ERM and MWM. Additionally, MWM corrected scapulohumeral rhythm significantly better than ERM did. DISCUSSION AND CONCLUSION: In subjects with FSS, ERM and MWM were more effective than MRM in increasing mobility and functional ability. Movement strategies in terms of scapulohumeral rhythm improved after 3 weeks of MWM.

Medial calcaneal neuropathy is associated with plantar fasciitis.

OBJECTIVE: To demonstrate a method of sensory nerve conduction study (NCS) for the medial calcaneal nerve (MCN) and confirm the medial calcaneal neuropathy in patients with plantar fasciitis (PF). METHODS: Twenty-six patients with clinical and ultrasonographic diagnosis of PF participated in the present study. An antidromic method for sensory NCS of MCN was performed in each patient and in 30 controls. The conduction latency, sensory nerve conduction velocity (SNCV) and amplitude of the sensory nerve action potential (SNAP) were measured and the correlation of the SNCV of MCN with both body weight and body mass index (BMI) was studied. RESULTS: The mean conduction latency obtained in the MCN was greater in the PF patients than in the normal controls. Mean SNCV and SNAP amplitude of the MCN were significantly less in the PF patients than in the normal controls. Body weight and BMI were greater in PF patients than in controls. Six patients were identified as having a medial calcaneal neuropathy by using the criteria of the lowest normal values of the NCS of MCN from the normal controls. CONCLUSIONS: Medial calcaneal neuropathy is associated with PF. The present method of sensory NCS is useful and objective in the diagnosis of the medial calcaneal neuropathy. SIGNIFICANCE: Medial calcaneal neuropathy was confirmed by the sensory NCS of MCN and shown to be associated with PF.

Measurement of motor nerve conduction velocity of the sciatic nerve in patients with piriformis syndrome: a magnetic stimulation study.

OBJECTIVE: To assess the motor nerve conduction of the sciatic nerve by a magnetic stimulation method in patients with piriformis syndrome. DESIGN: Prospective study. SETTING: An electrodiagnostic laboratory in a university hospital. PARTICIPANTS: Twenty-three patients with piriformis syndrome and 15 healthy persons for control. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Motor nerve conduction velocity (MNCV) of the sciatic nerve was measured at the gluteal segment by magnetic stimulation proximally at L5 and S1 roots and distally at sciatic nerve at gluteal fold and recording at the corresponding muscles. Diagnostic sensitivities were measured in the magnetic stimulation method and the conventional nerve conduction, long latency reflex, and needle electromyography studies. RESULTS: The mean MNCV of the sciatic nerve +/- standard deviation at the gluteal segment in L5 component was 55.4+/-7.8 m/s in patients with piriformis syndrome, which was slower than the mean value of 68.1+/-10.3 m/s obtained in healthy controls (P=.014). The MNCV of the sciatic nerve in S1 component showed no significant difference between the patients and controls (P=.062). A negative relation was found between the disease duration and the MNCV values of sciatic nerves in patients with piriformis syndrome (r=-.68, P<.01). The diagnostic sensitivity by magnetic stimulation is .467. CONCLUSIONS: Magnetic nerve stimulation provides a painless, noninvasive, and objective method for evaluation of sciatic nerve function in patients with piriformis syndrome.

Effects of task constraints on reaching kinematics by healthy adults.

Understanding the control of movement requires an awareness of how tasks constrain movements. The present study investigated the effects of two types of task constraints--spatial accuracy (effector size) and target location--on reaching kinematics. 15 right-handed healthy young adults (7 men, 8 women) whose mean age was 23.6 yr. (SD=3.9 yr.) performed the ringing task under six conditions, formed by the crossing of effector size (larger vs smaller size) and target location (left, right, or a central position). Significant main effects of effector size and target location were found for peak velocity and movement time. There was a significant interaction for the percentage of time to peak velocity. The findings suggested that task constraints may modulate movement performance in specific ways. Effects of effector size might be a consequence of feedforward and feedback control, and location effects might be influenced by both biomechanical and neurological factors.

A novel method for estimating the focal size of two confocal high-intensity focused ultrasound transducers.

Estimating the focal size and position of a high-intensity focused ultrasound (HIFU) transducer remains a challenge since traditional methods, such as hydrophone scanning or schlieren imaging, cannot tolerate high pressures, are directional, or provide low resolution. The difficulties increase when dealing with the complex beam pattern of a multielement HIFU transducer array, e.g., two transducers facing each other. In the present study we show a novel approach to the visualization of the HIFU focus by using shockwave-generated bubbles and a diagnostic B-mode scanner. Bubbles were generated and pushed by shock waves toward the HIFU beam, and were trapped in its pressure valleys. These trapped bubbles moved along the pressure valleys and thereby delineated the shape and size of the HIFU beam. The main and sidelobes of 1.1- and 3.5 MHz HIFU beams were clearly visible, and could be measured with a millimeter resolution. The combined foci could also be visualized by observing the generation of sustained inertial cavitation and enhanced scattering. The results of this study further demonstrate the possibility of reducing the inertial cavitation threshold by the local introduction of shock wave-generated bubbles, which might be useful when bubble generation and cavitation-related bioeffects are intended within a small region in vivo.

Intracerebral hemorrhage secondary to autonomic dysreflexia in a young person with incomplete C8 tetraplegia: A case report.

Intracerebral hemorrhage is an unusual complication of autonomic dysreflexia and can be fatal if massive bleeding occurs with brain herniation. We report the case of a man in his midthirties with incomplete tetraplegia who suffered right putaminal hemorrhage during an episode of autonomic dysreflexia. Prompt recognition and removal of the triggering factors of autonomic dysreflexia quickly brought his blood pressure under control and the patient had a favorable functional outcome after rehabilitation. A review of the literature suggests that the location of hemorrhage in autonomic dysreflexia-induced cases is similar to that in the general population. The most common triggering factors are bladder distension in men and labor induction in women. Hemorrhagic stroke can also occur in patients with incomplete spinal cord injury (SCI) who develop autonomic dysreflexia. The role of sympathetic skin response examination is also discussed. This life-threatening complication should be kept in mind in the case of people with SCI.