A morphometric study of the lumbar spinous process in the Chinese population

Our goal was to analyze the anatomical parameters of the lumbar spine spinous process for an interspinous stabilization device designed for the Chinese population and to offer an anatomical basis for its clinical application. The posterior lumbar spines (T₁₂-S₁) of 52 adult cadavers were used for measuring the following: distance between two adjacent spinous processes (DB), distance across two adjacent spinous processes (DA), thickness of the central spinous processes (TC), thickness of the superior margin of the spinous processes (TS), thickness of the inferior margin of the spinous processes (TI), and height of the spinous processes (H). Variance and correlation analyses were conducted for these data, and the data met the normal distribution and homogeneity of variance. DB decreased gradually from L_1-2 to L₅-S₁. DA increased from T₁₂-L₁ to L_2-3 and then decreased from L_2-3 to L_4-5. The largest H in males was noted at L₃ (25.45±5.96 mm), whereas for females the largest H was noted at L₄ (18.71±4.50 mm). Usually, TS of the adjacent spinous process was lower than TI. Based on the anatomical parameters of the lumbar spinous processes obtained in this study, an “H”-shaped coronal plane (posterior view) was proposed as an interspinous stabilization device for the Chinese population. This study reports morphometric data of the lumbar spinous processes in the Chinese population, which provides an anatomical basis for future clinical applications.     

High definition versus standard definition white light endoscopy for detecting dysplasia in patients with Barrett's esophagus

High‐definition endoscopy systems provide superior image resolution. The aim of this study was to assess the utility of high definition compared with standard definition endoscopy system for detecting dysplastic lesions in patients with Barrett's esophagus. A retrospective cohort study of patients with non‐dysplastic Barrett's esophagus undergoing routine surveillance was performed. Data were retrieved from the central hospital electronic database. Procedures performed for non‐surveillance indications, Barrett's esophagus Prague C0M1 classification with no specialized intestinal metaplasia on histology, patients diagnosed with any dysplasia or cancer on index endoscopy, and procedures using advanced imaging techniques were excluded. Logistic regression models were constructed to estimate adjusted odds ratios and 95% confidence intervals comparing outcomes with standard definition and high‐definition systems. The high definition was superior to standard definition system in targeted detection of all dysplastic lesions (odds ratio 3.27, 95% confidence interval 1.27–8.40) as well as overall dysplasia detected on both random and target biopsies (odds ratio 2.36, 95% confidence interval 1.50–3.72). More non‐dysplastic lesions were detected with the high‐definition system (odds ratio 1.16, 95% confidence interval 1.01–1.33). There was no difference between high definition and standard definition endoscopy in the overall (random and target) high‐grade dysplasia or cancers detected (odds ratio 0.93, 95% confidence interval 0.83–1.04). Trainee endoscopists, number of biopsies taken, and male sex were all significantly associated with a higher yield for dysplastic lesions. The use of the high‐definition endoscopy system is associated with better targeted detection of any dysplasia during routine Barrett's esophagus surveillance. However, high‐definition endoscopy cannot replace random biopsies at present time.     

Expanding what is known of the anatomy of the spinal accessory nerve

The spinal accessory nerve (SAN) is classically considered a motor nerve innervating the sternocleidomastoid and trapezius muscles. Its anatomical relevance derives from the high prevalence of lesions following head and neck surgeries. As expected, trapezius weakness and atrophy are the most common findings; however, it is also commonly accompanied by pain and other sensory deficits that have no clear explanation, suggesting other functions. We have recently seen two patients presenting with an unrecognized sign, that is, subclavicular/pectoral asymmetry secondary to the SAN lesion. Retrospectively, we reviewed other patients with similar findings in our case series and in the literature. We discuss the anatomical connections of the SAN with the superficial cervical plexus and propose an explanation for this finding. Of the 41 patients in our series, we identified this sign in all who had preoperative photographs. New insights on the anatomy and connections of the SAN may account for the diversity of symptoms and signs presented following an operative intervention as well as the variability of its severity. Clin. Anat. 28:467–471, 2015. © 2014 Wiley Periodicals, Inc.     

Start-up propulsion biomechanics changes with fatiguing activity in persons with spinal cord injury

Objective: Shoulder pathology is a common condition in wheelchair users that can considerably impact quality of life. Shoulder muscles are prone to fatigue, but it is unclear how fatigue affects start-up propulsion biomechanics. This study determines acute changes in start-up wheelchair propulsion biomechanics at the end of a fatiguing propulsion protocol.

Design: Quasi-experimental one-group pretest-postest design.

Setting: Biomechanics laboratory. Participants: Twenty-six wheelchair users with spinal cord injury (age: 35.5?±?9.8 years, sex: 73% males and 73% with a paraplegia).

Interventions: Protocol of 15 min including maximum voluntary propulsion, right- and left turns, full stops, start-up propulsion, and rests.

Outcome measures: Maximum resultant force, maximum rate of rise of applied force, mean velocity, mean fraction of effective force, and mean contact time at the beginning and end of the protocol during start-up propulsion.

Results: There was a significant reduction in maximum resultant force (P?<?0.001) and mean velocity (P?<?0.001) at the end of the protocol. Also, contact time was reduced in the first stroke of start-up propulsion (P?<?0.001). Finally, propelling with a shorter contact time was associated with a greater reduction in performance (maximum velocity) at the end of the protocol.

Conclusion: There are clear changes in overground propulsion biomechanics at the end of a fatiguing propulsion protocol. While reduced forces could protect the shoulder, these reduced forces come with shorter contact times and lower velocity. Investigating changes in start-up propulsion biomechanics with fatigue could provide insight into injury risk.     

Using EMG to deliver lumbar dynamic electrical stimulation to facilitate cortico-spinal excitability

BackgroundPotentiation of synaptic activity in spinal networks is reflected in the magnitude of modulation of motor responses evoked by spinal and cortical input. After spinal cord injury, motor evoked responses can be facilitated by pairing cortical and peripheral nerve stimuli.ObjectiveTo facilitate synaptic potentiation of cortico-spinal input with epidural electrical stimulation, we designed a novel neuromodulation method called dynamic stimulation (DS), using patterns derived from hind limb EMG signal during stepping.MethodsDS was applied dorsally to the lumbar enlargement through a high-density epidural array composed of independent platinum-based micro-electrodes.ResultsIn fully anesthetized intact adult rats, at the interface array/spinal cord, the temporal and spatial features of DS neuromodulation affected the entire lumbosacral network, particularly the most rostral and caudal segments covered by the array. DS induced a transient (at least 1 min) increase in spinal cord excitability and, compared to tonic stimulation, generated a more robust potentiation of the motor output evoked by single pulses applied to the spinal cord. When sub-threshold pulses were selectively applied to a cortical motor area, EMG responses from the contralateral leg were facilitated by the delivery of DS to the lumbosacral cord. Finally, based on motor-evoked responses, DS was linked to a greater amplitude of motor output shortly after a calibrated spinal cord contusion.ConclusionCompared to traditional tonic waveforms, DS amplifies both spinal and cortico-spinal input aimed at spinal networks, thus significantly increasing the potential and accelerating the rate of functional recovery after a severe spinal lesion.     

Spontaneous and reflex movements after diagnosis of clinical brain death: A lesson from acute encephalopathy

BackgroundOrgan transplantation after brain death (BD) of the donor has been promoted in many countries as an established medical treatment. However, some problems with brain-dead organ transplantation have been reported. For example, there is no evidence as to the optimal observation period for a diagnosis and no evidence to support the interpretation of the various body movements observed after the determination of BD.Case reportA previously healthy 17-month-old girl with severe febrile convulsive status was transferred to our intensive care unit. The convulsions were refractory and the patient required respiratory management due to whole brain edema on head CT. Later she was diagnosed with acute encephalopathy. The patient showed a flat EEG, no responses on auditory brainstem responses (ABR), and loss of brainstem reflexes on repeated daily examinations. No apnea test was performed. Based on the diagnosis of clinical BD, coordinator of Japan Organ Transplant Network explained about organ donation on the 17th day of the disease. Subsequently, the family responded that they could not consent to organ donation, and the patient did not proceed to the legal BD determination. Around five weeks after the onset, spontaneous body movements began to appear, as not only the spinal reflexes but also the brainstem involvement.ConclusionThe pathophysiology of acute encephalopathy is largely unknown, and it is difficult to determine the observation period necessary for BD determination. What we have learned from this case is that clinical BD remains ambiguous and cannot be confirmed even with a thorough neurological examination, EEG, and ABR.