Hand size affects branching of the deep ulnar nerve and deep palmar arch.

Purpose: Understanding the anatomy of the deep neurovascular structures of the hand is essential in surgical planning. There is a lack of literature regarding hand size and its influence in branching variation and the distances between branches of various neurovascular structures. Our study quantifies the variation in branching distances of the deep ulnar nerve and deep palmar arch branches.

Compound Motor Action Potentials During a Modest Nerve Crush.

Nerve crush injury results in axonotmesis, characterized by disruption of axons and their myelin sheaths with relative sparing of the nerve's connective tissue. Despite the widespread use of crush injury models, no standardized method for producing these lesions has been established. We characterize a crush model in which a narrow forceps is used to induce a modest and controlled compressive injury.

Histological Assessment of Wallerian Degeneration of the Rat Tibial Nerve Following Crush and Transection Injuries.

Background:  Wallerian degeneration (WD) following peripheral nerve injury (PNI) is an area of growing focus for pharmacological developments. Clinically, WD presents challenges in achieving full functional recovery following PNI, as prolonged denervation of distal tissues for an extended period of time can irreversibly destabilize sensory and motor targets with secondary tissue atrophy. Our objective is to improve upon histological assessments of WD.

What Protects Certain Nerves from Stretch Injury?

The human tibial nerves is less prone to injury following joint arthroplasty compared with the peroneal nerves. Besides the anatomical distribution, other features may confer protection from stretch injury. We therefore examined the size, shape and connective tissue distribution for the two nerves.

Effect of acute versus continuous glycemic control on duration of local anesthetic sciatic nerve block in diabetic rats.

Background And Objectives: The duration of nerve block is longer in streptozotocin (STZ)-induced diabetic rats for all local anesthetics (with and without adjuvants) compared with normal rats. Perioperative glycemic control is currently practiced to reduce adverse events in many at-risk patients, especially in diabetic patients, to prevent neuropathy, poor wound healing, and greater incidence of infection. The aim of this study was to investigate in diabetic rats the importance of glycemic control before peripheral nerve block.

Pudendal nerve stretch reduces external urethral sphincter activity in rats.

Purpose: Most animal models of stress urinary incontinence simulate maternal injuries of childbirth since delivery is a major risk factor but they do not reproduce the nerve stretch known to occur during human childbirth. We hypothesized that pudendal nerve stretch produces reversible dysfunction of the external urethral sphincter.

Materials And Methods: Female virgin Sprague-Dawley® rats were anesthetized with urethane.

Safety of local anesthetics administered intrathecally in diabetic rats.

Objectives: Although retrospective studies show the risk of neurological complications after spinal anesthesia with local anesthetics is small in diabetic patients, there is still concern about the safety of different local anesthetics in diabetics undergoing neuroaxial anesthesia. We examined block duration and histology of spinal cord and roots with intrathecal local anesthetics in diabetic rats.

Methods: Rats were made diabetic with streptozotocin injection.

Optimizing public health strategies for stroke education: need for a controlled trial.

This brief review examines certain strategies for increasing community awareness and recognition of the warning signs and symptoms of stroke. Attention should be given to the intended audience, especially at-risk groups. To enhance stroke literacy, a complete message should include the following 4 aspects: (1) a stroke is a serious medical problem that involves the blood supply to the brain, (2) all 5 approved warning signs and symptoms, (3) the many risk factors involved in stroke, and (4) the need to promptly call 911 for emergency services and treatment.

Local anesthetic sciatic nerve block and nerve fiber damage in diabetic rats.

Background And Objectives: A concern for anesthesiologists is whether local anesthetics are more toxic to peripheral nerves in diabetic patients. A previous study in streptozotocin-induced diabetic rats showed that larger doses of lidocaine produce moderate nerve injury after nerve block in normal rats and worse injury in diabetic rats. However, it is not clear whether a smaller local anesthetic dose that produces negligible nerve fiber damage in normal rats will produce significant nerve damage in diabetic rats and if adding adjuvant drugs modulates this effect.

Dual simulated childbirth injury delays anatomic recovery.

A dual childbirth injury model, including vaginal distension (VD) and pudendal nerve crush (PNC), may best represent the injuries seen clinically. The objective of this study was to investigate urethral function, anatomy, and neurotrophin expression after several simulated childbirth injuries. Groups of 140 rats underwent PNC, VD, PNC+VD, or neither (C).

Assessment of axonal growth into collagen nerve guides containing VEGF-transfected stem cells in matrigel.

The early events associated with axonal growth into 10-mm nerve gaps were studied histologically in the rat sciatic nerve model to determine if the outgrowth of blood vessels, Schwann cells, and axons could be enhanced. In the first two experimental groups, collagen nerve guides were filled with either saline or Matrigel. Marrow-derived mesenchymal stem cells (MSCs) were added to Matrigel in two other groups, one of which contained cells transfected with VEGF (MSC/VEGF).

The behavioral and immunological effect of GM-1 ganglioside on nerve root regeneration following C5 nerve root avulsion in a rat model.

Preganglionic nerve root avulsion precludes sensory return, but motor regeneration is possible with sparing of motoneurons. The effect of GM-1 ganglioside treatment was studied with parallel evaluation of the autoimmune response. Rats (N=64) received injections of either GM-1 ganglioside or saline for 30 days following either C5 root avulsion or a hemilaminectomy control.

Early behavioral and histological outcomes following a novel traumatic partial nerve lesion.

A new partial nerve lesion (PNL) model is needed to better simulate traumatic lesions seen clinically that result in both dysfunction and neuropathic pain. We assessed surgical variability and several outcome measures including histology during the acute postoperative period. A surgical lesion was created in the rat tibial nerve by removing a segment, later confirmed by myelinated axon counts.

Gross anatomy of the brachial plexus sheath in human cadavers.

Background And Objectives: Major nerves and vessels run alongside each other in a "neurovascular bundle" kept together by connective tissue that is often referred to by anatomists, surgeons, and anesthesiologists as the "sheath." Our goal was to macroscopically demonstrate the brachial plexus sheath in embalmed and fresh cadaver dissections.

Methods: Systematic dissections were performed on 11 embalmed cadavers (6 females and 5 males), plus one fresh, unembalmed male cadaver.

Time course of neuroanatomical and functional recovery after bilateral pudendal nerve injury in female rats.

The pudendal nerve innervates the external urethral sphincter (EUS) and is among the tissues injured during childbirth, which may lead to symptoms of stress urinary incontinence (SUI). To understand the mechanisms of injury and repair, urethral leak-point pressure (LPP) was measured 4 days, 2 wk, or 6 wk after bilateral pudendal nerve crush. Morphometric changes in the distal nerve and EUS were examined by light and electron microscopy.

Striated muscle and nerve fascicle distribution in the female rat urethral sphincter.

The anatomical basis for urinary continence depends on a thorough understanding of the tissues in the urethra. The objective of this study was to evaluate the morphology and neuroanatomy of urethral striated muscle, called the rhabdosphincter or external urethral sphincter, in normal female rats. Urethras from 12 female rats were dissected from the bladder, fixed, embedded in paraffin or epon, and sectioned every 1 mm.

Sensory neurons and fibers from multiple spinal cord levels innervate the rabbit lumbar disc.

Objective: To establish the neurotransmission pathway from the lumbar L5/6 intervertebral disc (IVD) to the spinal cord in the rabbit.

Design: Fluorogold particles injected into the posterior portion of the rabbit L5/6 IVD were traced by examining gold-positive neurons and fibers in the dorsal root ganglion (DRG) and spinal cord at various root levels.

Results: Fluorogold-labeled neurons were observed bilaterally in primary afferent DRG neurons from the L3 through L5 segments; a small number of gold-labeled neurons were found at the L1 level.

Repair of partial lesions with nerve grafting methods in the rat tibial nerve.

A partial nerve lesion and associated neuroma can be either left alone or repaired with a graft. A by-pass graft around the undisturbed lesion with end-to-side attachments might be a good alternative. This study in rats examines these strategies using walking-track analysis, muscle weights, and histology.

End-to-side nerve grafting of the tibial nerve to bridge a neuroma-in-continuity.

Standard treatment for a neuroma-in-continuity with partial retained function is neurolysis with or without grafting. The present study tests the outcome of a novel partial nerve lesion bypassed with an end-to-side bridge graft, intended to increase the number of axons crossing the defect while not disturbing intact axons. An 8-mm portion of tibial nerve was resected in 20 rats.

Characterization of a new animal model for evaluation of persistent postthoracotomy pain.

Chronic pain after thoracotomy is common, although its basis and therapy have not been well characterized. In this study we characterize the allodynic responses (mechanical and cold) as well as the histopathologic changes after thoracotomy and rib retraction in rats. The antinociceptive effect of systemic and intrathecal analgesics was also evaluated.

Assessment of recovery following a novel partial nerve lesion in a rat model.

Partial nerve lesions with a varying degree of retained function and often a painful neuroma pose a dilemma for the clinician. Surgical treatment of partial nerve lesion is perilous because of possible damage to intact axons and subsequent loss of retained function. We present a new rat model of a partial nerve lesion, allowing further study to improve treatment for this condition.

A comparison of peripheral nerve regeneration in acellular muscle and nerve autografts.

Regeneration of the rat sciatic nerve through acellular muscle and nerve autografts was evaluated 6-28 days postoperatively by the sensory pinch test, immunocytochemical staining for neurofilaments, and light and electron microscopy. Data points generated by the pinch test were plotted against postoperative time periods and by the use of regression analysis the initial delay period for muscle grafts was determined to 10.3 days.

Functional and neuroanatomical effects of vaginal distention and pudendal nerve crush in the female rat.

Purpose: We tested the hypothesis that neuroanatomical degeneration near the external urethral sphincter (EUS) would parallel urinary dysfunction after vaginal distention or bilateral pudendal nerve crush in female rats.

Materials And Methods: A total of 28 female rats underwent bilateral pudendal nerve crush or vaginal distention, or were unoperated controls. Two days later a catheter was implanted into the bladder dome and 2 days after that (4 days after injury) urethral leak point pressure testing was performed with the rat under urethane anesthesia.

The antinociceptive and histologic effect of sciatic nerve blocks with 5% butamben suspension in rats.

Unlabelled: Butamben, a lipophilic local anesthetic of the ester class, produces a differential nerve block of long duration. Epidural and peripheral nerve blocks with butamben, formulated as a 5%--10% suspension, result in prolonged analgesia without significant motor blockade. We evaluated the effect of butamben sciatic nerve block on antinociception using the rat paw formalin test, as well as withdrawal latencies to thermal stimulation, and assessed histologic changes in the nerve.

Motor pudendal nerve characterization in the female rat.

The aim of our study was to provide quantitative data on pudendal motor neuron cell bodies and axons in the female rat. To confirm earlier studies, fluorescent retrograde tracers were used to label the motor neurons for correlation with myelinated axon counts along the length of the motor pudendal nerve. The external urethral sphincter of female rats was injected with diamidino yellow and the external anal sphincter with fast blue.