Traumatically induced lymphangioma of the ulnar nerve. Case report.

Lymphangiomas, benign hamartomatous lesions involving lymphatic tissue, result from a failure of lymphatic channels to communicate with the venous system or normal lymphatic channels. The authors describe a case in which a lymphangioma arising within the ulnar nerve developed after trauma to the same area. This is the second reported case of a lymphangioma that originated from a peripheral nerve and the first case in which the lesion was associated with trauma. The authors propose that a lymphangioma involving the peripheral nerve may be the result of trauma.

Axonal cytoskeleton changes in experimental optic neuritis.

Axonal loss and degeneration in multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE) have been suggested by brain imaging, pathological and axonal transport studies. Further elucidation of the processes and mechanisms of axonal degeneration in demyelinating diseases is therefore of potential importance in order to alleviate the permanent disabilities of MS patients. However, detailed studies in this area are impeded by the small number of reliable models in which the onset and location of demyelination can be well-controlled. In this study, microinjection of polyclonal rabbit anti-galactocerebroside (anti-Gal C) antibody and guinea pig complement was used to induce local demyelination in the rat optic nerve. We found that treatment with appropriate volumes of the antibody and complement could induce local demyelination with minimal pressure- or trauma-induced damage. Local changes in neurofilaments (NFs) and microtubules (MTs) were examined with both immunohistochemistry (IHC) and electron microscopy (EM). On day 1 after microinjection, we observed moderate NF and MT disassembly in the local demyelinated area, although in most cases, no apparent inflammatory cell infiltration was seen. The NF and MT changes became more apparent on days 3, 5, 7 after microinjection, along with gradually increased inflammatory cell infiltration. These results suggested that acute demyelination itself may induce local cytoskeleton changes in the demyelinated axons, and that the ensuing local inflammation may further enhance the axonal damage. When the lesions were stained with specific antibodies for T lymphocytes, macrophages, and astrocytes, we found that most of the cells were macrophages, suggesting that macrophages may play a greater role in inflammation-related axonal degeneration and axonal loss. These results were confirmed and further characterized on the ultrastructural level.

Congenital entrapment of the lateral cutaneous nerve of the calf presenting as a personal sensory neuropathy.

OBJECTIVE: Presentation of an unusual case of congenital entrapment of the lateral cutaneous nerve of the calf (LCNC) mimicking a peroneal sensory neuropathy. METHODS: We report the case of as 16-year-old girl with a 3 year history of progressive tingling, numbness and pain in her right calf precipitated by athletic activities involving repeated flexion and extension of the knee. A Tinel's sign was present over the common peroneal nerve in the distal popliteal fossa but absent at the fibular neck. Motor and sensory examination of the common peroneal nerve was normal as were electrophysiological studies and MRI. RESULTS: At surgery, the LCNC, a sensory branch of the common peroneal nerve, was entrapped at a point where it pierced the tendon of the biceps femoris muscle. Transection of the part of the tendon overlying the LCNC resulted in complete and permanent relief of symptoms. SIGNIFICANCE AND CONCLUSION: The proximal location of the Tinel's sign, absence of motor or sensory deficits and normal electrophysiology suggested, preoperatively, that this was not an entrapment of the common peroneal nerve at the fibular neck but rather a more proximal abnormality likely involving only a part of the peroneal nerve or one of its sensory branches. As a result, the more proximal exposure of the peroneal nerve within the popliteal fossa revealed entrapment of the neuropathy of the common peroneal nerve or one of its branches, due to a normal nerve piercing an otherwise normal tendon. Secondly, there are no previously reported cases of surgically documented compression of the LCNC in an otherwise normal patient (i.e. non-diabetic).

Autologous vein-covered stent repair of a cervical internal carotid artery pseudoaneurysm: technical case report.

OBJECTIVE AND IMPORTANCE: Stenting of a cervical internal carotid pseudoaneurysm is presented using a stent covered with saphenous vein. This procedure resulted in immediate exclusion of the aneurysm and maintained patency of the carotid artery. CLINICAL PRESENTATION: A gunshot to the neck resulted in airway obstruction and respiratory arrest with neurological injury in a male patient. Angiographic investigation revealed an enlarging cervical internal carotid pseudoaneurysm, possibly the source of a cerebral embolism. Anticoagulation had to be stopped because of bleeding complications. A decision was made to conduct definitive percutaneous treatment of the pseudoaneurysm. TECHNIQUE: A Palmaz stent (JJIS, Warren, NJ) was covered with saphenous vein harvested from the patient's leg. Using standard technique and a simple innovation for stent construct introduction into the sheath, the vein-covered stent was placed across the opening of the aneurysm and dilated into position with a balloon. CONCLUSION: Immediate exclusion of a cervical internal carotid pseudoaneurysm was performed using an autologous vein-covered stent. One-month follow-up confirmed continued exclusion of the pseudoaneurysm and carotid patency without stenosis.

Head injuries due to falls caused by seizures: a group at high risk for traumatic intracranial hematomas.

This prospective review of adult patients with head injuries examines the incidence of head injuries due to falls caused by seizures, the incidence and severity of intracranial hematomas, and the morbidity and mortality rates in this patient population. A head injury was attributed to a fall caused by a seizure if the seizure was witnessed to have caused the fall, or the patient had a known seizure history, appeared postictal or was found convulsing after the fall, and no other cause for the fall was evident. A total of 1760 adult head-injured patients were consecutively admitted to the authors' service between 1986 and 1993. Five hundred eighty-two head injuries (33.1%) were due to falls and 22 (3.8%) of these were caused by seizures. Based on the prevalence rates for epilepsy in the general population of 0.5 to 2%, these results indicate that epileptics are several times more likely to suffer a head injury due to a fall. Mass lesions were found in 20 (90.9%) of these 22 patients and the remaining two patients suffered mild diffuse head injuries. There was a high incidence of extraaxial mass lesions: 17 (85%) of the 20 intracranial hematomas were either epidural (five cases) or acute subdural (12 cases) hematomas. Eighteen (81.8%) of the 22 patients required evacuation of a hematoma. Both the incidence of intracranial hematomas (90.9% vs. 39.8%, p < 0.001, chi-square analysis) and the rate of hematoma evacuation (81.8% vs. 32.3%; p < 0.001) was significantly greater in patients injured in falls due to seizures (22 cases) than in the group injured in falls from all other causes (560 cases). The higher incidence of hematomas and the need for evacuation were not explained by differences in age, seventy of head injury, or incidence of alcohol intoxication. Despite the greater incidence of mass lesions and the need for operative treatment in patients injured because of seizures, their mortality rate was similar to that of patients injured in falls from other causes. On the basis of their review of patients admitted to a neurosurgical center with complaints of head injury, the authors conclude that patients with head injuries due to a fall caused by a seizure should undergo computerized tomography scanning early in their management. Until a mass lesion has been excluded, any decrease in level of consciousness or focal neurological deficit should not be attributed to the seizure itself.

Neurologic trauma concerns.

Patients with underlying medical illnesses or conditions will comprise a progressively larger proportion of head-injury patients given the aging of the general population and improved survival in serious illnesses. Age and underlying illness can influence the presentation, management, and outcome of head injuries by increasing the frequency, severity, and complications from head injury. This article examines the conditions that are most often associated with head injury.

Synapse formation and preferential distribution in the granule cell layer by regenerating retinal ganglion cell axons guided to the cerebellum of adult hamsters.

To investigate constraints and preferences for synaptogenesis in the injured mammalian CNS, regenerating retinal ganglion cell (RGC) axons of adult hamsters were guided through a peripheral nerve (PN) graft to a target they do not usually innervate: the cerebellum (Cb). When identified by the presence of HRP anterogradely transported from the retina 2-9 months later, such RGC axons were found to have extended into the cerebellar cortex for up to 650 microns. Most of this growth was in the granule cell layer (GCL) and only a few axons entered the molecular layer. The preference for the GCL could not be explained by the position of the PN graft in the Cb, a selective denervation of the GCL, local damage to other neurons, or the distribution of reactive gliosis in the vicinity of the graft. Furthermore, by EM, more than 95% of the labeled retinocerebellar terminals and synapses were in the GCL. Retinocerebellar terminals were larger and contained more synapses than the regenerated RGC terminals previously studied in the superior colliculus. These results indicate that regenerating axons of CNS neurons can form persistent synapses with novel targets. The preferential synaptogenesis in the GCL suggests that such unusual connections are not formed randomly in the CNS of these adult mammals.

Synaptic connections made by axons regenerating in the central nervous system of adult mammals.

The restoration of connections in the injured central nervous system (CNS) of adult mammals is hindered by the failure of axons to grow back to their natural fields of innervation. Following transection of the optic nerve of adult rodents, the guided regeneration of retinal ganglion cell (RGC) axons along a transplanted segment of peripheral nerve (PN) has shown that these neurones retain their capacities to form well-differentiated synapses in both normal and abnormal targets. The main aim of this review is to describe the anatomical and functional characteristics of some of these connections and to suggest that their terminal distribution and morphology may be the result of a persistence in these targets of molecular determinants that influence normal connectivity in the intact animal.

Spinal cord concussion.

The hallmark of concussion injuries of the nervous system is the rapid and complete resolution of neurological deficits. Cerebral concussion has been well studied, both clinically and experimentally. In comparison, spinal cord concussion (SCC) is poorly understood. The clinical and radiological features of 19 SCC injuries in the general population are presented. Spinal cord injuries were classified as concussions if they met three criteria: 1) spinal trauma immediately preceded the onset of neurological deficits; 2) neurological deficits were consistent with spinal cord involvement at the level of injury; and 3) complete neurological recovery occurred within 72 hours after injury. Most cases involved young males, injured during athletics or due to falls. Concussion occurred at the two most unstable spinal regions, 16 involving the cervical spinal and three the thoracolumbar junction. Fifteen cases presented with combined sensorimotor deficits, while four exhibited only sensory disturbances. Many patients showed signs of recovery with the first few hours after injury and most had completely recovered within 24 hours. Only one case involved an unstable spinal injury. There was no evidence of ligamentous instability, spinal stenosis, or canal encroachment in the remaining 18 cases. Two patients, both children, suffered recurrent SCC injuries. No delayed deterioration or permanent cord injuries occurred. Spinal abnormalities that would predispose the spinal cord to a compressive injury were present in only one of the 19 cases. This suggests that, as opposed to direct cord compression, SCC may be the result of an indirect cord injury. Possible mechanisms are discussed.

Ultralight aircraft crashes: their increasing incidence and associated fractures of the thoracolumbar spine.

Ultralight aircraft, which originated in 1975 in the U.S. and have been available in Canada since 1980, have enjoyed a tremendous increase in popularity to the point where it is estimated that there are close to 20,000 ultralights in North America today. Two reasons account for their growing popularity: relatively low cost and simplicity, allowing almost any person to enjoy the sport of flying, which was unattainable for most just a few years ago. Unfortunately, inexperienced pilots and relatively new and unproven aircraft have been brought together to create a potentially lethal combination. On average, 60 deaths per year occur in the U.S. due to ultralight crashes, a number that will undoubtedly rise in the future. The U.S. and Canada have very few regulations covering the licensing of pilots or the design and construction of ultralight aircraft. The North American safety record is inferior to that of countries that have implemented stricter, more far-reaching regulations. Stricter pilot certification and enforced regulations governing design and construction of ultralight aircraft would improve the safety record of this sport. Ultralight aircraft crashes and their associated injuries came to our attention recently through the presentation of three cases of isolated fractures of the thoracolumbar spine in such crashes. Spinal fractures due to ultralight crashes have no unique features that separate them from those of other trauma victims. Physicians must, however, have a high index of suspicion for spinal injuries in these victims.

Osteoid osteoma of the cervical spine: case reports and literature review.

Osteoid osteoma, a benign osteoid-forming tumour, may be found in any bone in the body. Approximately 10% of cases involve the most common site and the cervical region the second commonest site for spinal osteoid osteomas. Two new cases of cervical spine osteoid osteoma are presented and the 21 previously reported cases are reviewed. This cervical spine tumour should be considered as a possible diagnosis in any young person complaining of neck or upper back pain, especially if the pain is worse at night, is relieved by salicylates and is accompanied by tenderness, neck stiffness and scoliosis of rapid onset. Detailed radiologic investigation aids in the diagnosis and accurately locates the lesion. Surgery is the definitive treatment and complete resection of the tumour results in rapid and permanent relief of pain.