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Biomedical subjects

A J Belzberg

Publications and source records attributed to A J Belzberg.

12 recordsLinked to original sources

A brachial plexopathy due to myositis ossificans. Case report and review of the literature.

Myositis ossificans (MO) is a disorder characterized by the intramuscular proliferation of fibroblasts and osteoblasts, with subsequent deposition of bone and cartilage. A typical clinical presentation involves traumatic injury to a young adult, usually localized to the thigh, buttock, or upper arm, with resultant MO and mildly restricted range of motion in adjacent joints. Rarely, MO is associated with peripheral neuropathies involving the radial, median, sciatic, and sural nerves. The authors present an unusual case of MO causing a brachial plexopathy. To their knowledge, this is the first description of such a presentation.

Adult↗

Diagnosis and treatment of thoracic outlet syndrome.

TOS represents a spectrum of disorders encompassing four related syndromes: arterial compression, venous compression, neurogenic compression, and a poorly defined pain syndrome. Patients can present with signs of arterial insufficiency, venous obstruction, painless wasting of intrinsic hand muscles, and pain. History and physical examination are the most important diagnostic studies, and radiographs of the chest and cervical spine and electromyography/nerve conduction studies are useful to identify other causes of pain and disability. Surgical intervention is indicated for patients failing nonoperative maneuvers and can usually yield satisfactory results. TOS may also be the most underrated, overlooked, and misdiagnosed, and the most important and difficult to manage peripheral nerve compression in the upper extremity.

Electrodiagnosis↗

Case of an ivory vertebra.

The differential diagnosis of an osteoblastic vertebral lesion (ivory vertebra) includes metastatic prostate cancer, lung cancer, lymphoma, osteosarcoma and Paget's disease. We report a case of a man who was initially diagnosed with Paget's disease on vertebral biopsy. He failed to respond to conventional bisphosphate therapy. The review of the original biopsy specimen showed metastatic carcinoid tumor involving the bone marrow. The various features of carcinoid tumors metastasizing to the skeleton are briefly reviewed.

Alendronate↗

Malignant peripheral nerve sheath tumors in the setting of segmental neurofibromatosis. Case report.

Approximately 100 cases of segmental neurofibromatosis (NF5) have been reported in the recent literature. Patients with NF5 present with café-au-lait macules, freckles, and/or neurofibromas limited to one or adjacent dermatomes. Neurofibromas arising in NF5 have been uniformly considered to be benign; patients were thought to have an excellent prognosis without the risk of developing malignant peripheral nerve sheath tumors (PNSTs), which are characteristic in patients with the generalized form of this disease, von Recklinghausen's NF. In this report the authors detail the first observations of malignant PNSTs in two patients with NF5. Indications for surgical removal of a neurofibroma in a patient with NF include pain. neurological impairment, compression of adjacent structures, cosmetic disfigurement, and rapid tumor growth suggestive of malignant degeneration. Surgical indications are similar for patients with NF5. All patients with neurofibromas should be considered at risk for malignant degeneration.

Adult↗

Intradural cervical disc herniation and Brown-Séquard's syndrome. Report of three cases and review of the literature.

Although cervical disc herniation commonly requires surgical intervention, the intradural sequestration of a herniated cervical disc fragment is rare. In searching the world literature on this topic, the authors found six case reports. They report three new cases of intradural cervical disc herniation in which the patients presented with Brown-Séquard's syndrome and they review the literature. Although Brown-Séquard's syndrome is a rare clinical finding in extradural disc herniation, six of the nine patients with intradural cervical disc herniation (our cases and those from the literature) presented with symptoms of this syndrome. The remaining patients presented with para- or quadriparesis. This suggests that intradural disc herniation should be considered preoperatively in patients in whom there is magnetic resonance imaging or myelographic evidence of cervical disc herniation and Brown-Séquard's syndrome. In patients who underwent anterior cervical discectomy for the treatment of intradural cervical disc herniations, better outcomes were demonstrated than in those in whom posterior procedures were performed.

Adult↗

Evidence for end-to-side sensory nerve regeneration in a human. Case report.

Division of a peripheral nerve produces an axotomy leading to neurite outgrowth from the proximal stump and wallerian degeneration in the distal stump. Because there is no longer a connection between the distal stump and neuronal cell bodies in the anterior spinal cord or dorsal root ganglion, it is assumed that no neurites should exist in the distal stump. The authors present the case of a patient who unexpectedly had a neuroma on the proximal end of the distal segment of a previously severed nerve. The lateral antebrachial cutaneous nerve had been surgically severed. Innervated by the radial nerve, a neuroma subsequently formed in the distal segment. Our hypothesis is that the proximal end of the distal portion of a severed nerve may be innervated by collateral sprouts of axons that branch at points of more distal plexus formation. This invokes a similar pathophysiology to the controversial notion of end-to-side nerve sprouting. Neuromas that develop on the "wrong side" of a nerve become an additional potential source of pain in patients with injured nerves.

Forearm↗

Unilateral nerve injury down-regulates mRNA for Na+ channel SCN10A bilaterally in rat dorsal root ganglia.

Injury makes sensory neurons abnormally excitable and triggers coincident alterations in relative levels of different types of voltage-gated sodium channels that they express. We report that nerve injury depress levels of SCN10A-specific mRNA in contralateral as well as ipsilateral dorsal root ganglia of rats, suggesting a possible peripheral mechanism for the contralateral 'mirror-image' hyperalgesia described in nerve-injured humans and experimental animals.

Animals↗

The human tail and spinal dysraphism.

Recent publications have endeavoured to differentiate between the true, or vestigial tail, and the pseudotail by clinical and pathological examination, and have indicated the benign nature of the true tail. The true tail arises from the most distal remnant of the embryonic tail, contains adipose, connective, muscle, and nerve tissue, and is covered by skin. Pseudotails represent a variety of lesions having in common a lumbosacral protrusion and a superficial resemblance to vestigial tails. A review of the case reports indicates spina bifida to be the most frequent coexisting anomaly with both. A review of occult spinal dysraphism shows it to be associated with cutaneous signs in more than 50% of instances. Three cases of spinal dysraphism with tail-like cutaneous structures are described and their radiological, operative, and pathological findings presented. The classification of each of the appendages into true tail or pseudotail remains obscure. Although the finding of these three tails was the subject of much curiosity, surgical treatment was clearly designed to adequately deal with the associated dysraphic state. The presence of a tail-like appendage in the lumbosacral region should alert the clinician to the possibility of underlying spinal dysraphism. Preoperative assessment must include a complete neurological history and examination as well as computed tomographic or magnetic resonance imaging.

Bone Neoplasms↗

Stabilization of traumatic atlanto-occipital dislocation. Case report.

Traumatic atlanto-occipital dislocation is most often fatal. Consequently, there are only scattered case reports of patients surviving this injury, and treatment modalities are anecdotal and varied. The case of an 18-year-old woman who suffered an anterior atlanto-occipital dislocation as the result of a motor-vehicle accident is presented. Rigid posterior fixation and complete reduction of the dislocation were achieved using an anatomically contoured steel loop secured to the occiput and cervical vertebrae. The addition of cancellous bone to the graft afforded long-term stability. This operative treatment provided anatomical realignment of the dislocation and allowed early mobilization of the patient with the use of aggressive rehabilitation. Previously reported cases of patients surviving anterior atlanto-occipital dislocation are reviewed. The use of cervical traction, halo bracing, and operative stabilization is discussed.

Accidents, Traffic↗

Postischemic therapy with MK-801 (dizocilpine) in a primate model of transient focal brain ischemia.

The purpose of this study was to develop a primate model for assessing EEG, behavior and histology, and to test the effect of NMDA receptor blockade in transient focal ischemia. Squirrel monkeys (Saimiri sciureus) under halothane anesthesia were subjected to 110 min of transient focal ischemia (n = 15) by temporary clip occlusion of the MCA. An eight-lead EEG was recorded. Neurobehavioral testing was done in a subgroup of animals (n = 6). Brain temperature (37.5 degrees C) was monitored and controlled to avoid hypothermia or intergroup temperature differences, and blood pressure was regulated to 60 mmHg. The entire brain was subserially sectioned, and 52 standardized coronal sections encompassing the infarct were examined histologically 2 wk after the ischemia. Animals were randomized to receive either (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801) 1 mg/kg of maleate salt or carrier solution, 20 min and again at 12 h after the onset of ischemia. Cingulate and retrosplenial cortex were examined for NMDA-antagonist-induced neuronal necrosis. No reduction, or trend toward reduction of neurobehavioral deficit was seen with MK-801. MCA occulsion reduced EEG power over the ischemic hemisphere. MK-801 appeared to cause brain activation, and globally increased power at several frequencies. MK-801 did not reduce infarction in either neocortex (p > 0.05) or striatum (p > 0.05). No selective neuronal necrosis was seen in the cingulate or retrosplenial cortex. We conclude that MK-801 given 20 min after the onset of transient ischemia offers no significant neuroprotective effect against either neurobehavioral deficit or ischemic infarction in this model of transient focal ischemia. Further experiments in unanesthetized animals are necessary to determine if MK-801-induced necrosis exists in the gyrencephalic brain, but the enhancement of primate brain electrical activity by MK-801 suggests that brain activation occurs in primates as it does in rodents.

Animals↗