Biomedical subjects

Jason H Huang

Publications and source records attributed to Jason H Huang.

11 recordsLinked to original sources

PubMed2007

Neural engineering to produce in vitro nerve constructs and neurointerface.

OBJECTIVE: Recently, our laboratory recapitulated a natural form of axon growth that occurs between late embryogenesis and early adulthood. In this article, we describe how this novel neural engineering approach may be used to produce a nervous tissue interface to integrate disconnected motor and sensory functions for external control. METHODS: For nervous system repair, we recently developed a unique method to engineer nervous tissue constructs in vitro consisting of bundles of axons spanning two populations of neuronal somata. To integrate electronics and nervous tissue to transform electrophysiological signals into electronic signals, we have designed a nervous tissue interface. RESULTS: Our nervous tissue interface consists of stretch-grown nervous tissue with one end interfaced with a multiple electrode array, enabling us to detect and record real-time efferent signals conducted down the nerve and stimulate afferent sensory signaling. CONCLUSION: Our ultimate goal is to develop a neurally controlled prosthesis and a nervous system interface that could be linked to the patient's thoughts, providing two-way signaling for motor control and feedback from multiple external stimuli.

Axons↗

PubMed2006

Tumors of the peripheral nerves and plexuses.

Peripheral nerve tumors are a diverse group of lesions histologically and in their clinical behavior. The genetic disorders neurofibromatosis type 1 and 2 and schwannomatosis are significant risk factors for the development of peripheral nerve tumors. An understanding of these disorders is important in allowing appropriate management. Active treatment of peripheral nerve tumors is reserved for lesions that are malignant or causing neurologic dysfunction, pain, compressive symptomatology, or cosmetic concern. The mainstay of treatment is surgical intervention, the nature of which will vary with the type of tumor and anatomical location. In the case of malignant tumors, adjuvant chemotherapy and radiotherapy are commonly used. Developments in the understanding of the genetics and molecular biology of peripheral nerve tumors are opening up potentially exciting new avenues of treatment. The prognosis of benign peripheral nerve tumors is excellent, with a recurrence rate of just 5% or less after successful surgery. Malignant tumors have proven to be more challenging, with a much higher recurrence rate and a 5-year survival rate of 64%.

Journal Article↗

PubMed2005

Diagnosis and treatment options for nerve sheath tumors.

The purpose of this review is to discuss the contemporary diagnosis and treatment options for nerve sheath tumors. Common nerve sheath tumors include schwannomas, neurofibromas and malignant nerve sheath tumors. Nerve sheath tumors can be associated with genetic disorders such as neurofibromatosis and schwannomatosis. There is great variation in terms of tumor location, clinical presentation and treatment strategy. Magnetic resonance imaging is the diagnostic study of choice for nerve sheath tumors and surgery has become the mainstay of treatment for most symptomatic lesions. Progress in microsurgical techniques has resulted in significant improvement in surgical outcome, with preservation of neurologic function. Complete resection of benign nerve sheath tumors is the goal of surgical intervention and this results in cure. In contrast, malignant nerve sheath tumors remain a major challenge with poor outcomes overall. Progress in multidisciplinary research may ultimately lead to novel therapeutic strategies.

Humans↗

PubMed2004

Case studies for illustration and discussion: peripheral nerve tumors.

This article gives a presentation of a variety of surgical cases of peripheral nerve tumors for illustration and discussion. The first three cases include a schwannoma, a neurofibroma, and a desmoid tumor of the brachial plexus region. Case 4 is that of a patient with a common peroneal ganglion cyst, and case 5 is that of a patient with an angiolipoma of the forearm. Cases 6 through 8 illustrate a plexiform neurofibroma, a malignant peripheral nerve sheath tumor, and a metastatic carcinoma to the brachial plexus region. In case 9, a patient with schwannomatosis was treated for multiple spinal schwannomas.

Adult↗

PubMed2004

Surgical management of brachial plexus region tumors.

BACKGROUND: Brachial plexus region tumors are uncommon and often present a challenge to neurosurgeons. METHODS: Provide a brief historical overview, a description of the anatomy, and contribute information that provides management guidelines and improves surgical outcomes for tumors of the brachial plexus region. We also review different surgical approaches followed by surgical outcome from recent studies, as well as our own experience of treating 42 patients with tumors of the brachial plexus region at the University of Pennsylvania Medical Center between 1990 and 2001. RESULTS: A thorough understanding of the anatomy, the clinical presentation, imaging techniques, and the various surgical approaches for brachial plexus tumor resection is necessary to ensure the best possible treatment outcome. CONCLUSION: We conclude that with proper patient selection and appropriate perioperative and intraoperative management, neurologic deficits from brachial plexus tumor surgery can be minimized.

Brachial Plexus↗

PubMed2004

Management of patients with schwannomatosis: report of six cases and review of the literature.

BACKGROUND: Schwannomatosis is a rare tumor syndrome characterized by the presence of multiple schwannomas without the stigmata of neurofibromatosis (NF) Type 1 or 2. To better understand the natural history and clinical management of the syndrome, a retrospective review was conducted of patients diagnosed with schwannomatosis over an 11-year period at the University of Pennsylvania Medical Center (UPMC). METHODS: Between 1990 and 2001, 131 patients underwent surgery for resection of spinal or peripheral nerve schwannomas in the Department of Neurosurgery at the University of Pennsylvania Medical Center. Among the 131 patients, there were 6 who had two or more pathologically proven schwannomas without radiographic or clinical evidence of vestibular schwannomas. The hospital charts, clinic notes, radiology films, operative reports, pathology slides, and reports from all 6 patients were retrospectively reviewed. RESULTS: The patient population consisted of 6 patients with a mean age of 48.7 (3 male: 3 female). All patients had enhanced brain magnetic resonance imaging (MRI) scans that were negative for vestibular schwannomas. Ophthalmological and general physical examinations did not reveal any findings suggestive of NF. There was no family history of NF or schwannomatosis. The locations of the schwannomas included intraspinal (multiple sites), paraspinal, brachial plexus, femoral nerve, sciatic nerve, calf, forearm, retroperitoneum, and middle cranial/infratemporal fossa region. The common presenting symptoms included paresthesias, palpable mass, pain, or weakness. All 6 patients underwent surgical resection of symptomatic lesions. CONCLUSIONS: For patients with schwannomatosis, surgery is indicated for symptomatic lesions, while asymptomatic tumors are followed conservatively. Because these patients are at increased risk for developing multiple schwannomas, we recommend regular surveillance and offer genetic counseling even though the pattern of inheritance is unknown.

Adolescent↗

PubMed2004

Mini-open carpal tunnel decompression.

Carpal tunnel syndrome is the most common entrapment neuropathy, and it is caused by compression of the median nerve at the wrist. The authors describe the mini-open carpal tunnel technique for surgical release of the transverse carpal ligament. The success of the procedure depends on meticulous technique with attention to certain important anatomic details and careful avoidance of injury to the palmar cutaneous nerve and the recurrent motor branch.

Carpal Tunnel Syndrome↗

PubMed2004

Thoracic outlet syndrome.

OBJECTIVE: Thoracic outlet syndrome (TOS) is one of the most controversial clinical entities in medicine. We provide a review of this difficult-to-treat disorder, including a brief overview, clinical presentations, surgical anatomy, treatment options, and outcomes. METHODS: TOS represents a spectrum of disorders encompassing three related syndromes: compression of the brachial plexus (neurogenic TOS), compression of the subclavian artery or vein (vascular TOS), and the nonspecific or disputed type of TOS. Neurovascular compression may be observed most commonly in the interscalene triangle, but it also has been described in the costoclavicular space and in the subcoracoid space. Patients present with symptoms and signs of arterial insufficiency, venous obstruction, painless wasting of intrinsic hand muscles, paresthesia, and pain. A careful and detailed medical history and physical examination are the most important diagnostic tools for proper identification of TOS. Electromyography, nerve conduction studies, and imaging of the cervical spine and the chest also can provide helpful information regarding diagnosis. Clinical management usually starts with conservative treatment including exercise programs and physical therapy; when these therapies fail, patients are considered for surgery. Two of the most commonly used surgical approaches are the supraclavicular exposure and the transaxillary approach with first rib resection. On occasion, these approaches may be combined or, alternatively, posterior subscapular exposure may be used in selected patients. CONCLUSION: TOS is perhaps the most difficult entrapment neuropathy encountered by neurosurgeons. Surgical intervention is indicated for vascular and true neurogenic TOS and for some patients with the common or nonspecific type of TOS in whom nonoperative therapies fail. With careful patient selection, operative intervention usually yields satisfactory results.

Humans↗

PubMed2004

Ulnar nerve entrapment neuropathy at the elbow: simple decompression.

Ulnar nerve entrapment neuropathy at the elbow, or the cubital tunnel syndrome, is frequently encountered in neurosurgical practice as the second most common peripheral nerve entrapment after carpal tunnel syndrome. Patients typically present with weakness or atrophy of the hand as well as paresthesias in the ulnar nerve distribution. The diagnosis can be confirmed with a careful clinical examination and electrophysiological studies. Patients who have failed conservative therapy are considered for surgery. Although a number of surgical options are available, simple decompression of the ulnar nerve can achieve satisfactory results with appropriate patient selection. We describe the relevant anatomy and surgical techniques for simple in situ decompression of the ulnar nerve at the elbow.

Decompression, Surgical↗

PubMed2004

Intramedullary cervical spine germinoma: case report.

OBJECTIVE AND IMPORTANCE: We report an extremely rare case of primary intramedullary germinoma in the cervical spinal cord arising in an 18-year-old man who had not undergone previous surgery or irradiation. CLINICAL PRESENTATION: The patient had a 2-month history of intermittent neck pain and a 4-week history of bilateral hand paresthesias and weakness. A magnetic resonance imaging scan demonstrated a heterogeneous cervical spine lesion with marked contrast enhancement extending from C3 to C6. INTERVENTION: The patient underwent a cervical laminotomy with tumor resection, and pathological examination revealed the tumor to be a germinoma. He recovered well from the surgery with minimal neurological deficits. A postoperative magnetic resonance imaging scan of the brain and spinal cord did not show any other tumors. In addition, imaging studies of the mediastinum, testes, and the rest of the body also did not demonstrate any other tumors. The patient received local radiation as well as three courses of chemotherapy. CONCLUSION: To our knowledge, this is the first report of an intramedullary cervical spine germinoma with confirmed tissue diagnosis. Although extremely uncommon, the possibility of germinoma should be included in the differential diagnosis for primary intramedullary spinal cord tumors.

Adolescent↗

PubMed2003

Intracranial hypotension after intraoperative lumbar cerebrospinal fluid drainage.

OBJECTIVE: Intraoperative lumbar cerebrospinal fluid drainage is frequently performed in a variety of neurosurgical procedures. A retrospective review is presented of the complications of lumbar cerebrospinal fluid drainage. METHODS: The records from 75 consecutive operations requiring intraoperative lumbar cerebrospinal drainage during a 1-year period at the Hospital of the University of Pennsylvania were reviewed to assess the types of complications attributable to spinal drainage and their rates of occurrence. The operations were categorized into 46 aneurysm clippings, 21 craniotomies for tumors, and 8 other cranial base procedures. RESULTS: Two patients developed transient postoperative neurological complications as a result of intracranial hypotension that resolved after epidural blood patching, with a reexploration craniotomy to drain an epidural collection performed in one patient. A third patient in the study developed a persistent deficit when intracranial hypotension led to intraoperative transtentorial herniation, which resulted in an unusual constellation of multiple brainstem infarcts that caused cranial neuropathy. CONCLUSION: Complications of intraoperative lumbar cerebrospinal fluid drainage resulting in transient (2 of 75 patients, 3%) or persistent (1 of 75 patients, 1%) neurological deficits caused by intracranial hypotension occur infrequently and may be related to preexisting conditions such as hydrocephalus.

Adult↗