PubMed Health⌕ Search

Biomedical subjects

Donald H Lee

Publications and source records attributed to Donald H Lee.

27 records · Page 2Linked to original sources
PubMed2003

Transient lesion in the splenium of the corpus callosum in an epileptic patient.

Pathogenesis of a rarely occurring transient, isolated focal lesion of the splenium of the corpus callosum in epilepsy patients is uncertain: frequent seizures or antiepileptic drug reduction causing ischemia or demyelination is possible. The several MRI sequences, including diffusion-weighted imaging, in this first case of occipital epilepsy suggest ischemia from rapid carbamazepine reduction, frequent seizures, or a combination of both.

Adult↗
PubMed2003

Tendon transfers for thumb opposition: a biomechanical study of pulley location and two insertion sites.

PURPOSE: The purpose of this biomechanical study was to test 5 proximal tendon pulley sites or routes of tendon transfer and 2 distal tendon insertion sites that are used commonly for performing a thumb opposition transfer. METHODS: Five fresh-frozen cadaver arms were used to test (1) an around flexor carpi ulnaris (FCU) pulley, (2) an FCU loop pulley, (3) a Guyon's canal pulley, (4) a junction of the distal edge of the transverse carpal ligament and the ulnar border of the palmar aponeurosis (Royle-Thompson pulley), and (5) a palmar thenar subcutaneous transfer (Camitz). Two tendon insertion sites were tested: a palmar radial insertion into the abductor pollicis brevis and a dorsal ulnar insertion into the thumb proximal phalanx. RESULTS: The Guyon's canal and Royle-Thompson pulleys produced the greatest amount of approximation of the thumb pulp to the fifth metacarpal head. The around the FCU pulley, FCU loop pulley, and Camitz transfer produced the greatest palmar abduction. The Guyon's canal and Royle-Thompson pulleys were the most mechanically efficient pulleys, producing the least amount of transmitted force. The palmar radial insertion site produced better thumb opposition, metacarpophalangeal joint abduction, metacarpophalangeal joint flexion, and approximation of the thumb pulp to the fifth metacarpal head. CONCLUSIONS: We conclude that the choice of the proximal pulley used may depend on the needs of the transfer, and a palmar radial thumb insertion is more effective than the dorsal ulnar insertion.

Biomechanical Phenomena↗
PubMed2003

Dural cavernous angioma: a preoperative diagnostic challenge.

BACKGROUND: Dural cavernous angiomas are uncommon benign vascular malformations which may present intraoperative difficulties in hemostasis when the diagnosis is not suspected preoperatively. Preoperative diagnosis can be difficult when angiomas show atypical features and share imaging characteristics with other entities. METHODS: A patient presented with a radiographically aggressive lesion, subsequently identified as a dural cavernous angioma. The lesion is reviewed and its clinical, radiographic, and pathological features are compared with other vascular malformations. CASE REPORT: A 40-year-old man presented with new onset seizures and an enhancing lesion infiltrating the floor of the right middle cranial fossa. Due to its aggressive radiographic appearance, initial considerations included chondrosarcoma, meningioma or metastasis. Pathological examination, however, revealed the lesion to be a cavernous angioma of dura. CONCLUSION: This uncommon lesion may present a diagnostic challenge with significant intraoperative implications. T2 sequence hyperintensity in a relevant lesion should raise suspicion of an hemangioma. It is important to be aware of this entity and its potential to mimic other entities on radiographic grounds.

Adult↗
PubMed2003

Pediatric Kienböck's disease: case report and review of the literature.

A 13-year-old boy with symptomatic Stage III Kienböck's disease was treated successfully with a radial shortening procedure. A comparison of the preoperative and postoperative radiographs and magnetic resonance imaging studies showed evidence of lunate revascularization and remodeling after a radial shortening osteotomy.

Adolescent↗
PubMed2003

Desmoplastic fibroma of the cranium: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Desmoplastic fibroma is a benign bone tumor that can be locally aggressive. It usually occurs in the long bones and mandible. We report on a patient with a desmoplastic fibroma arising in the temporal bone and review previously published cases of desmoplastic fibroma originating within the cranium. CLINICAL PRESENTATION: A 43-year-old woman presented with a 12-year history of progressively worsening head asymmetry. Magnetic resonance imaging and computed tomography demonstrated a mass originating from the bone and involving the adjacent soft tissues. INTERVENTION: A temporal parietal craniectomy was performed with excision of a large tumor involving the bone. An acrylic cranioplasty was used to replace the bone. Pathological examination of the lesion identified desmoplastic fibroma of the cranium. After surgery, the patient's cranial asymmetry was corrected. CONCLUSION: Desmoplastic fibroma of the cranium is rare. Surgical resection is the treatment of choice.

Adult↗
PubMed2003

Magnetic resonance angiography.

MRA is a robust technique that still is undergoing modifications and improvements. As a noninvasive, or minimally invasive, technique using intravenous contrast injection, it offers complementary assessment of intracranial and extracranial arteries at the time of MRI, using similar coils and sequences. Images are similar to, but of lower resolution than, those of conventional angiography.

Animals↗
PubMedDate not supplied

Clinical nerve conduction and needle electromyography studies.

The electrodiagnostic study, consisting of nerve conduction studies and needle electromyography, is a useful adjunct to the clinical examination of the peripheral nervous system. The three types of nerve conduction study are motor, sensory, and mixed, of which motor is the least sensitive. Electromyography records the intrinsic electrical activity of muscle fibers, thus providing the physiologic status of muscle function. To interpret the electrodiagnostic study results, the clinician must understand the anatomic and physiologic basis of the studies. Peripheral nerve entrapment initially results in focal demyelination; thus, nerve conduction velocity slows across the site. However, with radiculopathy and nerve root compression, the nerve conduction study may be normal. Both nerve trauma and polyneuropathy show marked differences in their effect on the results of electrodiagnostic studies.

Action Potentials↗