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Biomedical subjects

L Reinstein

Publications and source records attributed to L Reinstein.

At least 19 recordsLinked to original sources
PubMed1996

Conformal radiation treatment of prostate cancer using inversely-planned intensity-modulated photon beams produced with dynamic multileaf collimation.

PURPOSE: To implement radiotherapy with intensity-modulated beams, based on the inverse method of treatment design and using a multileaf collimation system operating in the dynamic mode. METHODS AND MATERIALS: An algorithm, based on the inverse technique, has been integrated into the radiotherapy treatment-planning computer system in our Center. This method of computer-assisted treatment design was used to derive intensity-modulated beams to optimize the boost portion of the treatment plan for a patient with a T1c cancer of the prostate. A dose of 72 Gy (in 40 fractions) was given with a six-field plan, and an additional 9 Gy (in five fractions) with six intensity-modulated beams. The intensity-modulated fields were delivered using dynamic multileaf collimation, that is, individual leaves were in motion during radiation delivery, with the treatment machine operating in the clinical mode. Exhaustive quality assurance measurement and monitoring were carried out to ensure safe and accurate implementation. RESULTS: Dose distribution and dose-volume histogram of the "inverse method" boost plan and of the composite (72 Gy primary + 9 Gy boost) plan were judged clinically acceptable. Compared to a manually designed boost plan, the inverse treatment design gave improved conformality and increased dose homogeneity in the planning target volume. Film and ion chamber dosimetry, performed prior to the first treatment, indicated that each of the six intensity-modulated fields was accurately produced. Thermoluminescent dosimeter (TLD) measurements performed on the patient confirmed that the intended dose was delivered in the treatment. In addition, computer-aided treatment-monitoring programs assured that the multileaf collimator (MLC) position file was executed to the specified precision. In terms of the overall radiation treatment process, there will likely be labor savings in the planning and the treatment phases. CONCLUSIONS: We have placed into clinical use an integrated system of conformal radiation treatment that incorporated the inverse method of treatment design and the use of dynamic multileaf collimation to deliver intensity-modulated beams. The system can provide better treatment design, which can be implemented reliably and safely. We are hopeful that improved treatment efficacy will result.

Humans↗
PubMed1995

The influence of scatter on the design of optimized intensity modulations.

In contrast to the traditional treatment planning process where beam parameters are adjusted in order to produce a desired dose distribution, the inverse treatment planning technique starts from the desired dose distribution and employs mathematical inversion to derive a set of optimal intensity profiles for beams with predefined directions. Crucial to the success of the inverse technique is the mathematical inversion process that yields the optimized intensity modulation. This paper systematically investigates the influence of phantom scatter in the process of designing the optimized intensity modulation and assesses its clinical consequences through the resultant treatment plans. Optimized intensity modulations and the resultant dose distributions were calculated for four prostate patients and for a simple cubic phantom under two conditions: one includes scatter and the other ignores scatter in designing the optimized intensity modulation. The effects of scatter were assessed by comparing the isodose distributions, the dose-volume histograms of the target and of the critical organs, and the tumor control probabilities and the normal tissue complication probabilities of two set prostate treatment plans. The comparison reveals that the dose homogeneity to the target is significantly improved when scatter is included in the optimization process. For prostate patients, the dose to the volume enclosed by the outer rectal contour is concomitantly reduced. Our results suggest that it is important to include the scatter in the iterative design of the optimized intensity modulations.

Biophysical Phenomena↗
PubMed1994

Physical medicine and rehabilitation in the 21st century.

In conclusion, physical medicine and rehabilitation in the 21st century will be: new, exciting technologies, different patient populations, different practice settings, fewer PM&R residents, and more physician assistants, all operating under a universal access, single payer, Canadian-style health care system. I began my presentation with a quote from Yogi Berra. I'll close by paraphrasing the immortal words of Charles Dickens in the opening lines of A Tale Of Two Cities. PM&R in the 21st century will be "the best of times, the worst of times, the epoch of belief, the epoch of incredulity."

Forecasting↗
PubMed1993

Underutilization of physician assistants in physical medicine and rehabilitation.

This study was undertaken to determine the utilization of physician assistants (PAs) in physical medicine and rehabilitation (PM&R). Survey questionnaires were sent to members of the American Academy of Physical Medicine and Rehabilitation, members of the American Academy of Physician Assistants, and administrators of free-standing rehabilitation facilities. One hundred thirty-seven of 1,082 physiatrists (13% of those responding) reported PAs employed in their practice settings, 83 of 549 PAs (15% of those responding) identified PM&R as their specialty, and 17 of 65 hospital administrators, (27% of those responding) reported PAs working at their facility. Seventy-nine percent (713 of 903) of physicians and 77% (50 of 65) of administrators were unaware that PA services provided in inpatient settings are reimbursed by Medicare. Eighty-four percent (108 of 129) of physiatrists employing PAs indicated that they would continue to do so even if the supply of physiatrists were adequate. PA responsibilities were concentrated in inpatient clinical areas. It is concluded that PAs are an underutilized source of health care for rehabilitation patients. Increased professional visibility and formal specialty training are recommended to enhance their contribution to the field.

Adult↗
PubMed1987

Pneumothorax: a complication of needle electromyography of the supraspinatus muscle.

A patient developed sudden, severe pleuritic chest pain during needle electromyography (EMG) of the right supraspinatus muscle. Chest x-rays revealed a 10% right pneumothorax. The patient was treated conservatively and there was complete resolution one week later. A review of the pertinent anatomy indicates that the supraspinatus muscle overlies the pleural cavity. Indications for needle EMG of the supraspinatus muscle are reviewed. A new technique that minimizes the risk of pneumothorax when performing needle EMG of the supraspinatus muscle is presented.

Electrodes↗
PubMed1986

Lower limb amputation of the donor site extremity after coronary artery bypass graft surgery.

A 68-year-old man with peripheral vascular disease and diabetes mellitus underwent coronary artery bypass graft surgery for angina pectoris unresponsive to medical treatment. Postoperatively, the left saphenous vein donor site became infected and developed a nonhealing ulcer. Three months after surgery, a left below-knee amputation was performed. The patient's prosthetic program was uneventful, and he became independent in ambulation with a prosthesis. This rare complication of coronary artery bypass graft surgery may be prevented by careful preoperative evaluation of peripheral circulation of the proposed donor site and consideration of alternative donor sites, such as the internal mammary artery. To our knowledge, this is the first detailed description and second reported case of lower limb amputation of the donor site extremity following such surgery.

Aged↗
PubMed1984

Femoral nerve dysfunction after retroperitoneal hemorrhage: pathophysiology revealed by computed tomography.

In three patients receiving anticoagulation therapy who developed retroperitoneal hemorrhage computed tomography (CT) clearly localized the resulting hematoma in each case. Three distinct syndromes are described. A hemorrhage within the iliacus muscle resulted in femoral nerve dysfunction. A large hemorrhage within the iliacus muscle which extended into the psoas muscle produced both femoral and obturator nerve dysfunction. A retroperitoneal hemorrhage extrinsic to both the iliacus and psoas muscles did not produce peripheral nerve dysfunction. The pathophysiology of peripheral nerve dysfunction in retroperitoneal hemorrhage is reviewed in detail.

Adult↗
PubMed1984

Peripheral nerve compression by brachial artery-basilic vein vascular access in long-term hemodialysis.

This report presents the first description of direct peripheral nerve compression as a complication of brachial artery-basilic vein vascular access in patients with uremia who are receiving long-term hemodialysis. Three patients are presented. An expanding basilic vein hematoma compressed the radial nerve in one patient. A graft associated abscess adjacent to the brachial artery compressed the median nerve in a second patient. A basilic vein aneurysm compressed the median nerve in a third patient. In two cases, electrodiagnostic studies were helpful in identifying the location and severity of the peripheral nerve dysfunction, and in excluding more common distal nerve dysfunction, which is sometimes seen in these patients as a result of circulatory alterations in the extremity caused by dialysis. Prompt surgical decompression led to significant recovery of nerve function in all three patients. It is concluded that direct peripheral nerve compression is a rare complication of brachial artery-basilic vein vascular access in patients with uremia who are receiving long-term hemodialysis.

Adult↗
PubMed1984

Electromyographic abnormalities in redundant nerve root syndrome of the cauda equina.

This report documents the seventh patient with redundant nerve root syndrome of the cauda equina in which electromyographic abnormalities were reported. A 79-year-old woman developed low back pain radiating into the left lower extremity. Electromyography (EMG) revealed partial denervation of the left medial gastrocnemius muscle. Metrizamide myelography disclosed a complete block of the spinal canal at the L3 vertebral level, and a coiled nerve root was present behind the L2 vertebral body. Computed tomography showed marked spondylotic narrowing of the spinal canal at the L3 to L4 vertebral level, and spinal stenosis at the L4 to L5 vertebral level. An L3 laminectomy revealed nodular bony overgrowth and ligamentous hypertrophy compressing the dura. Postoperatively, the patient experienced significant pain relief and increased ambulation ability. Electromyographic abnormalities in the left medial gastrocnemius muscle were still present at three- and six-month follow-up.

Aged↗
PubMed1983

Sciatic nerve compression by preexisting heterotopic ossification during general anesthesia in the dorsal lithotomy position.

This report documents the 4th patient reported with sciatic nerve compression by heterotopic ossification and the 1st case occurring during general anesthesia. A 25-year-old woman developed right sciatic nerve dysfunction after a 30-minute dilatation and curettage in the dorsal lithotomy position. Postoperative x-rays revealed a large area of heterotopic ossification above the right greater trochanter. The patient had sustained a traumatic midshaft fracture of the right femur seven years previously, which required intramedullary nail fixation. It is postulated that during the D and C in the dorsal lithotomy position, the heterotopic ossification was displaced posteromedically, compressing the sciatic nerve that had already been placed at maximal stretch. The patient recovered partially. Electrodiagnostic studies were of considerable value in localization of the lesion and confirmation of the mechanism of injury. It is concluded that preexisting heterotopic ossification of the hip may compress the sciatic nerve during surgery in the dorsal lithotomy position.

Adult↗
PubMed1983

de Quervain's stenosing tenosynovitis in a video games player.

This report describes a patient who developed signs and symptoms of de Quervain's stenosing tenosynovitis after prolonged playing with video games. An analysis of the biomechanics of video games playing indicates that grasping the joystick controller produces tension on the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons, and that video games playing requires many rapid, repetitive thumb and wrist movements which stress the APL and EPB tendons. It is concluded that prolonged playing with video games should be considered as an etiologic factor in patients with de Quervain's stenosing tenosynovitis.

Adult↗
PubMed1982

Peripheral neuropathy after multiple tetanus toxoid injections.

This case documents the 14th reported patient with peripheral neuropathy following tetanus toxoid injection. A 33-year-old man developed profound mixed sensorimotor peripheral neuropathy after receiving 2 tetanus toxoid injections over a 5-month period. Periodic serial electromyographic and nerve conduction studies performed over 2 years suggested both segmental demyelination and axonal neuropathy. The patient experienced partial recovery. Analysis of this case and 13 others reported in literature indicates that in almost all cases (85%), patients had received multiple tetanus toxoid injections. Also, it appears that a prolonged interval of 14 or more days between the tetanus toxoid injection and the onset of neurological symptoms is associated with a poorer prognosis for complete recovery.

Adult↗
PubMed1982

Peripheral neuropathy after concomitant dimethyl sulfoxide use and sulindac therapy.

The case is presented of a 63-year-old man with a long history of degenerative arthritis who took sulindac (Clinoril) 200 mg BID for 6 months with no untoward effects. Then, without physician knowledge, he began using 90% dimethyl sulfoxide (DMSO) topically to his upper and lower extremities. Shortly thereafter, he developed a profound mixed sensorimotor peripheral neuropathy. Serial electromyographic and nerve conducion studies performed at intervals of several months for 1 year suggested both segmental demyelination and axonal neuropathy. The patient experienced initial deterioration followed by gradual but incomplete recovery.

Arthritis↗
PubMed1981

Hand dominance in carpal tunnel syndrome.

In a review of the records of 169 patients having idiopathic carpal tunnel syndrome (CTS) documented by electrodiagnostic studies, CTS was found to occur significantly more frequently in the dominant hand of both right- and left-handed persons. The clinical implications of these findings are discussed, particularly as they relate to the role of repetitive hand activities in the etiology of CTS, and it is concluded that the increased daily activity of the dominant hand is a contributing factor in the development of CTS.

Adult↗
PubMed1981

Electromyographic abnormalities in Paget disease of the thoracolumbar vertebral column.

This report describes a patient with Paget disease of the lower thoracic and lumbosacral vertebrae who developed slowly progressive paraparesis. The electromyographic findings were abnormal in the thoracolumbar paraspinal muscles and the right medial gastrocnemius muscle. In the presence of a normal myelogram, we concluded that the denervation found by electromyography was due to neural ischemia rather than mechanical compression of neural tissue, as is sometimes the case.

Electromyography↗