Robert P. Iacono

Pain Management after Lower Extremity Amputation

&NA; Phantom pain may occur in up to 85% of patients after limb amputation. Although the pathophysiology of postamputation phantom pain is not well understood, it seems to be produced by a complex multifactorial interaction between the peripheral, sympathetic, and central nervous systems. The theoretical aspects of this are reviewed. Management of phantom limb pain may be both medical and surgical. Among the pharmacological agents proved effective against phantom pain are &bgr;‐blockers, tricyclic antidepressants, and anticonvulsants. Surgical management includes peripheral nerve stimulation, thermocontrolled coagulation of the spinal cord, spinal cord stimulation, transcutaneous nerve stimulation, and stereotactic deep brain stimulation. (Neurosurgery 20:496‐500, 1987)

L-dopa in uremic patients with the restless legs syndrome

Restless legs syndrome (RLS) is a poorly understood, often distressing condition that is particularly prevalent among patients with chronic renal failure. A wide variety of medications have been used to treat RLS with variable results. In order to evaluate the efficacy of carbidopa/levodopa therapy, eight consecutive uremic patients with RLS on maintenance hemodialysis were treated with doses ranging from 25/100 to 25/250 twice daily. Six of eight patients obtained satisfactory relief which has continued for 3 months follow-up. Carbidopa-levodopa appears to be an effective opinion in management of RLS in patients with chronic rental failure.

Interstitial thermoradiotherapy of brain tumors: Preliminary results of a phase I clinical trial

A Phase I clinical trial has been initiated to determine the feasibility, tolerance, and toxicity of interstitial thermoradiotherapy in the treatment of high-grade supratentorial brain gliomas. Hyperthermia was delivered by means of thermally-regulating ferromagnetic implants afterloaded into stereotactically placed plastic catheters. Heat treatments were given immediately before interstitial irradiation; in addition, five patients received a second heat treatment at the completion of brachytherapy. The desired target temperature for the 60-minute hyperthermia session was between 42 degrees C and 45 degrees C. Following hyperthermia, the catheters were afterloaded with Ir-192, which delivered a variable radiation dose of 14-50 Gy depending on the clinical situation. Interstitial irradiation was supplemented with external beam radiotherapy (40-41.4 Gy) in patients with previously untreated tumors. A total of 14 patients (4 males, 10 females) have been treated to date on this protocol. Eleven of the patients had a diagnosis of glioblastoma multiforme, whereas three had anaplastic astrocytoma. The mean implant volume was 61.5 cm3 (range: 9-119 cm3); the median number of interstitial treatment catheters implanted was 19 (range: 7-33). Continuous temperature monitoring was performed by means of multisensor thermocouple probes inserted in the center as well as in the periphery of the tumor. Of the 175 monitored intratumoral points, 83 (47%) had time-averaged mean temperatures of greater than 42 degrees C, and only 12 sensors (7%) exceeded a temperature of 45 degrees C. Among the 19 heat treatments attempted, there have been four minor acute toxicities, all of which resolved with conservative medical management and one major complication resulting in the demise of a patient. These preliminary results indicate that ferromagnetic implants offer a promising new approach to treating brain tumors with hyperthermia.

Pain and Sensory Symptoms in Parkinson's Disease

In this communication we discuss the clinical features and pathophysiology of primary sensory symptoms in Parkinsons disease.

Resolution of longstanding symptoms of multiple sclerosis by application of picotesla range magnetic fields

Recent clinical reports have suggested that treatment with extremely weak magnetic fields (MF) in the picoTesla range is an efficacious modality for the symptomatic therapy in patients with multiple sclerosis (MS) during the remission and exacerbation periods of the disease. The present communication concerns a 64 year old woman with a 22 year history of MS of the chronic-progressive type who presented with a longstanding history of ataxia of gait, weakness in the legs, difficulties with swallowing, loss of bladder control, blurred vision, diplopia, chronic fatigue, and cognitive impairment. In this patient two 30 minute treatments with MF on two separate days resulted in a dramatic improvement of symptoms. Specifically, the patient experienced marked improvement in balance and gait as well as increased strength in the legs to the extent that she was able to abandon the use of a walker within 48 hours after initiation of magnetic treatment. In addition, there was complete resolution of diplopia, bladder dysfunction, and fatigue with improvement in mood and cognitive functions. The report attests to the unique efficacy of extremely weak MF in the symptomatic treatment of patients with MS including those patients with a chronic progressive course of the disease and supports the hypothesis that dysfunction of synaptic conductivity due to neurotransmitter deficiency specifically of serotonin rather than demyelination underlies the neurologic deficits of the disease.

Successful Treatment of Phantom Pain with Dorsal Root Entry Zone Coagulation

We studied 22 patients with amputation due to trauma, gangrene, or cancer. All developed postamputation pain, underwent a dorsal root entry zone (DREZ) procedure, and were followed from 6 months to 4 years after surgery. Overall, only 8 (36%) of these 22 patients had pain relief. However, good results were obtained in 6 (67%) of 9 patients with phantom pain alone, and in 5 (83%) of 6 patients with traumatic amputations associated with root avulsion. Poor results were obtained in patients with both phantom and stump pain, or stump pain alone. The DREZ procedure has a well-defined, but limited role in the treatment of postamputation pain.

Cranial metastases from prostate cancer simulating meningioma: report of two cases and review of the literature.

Two cases of prostatic carcinoma metastatic to the cranium that presented with clinical and radiographic features simulating meningioma are described. The literature was reviewed, and 13 similar cases were identified. From the data gathered, we conclude that metastatic prostate cancer should be considered in the differential diagnosis of elderly males who present with characteristic clinical and radiological features of meningioma and that the classical description of meningioma is not specific.

Spinal Cord Mechanisms in Amitriptyline Responsive Restless Legs Syndrome in Parkinson's Disease

We discuss a case of a patient with restless legs syndrome that was responsive to administration of amitriptyline. The possible mode of action of amitriptyline in ameliorating this patients symptoms is discussed.

Risk Factors for Neuroleptic-Induced Movement Disorders

Chronic neuroleptic therapy may be associated with the development of diverse movement disorders including Tardive dyskinesia (TD), Parkinsonism, dystonia, and akathisia in a subset of schizophrenic patients. It is presently unknown why only a proportion of neuroleptic-treated patients develop these movement disorders. In the following communication, we present a series of studies which demonstrate that the development of these movement disorders may be facilitated by certain risk factors including disturbances in pineal melatonin functions, diabetes mellitus, cognitive deficits, suicidal behavior, and disturbances in the functions of the choroid plexus. Recognition of these biological factors may prove useful in: (a) further understanding of the pathophysiology of these disorders, and (b) identifying patients at risk for these movement disorders.

Influence of Enteral Feedings on Phenytoin Sodium Absorption from Capsules

The influence of enteral feedings (with Ensure) on the absorption of phenytoin sodium from capsules was studied. Six healthy adult volunteers were given a single dose of phenytoin capsules 400 mg po on two occasions. Blood specimens were collected for 48 hours after each dose. In a randomized, crossover fashion, each subject completed the following two phases: (1) phenytoin without enteral feedings, and (2) concomitant enteral feedings before phenytoin and continued at 100 ml/h for ten hours. The areas under the concentration versus time curves from 0-48 hours (AUCo-48) were not significantly different between the two phases (p > 0.5). The percent relative bioavailability of phenytoin with enteral feedings was 101.7 percent. This study suggests that enteral feedings do not affect the serum concentrations of phenytoin after a single dose given in capsule form.