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Biomedical subjects

J V Murphy

Publications and source records attributed to J V Murphy.

At least 19 recordsLinked to original sources
PubMed2001

Vagal nerve stimulation in tuberous sclerosis complex patients.

This is an open-label, retrospective, multicenter study to determine the outcome of intermittent stimulation of the left vagal nerve in children with tuberous sclerosis complex and medically refractory epilepsy. The records of all children treated with vagal nerve stimulation were reviewed in five pediatric epilepsy centers to locate those with tuberous sclerosis complex who had been treated with vagal nerve stimulation for at least 6 months. These patients were compared with (1) a series of patients obtained from the literature, (2) 10 similar control patients with epilepsy obtained from a registry of patients receiving vagal nerve stimulation, and (3) four published series of tuberous sclerosis complex patients whose epilepsy was surgically managed. Ten tuberous sclerosis complex patients with medically refractory epilepsy treated with vagal nerve stimulation were found. Nine experienced at least a 50% reduction in seizure frequency, and half had a 90% or greater reduction in seizure frequency. No adverse events were encountered. Comparison with published and registry patients revealed improved seizure control in the tuberous sclerosis complex patients. Comparison with the group undergoing seizure surgery demonstrated improved outcomes after surgery. Vagal nerve stimulation appears to be an effective and well-tolerated adjunctive therapy in patients with tuberous sclerosis complex and seizures refractory to medical therapy. Resective surgery has a better prospect for improved seizure control.

Adolescent↗
PubMed2000

Left vagal nerve stimulation in six patients with hypothalamic hamartomas.

Six patients with medically refractory epilepsy secondary to hypothalamic hamartomas were treated with intermittent stimulation of the left vagal nerve. Three of the patients had remarkable improvements in seizure control. Four of these six patients had severe autistic behaviors. Striking improvements in these behaviors were observed in all four during treatment with intermittent stimulation. This finding suggests that vagal nerve stimulation can control seizures and autistic behaviors in patients with hypothalamic hamartomas.

Adolescent↗
PubMed2000

Frostbite: pathogenesis and treatment.

Frostbite, once almost exclusively a military problem, is becoming more prevalent among the general population and should now be considered to be within the scope of the civilian physician's practice. Studies into the epidemiology of civilian frostbite have identified several risk factors that may aid the clinician in the diagnosis and management of cold injuries. Research into the pathophysiology has revealed marked similarities in inflammatory processes to those seen in thermal burns and ischemia/reperfusion injury. Evidence of the role of thromboxanes and prostaglandins has resulted in more active approaches to the medical treatment of frostbite wounds. Although the surgical management of frostbite involves delayed debridement 1 to 3 months after demarcation, recent improvements in radiologic assessment of tissue viability have led to the possibility of earlier surgical intervention. In addition, several adjunctive therapies, including vasodilators, thrombolysis, hyperbaric oxygen, and sympathectomy, are discussed.

Clinical Protocols↗
PubMed1999

Left vagal nerve stimulation in children with medically refractory epilepsy. The Pediatric VNS Study Group.

OBJECTIVE: To assess the use of intermittent left vagal nerve stimulation in a large population of children with pharmacoresistant epilepsy. STUDY DESIGN: Sixty children who were entered into controlled or compassionate use protocols of left vagal nerve stimulation all had been monitored for at least 3 months after their left vagal nerve stimulators were activated. RESULTS: The age range was 3 to 18 years (median 15 years). Sixteen of these 60 patients were younger than 12 years. Fifty-seven percent of the patients had partial complex seizures, and generalized tonic clonic seizures occurred in 27%. After 3 months of intermittent stimulation of the left vagal nerve, a median reduction in seizure frequency of 23% occurred in 60 patients. At 6 months the median reduction was 31% in 55 patients, at 12 months 34% in 51 patients, and at 18 months 42% in 46 patients. Improvement was not associated with any seizure type or seizure cause. Adverse events during stimulation included fever, coughing, colds, and voice alteration. None of these necessitated cessation of stimulation. Complications included aspiration pneumonia and necrosis of skin overlying the generator. CONCLUSIONS: Intermittent stimulation of the left vagal nerve appears to be a safe, adjunctive therapy for the treatment of children with epilepsy intractable to available antiepileptic drugs. The reduction in seizure frequency in children was similar to that reported in adults.

Adolescent↗
PubMed1998

Adverse events in children receiving intermittent left vagal nerve stimulation.

The purpose of this study was to determine the frequency of unexpected events during intermittent vagal nerve stimulation in 24 patients stimulated for a total of 61 patient years. The charts of 24 children undergoing periodic stimulation of the left vagal nerve on research protocols were reviewed to determine the nature and frequency of adverse events and the total length of time they were stimulated. Fifteen adverse events were discovered in 12 patients. Thirteen were likely related to the device, and four other events might have been related. Two of these resulted in voluntary termination of vagal nerve stimulation, and the rest were treatable. Vagal nerve stimulation was tolerated in this series of patients. As opposed to the more standard drug therapies, adverse events during vagal nerve stimulation do not necessitate termination of therapy, but these events frequently lead to unforeseen surgery under general anesthesia.

Adolescent↗
PubMed1998

A novel potassium channel gene, KCNQ2, is mutated in an inherited epilepsy of newborns.

Idiopathic generalized epilepsies account for about 40% of epilepsy up to age 40 and commonly have a genetic basis. One type is benign familial neonatal convulsions (BFNC), a dominantly inherited disorder of newborns. We have identified a sub-microscopic deletion of chromosome 20q13.3 that co-segregates with seizures in a BFNC family. Characterization of cDNAs spanning the deleted region identified one encoding a novel voltage-gated potassium channel, KCNQ2, which belongs to a new KQT-like class of potassium channels. Five other BFNC probands were shown to have KCNQ2 mutations, including two transmembrane missense mutations, two frameshifts and one splice-site mutation. This finding in BFNC provides additional evidence that defects in potassium channels are involved in the mammalian epilepsy phenotype.

Amino Acid Sequence↗
PubMed1998

Chronic stimulation of the left vagal nerve in children: effect on swallowing.

PURPOSE: To learn whether stimulation of the left vagal nerve would influence swallowing. METHODS: Eight children receiving intermittent left vagal nerve stimulation (VNS) for their pharmacoresistant epilepsy underwent barium swallow studies with their generators off, on, and at maximally tolerated settings. RESULTS: Laryngeal penetration of barium was present in three patients without stimulation, and was caused by VNS in one other patient. Aspiration never occurred. CONCLUSIONS: Stimulation of the left vagal nerve under conditions used to treat epilepsy does not cause aspiration.

Age Factors↗
PubMed1998

Vagus nerve stimulation therapy for partial-onset seizures: a randomized active-control trial.

OBJECTIVE: The purpose of this multicenter, add-on, double-blind, randomized, active-control study was to compare the efficacy and safety of presumably therapeutic (high) vagus nerve stimulation with less (low) stimulation. BACKGROUND: Chronic intermittent left vagus nerve stimulation has been shown in animal models and in preliminary clinical trials to suppress the occurrence of seizures. METHODS: Patients had at least six partial-onset seizures over 30 days involving complex partial or secondarily generalized seizures. Concurrent antiepileptic drugs were unaltered. After a 3-month baseline, patients were surgically implanted with stimulating leads coiled around the left vagus nerve and connected to an infraclavicular subcutaneous programmable pacemaker-like generator. After randomization, device initiation, and a 2-week ramp-up period, patients were assessed for seizure counts and safety over 3 months. The primary efficacy variable was the percentage change in total seizure frequency compared with baseline. RESULTS: Patients receiving high stimulation (94 patients, ages 13 to 54 years) had an average 28% reduction in total seizure frequency compared with a 15% reduction in the low stimulation group (102 patients, ages 15 to 60 year; p = 0.04). The high-stimulation group also had greater improvements on global evaluation scores, as rated by a blinded interviewer and the patient. High stimulation was associated with more voice alteration and dyspnea. No changes in physiologic indicators of gastric, cardiac, or pulmonary functions occurred. CONCLUSIONS: Vagus nerve stimulation is an effective and safe adjunctive treatment for patients with refractory partial-onset seizures. It represents the advent of a new, nonpharmacologic treatment for epilepsy.

Adolescent↗
PubMed1997

Left vagus nerve stimulation in children with refractory epilepsy: an update.

This report updates previous reports regarding the tolerance and efficacy of periodic vagus nerve stimulation in a group of 19 children with medically and surgically intractable epilepsy. After vagal stimulator implantation, follow-up continued from 2 months to 30 months, with the study period ending in October 1995. Of the 19 patients, 6 (32%) had more than a 90% reduction in the number of monthly seizures, and 10 (53%) had more than a 50% reduction. Global evaluation scores indicated that only 1 patient had deterioration from baseline, 5 had no change, and the remainder had modest to remarkable improvement. All 3 children with unsuccessful corpuscallosotomy had improvement after implantation of the stimulator, and 5 of 6 children with Lennox-Gastaut syndrome had a 90% reduction of seizures. Five patients required fewer antiepileptic medications, and 1 patient had an increase in medication. Adversities included 2 possible wound infections, 1 instance of generator failure, and hoarseness during stimulation in all patients. Changing stimulation parameters to increase the rate of stimulation and reduce the interval between stimulations resulted in improved seizure control in 4 of 5 patients. Periodic VNS was well tolerated by these children and may have a role in the management of refractory epilepsy.

Adolescent↗
PubMed1997

Neurological effects associated with use of the insect repellent N,N-diethyl-m-toluamide (DEET).

BACKGROUND: N,N-Diethyl-m-toluamide, an effective tick repellent, when applied to the skin, is the major component of essentially all of the products marketed for this purpose. It is used by about 30% of the US population, and by 23-29% of children in this population. Reports of neurologic adversity and death are rare and primarily involve children, but the dose relationship between N,N-diethyl-m-toluamide exposure and the symptoms reported in the clinical literature is difficult to establish. METHODS: Animal toxicology studies, clinical reports of neurological adversities in children and adults, and the available Poison Control Center records have been reviewed in an effort to understand the relationship between the N,N-diethyl-m-toluamide exposure and reported adverse events. CONCLUSIONS: Based on (1) the animal toxicology database on N,N-diethyl-m-toluamide, (2) the reports of adverse events in humans, and (3) the possible alternate etiologies for the symptoms reported in most patients, the risk of adversity from label-directed use of N,N-diethyl-m-toluamide appears low. Future efforts should focus on the prospective collection of adversity data with special attention paid to the documentation of clinical effects.

Administration, Cutaneous↗
PubMed1995

Left vagal nerve stimulation in children with refractory epilepsy. Preliminary observations.

OBJECTIVE: To observe the tolerance and efficacy of periodic left vagal nerve stimulation in a group of children with medically intractable epilepsies. DESIGN: A vagal nerve stimulator (Cyberonics Inc, Webster, Tex) was implanted in 12 children with medically and surgically refractory epilepsies. These children were followed up for 2 to 14 months. OUTCOME MEASUREMENTS: (1) The number of seizures recorded during the final month of observation was compared with the number recorded during the month before the implantation of the vagal nerve stimulator. (2) Parents were asked to compare overall status of their child, relative to the period prior to using the vagal nerve stimulator, on a global rating scale. (3) The number of antiepileptic drugs at the last visit was compared with the number before the use of this device. (4) Adverse events were recorded. RESULTS: Five of the 12 patients had a greater than 90% reduction in the number of monthly seizures. Global evaluation scores indicated that there were no deteriorations from baseline and that there was a considerable number with improved status. Four patients were able to reduce the number of antiepileptic drugs used. No significant adversities were noted. CONCLUSIONS: The vagal nerve stimulator is well tolerated in children with intractable epilepsies, and it may have a role in their medical management. We were unable to determine specific epilepsies or seizures that were sensitive to this intervention.

Adolescent↗
PubMed1994

Diagnosis of childhood seizure disorders.

Convulsive epilepsies are generally unmistakable. Absence epilepsies, which are easily recognized by the provocation of an episode during hyperventilation and by the typical features of the EEG, can be overdiagnosed, especially in the child who daydreams in class and has scattered, asymptomatic, epileptogenic EEG changes. As in adults, complex partial seizures in children can be difficult to distinguish from certain behaviors. Several types of benign childhood epilepsies need to be distinguished from the more intractable and lesional childhood epilepsies. Two common examples, benign rolandic epilepsy and benign occipital epilepsy, can be recognized by their unique EEG changes and clinical features. Juvenile myoclonic epilepsy generally does not remit spontaneously but should be recognized because it appears to respond to valproate. Some recurrent nonepileptic events seen in children can be mistaken for seizures, including shuddering attacks, paroxysmal vertigo, breath-holding spells, cardiogenic syncope, night terrors, and movement disorders, such as paroxysmal kinesigenic choreoathetosis.

Adolescent↗
PubMed1988

Valproate monotherapy in children.

Seizures are more common in children than in adults. Since most pediatric epilepsies can be controlled with a single antiepileptic drug, children with epilepsy should receive monotherapy when possible or switch from polytherapy to monotherapy. More than half of the epileptic patients receiving multiple antiepileptic drugs will have better seizure control as well as fewer side effects with monotherapy. Most of the pediatric epilepsies occur as primary generalized seizures, for which valproate is a preferred drug. Children can begin to receive valproate treatment in a dosage of 20 to 30 mg/kg per day in two or three divided doses. After several days, plasma levels may be useful in adjusting the dosage. The major adverse effect of valproate in children is fatal hepatotoxicity. The risk of this complication is considerably lower with valproate monotherapy (one per 10,000 patients) than with polytherapy. Other advantages of valproate monotherapy, compared with polytherapy, include the avoidance of drug interactions, lower cost, and reduced potential for impaired cognitive function, which is particularly important in children.

Anticonvulsants↗