The US health care system: Part 1: Our current system.

The US health care crisis is of great concern to American neurologists. The United States has the world's most expensive health care system yet one-sixth of Americans are uninsured. The cost and volume of procedures is expanding, while reimbursement for office visits is declining. Pharmaceutical costs, durable goods, and home health care are growing disproportionately to other services. Carriers spend more for their own administration and profit than on payments to physicians. This first article on the US health care system identifies problems and proposes solutions, many of which are championed by the American Academy of Neurology through its legislative and regulatory committees.

Invited article: the US health care system: part 2: proposals for improvement and comparison to other systems.

In the search for a universal, high quality, affordable health care system, Americans seek to identify and correct a series of current problems. In part one of this two-part series, we presented problems along with some suggested actions. This second part presents other health care systems in Europe and Canada. These different systems provide universal care and at a lower cost than in the United States. Further domestic proposals are presented from the Massachusetts plan and positions from US presidential candidates. These systems and proposals raise ideas about possible changes in the US health care system. Knowledge of these issues and other health care systems will help foster a meaningful dialog about changes in the US health care system.

Retrospective review of MEG visual evoked hemifield responses prior to resection of temporo-parieto-occipital lesions.

Visual evoked cortical magnetic field (VEF) waveforms were recorded from both hemifields in 21 patients with temporo-parieto-occipital mass lesions to identify preserved visual pathways. Fifteen patients had visual symptoms pre-operatively. Magnetoencephalographic (MEG) VEF responses were detected, using single equivalent current dipole (ECD), in 17/21 patients studied. Displaced or abnormal responses were seen in 15 patients with disruption of pathway in one patient. Three of 21 patients had alterations in the surgical approach or the planned resection based on the MEG findings. The surgical outcome for these three patients suggests that the MEG study may have played a useful role in pre-surgical planning.

MEG localization of language-specific cortex utilizing MR-FOCUSS.

OBJECTIVE: To demonstrate noninvasive localization of cognitive cortical areas involved in language processing with magnetoencephalography (MEG) interpreted by multiresolution FOCUSS (MR-FOCUSS), a current density imaging technique. METHOD: MEG data were collected during verb-generation and picture-naming tasks from 18 right-handed control subjects and 24 right-handed patients with epilepsy. RESULTS: The averaged epic data from the verb-generation task, analyzed by MR-FOCUSS, showed initial activation in the left supramarginal gyrus, superior temporal gyrus, and angular gyrus at 239 +/- 31 ms in all subjects, consistent with other language mapping studies. Average amplitude of underlying cortical sources was approximately 452 pAm. The averaged epic data from the picture-naming task, analyzed by MR-FOCUSS, showed activation in the left inferior frontal gyrus (IFG) area starting at 436 +/- 40 ms in all subjects. Average amplitudes of underlying cortical sources were approximately 380 pAm. CONCLUSION: The time course of neuronal language processing can be imaged noninvasively with millisecond resolution by magnetoencephalography using the multiresolution FOCUSS technique.

A prospective study of the incidence of the purple glove syndrome.

PURPOSE: Phenytoin (PHT) has been widely used intravenously for the treatment of seizures since 1956, and for many years, it has been considered first-line therapy for status epilepticus. It is routinely administered intravenously in emergency departments and hospitals for patients who have had isolated seizures and for many patients undergoing neurosurgical procedures who are unable to receive oral medication. Adverse reactions from PHT have been widely studied for years, but in the past decade, new adverse reactions have been identified. One of these adverse reactions is the purple glove syndrome (PGS), characterized by edema, discoloration, and pain distal to the site of i.v. administration of PHT. Because there have been no prospective reports of the incidence of PGS, the objective of the study was to report the incidence of this syndrome. METHODS: We enrolled 179 consecutive exposures to i.v. PHT at Henry Ford Hospital. Distal portions of the upper extremities were examined and digitally photographed by one of the authors (J.G.B.). The photos were blindly evaluated by the third author (G.L.B.) for PGS. Demographic and pertinent medical history was recorded for all patients, and outcome for those who experienced PGS was recorded. Associations between PGS, demographic, and medical history information were assessed. RESULTS: In only three of the 179 exposures did PGS develop. In both patients, the severity of the clinical picture was mild and did not required prolonged hospitalization or specialized treatment. CONCLUSIONS: PGS is an infrequent and mild adverse effect of i.v. PHT administration.

Managing the pharmaceutical industry-health system interface.

BACKGROUND: Direct-to-consumer advertising, media, and Internet marketing to physicians and patients, as well as enticing marketing strategies, are used by the pharmaceutical industry to ensure market share growth of new drugs. Our health system adopted a strict vendor policy governing detailing and sampling activities of pharmaceutical representatives, but realized that further analysis of vendor influence in our system was needed. OBJECTIVE: An assessment of tangible benefits, ethical concerns, and financial liabilities and gains was conducted to reassess the need for further vendor restriction. CONCLUSIONS: Based on our findings, several recommendations have been made. Medical practices and health systems are encouraged to establish and enforce explicit vendor policies, measure their effectiveness, partner proactively with representatives to deliver a drug-detailing message consistent with system initiatives, monitor and regulate continuing medical education funding, and implement strategies to ensure appropriate drug use.

Analysis of MEG signals of spreading cortical depression with propagation constrained to a rectangular cortical strip. I. Lissencephalic rabbit model.

Magnetic fields arising from the rabbit cortex during spreading cortical depression (SCD) were measured in order to study the currents in the neocortex during SCD. SCD was constrained to propagate in a rectangular cortical strip perpendicular to the midline. This simplified in vivo cortical preparation enabled us to correlate magnetoencephalographic (MEG) signals to their underlying currents within the cortical strip. The propagation of SCD was monitored with an array of electrodes placed along the strip. The propagation speed for SCD in the lissencephalic rabbit brain was 3. 5+/-0.3 mm/min (mean+/-S.E.M., n=14). Slow, quasi-dc, MEG signals were observed as the SCD entered into the longitudinal fissure. The currents giving rise to the MEG signals were perpendicular to the cortical surface and directed from the surface to deeper layers of the cortex. A distributed dipolar source model was used to relate the data to the underlying cortical current. The moment of the single equivalent current dipole source was 38+/-9 nA-m (n=17). This study clarified the nature of the cortical currents during SCD in a lissencephalic in vivo preparation.

Analysis of MEG signals of spreading cortical depression with propagation constrained to a rectangular cortical strip. II. Gyrencephalic swine model.

Currents produced during spreading cortical depression (SCD) in a gyrencephalic species (swine) were studied with magnetoencephalography (MEG) and electrocorticography (ECoG). SCD, initiated using electrical stimulation of the cortex, was constrained to propagate within a rectangular cortical strip in order to simplify the interpretation of the underlying currents. The ECoG signals monitored along the strip revealed that SCD propagated from an initiation site on the gyrus at a rate of 7.9+/-3.2 mm/min (n=23), entered the deep coronal sulcus and in most cases emerged from the other side of the sulcus, continuing to propagate across the next gyrus at a rate of 5.9+/-2.7 mm/min (n=22). The apparent propagation velocity within the sulcus was reduced to 1.7+/-0.8 mm/min (n=21). Strong MEG signals were observed as SCD entered the sulcus. The direction of magnetic field was opposite for SCD's on opposite banks of the sulcus. The currents were directed from a superficial layer to deeper layers of the cortex. The characteristics of SCD and associated MEG patterns from a gyrencephalic species may be similar to those in human patients during migraine aura.

Retrospective analysis of the effects of psychotherapeutic interventions on outcomes of psychogenic nonepileptic seizures.

PURPOSE: Uncertainty exists regarding the effectiveness of psychotherapy in patients with psychogenic nonepileptic seizures (PNES). We retrospectively reviewed the outcomes of therapeutic interventions in a cohort of patients with PNES. METHODS: We identified patients with PNES by outpatient video-EEG (VEEG) between 1992 and 1996. We retrospectively analyzed the effects on outcomes of various types of interventions for PNES administered at random, using a structured interview and review of medical records. Patients with subjective events and severe psychosis were excluded. Patients who required inpatient monitoring because the outpatient VEEG was inconclusive were also excluded. RESULTS: One hundred patients were diagnosed with PNES between 1992 and 1996: 61 patients completed the study. The average age was 43.3 years, and 90% were female. Nine (15%) had had PNES <1 year, and 7 (11%) had epilepsy. Eleven of 16 patients (68%) who received five or more counseling sessions, including showing the videotaped recording of the nonepileptic spell (13 of 16) by the comprehensive epilepsy program (CEP) psychotherapist had cessation (7 of 16) or reduction (4 of 16) of their episodes. Eleven of 15 patients (73%) who received only the feedback and care of their CEP neurologists had similar favorable outcome. Twelve of 25 patients (48%) who received counseling by a non-CEP psychotherapist or psychiatrist had cessation (10 of 25) or reduction (2 of 25) of episodes. Five patients who received no feedback or intervention had no improvement (4 of 5) or worsening (1 of 5) of the PNES. CONCLUSIONS: Psychotherapy or feedback provided by CEP professionals with experience in epilepsy and PNES improves outcome and may be superior to other or no interventions.

Intramuscular fosphenytoin (Cerebyx) in patients requiring a loading dose of phenytoin.

Fosphenytoin (Cerebyx), is a water soluble prodrug that is rapidly and completely converted to phenytoin. This study reports the injection-site tolerance and safety of intramuscular fosphenytoin (> 10 mg/kg doses) in 60 patients requiring a phenytoin loading dose. Patients received injections at single or multiple sites with volumes ranging from 4 to 30 ml per injection site. The majority of patients had no irritation (erythema, swelling, tenderness, bruising) or complaints of discomfort related to fosphenytoin injection either after injection (95%) or at follow-up (88%). Irritation, when reported, was mild in all cases. Forty of 60 patients (67%) reported transient side effects, primarily involving the central nervous system, such as nystagmus, dizziness or ataxia, which are commonly associated with phenytoin therapy. All patients received prescribed doses; no patient had an injection(s) stopped due to intolerance or side effects. No serious adverse events occurred with intramuscular fosphenytoin. In this study, intramuscular fosphenytoin was demonstrated to be a safe and well tolerated, and in many instances, a preferable alternative to other means of phenytoin loading.

Oculogyric crisis induced by carbamazepine.

A 32-year-old man with mental retardation and uncontrolled complex partial epilepsy receiving carbamazepine (CBZ) and divalproex sodium (VPA), developed frequent episodes of forced upward gaze after increase in the daily VPA dosage. CBZ dosage was decreased, with prompt resolution of symptoms. The upward gaze problem recurred several months later. CBZ dosage was decreased further with subsequent resolution of symptoms. Therefore, the oculogyric crisis (OGC) appeared to be induced by CBZ.

Efficacy of gadolinium administration in magnetic resonance imaging screening of patients with complex partial seizures and results of a normal neurologic examination.

RATIONALE AND OBJECTIVES: Magnetic resonance imaging has become a standard screening tool in the evaluation of patients with complex partial seizures. This study prospectively addresses the efficacy, if any, of routinely adding gadolinium-enhanced images to routine T2-weighted images in patients with a normal neurologic examination. METHODS: One hundred consecutive patients with electroencephalogram and clinical evidence of complex partial seizures and no other neurologic abnormalities were examined prospectively with axial and coronal T2-weighted spin-echo images, followed by axial and coronal gadolinium-enhanced T1-weighted scans. RESULTS: The scans in 73 patients were interpreted as normal, 14 had nonspecific white matter lesions, 5 had asymmetry of the temporal horns, and 2 had asymmetric signal intensity in the temporal lobes, and the scans in 6 showed abnormal gadolinium enhancement. Of the lesions in the six patients whose scans showed abnormal enhancement, four were seen well on the T2-weighted images. Of the remaining two, one was a small cerebellar venous angioma, and the other, a probable tiny convexity meningioma. One temporal lobe glioma seen on the T2 scans did not enhance with gadolinium. CONCLUSIONS: Routine administration of gadolinium does not appear to be of benefit in imaging patients with complex partial seizures who are otherwise neurologically normal.

Presurgical localization of functional cortex using magnetic source imaging.

The boundaries of somatosensory cortex were localized noninvasively by means of a large-array biomagnetometer in six patients with mass lesions in or near eloquent cortex. The results were used by neurosurgeons and neurologists in preoperative planning and for reference in the operating room. The magnetic source imaging (MSI) localizations from somatosensory evoked potentials were used to predict the pattern of phase reversals measurable intraoperatively on the cortical surface, providing a quantitative comparison between the two measures. The magnetic localizations were found to be predictive in all six cases, with the two sets of localizations falling within an 8-mm distance on average. Somatosensory localizations using MSI offer accuracy in localizing somatosensory cortex stereotactically and in depicting its relationship to lesions. Such data are valuable preoperatively in assessing the risks associated with a proposed surgical procedure and for optimizing subsequent minimum-risk surgical strategy.

Central neurogenic mechanisms of migraine.

Evidence obtained from clinical studies, magnetoencephalography, and 31P magnetic resonance spectroscopy indicates that spreading depression is the underlying basis of migraine aura. Magnetoencephalographic and 31P magnetic resonance spectroscopic evidence also exists to explain interictal central neuronal hyperexcitability in migraine sufferers. A low intracellular brain magnesium concentration may be the link between the physiologic threshold for migraine and the attack itself.

Evidence for multiple generators in evoked responses using finite difference field mapping: auditory evoked fields.

Electric potential maps and magnetic field maps have been used to study brain electrical activity. During the temporal course of an evoked cortical response, the electrical activity of specific neuronal subpopulations change in a sequential manner giving rise to measurable electrical potentials and magnetic fields. For these potentials and fields, both the amplitude and rate of amplitude change have characteristic, time-dependent waveforms. Presently, amplitude waveforms from multiple locations are used to generate magnetic field and electric potential maps which have been found to be useful in understanding the activity of the neurons which give rise to these maps (Romani 1990). This paper introduces a data transformation technique which results in a derived map that we have termed a "finite difference field map" (FDFM). This mapping technique provides information associated with the rate at which the amplitude of the neuronal electric activity changes. In this paper, some advantage of FDFM analysis are illustrated by application of this technique to the study of the auditory evoked cortical field (AECF) N1m waveform. Using data obtained from normal subjects it will be demonstrated that application of the FDFM technique allows the localization of the primary N1m source at an earlier latency than is possible using the conventional waveform data. The source location determined at an early latency by FDFM analysis was identical to that obtained at later from the conventional field data. These data suggest that the primary N1m source is stationary. In addition, analysis of the time sequence of FDFM field maps contains evidence of a second spatially separate source which is co-active with primary N1m source.

NMR spectroscopic and magnetoencephalographic studies in migraine with aura: support for the spreading depression hypothesis.

The authors propose that patients who suffer from migraine with aura have a susceptibility to spontaneous neuronal discharges and subsequent spreading depression. This is based upon a state of central neuronal excitability involving the excitatory neurotransmitter glutamate, in combination with supersensitivity of the N-méthyl-D-aspartate (NMDA) receptor. This hypersusceptibility is supported by increased turnover of high-energy phosphates, low intracellular Mg2+ and large amplitude depolarizing waves on magnetoencephalography (MEG).

Magnetic fields associated with anoxic depolarization in anesthetized rats.

We have performed simultaneous measurements of the DC-magnetoencephalogram (DC-MEG) and DC-electrocorticogram (DC-ECoG) in rats (n = 6) subjected to 90 s of reversible anoxia. The onset of major shifts of electric and magnetic signals occurred at 52 +/- 18 (S.D.) and 68 +/- 14 (S.D.), respectively, and reached a peak at 83 +/- 27 and 102 +/- 19 (S.D.) s, respectively, after termination of mechanical ventilation. DC-ECoG signal deflections were always associated with DC-MEG deflections. The time of onset and peak signals in both DC-MEG and DC-ECoG changes caused by asphyxia were highly correlated (r + 0.83, 0.94; P less than 0.05, 0.001; respectively). Our observations suggest that the non-invasive technique of DC-MEG is reliable and may provide insight into the mechanisms of anoxic cerebral depolarization.

Techniques for DC magnetoencephalography.

DC shifts are known to occur in association with a number of physiologic phenomena including spreading depression, hypoxia, epilepsy, and hypercapnia and possibly in migraine, closed head injury, and ischemia. Magnetoencephalography (MEG) makes it possible to record these shifts by prolonged DC monitoring of brain activity and offers several advantages over DC EEG and DC electrocorticography. Among the advantages of MEG is its non-invasive nature and the lack of impedance changes at the electrode-tissue interface that produce baseline shifts in DC EEG. In DC MEG measurements, great care must be taken in dealing with a variety of artifactual signals. Environmental noise can be reduced by magnetic shielding and recognized by use of reference magnetometers. Patient-generated artifacts are numerous and can be recognized and limited by a variety of methods.