Hemiplegic migraine during pregnancy: unusual magnetic resonance appearance with SPECT scan correlation.

OBJECTIVE: This article discusses the pathophysiology and implications for treatment of hemiplegic migraine within a case study presentation. BACKGROUND: We evaluated a 31-year-old white woman for hemiplegia in her 36th week of pregnancy. She initially presented with severe headache, dysarthria, lethargy, and left-sided numbness and weakness. Hemiplegic migraine remains a diagnosis made by exclusion; neurologic examination of these patients is localizing, but nonspecific. DESIGN: Magnetic resonance imaging and single photon emission computed tomography scanning were performed on this patient during an exacerbation of headache associated with dense hemiplegia. RESULTS: Magnetic resonance imaging showed a superficial cerebral hemispheric signal abnormality with enhancement. Single photon emission computed tomography scanning confirmed hyperperfusion of that hemisphere. CONCLUSIONS: We believe the imaging evidence in our patient suggests that hemiplegia was caused and sustained by hyperperfusion. This case lends supportive evidence to a primarily vasodilatory mechanism and hyperperfusion as an etiology of the paralysis in such headaches and perhaps migraine with aura.

Indications for treatment of asymptomatic carotid stenosis.

Atherosclerosis of the carotid bifurcation is an observable sign of systemic disease driven by key risk factors and resulting in an epidemic of stroke, myocardial infarction, and vascular death worldwide. Aggressive integrative preventive interventions of controlling hypertension, hyperlipidemia, diabetes mellitus, smoking, systemic inflammation/infarction, depression, and hyperhomocyst(e)imia are needed in the medical management of these high-risk patients. Surgical indications for asymptomatic surgery may be recalled through the acronym CAROTID, which emphasizes knowledge of risk benefit to a particular patient, adequate disclosure, and physician--patient equipoise.

The delay in reporting symptoms of carotid artery stenosis in an at-risk population. The Asymptomatic Carotid Atherosclerosis Study experience: a statement of concern regarding watchful waiting.

OBJECTIVE: To examine whether patients in the Asymptomatic Carotid Atherosclerosis Study reported symptoms of cerebral and retinal ischemia promptly to the investigating team. DESIGN: Cohort study within the Asymptomatic Carotid Atherosclerosis Study, a prospective, randomized, multicenter clinical trial, with a median follow-up time of 2.7 years. SETTING: Thirty-nine clinical sites across the United States and Canada. PATIENTS: Patients with asymptomatic carotid artery stenosis (> or = 60% reduction in diameter) who experienced either a transient ischemic attack (TIA) (n = 115) or stroke (n = 127) during the follow-up period, as verified by an external committee. MAIN OUTCOME MEASURE: Proportion of patients who reported cerebrovascular symptoms to a study nurse or physician within 3 days of occurrence. RESULTS: Thirty-seven patients (32.2%) experiencing TIA and 57 (44.9%) experiencing stroke reported symptoms to the study staff within 3 days of onset. For TIA, there was a statistically significant inverse association between prompt reporting and the amount of time a patient was enrolled in the study before the event occurred (48% with TIA occurring within 6 months vs 9% with TIA after year 3; P = .04). For stroke, there was a statistically significant association between prompt reporting and treatment arm (56% for the surgical vs 38% for the medical group; P = .05). For either TIA or stroke, none of the other factors examined were significantly associated with prompt reporting. CONCLUSIONS: Despite extensive education and reinforcement, fewer than 40% of all first events were reported within 3 days and fewer than 25% were reported in less than 24 hours. Frequent outpatient evaluation of high-risk patients and careful review of symptoms is necessary to determine when asymptomatic carotid artery stenosis has become symptomatic to offer appropriate forms of therapy.

Outcome of severe brain injury: a multimodality neurophysiologic study.

We screened all head-injured trauma patients admitted to Lehigh Valley Hospital during a 2-year period. From 725 screened patients, 69 patients in a coma on the second day after trauma were entered into this study. During the first week, these patients underwent electroencephalography (EEG), evoked potentials, ocular pneumoplethysmography, and transcranial Doppler (TCD) sonography. Clinical examinations were undertaken 2 and 7 days after trauma. Test results were correlated with functional clinical outcome at 6 months. In a multiple regression analysis, EEG was the major independent variable that significantly predicted 6-month outcome based on Glasgow Outcome Scale score. Transcranial Doppler sonography contributed a small additional component. Though EEG was the most significant predictive factor in this neurophysiological battery, it did not add significantly to the predictive power of Glasgow Coma Scale score determined at day 7. These findings suggest that in neurophysiologic testing in this type of patient is not useful in improving predictive outcome data.

Accurate measurement of carotid stenosis. Chaos in methodology.

The methods used for measurement of carotid artery stenosis are not uniform. Witness the chaos that developed when the North American Symptomatic Carotid Endarterectomy Trial (NASCET) group changed its classification system from area to linear measurements only to discover that the European Carotid Stenosis Trial (ECST) used still another angiographic definition of degree of stenosis so that the data from the two studies were not comparable. Fortunately, this has been reconciled by recalculation of the data. In still other studies, using unvalidated ultrasound instruments has made it difficult or impossible to compare results. In part, these problems have been the result of misdirected attempts to amalgamate concepts from Doppler and duplex ultrasound with those of arteriography. The former is more precise and accurate than the latter, yet its methodology is harder to apply and has not been generally distributed. Even such anatomical terms as "carotid bulb" are not standard. Ultrasonographers consider it to be the distal common carotid artery, to vascular surgeons it is the carotid sinus, while still others consider it to be both or neither. The present authors advocate a uniform methodology utilizing duplex ultrasound and predict that it plus magnetic resonance angiography will become the standard by which extracranial carotid artery disease is evaluated in the future.

Internal carotid artery redundancy is significantly associated with dissection.

BACKGROUND AND PURPOSE: Redundant internal carotid arteries have been considered a risk factor in tonsillectomy, adenoidectomy, and surgical treatment of peritonsillar abscess and also a potentially treatable cause of stroke. However, an association between internal carotid artery redundancy and spontaneous dissection has not yet been clearly demonstrated. METHODS: We reviewed, for spontaneous carotid artery dissection, records of all patients admitted to our institution during the period from 1986 through 1992 with the diagnosis of stroke or transient ischemic attack. We also reviewed 108 percutaneous cerebral arteriograms performed between September 1992 and December 1992 for presence of carotid artery redundancies. RESULTS: Thirteen patients exhibited spontaneous dissection. Of these, 8 of 13 (62%) patients and 13 of 20 (65%) internal carotid arteries, viewed to the siphon, had significant redundancies, kinks, coils, or loops. Of 108 consecutive arteriograms of patients without dissection, in which 187 internal carotid arteries were viewed to the siphon, there were 20 (19%) patients and 22 (12%) of 187 vessels with significant redundancy. Five patients in the dissection group and 2 in the nondissection group had bilateral internal carotid artery redundancy (P = .0019 and P = .0001, respectively). CONCLUSIONS: We found a significant correlation between internal carotid artery redundancy and dissection, particularly if redundancy is present bilaterally.

Unilateral supraclinoid internal carotid artery stenosis with moyamoya-like vasculopathy. Noninvasive assessments.

Presented are the results of an extensive noninvasive assessment of supraclinoid internal carotid artery (ICA) stenosis with moyamoya-like vasculopathy in 3 patients with a history of stroke. Five noninvasive criteria for the diagnosis based on magnetic resonance imaging of the brain, and hemodynamic testing using ocular pneumoplethysmography, duplex carotid ultrasound, and transcranial Doppler sonography were established: (1) normal ocular pneumoplethysmography demonstrating no pressure significant stenosis to the level of the ophthalmic artery; (2) abnormal Doppler spectral waveforms showing either no flow or a high-resistance flow pattern for the ipsilateral cervical internal carotid artery; (3) paradoxically low flow velocities for the ipsilateral intracranial (ICA) and middle cerebral artery (MCA), and markedly abnormal high velocities for the contralateral ICA and MCA; (4) decreased ipsilateral MCA vasomotor reactivity; and (5) deep MCA territory ipsilateral subcortical watershed infarction evidenced by magnetic resonance imaging. This report demonstrates that a noninvasive battery of tests may be useful in the early diagnosis and treatment of these patients.

The impact of cardiac index on cerebral hemodynamics.

BACKGROUND AND PURPOSE: Current noninvasive testing allows accurate assessment of cerebrovascular hemodynamics. The cardiovascular influence on the noninvasive assessment of cerebrovascular studies has not been defined. This study was designed to determine the effect of cardiac index (CI) on cerebral blood flow velocities, ocular pulse amplitude, ophthalmic systolic pressure, and ocular blood flow (OBF) as currently estimated by noninvasive laboratories. METHODS: Based on a retrospective study of 181 patients, we prospectively evaluated 45 patients undergoing right heart catheterization for hemodynamic monitoring to correlate the relation between CI, transcranial Doppler sonography, and ocular pneumoplethysmography. Patients with hemodynamic instability, severe carotid stenoses, massive cerebral infarct, or sepsis were ineligible for the study. Simultaneous recordings of systemic blood pressure, ophthalmic systolic pressure, heart rate, ocular pulse amplitude, middle cerebral artery blood flow velocities, and cardiac output were obtained on all patients. OBF was calculated from the heart rate and ocular pulse amplitude. RESULTS: The relation between OBF and CI is expressed by the equation CI = 2.36 + 0.61 x OBF (r = .47, P = .0010). The middle cerebral artery peak systolic velocities and CI had a correlation of .36 (P = .0181). The equation, derived from the linear relation between OBF and CI, was then validated on a sample of 15 patients. With the apparent linear relation between OBF and CI, we used the derived equation to predict CI from OBF. The OBF determination predicted CI within 30% in all patients and within 20% in 53.3% of the patients. CONCLUSIONS: We demonstrated that OBF and middle cerebral artery systolic velocity decrease with diminishing CI. Our findings suggest that CI may be potentially estimated in selected patients by noninvasive assessment of OBF using ocular pneumoplethysmography.

A private practice model for teaching and research activities.

The majority of neurologists in the United States are in fee for service patient management, dividing their time between hospital and office based practice. Many have had subspecialty training or have had research experience. It is our belief that research should be a component of a neurologist's practice. This is particularly true for an assessment of outcome. In order to accomplish this, we have developed a system which includes patient management, teaching, and clinical research, within our fee for service model.

Post traumatic extracranial vertebral artery dissection with locked-in syndrome: a case with MRI documentation and unusually favourable outcome.

A patient with a right vertebral artery dissection occurring after minor head trauma progressed to a massive pontine infarction. An unusually favourable outcome and MRI imaging are discussed.

Duplex ultrasound and ocular pneumoplethysmography concordance in detecting severe carotid stenosis.

Concordance between two independent tests should serve to increase the accuracy of diagnosis. A combination of ocular pneumoplethysmography and duplex ultrasound, which uses high-resolution B-mode imaging plus spectral analysis, was used to evaluate 289 consecutive patients prior to biplane carotid angiography. Where there was concordance, the noninvasive tests predicted the presence or absence of hemodynamically severe carotid stenosis (75% or greater cross-sectional area reduction) with a sensitivity of 96.8%, a specificity of 95.9%, an accuracy of 96.2%, and positive and negative predictive values of 91.0% and 98.6%, respectively. Of the 538 study arteries, only four (0.74%) angiographically severe lesions escaped detection by both noninvasive tests. Sources of diagnostic error for both tests were defined. We believe that the combination of duplex ultrasound and ocular pneumoplethysmography significantly improves the overall assessment of carotid atherosclerosis.

Mechanical injury of peripheral nerves. Fine structure and dysfunction.

In summary we have examined the morphology of the normal peripheral nerve, presented the types of mechanical nerve injury and associated histopathology, and discussed possible mechanisms responsible for symptoms of pain, paresthesiae, and weakness associated with these lesions. Neurapraxia consists of intussusception of axon and myelin through the nodes of Ranvier resulting in prolonged nerve conduction block. Axonotmesis and neurotmesis describe more severe disruptions of nerve fiber architecture, are difficult to distinguish electrophysiologically, and have poorer prognoses for functional regenerative repair. Chronic entrapment lesions consist of telescoping myelin internodes and tapering of the sheaths with bulbous polarization of internodes away from the site of injury. Both acute and chronic lesions chiefly involve large myelinated fibers and both may create neuralgia, although the mechanism by which this occurs is poorly understood. Presently, increasing evidence suggests ectopic impulse generators and ephaptic transmission may be responsible for sensorimotor phenomena in these lesions.

Intracranial metastases due to prostatic carcinoma.

From 1973 to 1982, 189 patients were treated at the Dartmouth-Hitchcock Medical Center for Stage C or D prostatic carcinoma. In eight of these cases (4.2%), there was clinical or pathological evidence for intracranial metastases. The condition of subdural neoplastic spread, not from contiguous bone, was identified in five cases, two of which were suspected before death. Four of these five patients were thrombocytopenic or pancytopenic at the time of the diagnosis. Intraparenchymal brain metastases were identified in six cases. Cerebellar, temporal bone, cavernous sinus, and splenium infiltration by tumor were unusual findings in individual cases. The results of chest x-rays and respiratory status were poor predictors of lung metastases in four of five patients on whom autopsies were performed. This article describes the spectrum of radiographic and pathologic findings of intracranial prostatic carcinoma, and suggests that the likely mechanism of brain metastasis in these cases is by the dural veins and Virchow-Robin spaces.

Middle cerebral artery occlusion with migraine.

A seven-year-old boy with migraine and a family history of hemiplegic migraine is described who, during an exacerbation, developed dysphasia and right hemiparesis. A CT scan showed a hypodense left cerebral lesion. Angiography revealed occlusion of the left middle cerebral artery at its origin. This represents the youngest case of stroke with migraine and, to our knowledge, is the first case report of angiogram-documented middle cerebral occlusion associated with migraine.