Subacute combined degeneration: clinical, electrophysiological, and magnetic resonance imaging findings

OBJECTIVE: Vitamin B12 deficiency is a systemic disease that often affects the nervous system. One of the most prevalent manifestations is subacute combined degeneration (SCD) of the spinal cord. To access the clinical, electrophysiological, and structural abnormalities associated with SCD, a study was conducted in nine patients. METHODS: Clinical, electrophysiological (electroneurography, somatosensory and motor evoked potentials), and MRI evaluations were performed in patients before and after treatment. RESULTS: The most prominent clinical and electrophysiological findings in all patients were dysfunctions of the posterior column. Corresponding hyperintense lesions in the posterior column of the spinal cord were found in two patients by T2 weighted MRI. Damage to the central motor pathway was identified in four patients. Demyelinating neuropathy was present in one patient and axonal neuropathy in four. All patients showed improvement of their symptoms after treatment with cobalamin. Abnormalities of the spinal cord on MRI disappeared early in recovery. Motor evoked potentials and median somatosensory evoked potentials typically normalised after treatment, whereas tibial somatosensory evoked potentials remained abnormal in most patients. CONCLUSIONS: Clinical, electrophysiological, and MRI findings associated with SCD in vitamin B12 deficiency are diverse. Thus vitamin B12 deficiency should be considered in the differential diagnosis of all spinal cord, peripheral nerve, and neuropsychiatric disorders.     

Grouped crises and status epilepticus in complex partial epilepsy

INTRODUCTION: In complex partial crises (CPC) some characteristics of the way in which they occur may be helpful in localizing the focus of origin in the cerebral cortex. Thus, the appearance of any kind of status epilepticus will not predominate depending on the origin of the epileptic focus, but the complex partial state will be rare when the origin is temporal and more frequent when the origin is frontal. The appearance of CPC in a cluster form is, on the other hand, characteristic of crises originating in the frontal lobe. MATERIAL AND METHODS: We review the clinical history of 151 epileptics with CPC, evaluating the way in which the crises appear, together with other clinical data. We define the start of the crisis in a specific lobe, when this was the site of maximum voltage of the epileptic anomaly or of maximum phase opposition. RESULTS: 10% of the patients showed grouping of their CPC; in the remainder the appearance was isolated, 15% showed status epilepticus at some point in their illness. We found a statistical difference when relating this to the anomalous topography of the EEG; between 15% and 42% more patients with status epilepticus were counted when the topography of the anomaly in the EEG was extratemporal. There was also between 37.2% and 76.4% more patients with cluster crises in the cases with an extratemporal focus.     

Spontaneous intracranial hypotension: clinical and magnetic resonance imaging characteristics

OBJECTIVE: To evaluate the antimicrobial susceptibility pattern of oxacillin susceptible (OSSA) and resistant Staphylococcus aureus (ORSA) isolates to other antimicrobial agents that can be used for the treatment of staphylococcal infections. MATERIAL AND METHOD: We evaluated 117 clinical S. aureus isolates from several S?o Paulo hospitals. Clinical isolates from Campinas, SP and from Jo?o Pessoa, PB, were also included. The in vitro susceptibility testing was performed by broth microdilution as described by the National Committee for Clinical Laboratory Standards (NCCLS). The minimum inhibitory concentration (MIC) was evaluated for 24 antimicrobial agents, including beta-lactams, fluoroquinolones, aminoglycosides, glycopeptides, macrolides, lincosamides and streptogramins. Both commercially available and experimental drugs were included in the study. Cross-resistance among fluoroquinolones was evaluated by susceptibility testing 24 isolates to 10 fluoroquinolones. RESULTS: The antimicrobial agents that showed the highest in vitro activity were the glycopeptides, the streptogramin RP-59.500, and the mupirocin (100% susceptibility). Eighty-seven percent of the OSSA and only 38% of the ORSA isolates were susceptible to ciprofloxacin (MIC50 0.25 microgram/mL and > 4 micrograms/mL, respectively). Cross-resistance among fluoroquinolones were noted even for the experimental drugs. Two fluoroquinolones remained active against ciprofloxacin-resistant isolates, clinafloxacin and WIN-57.273. However, the ciprofloxacin-resistant isolates had MICs eight-to 64-fold higher than the ciprofloxacin-susceptible isolates, suggesting that the MICs may continue to increase when these fluoroquinolones become commercially available. CONCLUSION: Our results showed a high rate of antimicrobial resistance among S. aureus from the Brazilian hospitals. Very few drugs can still be used for the treatment of staphylococcal infections.     

Neuron loss localizes human temporal lobe epilepsy by in vivo proton magnetic resonance spectroscopic imaging

Temporal lobe epileptogenic foci were blindly localized in 8 patients with medically refractory unilateral complex partial seizures using noninvasive in vivo proton magnetic resonance spectroscopic imaging (1H-MRSI) with 4-ml effective voxel size. The brain proton metabolite signals in 8 matched normal controls were bilaterally symmetrical within +/- 10%. The hippocampal seizure foci had 21 +/- 5% less N-acetyl aspartate signal than the contralateral hippocampal formations (p < 0.01). The focal N-acetyl aspartate reductions were consistent with pathology findings of mesial temporal sclerosis with selective neuron loss and gliosis in the surgically resected epileptogenic foci. Proton MRSI correctly localized the seizure focus in all 8 cases. By comparison, MR imaging correctly localized 7 of 8 cases and single photon emission computed tomography correctly localized 2 of 5 cases. No lactate was detected in these interictal studies. No significant changes in choline or creatine were observed. In conclusion, 1H-MRSI is a useful tool for the noninvasive clinical assessment of intractable focal epilepsy. These preliminary results suggest that 1H-MRSI can accurately localize temporal lobe epileptogenic foci.     

Anesthetic implications of epilepsy, status epilepticus, and epilepsy surgery

Epilepsy is a clinical paroxysmal disorder of recurring seizures, excluding alcohol or drug withdrawal seizures or such recurring exogenous events as repeated insulin-induced hypoglycemia. Epilepsy has a profound impact on each individual diagnosed with this disease. Seizures have been and are thought to arise as a result of abnormalities in (a) neural circuits, (b) excitation/inhibition balance, (c) potassium, and (d) genetic abnormalities. Therapy for epilepsy is either medical, entailing the use of a variety of antiepileptic drugs, or surgical. An urgent approach to seizure control is indicated when status epilepticus occurs. When all standard therapy fails, general anesthesia can be used to control status epilepticus. Surgery is an option in the treatment of epilepsy and requires extensive preoperative evaluation. The primary concerns for the neuroanesthesiologist anesthetizing the patient with epilepsy are the capacity of anesthetics to modulate or potentiate seizure activity and the interaction of anesthetic drugs with antiepileptic drugs. Proconvulsant and anticonvulsant properties have been reported for nearly every anesthetic. If seizure spikes are to be evoked during seizure surgery, then light anesthesia with a proconvulsant anesthetic is used. Conscious analgesia can be used for awake seizure surgery. However, if electrocorticography is not planned, then a general anticonvulsant anesthetic maintenance regimen is used. The latter technique also may be useful in patients whose anesthetic management is complicated by an incidental history of epilepsy.     

Occurrence, causes and clinical characteristics of status epilepsy in adults

INTRODUCTION: Status epilepticus, particularly grand mal, is one of the gravest and most dramatic conditions in neurology requiring immediate attention. Status epilepticus can occur in epileptic patients, often with higher mortality rates in symptomatic than idiopathic, but also as an initial symptom of a number of neurological and systemic diseases. No data are available on the exact incidence rates of status epilepticus. According to some assessments, 10% of patients have at least one status epilepticus in their lifetime (3,6). The prognosis mostly depends on the main cause, time in which seizures are stopped and age of patients. Latest data available in literature suggest the mortality rate of 2-8%. MATERIALS AND METHODS: We analyzed frequency of hospital admissions, causes and clinical characteristics of status epilepticus in adults. The study was retrospective, based on case histories of epileptic patients from the Intensive Care Unit of the Neurology Clinic in Novi Sad in 1990, 1993 and 1995. Special emphasis was placed on differences in studied parameters between cases confirmed earlier and those with status epilepticus occurring as an initial symptom of some other illness or condition. RESULTS: Number of hospital admissions rose slightly in the interval observed in comparison with total admissions (0.68% in 1990, 1.24% in 1993, and 1.73% in 1995) (Tabs 1 and 2). During 1993, status epilepticus was more frequent in cases confirmed earlier (69%) compared with the years 1990 (56%) and 1995 (43%) (Graf.1). Epileptic patients were younger on the average than nonepileptic ones (Tab. 3). Status epilepticus occurred more often in male patients (Tab. 4). Irregular treatment was the prevailing cause in epileptic patients (Tab 5). Symptomatic status epilepticus was reported higher in 1990 and 1995, and stroke was definitely the predominant cause (Tab 6). Convulsive grand mal status prevailed in all patients (Graf 2). Focal status was a more frequent finding in nonepileptic patients (Graf 3). Every third in 16 patients died in 1993 and every fifth in 23 in 1995 probably due to the acute destructive brain damage rather than the status itself. No deaths occurred in 1990. DISCUSSION: According to research carried out by other authors, half of grand mal status cases occurred in confirmed epileptics (4). In our study the grand mal status was reported in 70.4% cases of epilepsy. Primary cause was abrupt withdrawal of antiepileptic treatment, infections, alcohol abuse and use of convulsive drugs. This is compatible with our results which confirm that grand mal status either primary or with secondary generalization prevail in both groups of patients (7,8,9). In terms of causes of status epilepticus in nonepileptic patients, literature data mainly suggest cerebral trauma, frontal brain tumors, cerebral arteriosclerosis or other vascular disorders and anaphylaxis (4). Our results point to stroke as the major cause of status epilepticus in nonepileptic patients, similar with data presented by Towne (10). There is no data in literature concerning the relation between sex of patients and occurrence of status. In our study status epilepticus occurred more frequently in male patients. CONCLUSION: The grand mal status was the major clinical type of status in all patients and was primarily caused by discontinued or irregular antiepileptic treatment in patients with confirmed epilepsy, and by stroke in nonepileptic patients.     

Medial temporal lobe epilepsy: videotape analysis of objective clinical seizure characteristics

PURPOSE: The syndrome of temporal lobe epilepsy has been described in great detail. Here we focus specifically on the clinical manifestations of seizures originating in the hippocampus and surrounding mesial temporal structures. METHODS: Seizure origin was confirmed in 67 cases by depth EEG recording and surgical cure after mesial temporal resection. RESULTS: Among nonlateralized manifestations, we commonly found oral automatisms, pupillary dilatation, impaired consciousness, and generalized rigidity. Appendicular automatisms were often ipsilateral to the seizure focus, whereas dystonia and postictal hemiparesis were usually contralateral. Head deviation, when it occurred early in the seizure, was an ipsilateral finding, but was contralateral to the seizure focus when it occurred late. Clear ictal speech and quick recovery were found when seizures originated in the non-language-dominant hemisphere, but postictal aphasia and prolonged recovery time were characteristic of seizure origin in the language-dominant hemisphere. CONCLUSIONS: These signs help to define the mesial temporal lobe epilepsy (MTLE) syndrome and often provide information as to the side of seizure origin.     

Torsion of an accessory hepatic lobe in a child: ultrasound, computed tomographic, and magnetic resonance imaging findings

A case of acute epigastric pain resulting from torsion of an accessory hepatic lobe is reported. Sonographic, computerized tomographic, and magnetic resonance findings are illustrated and the surgical management is discussed.     

Myocardial perfusion imaging: clinical experience and recent progress in radionuclide scintigraphy and magnetic resonance imaging

In the past 20 years, radionuclide scintigraphy has proven to be a sensitive clinical tool in the assessment of myocardial perfusion abnormalities. Magnetic resonance imaging may also be used to study myocardial perfusion, but its potential value still has to emerge in the clinical setting. This review addresses the potential and achievements of both methods in clinical cardiology.     

Case report: rapidly progressive neuropathic arthropathy in syringohydromyelia--radiographic and magnetic resonance imaging findings

A rapidly progressive neuropathic shoulder joint in a patient with syringohydromyelia is presented. He developed marked destruction of the shoulder joint over 5 weeks. The MRI findings in the pre- and post-resorptive phases of the arthropathy are presented for the first time. Low signal intensity areas are observed in the medullary cavity of the bone on both T1- and T2-weighted spin-echo images even before the actual resorptive process starts. Additional major findings are the joint effusion and synovial thickening.     

Lateralization of temporal lobe epilepsy based on regional metabolic abnormalities in proton magnetic resonance spectroscopic images

Magnetic resonance spectroscopic imaging (MRSI) is capable of determining the spatial distribution in vivo of cerebral metabolites, including N-acetylaspartate (NAA), a compound found only in neurons. We used this technique in 10 patients with temporal lobe epilepsy (TLE) to determine the location of maximal neuronal/axonal loss or damage and to evaluate the potential of MRSI for presurgical lateralization. Asymmetry of the relative resonance intensity of NAA to creatine was determined for mid and posterior regions of the temporal lobes defined anatomically and also for "metabolic lesions" defined as the regions of maximal abnormality on MRSI. MRSI revealed decreased relative signal intensity in at least one temporal lobe of all patients. Two patients had a widespread reduction in NAA in both temporal lobes. The region of maximal abnormality was usually in the posterior temporal lobe but sometimes in the mid temporal lobe. The side of lowest NAA was ipsilateral to the clinical electroencephalographic lateralization in all patients. Lateralization based on NAA to creatine correlated with the atrophy of amygdala and hippocampus in 8 patients who showed this on magnetic resonance imaging volumetric measurements. MRSI can demonstrate regional neuronal loss or damage that correlates with clinical electroencephalographic and structural lateralization in temporal lobe epilepsy. The ability to identify a region of maximal metabolic abnormality on spectroscopic images may confer greater sensitivity than that available from single voxel methods. The maximal metabolic abnormality may not be located in a voxel defined a priori, and based on anatomical considerations, without knowledge of the distribution of the metabolic abnormality.     

Acute inversion injury of the ankle: magnetic resonance imaging and clinical outcomes

This study was undertaken to compare the clinical and magnetic resonance imaging results of 24 patients who had sustained ligament injuries after acute inversion injury of the ankle. On magnetic resonance imaging, the following lesions were detected: anterior talofibular ligament tear in 23 patients, calcaneofibular ligament lesion in 15, posterior talofibular ligament lesion in 11, interosseous talocalcaneal ligament lesion in 13, cervical ligament lesion in 12, and deltoid ligament lesion in 8. Compared with the clinical outcome at the follow-up study, there was a statistically significant relationship between interosseous talocalcaneal ligament lesion and each of giving way, pain, and limitation of ankle motion; between cervical ligament lesion and both giving way and pain; and between deltoid ligament lesion and giving way (P < 0.05).     

Friedreich's ataxia with retained tendon reflexes: molecular genetics, clinical neurophysiology, and magnetic resonance imaging

Lower limb areflexia is generally regarded as an essential criterion for the diagnosis of Friedreich's ataxia (FRDA). We describe a family with a recessive form of early-onset ataxia in which one member had a phenotype typical of FRDA whereas another, with retained tendon reflexes in the lower limbs, did not have electrophysiologic evidence of the usual severe afferent axonal neuropathy of FRDA. In contrast, somatosensory evoked potentials, eye-movement recordings, and MRI of the head and cervical cord provided results highly suggestive of FRDA in both patients. We performed genetic linkage analysis in this family, using markers tightly linked to the FRDA locus on chromosome 9. Inheritance of identical paternal and maternal genotypes by the affected members, but not by their unaffected siblings, provided supporting evidence that this disorder may result from mutation within the FRDA gene or is tightly linked to the investigated loci on chromosome 9.     

High-altitude cerebral edema evaluated with magnetic resonance imaging: clinical correlation and pathophysiology

CONTEXT: Because of its onset in generally remote environments, high-altitude cerebral edema (HACE) has received little scientific attention. Understanding the pathophysiology might have implications for prevention and treatment of both this disorder and the much more common acute mountain sickness. OBJECTIVES: To identify a clinical imaging correlate for HACE and determine whether the edema is primarily vasogenic or cytotoxic. DESIGN: Case-comparison study. SETTING: Community hospitals accessed by helicopter from mountains in Colorado and Alaska. PATIENTS: A consecutive sample of 9 men with HACE, between 18 and 35 years old, 8 of whom also had pulmonary edema, were studied after evacuation from high-altitude locations; 5 were mountain climbers and 4 were skiers. The control group, matched for age, sex, and altitude exposure, consisted of 3 subjects with high-altitude pulmonary edema only and 3 who had been entirely well at altitude. Four patients with HACE were available for follow-up imaging after complete recovery. MAIN OUTCOME MEASURES: Magnetic resonance imaging (MRI) of the brain during acute, convalescent, and recovered phases of HACE, and once in controls, immediately after altitude exposure. RESULTS: Seven of the 9 patients with HACE showed intense T2 signal in white matter areas, especially the splenium of the corpus callosum, and no gray matter abnormalities. Control subjects demonstrated no such abnormalities. All patients completely recovered; in the 4 available for follow-up MRI, the changes had resolved entirely. CONCLUSIONS: We conclude that HACE is characterized on MRI by reversible white matter edema, with a predilection for the splenium of the corpus callosum. This finding provides a clinical imaging correlate useful for diagnosis. It also suggests that the predominant mechanism is vasogenic (movement of fluid and protein out of the vascular compartment) and, thus, that the blood-brain barrier may be important in HACE.     

Prolonged non-convulsive status epilepticus as an early clinical manifestation of epilepsy in connection with HIV infection--case report with EEG and MRI follow-up]

The non-convulsive status epilepticus (NCSE) is a complication of petit mal epilepsy or epilepsy with temporal lobe seizures. Very rarely it is the primary manifestation of a symptomatic epilepsy. This report is on a 30-year old female inpatient with NCSE as the primary manifestation of symptomatic epilepsy, occurring four years after HIV infection (stage B3 according to the CDC classification) through heterosexual contact. After an initial tonic-clonic seizure, the patient suffered from NCSE for four weeks with diminished consciousness and major cognitive deficits. During this whole time period the EEG showed bilateral synchrone 1-2 Hz spike-wave complexes. After several failed treatment attempts, the NCSE was successfully and permanently treated with a combination of valproic acid and ethosuximide. The cerebrospinal fluid, cranial CT and cranial MRI were completely uneventful with regard to a CNS infection by the HI-virus or other infectious agents. 20 days after the initial symptoms, MRI showed bilateral cortical-subcortical and bilateral hippocampal lesions which stood out as focal edema zones, gradually disappeared completely and occurred in combination with the development of a discrete brain and right sided hippocampal atrophy. The EEG continued to show signs of right-temporal epileptic discharges with tendencies to generalise after 3 months but normalised after 6 months. Epileptic seizures are rarely an initial clinical sign of an infection with the HI-Virus even if no signs of encephalitis is detectable in the cerebrospinal fluid or in the cerebral MRI.     

Relationship between imaging and pathological features and clinical factors in surgical cases of temporal lobe epilepsy]

The advantages of the free TRAM flap over the conventional Tram flap are known. The use of its main pedicle--the deep inferior epigastric system--improves the blood supply, decreasing the risk of skin and fat necrosis. The harvesting of 5-7 cm of muscle, and the preservation of its lateral border decreases the risk of abdominal wall bulge or hernias. Delayed breast reconstructions in patients submitted to radiotherapy were performed by end to side anastomosis between flap vessels and axillary vessels, avoiding the thoracodorsal irradiated vessels, and improving the blood flow. Ten patients were submitted to breast reconstruction by free TRAM flaps. There was one total flap necrosis, and one delayed healing around the periumbilical suture. Neither skin nor fat necrosis were seen. One patient developed an abdominal wall bulge. Two patients presenting tumor metastasis abandoned the plastic surgery outpatient clinic. Two patients refused the nipple-areolar complex (NAC) reconstruction. The outcome of five NAC reconstructions was very good, breasts being symmetrical without an opposite breast operation.     

Magnetoencephalography in partial epilepsy: clinical yield and localization accuracy

The goals of this study were to determine (1) the yield of magnetoencephalography (MEG) according to epilepsy type, (2) if MEG spike sources colocalize with focal epileptogenic pathology, and (3) if MEG can identify the epileptogenic zone when scalp ictal electroencephalogram (EEG) or magnetic resonance imaging (MRI) fail to localize it. Twenty-two patients with mesial temporal (10 patients), neocortical temporal (3 patients), and extratemporal lobe epilepsy (9 patients) were studied. A 37-channel biomagnetometer was used for simultaneously recording MEG with EEG. During the typical 2-3-hour MEG recording session, interictal epileptiform activity was observed in 16 of 22 patients. MEG localization yield was greater in patients with neocortical epilepsy (92%) than in those with mesial temporal lobe epilepsy (50%). In 5 of 6 patients with focal epileptogenic pathology, MEG spike sources were colocalized with the lesions. In 11 of 12 patients with nonlocalizing (ambiguous abnormalities or normal) MRI, MEG spike sources were localized in the region of the epileptogenic zone as ultimately defined by all clinical and EEG information (including intracranial EEG). In conclusion, MEG can reliably localize sources of spike discharges in patients with temporal and extratemporal lobe epilepsy. MEG sometimes provides noninvasive localization data that are not otherwise available with MRI or conventional scalp ictal EEG.     

Epidural spinal infection. Variability of clinical and magnetic resonance imaging findings

STUDY DESIGN: This study evaluates the magnetic resonance characteristics of spinal epidural abscesses and their associated disc space infections. OBJECTIVES: The results were correlated with history, clinical, and laboratory findings to provide guidelines for early and appropriate diagnosis of epidural spinal infections. SUMMARY OF BACKGROUND DATA: Imaging signs of spinal infections have been reported before, but not with special attention to early clinical and imaging findings. METHODS: Thirteen patients (10 men, 3 women; age range, 32-64 years) with progressive sensorimotor deficit were studied. All patients had a neurologic examination after admission and a magnetic resonance imaging scan done within the first 48 hours. In all cases, T1-weighted images before and after administration of gadolinium were obtained. T2-weighted images were acquired in eight cases as well. Ten patients subsequently underwent open surgery; in three cases, a percutaneous biopsy and drainage was performed. RESULTS: Cervical discitis was found in five patients, and thoracic discitis was seen in another five cases. Three patients had an epidural infection without a concomitant discitis. Neurologic and clinical findings varied considerably. Despite clinical signs of spinal cord involvement, a spinal cord lesion was demonstrated only once. Signal change in T2-weighted images may be the first sign of disc space infection. Because a neurologic deficit may occur before any change is visible, follow-up examinations may be required if epidural infection is suspected on clinical grounds. CONCLUSIONS: Magnetic resonance imaging is the appropriate method for diagnostic work-up of progressive neurologic deficit resulting from epidural infection.     

Serendipity in diagnostic imaging: magnetic resonance imaging of the breast

BACKGROUND: Magnetic resonance imaging (MRI) of the breast has been proposed as a noninvasive diagnostic test for evaluation of suspicious ("index") lesions noted on mammography and/or clinical breast examination (CBE). However, women may have incidental ("serendipitous") lesions detected by MRI that are not found on mammography or CBE. To understand better whether or not biopsy procedures should be performed to evaluate serendipitous lesions, we estimated the breast cancer risk for women with this type of lesion. METHODS: A decision analysis model was used to estimate the positive predictive value (i.e., the chance that a woman with a serendipitous lesion has cancer) of MRI for serendipitous lesions in women who had an abnormal mammogram and/or CBE suspicious for cancer (where a biopsy procedure is recommended). We restricted the analysis to data from women whose index lesions were noncancerous and used meta-analysis of published medical literature to determine the likelihood ratios (measures of how test results change the probability of having cancer) for MRI and the combination of CBE and mammography. The positive predictive value of MRI was calculated using the U.S. population prevalence of cancer (derived from registry data) and the likelihood ratios of the diagnostic tests. RESULTS: Under a wide variety of assumptions, the positive predictive value of MRI was extremely low for serendipitous lesions. For instance, assuming sensitivity and specificity values for MRI of 95.6% and 68.6%, respectively, approximately four of 1000 55- to 59-year-old women with serendipitous lesions would be expected to have cancer (positive predictive value = 0.44%, 95% confidence interval = 0.24%-0.67%). CONCLUSION: In women with a suspicious lesion discovered by mammography and/or CBE that is found to be benign, serendipitous breast lesions detected by MRI are extremely unlikely to represent invasive breast cancer. Immediate biopsy of such serendipitous lesions may, therefore, not be required.