Focal cortical dysplasia: neuropathological subtypes, EEG, neuroimaging and surgical outcome

Since the original description by Taylor, the term focal cortical dysplasia has been used to refer to a wide range of alterations of the cortical mantle. More recently, these conditions have been described from neuroimaging, neuropathological and genetic standpoints, generating several classifications. It is widely recognized that these classifications are unsatisfactory. We propose a simplified classification of focal cortical dysplasias based on easily recognized neuropathological characteristics. We retrospectively re-examined histological sections of cortex from 52 of 224 (23%) patients operated on for drug-resistant partial epilepsy in which cortical dysplasia was present but not associated with other brain pathologies except hippocampal sclerosis. Three subgroups were identified: (i) architectural dysplasia (31 patients) characterized by abnormal cortical lamination and ectopic neurones in white matter; (ii) cytoarchitectural dysplasia (six patients) characterized by giant neurofilament-enriched neurones in addition to altered cortical lamination; and (iii) Taylor-type cortical dysplasia (15 patients) with giant dysmorphic neurones and balloon cells (all but two patients) associated with cortical laminar disruption. The patients with architectural dysplasia had lower seizure frequency than those with cytoarchitectural and Taylor-type dysplasia, and the epileptogenic zone was mainly in the temporal lobe. In patients with Taylor-type dysplasia, the epileptogenic zone was mainly extratemporal, and interictal stereo-EEG was distinctive. MRI was unrevealing in 34% of patients, but distinctive signal alterations characterized most patients with Taylor-type dysplasia, while focal hypoplasia with MRI abnormalities was found in architectural dysplasia. Patients with Taylor-type dysplasia had the best outcome, with 75% seizure-free (Engel class Ia) after at least a year of follow-up compared with 50% of cytoarchitectural dysplasia and 43% of architectural dysplasia patients seizure-free. This three-category classification is based on easily recognized histopathological characteristics and avoids complicated terminology, while the distinctive ensemble of other characteristics defines clinically homogeneous groups.

Clinical ictal symptomatology and anatomical lesions: their relationships in severe partial epilepsy

High-resolution imaging techniques can demonstrate anatomic alterations in most patients identified as candidates for surgical treatment of their partial epilepsy. The demonstration of an anatomic lesion is only one step in the presurgical diagnostic procedure, which includes video-EEG and, when necessary, video-stereo-EEG recordings of seizures. A review of the literature shows that the simple removal of the magnetic resonance imaging (MRI)-evident lesion ("lesion-ectomy") reduces but does not completely suppress seizures in a large percentage of patients, especially those with neuronal migration disorders. This phenomenon could, at least in part, be explained by preliminary data (in 33 patients) showing that less than 20% of seizures correspond to a well-localized, intralesional discharge in about 40% of stereo-EEG-investigated patients with at least one intralesional electrode. The authors illustrate some anatomo-electroclinical examples of intraindividual variability of the ictal symptomatology, raising the problem of the decision about the extent of the surgical removal. Recent histologic and immunohistochemical studies have demonstrated several kinds of structural alterations in the stereo-EEG-defined epileptogenic zone, not always overlapping with the MRI-visible lesion. This aspect can further explain some failures of MRI-guided lesionectomies. That relationships between "lesions" and epileptogenic zones may be variable is also suggested by reports of patients who present with multiple lesions (i.e., cavernous angiomas, Bourneville syndrome) and are cured by removal of only one of them.

The success of 6-month stenting in endonasal frontal sinus surgery

The ultimate success or failure of frontal sinus surgical procedures, whether they be endonasal or external, is determined essentially by the rate of restenosis of the frontal sinus outflow tract or neo-ostium postoperatively. Long-term stenting for a period of several months significantly reduces the rate of restenosis, particularly in difficult cases. We retrospectively reviewed the cases of 12 patients who received 21 frontal nasal stents, which were left in place for 6 months. Based on outcomes measures that included endoscopy or radiologic findings and patients' self-evaluations, we conclude that frontal nasal stents that are left in place for 6 months are more effective than stents that are removed earlier. We recommend that this type of management be considered in difficult revision cases and before performing an external operation.

The irony of being Oscar: the legendary life and death of Oscar Wilde

In this second in a series of famous historic personages who suffered from ear disease (see Yardley M, Rutka J. Troy, Mycenae, and the Otologic Demise of Herr Heinrich Schliemann. J Otolaryngol 1998; 27:217-221), we review the life and otology-related death of the legendary playwright Oscar Wilde. In his time, Wilde ridiculed the social hypocrisy of the Victorian age, championed the individual, and pleaded for a more tolerant and forgiving society in his many books, plays, and letters. Very much the acerbic and iconoclastic wit, Wilde's private and later very public affair de coeur with Lord Alfred Douglas, the son of the Marquis of Queensberry, still continues to interest and paradoxically shock our sensitivities. Wilde's ultimate demise from an otogenic bacterial meningitis appears all the more ironic when one considers the role his father, Sir William Wilde, played as one of the founding fathers of modern otology.

Circulating levels of tumour necrosis factor-alpha and its soluble receptors are increased in the blood of patients with amyotrophic lateral sclerosis

An immunologic pathogenesis for amyotrophic lateral sclerosis (ALS) has been recently proposed. We tested the whole tumour necrosis factor (TNF) system in the serum of 51 ALS patients at different stages of the disease and 36 healthy controls. Antigenic TNF-alpha and its soluble receptors (sTNF-Rs), measured by ELISA, were significantly higher in ALS patients than in healthy controls. However, biologically active TNF-alpha, corresponding to the sTNF-Rs-unbound trimeric TNFalpha molecule and assayed by its cytotoxic activity on a sensitive cell line, was similar between ALS patients and healthy controls. Neither antigenic TNF-alpha, bioactive TNF-alpha nor sTNF-Rs correlated with disease severity, disease duration, or weight loss. In conclusion, we reported an activation of the TNF system in ALS. The role of this activation in the pathogenesis of the disease remains elusive.

[What is the value of the Denecke surgical therapy concept in deglutition disorders?]

BACKGROUND

Denecke developed 1957 a surgical strategy consisting of three or four operative steps for rehabilitation of patients with unilateral paralysis of IXth and Xth cranial nerve. These four steps are the following: myotomy of the cricopharyngeal muscle, resection of the paralyzed pharyngeal wall, medialization of the paralyzed vocal cord and fixation of the soft palate to the posterior pharyngeal wall which can be facultative.

PATIENTS AND METHODS

For the first time we have reviewed patients operated on with the Denecke operation in a retrospective study. The surgical results should be analyzed to deduce some parameters for surgical indication.

RESULTS

16 patients were reviewed in regard to nourishment status, situation of tracheostomy, former pneumonias, classification of Miller and Eliachar for aspiration and subjective evaluation. The follow-up was 21 +/- 16 months postoperatively. In 8 cases surgical intervention was successful. In 2 additional cases the results were partially satisfying.

CONCLUSIONS

The surgical procedure of Denecke was successful for improving substantially nourishment and aspiration status of considerably reduced patients in about 50% of the reviewed cases. Preoperative cinematography of swallowing, manometry and an interdisciplinary approach are required to clearly define the indications for surgical intervention.

Experience from a multidisciplinary "dizzy" clinic

OBJECTIVE

To describe the experience of a combined otolaryngology and neurology multidisciplinary clinic in the evaluation, investigation, and management of patients with dizziness.

STUDY DESIGN

Prospective clinical study.

SETTING

Patients were seen in a tertiary referral, multidisciplinary clinic at The Toronto Hospital, University of Toronto, Ontario, Canada.

INTERVENTION

A thorough history, formal otoneurologic examination, and appropriate laboratory investigations were performed. After their assessment, the patient's diagnoses were classified as peripheral, central, psychogenic, or undiagnosed and were then subdivided into specific clinical diagnoses.

RESULTS

The first 812 consecutive patients seen in the multidisciplinary clinic from January 1, 1993 to December 31, 1998 are reported. Five hundred twenty-five (64.7%) patients were found to have a peripheral vestibular cause for their dizziness, 66 (8.1%) had a central cause, 108 (13.3%) had a diagnosis unknown, and 73 (9.0%) were thought to be psychogenic. In 40 (4.9%) patients, a peripheral and central cause were found. More than one type of peripheral disorder was noted in 17.9% of patients with a peripheral vestibular cause for their dizziness, and 12.3% of patients with a central cause for their dizziness had more than one specific type of central nervous system disorder.

CONCLUSIONS

Most patients that were seen in a multidisciplinary clinic had a peripheral vestibular disorder. Central causes of dizziness were relatively uncommon. Serious diseases such as tumor, multiple sclerosis, and encephalitis were rare and unlikely to present with dizziness only. It is important to realize that a patient may have more than one type of disorder accounting for the symptoms, which may represent a spectrum of disease affecting the inner ear.

Research perspectives in cortical dysplasia and associated epilepsies

Our understanding of cortical alterations and related epilepsies has grown enormously in the last decade thanks to the explosion of basic information from laboratory neuroscience combined with advances in diagnostic tools, therapeutic approaches and surgical techniques. In the present paper, we briefly review the most important advances in these fields from the point of view of the clinician concerned with cortical malformation-related epilepsies. We propose that a highly effective way forward, expected not only to widen knowledge of the basic mechanisms of seizure generation, but also to improved the management of patients, would be to promote interdisciplinary research programmes on resected human cortex that involve neurosurgeons, neurologists and laboratory neuroscientists.

Evaluation of the dizzy patient: experience from a multidisciplinary neurotology clinic

In 1993 a multidisciplinary neurotology clinic was established at the Toronto Hospital, University of Toronto, where patients with symptoms of dizziness were assessed by both otolaryngologists and neurologists. The results from the first 400 patients seen in consultation are described. The disease pathologies identified in this patient population with dizziness showed some significant differences from other published series, which we believe reflects the specialized tertiary nature of referrals to this clinic. A model for the collaborative investigation of the dizzy patient is provided consistent with the current trend towards multidisciplinary approaches in medicine.

Quantitative electroencephalography in amyotrophic lateral sclerosis

OBJECTIVES

The authors evaluated quantitative EEG (QEEG) in patients with amyotrophic lateral sclerosis (ALS), in order to see if the confined cortical degeneration found in anatomical and functional examinations of central (rolandic) regions could give rise to abnormalities of cortical electrical activity.

MATERIAL AND METHODS

Eighteen patients with ALS were compared with 14 control subjects comparable for age and sex. The QEEG analysis was blind to the clinical data. Frequency analysis of 30 EEG epochs, each of 2.6 s duration, was performed.

RESULTS

QEEG in ALS patients showed a significant well-localized decrease of alpha activity only in the central regions, while theta and delta relative power did not show any difference from controls.

CONCLUSION

We suggest that QEEG is able to show evidence of subtle EEG changes probably due to loss of cells in the somatomotor cortex selectively affecting the generator sites.

[Clinical characteristics critical for patients "recovered" after surgical treatment for temporal lobe epilepsy]

We analyse subjective and objective clinical manifestations, in 33 patients, among the 63 with "pure" temporal lobe epilepsy, for which we obtained at least a video-EEG or video-stereo-EEG ictal recording. We compared video-EEG recordings (103 seizures, mean 3.9; min 1, max. 23) and video-stereo-EEG recordings (77 seizures, mean 3.2; min 1, max. 13) with anamnestical data, in order to define the degree of reliability of patient and relatives reports. Overall agreement between anamnestic and video-recorded informations is excellent for subjective symptoms, and fairly good for objective signs. Subjective manifestations (reported in 90.1% of this group) are described in detail as well as the objective ones, these latter split divided into early and late manifestations.

[EEG video recording]

We analyse EEG data from video-EEG recordings of 24 patients, selected among the 63 with "pure" temporal lobe epilepsy. As to interictal EEG features, 62.5% of patients show a less regular background activity on the affected side, in 70% of patients slow waves are either localised or lobar, while in 58% are spikes. Slow waves and spikes have the same well-defined localisation in 37.5% of the patients. Ictal recordings show an initial EEG pattern with high localising value (low-voltage fast activity, flattening or slow waves interruption) in 74/121 seizures (61%). Five out of these 24 patients were operated on without invasive recordings on the basis of ictal video-EEG data. In the 19 patients left, video-EEG ictal informations were used for the planning of the stereo-EEG exploration.

[Surgical treatment of temporal lobe epilepsy: reality and prospectives]

This chapter provides a synthetic overview of the topics treated in this issue. Presurgical diagnostic procedures are schematically described and an analysis of surgical results is made in comparison with those obtained from other epilepsy surgery groups. Surgical complications linked both to invasive presurgical diagnostic procedures and therapeutic surgical acts are described. Finally, the creation of new epilepsy surgery centres is suggested on the basis of epidemiological data, which demonstrate the discrepancy among the patients operated on at present and those who could benefit from the surgical treatment.

Motor evoked potentials and disability in secondary progressive multiple sclerosis

BACKGROUND

To investigate the mechanisms underlying disability in multiple sclerosis (MS), 40 patients with the relapsing-remitting form of the disease and 13 patients with secondary progressive MS underwent multimodal evoked potential (EP), motor evoked potential (MEP), and spinal motor conduction time evaluation. Clinical disability was evaluated by the expanded disability status scale (EDSS) and functional system scales. In secondary progressive MS patients, magnetic resonance imaging (MRI) was used to obtain a semiquantitATive estimate of the total lesion load of the brain.

RESULTS

Spinal motor conduction time was significantly longer in secondary progressive MS patients than controls (p < 0.001) and relapsing-remitting MS patients (p < 0.05), but did not differ between relapsing-remitting patients and controls. Spinal motor conduction times also correlated directly with EDSS scores (p < 0.001) and pyramidal functional system scores (p < 0.001). Brain lesion load (4960.3 +/- 3719.0 mm2) and the total number of lesions (67.7 +/- 37.0) in secondary progressive MS did not correlate with disability scores. For the following EPs, the frequencies of abnormalities were significantly higher in secondary progressive MS patients than relapsing-remitting patients: visual evoked potentials (p < 0.05), somatosensory evoked potentials and upper limb motor evoked potentials (p < 0.01), and brainstem auditory evoked potentials, lower limb somatosensory evoked potentials and lower limb motor evoked potentials (p < 0.001).

CONCLUSIONS

These findings suggest that disability in secondary progressive MS patients is mainly due to progressive involvement of corticospinal tract in the spinal cord.

Conjugal amyotrophic lateral sclerosis: toxic clustering or change?

We describe a southern Italian couple, married for 28 years, who developed amyotrophic lateral sclerosis (ALS) within 30 months of each other. They had drunk water taken from an artesian well for nearly thirty years. Samples of the water were investigated in the search for heavy metals and pesticides using high performances liquid chromatography, gas chromatography and absorption spectrometry. No heavy metals, pesticides or known environmental toxic substances were found in significant concentration. This would seem to support the view that conjugal ALS in Caucasians is due to mere coincidence.

[Color Doppler sonography of peripheral and cerebral fetal vessels in comparison as prognostic criterion in predicting intrauterine distress]

Doppler sonography of the fetal descending aorta, renal artery, middle cerebral artery and umbilical artery in a population of 74 fetuses with a abdominal circumference below the fifth percentile of the reference limits were done. All fetuses were free from structural and chromosomal abnormalities. The pulsatility- and the resistance indices as well as the ratios between these indices from peripheral and cerebral vessels were calculated and correlated to the fetal distress. The measurement of the pulsatility index of the middle cerebral artery provided the best results in predicting the development of fetal distress. Better results were achieved by the use of ratios of pulsatility-indices of various vessels than by the examination of the vessels alone. Our results suggest the usefulness of the examination of the middle cerebral artery and their ratios compared to the renal artery.

[Efficacy of high-frequency cinematography in diagnosis of dysphagia]

Dysphagia is a common symptom in clinical practice. Due to the broad spectrum of underlying diseases many disciplines are involved in the therapy and diagnosis of dysphagia, where radiology plays a central role. The radiologist is confronted with different diagnostic problems and has to choose the most appropriate type of investigation. In many cases no organic disorder can be demonstrated by clinical examination, endoscopy or conventional radiological techniques. In this setting cineradiography is an outstanding tool for finding functional or structural changes in the swallowing chain. This study underlines the efficiency of cineradiography in the diagnosis of dysphagia.

Color flow mapping of the middle cerebral artery in 23 hydrocephalic fetuses

Color flow mapping was performed on 23 fetuses with hydrocephaly. The measurements on the middle cerebral artery posed no problem. We found end-diastolic frequencies in all cases. The pulsatility-indices were raised in only 4 cases. Color Doppler sonography gave no extra information about diagnosis or prognosis.

Metaanalysis of prophylactic drug treatment in the prevention of postoperative bleeding

Prophylactic drug treatment is one of several strategies to reduce postoperative blood loss and potentially limit homologous blood use in open heart surgery. A computerized MEDLINE search supplemented with manual bibliography reviews was performed for randomized clinical trials published in peer-reviewed English-language journals from January 1980 to June 1993. A metaanalysis was conducted of trials evaluating desmopressin (group DD, n = 13), epsilon-aminocaproic acid or tranexamic acid (group EA, n = 4), and aprotinin (group AP, n = 16). Eligible studies used placebo controls and administered the drug in a prophylactic manner. The primary study end point was postoperative chest tube loss (mL, mean +/- standard deviation). There was a significant reduction in postoperative chest tube loss detected for each of the active treatments versus the placebo (DD versus controls: percent reduction 0.11, p = 0.0021; EA versus controls: percent reduction 0.30, p < 0.0001; and AP versus controls: percent reduction 0.36, p < 0.0001). Therapy with EA or AP was associated with a greater reduction in chest tube loss than DD (EA versus DD, p = 0.0033, and AP versus DD, p < 0.0001). Secondary study end points were transfusion requirements, chest reexploration, and perioperative mortality. The volume of postoperative red cell transfusion (mean +/- standard deviation) was reduced with EA (p < 0.0001) or AP treatment (p < 0.0001) compared with a placebo or DD, whereas the proportion of patients given transfusions was limited only in the AP-treated patients (odds ratio 0.23; 95% confidence interval, 0.16 to 0.33; p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Normal values of color Doppler ultrasound in pregnancy]

In addition to the flowmetrie of aorta fetalis and a. umbilicalis, color flow mapping enables the examination of the renal and middle cerebral arteries in the assessment of the fetal blood circulation. The resistance and pulsatility-indices of aorta fetalis, umbilical artery, renal artery and middle cerebral artery were calculated in a prospective examination of a normal study group of 123 pregnant women. Moreover, ratios were established from the pulsatility-indices of renal artery and aorta fetalis, renal artery and umbilical artery, middle cerebral artery and aorta fetalis, middle cerebral artery and umbilical artery. By the use of these ratios, we hope to detect more reliably changes in the fetal blood circulation.

[Brain sparing autoregulation of fetal circulation in HELLP syndrome--demonstrated by Doppler ultrasound findings]

In a case report of severe placental insufficiency in the HELLP-Syndrome with diastolic reverse flow in aorta and umbilical artery, the changes of flow in the renal artery and middle cerebral artery were demonstrated. A preferential perfusion of fetal brain at the expense of fetal kidneys was shown during fetal hypoxia.

Juvenile myoclonic epilepsy of Janz: clinical observations in 60 patients

We studied 60 patients with juvenile myoclonic epilepsy (JME). There was a high positive family history for epilepsy (33.3%). Age at onset of epilepsy ranged from 4 to 18 years with an average of 13.9 years. 88.3% of patients were seizure-free. The most effective drug was valproate. In eight patients drug withdrawal was attempted but all patients relapsed during a follow-up period of 1 year. Video-EEG studies were performed in eight newly diagnosed patients; myoclonic jerks were recorded in five patients.

Intrauterine growth in the offspring of epileptic mothers

The present paper concerns the fetal growth of 315 newborns of epileptic mothers prospectively followed from the beginning of pregnancy. In comparison with Italian standards, neonatal weight, length and head circumference at birth were below the 10th percentile in respectively 15.7%, 1.1% and 19.2% of the newborns. Weight at birth was above the 90th percentile in 8 cases. Observed frequencies were significantly higher than expected frequencies for both weight and head circumference. The percentage of newborns with a small head circumference increased significantly according to the number of drugs taken by the mother during the first three months of pregnancy: 7.1% with no drug, 16.8% with one drug, 23.6% with two drugs and 50% with three drugs. A statistically significant correlation was found between gestational age-adjusted head circumference and drug-level scores during the first trimester. Head circumferences below the 10th percentile were fewer among newborns treated with CBZ than among newborns treated with either PB or VPA.

[Possible factors affecting dilatation of maternal kidney calices in pregnancy]

In a retrospective analysis we examined several factors in regard to the dilatation of the renal calyces during pregnancy in a normal group of 187 pregnant women between 8 and 42 weeks of pregnancy. The dilatation of the calyceal system was more frequent in case of preceded pyelonephritis, in primipara and bipara, and in younger pregnant patients. We found a significant increase of the dilatation with progress of pregnancy.

[Ultrasonography of pregnancy-induced dilatation of maternal kidney calices in a normal patient sample]

To examine the physiological changes of the calyceal system during pregnancy, we selected a normal group of 187 pregnant women by anamnestic, clinical, ultrasonic and laboratory findings. The sonographic investigation of renal pelvis, renal calyces and ureters revealed a more frequent and more pronounced dilatation of the right side. The dilatation was more marked as expected by literature. The complete involution post partum occurred mostly during the first ten days. Even after marked dilatations, a parenchymal reduction could not be found.

Regional differences in pigeon optic tract, chiasm, and retino-receptive layers of optic tectum

Electron-microscopic examination of the pigeon optic chiasm, tract, stratum opticum, and retino-receptive layers of the optic tectum revealed regional differences at each level. Axonal size in the fiber pathways paralleled that previously reported for pigeon optic nerve, with mean diameter values of 0.96 micrometer for optic chiasm and 1.06 micrometer for optic tract. The dorsolateral aspects of these pathways contained a heterogeneous population of fibers (mean diameter congruent to 1.44 micrometer) similar to that found in the nasal portion of optic nerve, while the ventromedial regions were occupied by a more homogeneous population of smaller fibers (mean diameter congruent to 0.82 micrometer) resembling those observed in the temporal portion of the nerve. The retino-receptive layers of anteroventral optic tectum (avT) differed ultrastructurally from those of posterodorsal tectum (pdT) with respect to the thickness of horizontal dendrites in layer 2-3, the size of optic terminals in layers 2-7, and the number of synaptic contacts per terminal. These findings point towards a regional variation in the processing of visual information throughout the retino-tectal system and suggest that neurons in avT vs. pdT should show differences in the way they modify the neurophysiological characteristics of their respective optic inputs.