Phenotypic expression of benign familial neonatal convulsions linked to chromosome 20.

OBJECTIVES: To determine whether the syndrome of benign familial neonatal convulsions in a large family was linked to markers on chromosome 20q and to study the seizure patterns in affected individuals. DESIGN: A clinical and molecular biologic study of a single large family in which the probands were identical twins with benign familial neonatal convulsions. PATIENTS: Thirteen living affected family members and 27 living unaffected family members were evaluated. RESULTS: Multipoint linkage analysis with use of the chromosome 20q markers CMM6 and RMR6 gave a maximum lod score of 3.13 at theta = 0.063, indicating linkage in this family. Of the 13 affected members, 10 had known neonatal seizures. Four subjects had febrile seizures, of whom only two had known neonatal seizures. Two members had afebrile seizures later, one of whom had not previously suffered neonatal or febrile seizures. CONCLUSION: The phenotypic heterogeneity in this family, with an epilepsy syndrome determined by a single gene, was striking. This suggests that molecular genetic approaches to the common forms of idiopathic epilepsy, involving patients with clinically similar phenotypes from unrelated families, may be inappropriate.

Twin birth is not a risk factor for seizures.

There is a belief that perinatal factors are a major cause of epilepsy. We studied a community-based sample of twins, a group with a marked excess of adverse perinatal events. The observed number of non-twin siblings with seizures did not differ from that predicted by the age-specific cumulative incidence rate of seizures (4.2% at age 10 years) in the twins. The types of epilepsies in the twins were largely benign and self-limited and not those associated with brain damage. Zygosity, birth order, and birth weight did not predict affected status. Within affected sibships, the frequency of seizures in co-twins of dizygotic probands (9%) was not different from the frequency in non-twin siblings (12%) but was much less than the frequency in co-twins of monozygotic probands (38%; p < 0.001), reflecting a major genetic component to certain epilepsies. These data show that twins do not have an increased risk of seizures and strongly suggest that perinatal factors have little bearing on the etiology of the common epilepsies in the community.

Interictal language fluency in temporal lobe epilepsy.

Mild language production difficulties, particularly in confrontation naming, have been documented previously in patients with left temporal lobe epilepsy (LTLE). These difficulties, however, do not seem to be reflected in the conversational speech of these patients. In order to compare speech fluency in patients with left and right temporal lobe epilepsy (RTLE) experimentally, we studied global pause-to-speech ratios in patients with unilateral temporal lobe epilepsy, using cases with primary generalized epilepsy (PGE) as controls. We hypothesized that left-sides cases would exhibit longer pause durations than right-sided cases. Speech samples were elicited by asking subjects to describe five different New Yorker cartoons, with three repetitions of each description. Phonation was converted to graphic output, and pauses between 200 ms and 4000 ms were summated and divided by total phonation time. This measure did not discriminate significantly between the groups, although the LTLE group tended to pause longer than the RTLE or PGE groups. Increased variability in pause duration in the LTLE group during cycle 1 suggested that some individuals with LTLE are vulnerable to disruption when planning demands are high. A post hoc correlational analysis showed that variation in fluency was primarily explained by orthographically-based lexical retrieval, suggesting that individual differences in fluency are related to limitations in a high-level capacity relevant to the production of speech. It is unlikely that such limitations are specific to LTLE.

Monitoring of Tübingen endosseous dental implants by glycosaminoglycans analysis of gingival crevicular fluid.

Glycosaminoglycans (GAG) in gingival crevicular fluid (GCF) samples were determined by cellulose acetate electrophoresis and densitometric scanning. Two GAG bands, hyaluronic acid and chondroitin-4-sulphate (C4S), were detected in GCF from implants, similar to the profile from teeth. High GCF volumes and GAG contents, notably C4S, may reflect postoperative alveolar bone responses, particularly resorption, at different stages of healing and function of successful implants. They may also indicate adverse tissue changes in failing implants. A comparison of crowned implants and matched teeth suggests that the periodontal ligament contributes to the GCF GAG profile. This may be a useful laboratory method of monitoring implants to detect adverse tissue responses at an early stage.

The psychological impact of implant-retained mandibular prostheses: a cross-sectional study.

Investigation of the psychological impact of implant-retained overdentures has demonstrated some positive benefits over traditional prosthetic treatment (ie, conventional complete dentures). The aim of the present study was to determine whether treatment response could be understood by controlling the degree of alveolar ridge resorption present. In a cross-sectional single-wave study by means of a questionnaire, patients who had received implant-retained mandibular dentures were compared with patients who had conventional mandibular dentures. For purposes of comparison, all patients in both groups wore conventional maxillary dentures. From the 87 patients who were invited to complete a postal questionnaire, 76 replies were received (85% response rate). The implant (n = 41) and denture (n = 35) patients were assessed on self-rated symptoms, denture satisfaction, psychological distress, body satisfaction, and self-esteem using standardized scales. All patients had the extent of alveolar bone loss classified according to Cawood and Howell's (1991) system during a clinical examination. The results indicated that the response of patients to implants or dentures was influenced by the degree of bone loss. Patients with extensive resorption who received implants appeared, from a psychological perspective, to receive more benefit than their nonimplant counterparts. Hence, there is some evidence to support the inclusion of clinical measures of alveolar bone loss when considering the psychological impact accruing from implant-based treatments.

Oral rehabilitation with implant-retained prostheses following ablative surgery and reconstruction with free flaps.

Ablative surgery of the oral tissues may result in significant facial deformity, poor oral function, and psychologic detriment. Immediate surgical reconstruction with vascularized free flaps has become increasingly popular, but the oral rehabilitation of these patients with conventional dental prostheses is usually unsuccessful. The results and clinical experiences of treating a group of 17 patients with ablative surgery, immediate reconstruction with free flaps, and restoration with mandibular implant-retained prostheses are presented after follow-up periods of 6 months to 7 years. Most patients expressed a high degree of satisfaction with their prostheses. General principles and guidelines for the provision of this effective treatment modality are discussed.

Reconstructive preprosthetic surgery. I. Anatomical considerations.

When considering preprosthetic surgery of the edentulous jaws, it is important that the clinician fully understands the anatomical consequences of reduction of the residual ridges. Based on a classification of the edentulous jaws, changes in the relationship of the jaws to each other, in muscle relations and function, in the oral mucosa and in facial morphology have been measured relative to the stage of resorption of the edentulous jaws.

A classification of the edentulous jaws.

A classification of the edentulous jaws has been developed based on a randomised cross-sectional study from a sample of 300 dried skulls. It was noted that whilst the shape of the basalar process of the mandible and maxilla remains relatively stable, changes in shape of the alveolar process is highly significant in both the vertical and horizontal axes. In general, the changes of shape of the alveolar process follows a predictable pattern. Such a classification serves to simplify description of the residual ridge and thereby assist communication between clinicians; aid selection of the appropriate surgical prosthodontic technique; offer an objective baseline from which to evaluate and compare different treatment methods; and help in deciding on interceptive techniques to preserve the alveolar process. An awareness of the pattern of resorption that takes place in various parts of the edentulous jaws, enables clinicians to anticipate and avert future problems.

Prosthetic rehabilitation of the atrophic maxilla using pre-implant surgery and endosseous implants.

Pre-implant surgery was carried out in 20 patients with advanced atrophy of the edentulous maxilla, using autogenous bone grafts. Endosseous implants were placed after the initial healing period and these were used to retain removable overdentures. Patients were observed for up to 5 years with 15 of the 105 implants placed being lost and two remaining as sleepers. The resulting implant success rate was 84%. Three patients had to return to conventional dentures while the remaining 17 expressed a high degree of satisfaction with their implant retained prostheses. Pre-implant surgery successfully extends the scope for implant therapy by providing sufficient bone for implant placement. The survival rate of implants in these cases appears promising up to 3 years, although further data is required to confirm the effectiveness of this treatment in the long term. Implant retained overdentures are able to successfully restore both oral function and facial form. The rehabilitation of the atrophic, edentulous maxilla remains difficult and complex, even when using pre-implant surgery and implant retained prostheses.

Prosthetic management of the atrophic mandible using endosseous implants and overdentures: a six year review.

This paper presents the treatment results and experiences gained from a retrospective study of patients treated with the IMZ osseo-integrated implant system and mandibular overdentures. Patients experiencing problems wearing conventional dentures were assessed by the implant team and 65 cases were treated with 154 endosseous implants placed in the edentulous mandible. Two to four implants were placed in each case and in addition some patients have had augmentation of the mandible with hydroxyapatite. The definitive mandibular prostheses were supported by both implants and the residual ridges. A variety of retention systems were utilised, which included different types of bar and clip, stud attachments, and magnets. The patients have been followed up regularly and evaluated after periods of between one and six years. Six implants have failed over this time resulting in a success rate of over 96%. Most patients expressed a high degree of satisfaction with their new overdentures. There was, however, a considerable burden of maintenance care required for the patient group examined. The findings demonstrate that implant retained overdentures offer a highly effective means of oral rehabilitation for the atrophic mandible, restoring both oral function and facial form.

The immediate or delayed replacement of teeth by permucosal intra-osseous implants: the Tübingen implant system. Part 2: Surgical and restorative techniques.

The previous paper emphasised the importance of case selection in determining success in the use of the Tübingen implant system. Adherence to strict clinical techniques has an equally important influence on implant success and failure. This paper describes the surgical and restorative techniques involved in the use of the Tübingen implant and comments on the authors' initial experiences with this system.

The immediate or delayed replacement of teeth by permucosal intra-osseous implants: the Tübingen implant system. Part 1. Implant design, rationale for use and pre-operative assessment.

No single implant system is applicable to all clinical problems which may be treated with implants. Clinicians who wish to develop expertise in the field of dental implantology should decide which clinical situations they wish to treat with implants and then receive an appropriate level of instruction in the use of systems which have been shown, in refereed literature, to be successful in the treatment of such problems. The Tübingen implant system has been in clinical use for more than 13 years, following preliminary basic research and animal studies, and is supported by an extensive literature. It is applicable primarily to the immediate or delayed replacement of individual teeth which are subsequently to be restored with a post crown. It may also be used in other situations, such as in combination with bridge restorations. This is the first of two papers which describe in detail the range of applications, patient selection and assessment, and the surgical and restorative techniques involved in its use.

Vascularized iliac crest with internal oblique muscle for immediate reconstruction after maxillectomy.

The vascularized iliac crest graft with internal oblique muscle as a method of reconstruction after maxillectomy has been used routinely at the Regional Maxillofacial Unit in Liverpool since 1993. Twenty-four consecutive operations have now been done and this paper reports an audit of our experience. An analysis of case-notes was made retrospectively after checking theatre diaries and records. A detailed inspection of the case-notes was undertaken to ascertain the presenting diagnosis, the complications and the outcome in terms of recurrence and disease survival. The type of defect was recorded, as was whether it had been possible to rehabilitate the patient both dentally and facially. At the time of this study 9 patients (38%) had died of their disease leaving 15 surviving. In 13 cases full dental and facial rehabilitation had been achieved or patients were waiting for an implant-retained prosthesis. Donor site problems important enough to be recorded in the notes were minimal, one case of abdominal wall weakness was noted, which required no intervention. The vascularized iliac crest graft with internal oblique muscle offers a complete solution for reconstruction after maxillectomy, providing there has been no sacrifice of the overlying facial skin and oral sphincter. There is sufficient height and depth of bone to maintain a facial profile and the muscle epithelializes to provide an ideal oral and nasal lining. This flap provides a base to enable full dental and facial prosthetic rehabilitation with either implant-retained or conventional prostheses.

A retrospective study of the maintenance requirements associated with implant stabilised mandibular overdentures.

The maintenance requirements of a group of 58 patients, treated with the IMZ osseointegrated implant system and mandibular overdentures were investigated. Prostheses were retained by either bar and clip or separate stud attachments. The patients were followed up regularly for periods of between one and six years. The median number of maintenance procedures required per patient per year varied between 1-5. Detailed examination of the data revealed that a wide range of maintenance procedures was required, including replacement prostheses in 46% of cases. There were some differences related to the retentive elements used for the prostheses.

Validation of a questionnaire for clinical seizure diagnosis.

A detailed questionnaire has been devised for diagnosis of seizure type. It is suitable for administration by trained interviewers, either directly or by telephone. A comparison of physician-based and questionnaire-based diagnoses showed almost perfect agreement in classification of patients into those with seizures of either generalized or focal origin. Substantial to almost-perfect agreement was reached in diagnosis of patients with most individual seizure types. Disagreement in differentiation between simple and complex partial seizures (CPS) probably reflects the limitations of the clinical method rather than of the questionnaire itself. The questionnaire should be of value in large-scaled clinical and epidemiologic studies.

Epilepsies in twins: genetics of the major epilepsy syndromes.

We studied twins to examine the genetics of epilepsy syndromes. We ascertained 358 twin pairs in whom one or both reported seizures. After evaluation, 253 of 358 (71%) had seizure disorders and 105 pairs were false positives. Among the monozygous (MZ) pairs, more were concordant for seizures (48 of 108; casewise concordance = 0.62 +/- 0.05) than among the dizygous (DZ) pairs (14 of 145; casewise concordance = 0.18 +/- 0.04). In 94% of concordant MZ pairs, and 71% of concordant DZ pairs, both twins had the same major epilepsy syndrome. When analyzed according to major epilepsy syndrome, the casewise concordances for generalized epilepsies (MZ = 0.82; DZ = 0.26), both idiopathic (MZ = 0.76; DZ = 0.33) and symptomatic (MZ = 0.83; DZ = 0), were greater than those for partial epilepsies (MZ = 0.36; DZ = 0.05), with intermediate values seen for febrile seizures (MZ = 0.58; DZ = 0.14) and unclassified epilepsies (MZ = 0.53; DZ = 0.18). We conclude that genetic factors are particularly important in the generalized epilepsies but also play a role in the partial epilepsies. The high frequency of concordant MZ pairs with the same major syndrome strongly suggests there are syndrome-specific genetic determinants rather than a broad genetic predisposition to seizures.