Biomedical subjects
Frederick Andermann
Publications and source records attributed to Frederick Andermann.
Epilepsy and motor vehicle driving--a symposium held in Québec City, November 1998.
BACKGROUND: This report summarizes an invitational symposium on epilepsy and Canadian laws governing motor vehicle driving held in Québec City in November 1998. METHODS: Invited neurological experts from Canada, the USA, and Europe; and representatives of provincial and territorial licensing bodies, the Canadian Council of Motor Transport Administrators, the Canadian Medical Protective Association, and the Canadian Medical Association participated. An edited version of transcribed audiotapes was prepared. Specific issues discussed were whether or not a physician should be required to report a patient with epilepsy to the licensing authority (mandatory reporting), the nature and quantification of the risks posed by epileptic drivers, and what would be a reasonable law regulating driving by people with epilepsy in Canada. RESULTS: The consensus among medical experts was that mandatory reporting should be abolished in Canada and that a 6-12 month seizure-free period was appropriate before most patients could return to driving private cars. Experts also believed that these standards should be uniform across Canada. There was strong disagreement with the recommendation of the Canadian Medical Association that all such drivers be reported to provincial licensing authorities even in provinces without mandatory reporting rules. CONCLUSIONS: Physicians should be familiar with and follow the rules regarding epilepsy and driving in the provinces where they practice. Nevertheless, current evidence is against mandatory physician reporting of drivers with epilepsy and the neurologists recommended that this be abolished throughout Canada. Shorter seizure-free intervals should also be considered before resuming driving of private cars.
Status epilepticus presenting in a patient with neurosyphilis and a previously asymptomatic arachnoid cyst.
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Subcortical band heterotopia (SBH) in males: clinical, imaging and genetic findings in comparison with females.
Subcortical band heterotopia (SBH) or double cortex syndrome is a neuronal migration disorder, which occurs very rarely in males: to date, at least 110 females but only 11 in males have been reported. The syndrome is usually associated with mutations in the doublecortin (DCX) (Xq22.3-q23) gene, and much less frequently in the LIS1 (17p13.3) gene. To determine whether the phenotypic spectrum, the genetic basis and genotype-phenotype correlations of SBH in males are similar to those in females, we compared the clinical, imaging and molecular features in 30 personally evaluated males and 60 previously reported females with SBH. Based on the MRI findings, we defined the following band subtypes: partial, involving one or two cerebral lobes; intermediate, involving two lobes and a portion of a third; diffuse, with substantial involvement of three or more lobes; and pachygyria-SBH, in which posterior SBH merges with anterior pachygyria. Karyo typing and mutation analysis of DCX and/or LIS1 were performed in 23 and 24 patients, respectively. The range of clinical phenotypes in males with SBH greatly overlapped that in females. MRI studies revealed that some anatomical subtypes of SBH, such as partial and intermediate posterior, pachygyria-SBH and diffuse bands with posterior predominance, were more frequently or exclusively present in males. Conversely, classical diffuse SBH and diffuse bands with anterior predominance were more frequent in females. Males had either mild or the most severe band subtypes, and these correlated with the over-representation of normal/borderline intelligence and severe mental retardation, respectively. Conversely, females who had predominantly diffuse bands exhibited mostly mild or moderate mental retardation. Seven patients (29%) had missense mutations in DCX; in four, these were germline mutations, whereas in three there was evidence for somatic mosaicism. A germline missense mutation of LIS1 and a partial trisomy of chromosome 9p were identified in one patient (4%) each. One male each had a possible pathogenic intronic base change in both DCX and LIS1 genes. Our study shows that SBH in males is a clinically heterogeneous syndrome, mostly occurring sporadically. The clinical spectrum is similar to that of females with SBH. However, the greater cognitive and neuroradiological heterogeneity and the small number of mutations identified to date in the coding sequences of the DCX and LIS1 genes in males differ from the findings in females. This suggests other genetic mechanisms such as mutations in the non-coding regions of the DCX or LIS1 genes, gonadal or somatic mosaicism, and finally mutations of other genes.
Factors predictive of suboptimal seizure control following selective amygdalohippocampectomy.
OBJECT: Selective amygdalohippocampectomy (SelAH) is used in the treatment of mesial temporal lobe epilepsy (MTLE). The goal of this study was to determine factors predictive of poor postoperative seizure control (Engel Class III or IV) following SelAH. METHODS: A retrospective study was conducted of 27 patients with poor seizure control postoperatively (Engel III/IV group), in comparison with 27 patients who were free from seizures after surgery (Engel I/II group). The results of electroencephalography, magnetic resonance (MR) imaging, and pathological studies were reviewed, and volumetric MR image analysis was used to compare the extent of the mesial structures that had been resected. In 56% of patients in the Engel III/IV group, significant bitemporal abnormalities were displayed on preoperative EEG studies, compared with 24% of patients in the Engel I/II group (p < 0.05). An analysis of preoperative MR images disclosed five patients (19%) in the Engel III/IV group and no patient in the Engel I/II group with normal hippocampal volumes bilaterally. Thirteen patients in the Engel III/IV group subsequently underwent either extension of the SelAH (six cases) or a corticoamygdalohippocampectomy (seven patients). Three patients from the former and one patient from the latter subgroup subsequently became seizure free (four patients total [34%]). The remaining nine patients did not improve despite the fact that they had undergone near-total resection of mesial structures. CONCLUSIONS: The majority of patients receiving suboptimal seizure control following SelAH did not meet the criteria for unilateral MTLE, based on EEG, MR imaging, and/or histopathological studies. These patients were therefore unlikely to benefit from additional resection of mesial structures. With the benefits of modern imaging, and by strict adherence to selection criteria, SelAH can be predicted to yield excellent postoperative seizure control for nearly all patients with unilateral MTLE. There remains a subpopulation, however, that meets the criteria for MTLE, but does not become free from seizure following SelAH.
Ulcerative colitis, status epilepticus and intractable temporal seizures.
Three patients with ulcerative colitis (UC) and without any other risk factors, developed intractable status epilepticus de novo. Intractable temporal lobe seizures followed and were investigated 7-19 years later. Two had bi-temporal abnormalities and catastrophic memory loss and the third, severe temporoparietal damage. Status occurred in the context of steroid taper, fasting and abdominal surgery respectively, and it is unlikely that it was merely due to coincidence. Encephalitis or vasculitis were suspected in all cases, but without evidence; metabolic factors may have been present. Status epilepticus in UC may lead to catastrophic sequelae.
Temporal pole and mesiotemporal epilepsy: introductory remarks.
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Severe Amnesia in Epilepsy: Causes, Anatomopsychological Considerations, and Treatment.
Severe amnesia in epileptic patients is a catastrophic condition that may be due to different etiologies. Because of the striking findings and thorough neuropsychological studies of Patient H.M., the literature has focused on postsurgical occurrence of such memory impairment, with much less emphasis on other causes. Here we summarize, for comparison, the history of H.M. We report five patients with pronounced memory loss who had extensive neuropsychological and electroencephalographic testing. MRI was also performed in four of the patients, MRI volumetric measurements of amygdala and hippocampal formation in three, and measurements of entorhinal cortex in two. The amnesia occurred after head trauma in one patient, following encephalitis in one, after partial status epilepticus in two, and after unilateral surgical resection in a woman with bilateral lesions. On the basis of these studies it was impossible to distinguish the role of recurrent temporal lobe epileptic seizures as distinct from underlying lesions in the genesis and course of the memory loss. We review here the anatomical substrate, neuropsychological, and other investigations and the etiological factors leading to the amnesia in these patients, together with current concepts regarding possible causes of such severe memory dysfunction. In patients with this degree of severity of memory deficit, temporal resection in an attempt to control seizures did not lead to a measurable increase in memory problems. It also, however, did not bring about worthwhile improvement in seizure control.
Pseudoseeing Is Pseudobelieving. To the Editor.
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