SEARCH · PubMed Health

Results for “Temporal Lobe Resection”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources

PubMed1997

Hippocampal connexin 43 expression in human complex partial seizure disorder.

An increase in the cellular production of gap junction proteins and increased numbers of gap junctions in the neuronoglial syncytium of an epileptic focus have been proposed as a possible mechanism underlying synchronization of discharge. To study this issue, both Northern and Western blot analyses of the gap junction protein connexin 43 mRNA and protein abundance were performed on hippocampal tissue resected from patients presenting with a complex partial seizure disorder arising from the medial temporal area and the hippocampus in particular. Samples from 15 patients with medically intractable seizures were compared to those from 5 nonepileptic patients requiring temporal lobectomy in life-threatening situations. Six of the 15 epileptic patients underwent noninvasive electrographic recording, whereas the remaining 9 patients required intracerebral electrodes for extraoperative recording and therefore showed a more discrete focality than the noninvasive recordings. A decline in the mean levels of connexin 43 mRNA expressed predominantly in astrocytes was noted in the epileptic patient groups, particularly for those cases requiring intracranial electrode placement where ictal onset was more clearly established to be intrahippocampal. Quantitation of connexin 43 protein in both epileptogenic and nonepileptogenic hippocampal tissues showed no significant differences in expression. Although mean values for mRNA showed a decline, clinical outcomes postoperatively showed no correlation with either mRNA or protein expression individually in our epileptic population. The findings indicate that there is effectively no upregulation of mRNA and no increased production of connexin 43 protein in response to the development of epileptogenicity. Rather it appears the influence of gap junctions as a substrate of epileptogenicity in any mechanism(s) underlying synchrony or electrical propagation may be a function of the dynamic state (open versus closed) of the membrane-bound gap junction.

Adult↗

PubMed2000

Dysgenetic mesial temporal sclerosis: an unrecognized entity.

Mesial temporal sclerosis (MTS) is the most frequently encountered lesion in adult patients with intractable temporal epilepsy; it is found in isolation in approximately two-thirds of surgically treated cases. Whereas the exact etiology of MTS is still controversial, several reports suggest that this pathologic lesion is both the cause and the consequence of chronic seizures and develops progressively during childhood secondary to recurrent seizures. In order to evaluate the clinical importance of MTS in children, we retrospectively reviewed the clinical charts of children who underwent surgery for medically intractable temporal epilepsy and report cases presenting an amygdalo-hippocampic dual pathology. Six children aged 1.5-16 years (mean +/- SD: 7.5 +/- 3 years) presenting with partial complex seizures (5 cases) or extension spasms (1 case), with onset from 6 months to the age of 8.5 years (mean seizure onset +/- SD: 3 +/- 5 years) underwent anterior temporal lobectomy including resection of the amygdala and hippocampus. All patients exhibited variable degrees of severity of neuronal loss and gliosis in the amygdala and/or hippocampus. The pathological picture of MTS was not isolated, however. Careful pathological examination has thus shown foci of amygdalo-hippocampic neuronal dysplasia in six patients, with concomitant bilaminated fascia dentata in two cases. Postoperatively, no mortality or morbidity was encountered. After a mean follow-up of 2.5 years, four patients are seizure free. One patient had a 80% rate of improvement in seizure frequency, though still having occasional febrile convulsions. In another patient, complex partial seizures resolved, but rare episodes of absence were still observed. These data are in keeping with the hypothesis that MTS could be secondary to repeated seizures. The analysis of this series of patients could suggest that mesiotemporal dysplastic lesions within the amygdalo-hippocampic structures induce seizures, which, in turn, will favor the development of MTS during childhood. MTS could then lead to synaptic reorganization, which can express abnormal hyperexcitability and result in more recurrent seizures. In this way a vicious circle is set up, which may explain the progression of seizures in some patients.

Adolescent↗

PubMed2000

Intracranial EEG seizure-onset patterns in neocortical epilepsy.

PURPOSE: We investigated neocortical seizure-onset patterns recorded by intracranial EEG with regard to anatomic location, pathologic substrate, and prognostic value for surgical outcome. METHODS: Seizure onset was analyzed in 53 neocortical resective epilepsy surgery patients. Anatomic location was divided into temporal and extratemporal. Pathologic substrate was classified as developmental, mature, and negative or non-specific gliosis. Onset frequency was categorized by visual analysis into tradition EEG frequency bands. Spatial extent was divided into focal (fewer than four contacts) and regional (more than five contacts). Waveform at seizure onset was divided into several types based on their morphology. Onset features were examined with respect to anatomic location, pathologic substrate, and surgical outcome. RESULTS: Seizure-onset frequency was significantly related to spatial distribution and to anatomic location. Extratemporal and regional onset were more commonly in the gamma range, and temporal and focal onset in the beta frequency range or slower. Waveform could be categorized into five different patterns, of which low voltage fast activity (LVFA) was the most common form (57%). LVFA and rhythmic alpha-theta spike activity were more common in developmental than in mature pathology, whereas rhythmic sinusoidal waves at onset were found in only mature substrates. Waveform pattern showed a possible correlation with surgical outcome (p = 0.097): LVFA and rhythmic sinusoidal waves onset patterns were associated with favorable outcome more often (40.4%) than the other three patterns (6.3%). Slow onset suggested poor outcome in the subgroup of developmental pathology (p = 0.062). CONCLUSIONS: Certain electrographic seizure-onset features are associated with specific substrates and outcomes, whereas others reflect the anatomic location and its connections independent of the pathology.

Adolescent↗

PubMed2002

The natural history of Rasmussen's encephalitis.

Rasmussen's encephalitis (RE) is a chronic inflammatory disease of unknown origin, usually affecting one brain hemisphere. In the present study, a comprehensive assessment of the natural history of the disorder is presented. Seizure frequency, degree of hemiparesis and degree of cerebral hemiatrophy in 13 patients with histopathologically proven RE are analysed over the time course prior to resective epilepsy surgery or introduction of long-term immunosuppressive pharmacotherapy. For the assessment of the degree of cerebral hemiatrophy, on defined slices comprising the Sylvian fissure of hard copies of serial MRI investigations, the hemispheric ratio (HR) was determined. The data show an initial prodromal phase with an intermediate frequency of focal onset seizures and mostly no hemiparesis. The occurrence of this stage was mainly observed in the adolescent and adult patients. All patients went through an acute phase with a median duration of 8 months. During this stage, there were frequent simple partial motor seizures, development of hemiparesis and volume loss of the affected hemisphere. After this, the patients passed into a residual stage with a marked decrease in seizure frequency. Twelve months after the onset of the acute stage, the average HR was 0.72. These data allow an estimation of the prognosis of newly affected patients, and demonstrate that most of the brain damage in RE occurs during the first 8-12 months. These findings should be taken into consideration when future therapeutic approaches to RE are evaluated.

Adolescent↗

PubMed1998

Synaptophysin immunohistochemistry densitometry measurement in resected human hippocampus: implication for the etiology of hippocampal sclerosis.

Synaptophysin (SY) is a protein expressed at presynaptic vesicles. SY immunohistochemistry (IHC) was undertaken in surgically resected hippocampal specimens from 25 patients with intractable epilepsy. All were investigated with chronic ictal EEG videotelemetry, which showed a temporal onset in each case, and all had normal magnetic resonance imaging (MRI). The density of reaction product of SY IHC was used to generate optical density (OD) measurements as an estimate of synaptic density in CA1 and CA4 fields (ODCA1 and ODCA4), and inner third and outer two-thirds of the molecular layer of the dentate gyrus (ODIML and ODOML). There was significant correlation between ODCA1 (r=0.619, P=0.001) and ODCA4 (r=0.639, P=0.001) and onset age of epilepsy. There was no correlation between ODCA1 and duration of epilepsy. There was correlation between ODCA4 and duration (r=-0.412, P=0.041), but partial correlations showed no significant correlation between ODCA4 and duration when controlling for onset, although correlation between ODCA4 and onset when controlling for duration remained significant (r=0.536, P < 0.01). Univariate ANOVA revealed onset age to be the only predictor of ODCA1 and ODCA4. Chronological age and duration were not predictors. There was no correlation between ODIML or ODOML and either onset age or duration. ODIML and ODOML were not predicted by onset age, duration or chronological age. These findings support the hypothesis that the major cause of hippocampal sclerosis is an age specific insult rather than the result of repeated seizures.

Adult↗

PubMed2006

Neocortical microenvironment in patients with intractable epilepsy: potassium and chloride concentrations.

PURPOSE: The regulation of extracellular ion concentrations plays an important role in neuronal function and epileptogenesis. Despite the many studies into the mechanisms of epileptogenesis in human experimental models, no data are available regarding the fluctuations of extracellular potassium ([K(+)](o)) and chloride ([Cl(-)](o)) concentrations, which could underlie seizure susceptibility in human chronically epileptic tissues in vivo. METHODS: By using cerebral microdialysis during surgical resection of epileptic foci, the basic [K(+)](o) and [Cl(-)](o) as well as their changes after epicortical electric stimulation were studied in samples of dialysates obtained from 11 patients by ion-selective microelectrodes. RESULTS: The mean basal values of [K(+)](o) and [Cl(-)](o) in all patients were 3.83 +/- 0.08 mM and 122.9 +/- 2.6 mM, respectively. However, significant differences were observed in the basal levels of both [K(+)](o) and [Cl(-)](o) between different patients. Statistically, no correlation was found between basal [K(+)](o) or [Cl(-)](o) and electrocorticogram (ECoG) spike activity, but in one patient, dramatically lowered baseline [Cl(-)](o) was accompanied by enhanced ECoG spike activity. Application of epicortical electrical stimulation increased [K(+)](o) but not [Cl(-)](o) in all cases. According to the velocity as well as spatial distribution of [K(+)](o) reduction to the prestimulation levels, three different types of responses were observed: slow decline, fast decline, and slow and fast declines at adjacent sites. CONCLUSIONS: These data may represent abnormalities in ion homeostasis of the epileptic brain.

Adolescent↗

PubMed1998

Induced expression of NMDAR2 proteins and differential expression of NMDAR1 splice variants in dysplastic neurons of human epileptic neocortex.

Immunocytochemistry was used to study the expressions of glutamate receptor subunit proteins for NMDAR2A/B, NMDAR1 splice variants, and AMPA Glu-R2/3 in human brain resected for intractable epilepsy associated with cortical dysplasia. NMDAR2A/B intensely labeled dysplastic neurons showing staining in both the cell bodies and dendritic profiles. However, nondysplastic neurons were not immunoreactive to NMDAR2A/B. The antibody selective to NMDAR1 splice variants of NR1-1a. -1b, -2a, and -2b labeled dysplastic neurons, but few nondysplastic neurons. In contrast, the antibody to splice variants of NR1-1a, -1b, 2a, -2b, -3a, -3b, -4a, and -4b labeled both dysplastic and nondysplastic neurons. The different labeling patterns by these two antibodies indicate that variants of NMDAR1-3a, -3b, -4a, and -4b are present in nondysplastic neurons. Both dysplastic neurons and nondysplastic neurons were immunoreactive to AMPA GluR2/3, but denser immunoreactivity was observed in dysplastic neurons. We also found that the locations of dysplastic neurons labeled by NMDAR2A/B were related to focal epileptic EEG seizure onsets or spiking and to focal behavioral seizure types. Our results suggest that there is hyperexcitability of dysplastic cortical regions, at least in part, from the presence of NMDAR2 subunits and selectively expressed NMDAR1 splice variants in dysplastic neurons.

Adolescent↗

PubMed2000

Risk factors for unsuccessful testing during the intracarotid amobarbital procedure in preadolescent children.

PURPOSE: Identification of risk factors for unsuccessful testing during intracarotid amobarbital procedure (IAP) in preadolescent children. METHODS: A pediatric IAP protocol was attempted in 42 candidates for epilepsy surgery (5-12 years old; mean, 10 years) based on the ability to pass a practice test. Language dominance was defined by marked asymmetry until first verbal response and paraphasic errors. Intact hemispheric memory was defined by recall of >/=60% of test items. The odds ratios of baseline variables (age at IAP, Full-Scale IQ, side of disease, age at seizure onset, amobarbital dose) were calculated for various IAP outcomes. RESULTS: IAPs were accomplished in 40 children. Language dominance was established in 25 (62.5%) of 40 patients: all 21 focal resection candidates were left language dominant; four hemispherectomy candidates had intact language after injection of the damaged hemisphere. In 12 (30%) of 40 patients, language testing failed because of agitation or obtundation. Compared with the 21 children with language dominance established by bilateral IAP, these 12 children had lower mean Full-Scale IQ (66.4 vs. 87.9; p = 0.014), and more frequently, the epileptogenic lesion in the left hemisphere (presumed dominant by right-handedness; 78 vs. 33%; p = 0.04). Excluding hemispherectomy candidates (intentionally only one injection), memory testing could not be completed in 13 (36%) of 36 children because of obtundation or agitation. These children were significantly younger than the 23 (64%) of 36 with successful bilateral memory testing (mean age, 107.6 vs. 128.7 months; p = 0. 006). The eight (25%) of 32 children with failing retention scores after ipsilateral injection had lower Full-Scale IQ than did the 24 (75%) patients who passed (mean, 59.6 vs. 81.7 months; p = 0.03). CONCLUSIONS: The IAP successfully established hemispheric language dominance and memory representation for just under two thirds of the preselected preadolescent children. Risk factors for unsuccessful testing included low Full-Scale IQ (especially <80), young age (especially <10 years), and seizures arising from the left hemisphere presumed dominant by right-handedness.

Age Factors↗

PubMed2002

Intraoperative radiation therapy (IORT) for previously untreated malignant gliomas.

BACKGROUND: Intraoperative radiation therapy (IORT) is one of the methods used to deliver a large single dose to the tumor tissue while reducing the exposure of normal surrounding tissue. However, the usefulness of intraoperative electron therapy for malignant gliomas has not been established. METHODS: During the period from 1987 to 1997, 32 patients with malignant gliomas were treated with IORT. The histological diagnoses were anaplastic astrocytoma in 11 patients and glioblastoma in 21 patients. Therapy consisted of surgical resection and intraoperative electron therapy using a dose of 12--15 Gy (median, 15 Gy). The patients later underwent postoperative external radiation therapy (EXRT) with a median total dose of 60 Gy. Each of the 32 patients treated with IORT was randomly matched with patients who had been treated with postoperative EXRT alone (control). Patients were matched according to histological grade, age, extent of tumor removal, and tumor location. RESULTS: In the anaplastic astrocytoma group, the one-, two- and five-year survival rates were 81%, 51% and 15%, respectively in the IORT patients and 54%, 43% and 21%, respectively in the control patients. In the glioblastoma group, one-, two- and five-year survival rates were 63%, 26% and 0%, respectively in the IORT patients and 70%, 18% and 6%, respectively in the control patients. There was no significant difference between survival rates in the IORT patients and control patients in either the anaplastic astrocytoma group or glioblastoma group. CONCLUSIONS: IORT dose not improve survival of patients with malignant gliomas compared to that of patients who have received EXRT alone.

Adult↗

PubMed2003

Seizure control and cognitive outcome after temporal lobectomy: a comparison of classic Ammon's horn sclerosis, atypical mesial temporal sclerosis, and tumoral pathologies.

PURPOSE: Neuropathologic examination of resected tissue after anterior temporal lobectomy (ATL) for treatment of complex partial seizures revealed several distinct histologic substrates. Our study examined the relation between neuropathology, seizure control, and cognition in ATL patients and described preliminary profiles to aid in the prediction of outcome. METHODS: Of the 149 patients who underwent ATL from 1980 to 1999, long-term follow-up was available for 145. Specimens from 124 of the 145 patients had histologic findings consistent with one of three diagnoses: classic Ammon's horn sclerosis (cAHS; n = 75), atypical mesial sclerosis (Atypical; n = 21), or low-grade tumor (Tumor; n = 28). The other 20 patients had diverse pathologies that were insufficient for analysis. ATL patients underwent a complete preoperative and 68 underwent a postoperative neuropsychological evaluation. RESULTS: Of the 145 patients, 84% of cAHS, 57% of Tumor, and 29% of Atypical patients had a > or =95% reduction in seizure frequency. Neuropsychological testing suggested that cAHS patients demonstrate more generalized preoperative cognitive impairment than do the Atypical or Tumor patients. The Atypical group recalled significantly less nonverbal material after surgery than did the cAHS or Tumor groups. Stratification by both pathology and surgery side revealed that the right Atypical patients declined more on information processing and set shifting. CONCLUSIONS: Patients with cAHS or Tumor demonstrated better seizure control and fewer declines in cognitive functioning after ATL than did the Atypical patients, highlighting the need to investigate this group as a distinct entity.

Adolescent↗

PubMed2005

Limitations of Wada memory asymmetry as a predictor of outcomes after temporal lobectomy.

BACKGROUND: The intracarotid amobarbital (Wada) test can be used to evaluate hemispheric memory capacity before anterior temporal lobectomy (ATL). Most patients demonstrate better memory with injection ipsilateral to planned resection (expected asymmetry [EA]), but a substantial minority show better memory with contralateral injection (unexpected asymmetry [UA]). Both degree and direction of Wada memory asymmetry (WMA) have been associated with worse surgical outcome in small series. Reports also suggest that UA is associated with greater decline in verbal memory after left ATL (L-ATL). METHODS: The relationship between WMA and surgical outcome (at 3 months, 1 year, and last follow-up) was examined in a large group of ATL patients (108 L, 119 R) with both EA and UA. Also, memory in a subgroup (96 L, 108 R) was examined, comparing subscores of the Rey Auditory Verbal Learning Test obtained preoperatively, at 3 months, and at 1 year. RESULTS: Thirty-six percent of L-ATL and 8% of R-ATL patients had UA. UA was associated with worse surgical outcome at 1 year for R-ATL patients but was not associated with worse outcome for L-ATL patients. There was no correlation between WMA and persistent postoperative verbal memory change for patients with L- or R-ATL. CONCLUSIONS: Unexpected asymmetry is uncommon in patients with right anterior temporal lobectomy (R-ATL) and may be a risk marker of poor surgical outcome. This relationship may be obscured by language confounds in patients with L-ATL. The results suggest that Wada asymmetry (using mixed stimuli) does not predict postoperative verbal memory; it is unclear whether this finding is generalizable to centers using only nonverbal stimuli.

Adolescent↗

PubMed2003

How long does it take for partial epilepsy to become intractable?

BACKGROUND: Much remains unknown about the natural history of intractable localization-related epilepsy, including how long it typically takes before intractability becomes evident. This information could guide the design of future studies, resolve certain discrepancies in the literature, and provide more accurate information about long-term prognosis. METHODS: Individuals evaluated for resective surgery for refractory localization-related epilepsy were prospectively identified at the time of initial surgical evaluation at seven surgical centers (between 1996 and 2001). The latency time between onset of epilepsy and failure of second medication and history of remission (>/=1 year seizure-free) before surgical evaluation were examined with respect to age at onset, hippocampal atrophy, febrile seizures, and surgical site. RESULTS: In the 333 patients included in the analysis, latency time was 9.1 years (range 0 to 48) and 26% reported a prior remission before surgery. A prior remission of >/=5 years was reported by 8.5% of study participants. Younger age at onset was strongly associated with longer latency time (p < 0.0001) and higher probability of past remission (p < 0.0001). In multivariable analyses, age at onset remained as the most important explanatory variable of both latency time and prior remission. CONCLUSIONS: A substantial proportion of localization-related epilepsy may not become clearly intractable for many years after onset. This is especially true of epilepsy of childhood and early adolescent onset. If prospective studies confirm these findings and the underlying mechanisms behind these associations become understood, this raises the possibility of considering interventions that might interrupt such a process and some day prevent some forms of epilepsy from becoming intractable.

Adolescent↗

PubMed2005

Changes in depression and anxiety after resective surgery for epilepsy.

OBJECTIVE: To determine changes in depression and anxiety after resective surgery. METHODS: Data from subjects enrolled in a prospective multicenter study of resective epilepsy surgery were reviewed with the Beck Psychiatric Symptoms Scales (Beck Depression Inventory [BDI] and Beck Anxiety Inventory [BAI]) and Composite International Diagnostic Interview (CIDI) up to a 24-month period. chi2 analyses were used to correlate proportions. RESULTS: A total of 358 presurgical BDI and 360 BAI results were reviewed. Moderate and severe levels of depression were reported in 22.1% of patients, and similar levels of anxiety were reported by 24.7%. Postoperative rates of depression and anxiety declined at the 3-, 12-, and 24-month follow-up periods. At the 24-month follow-up, moderate to severe levels of depression symptoms were reported in 17.6 and 14.7% of the patients who continued to have postoperative seizures. Moderate to severe depression and anxiety were found in 8.2% of those who were seizure-free. There was no relationship, prior to surgery, between the presence or absence of depression and anxiety and the laterality or location of the seizure onset. There were no significant relationships between depression or anxiety at 24-month follow-up and the laterality or location of the surgery. CONCLUSIONS: Depression and anxiety in patients with refractory epilepsy significantly improve after epilepsy surgery, especially in those who are seizure-free. Neither the lateralization nor the localization of the seizure focus or surgery was associated with the risk of affective symptoms at baseline or after surgery.

Adult↗

PubMed1997

Skull base chordomas: a management challenge.

Because of their critical location, invasive nature, and aggressive recurrence, skull base chordomas are challenging and, at times, frustrating tumors to treat. Both radical surgical removal and high-dose radiation therapy, particularly proton beam therapy, reportedly are effective in tumor control and improve survival rates. The authors posit that these tumors are best treated with radical surgery and proton-photon beam therapy. During the last 5 years, they treated 25 patients (15 females and 10 males) who harbored pathologically diagnosed skull base chordomas. The mean age of the patients was 38.4 years (range 8-61 years). Previous surgery or radiation therapy was performed at other institutions in seven and two patients, respectively. The authors performed 33 surgical procedures on 23 patients. Radical removal (defined as absence of residual tumor on operative inspection and postoperative imaging) was achieved in 10 patients; subtotal resection (defined as resection of > 90% of the tumor) was achieved in 11 patients; and partial resection (defined as resection of < 90% of the tumor) was achieved in two patients. Radical surgical removal included not only the excision of soft-tumor tissue, but also extensive drilling of the adjacent bone. Adjuvant therapy consisted of postoperative combined proton-photon beam therapy (given to 17 patients and planned for one patient) and conventional radiation therapy (two patients); three patients received no adjunct therapy. To date, four patients have died. One patient who had undergone previous surgery and sacrifice of the internal carotid artery died postoperatively from a massive stroke; one patient died from adenocarcinoma of the pancreas without evidence of recurrence; and two patients died at 25 and 39 months of recurrent tumor. Permanent neurological complications included third cranial nerve palsy (one patient) and hemianopsia (one patient); radiation necrosis occurred in three patients. Of the 21 patients followed for more than 3 months after surgery, 16 have had no evidence of recurrence and five (including the two mortalities noted above) have had recurrent tumors (four diagnosed clinically and one radiologically). The mean disease-free interval was 14.4 months. A longer follow-up period will, hopefully, support the early indication that radical surgical removal and postoperative proton-photon beam therapy is an efficacious treatment. The use of skull base approaches based on the tumor classification introduced in this paper is associated with low mortality and morbidity rates.

Adolescent↗

PubMed2002

Surgical pathology of drug-resistant partial epilepsy. A 10-year-experience with a series of 327 consecutive resections.

Herein we reviewed the histopathological findings in 327 consecutive surgical specimens from patients with pharmaco-resistant epilepsy (PRE). Three major pathological groups (78.3% of all cases) were identified: Ammon's horn sclerosis (85 cases as an isolated lesion plus 18 as one part of a dual pathology), tumors (94 cases), and malformations (77 cases). Tumors, often associated with cortical dysplasias (CDs), were all of low histological grade and included 61 dysembryoplastic neuroepithelial tumors (DNTs), 29 gangliogliomas, and 4 pleomorphic xanthoastrocytomas (PXAs). Among the malformations were observed 52 CDs, 13 cavernomas, 8 cortical tubers, and 4 cysts. The remaining findings consisted of 16 scars (mostly post-traumatic) and 4 Rasmussen's encephalitis. Fifty-one (15.6%) specimens contained non-specific changes, and histological samples from 215 patients with presurgical implantation of electrodes revealed iatrogenic changes. All these figures are in agreement with the most recent and comparable series, and confirm the high incidence of DNTs that appear clearly as the most common tumoral entity in PRE. Our data also support the hypothesis of a close histogenetic relationship between DNT, ganglioglioma, and PXA, with a putative common origin from pluripotential progenitor CD34 positive cells of the subpial granular layer. As for CDs, our study confirms the clinical relevance of two main subtypes: severe CD (or Taylor's type CD) with neuronal cytomegaly and balloon cells, and non-Taylor's type CDs with a better outcome. Eventually, this series demonstrates that most patients have significant histopathological lesions, among which, aspects that are relevant to the diagnostic surgical pathologist are highlighted [published with a complete image database on CD-Rom].

Adolescent↗

PubMed2006

The subtemporal interdural approach to dumbbell-shaped trigeminal schwannomas: cadaveric prosection.

OBJECTIVE: Successful resection of dumbbell-shaped trigeminal schwannomas via a subtemporal interdural approach requires an understanding of both the anatomy related to the bone dissection of the petrous apex (Kawase's triangle or quadrilateral) and meningeal anatomy. We studied the meningeal anatomy related to this approach and describe the dural incisions and stepwise mobilization. METHODS: Meningeal anatomy around Meckel's cave and porus trigeminus was examined during the subtemporal interdural anterior transpetrosal approach in both sides of 15 cadaveric heads. Histological study of the Meckel's cave region was performed in two cadaveric heads. RESULTS: The Gasserian ganglion and trigeminal roots have two layers of dura propria on their dorsolateral surface: an inner layer from the posterior fossa dura propria that constitutes the dorsolateral wall of Meckel's cave and an outer layer from the dura propria of the middle fossa. The cleavage plane between these two layers continues distally as the cleavage plane between the epineural sheaths of the trigeminal divisions and the dura propria of the middle fossa. This cleavage plane serves as the anatomic landmark for the interdural exposure of the contents of Meckel's cave. The superior petrosal sinus is sectioned at the medial aspect of Kawase's triangle and reflected along with the porus trigeminus roof. CONCLUSION: Understanding the critical meningeal architecture in and around Meckel's cave allows experienced cranial neurosurgeons to develop a subtemporal interdural approach to dumbbell-shaped trigeminal schwannomas that effectively converts a multiple-compartment tumor into a single-compartment tumor. Dural incisions and stepwise mobilization complements our previous description of the bony dissection for this approach.

Cadaver↗

PubMed2006

Reduction of AEDs in postsurgical patients who attain remission.

PURPOSE: Little evidence guides practice regarding the reduction of antiepileptic drugs (AEDs) in individuals who achieve significant periods of remission after resective surgery. METHODS: In a prospective study of 396 individuals who underwent resective surgery for intractable seizures, the impact of reducing AEDs on relapse and predictors of relapse were examined. RESULTS: Of 301 study subjects who attained a 1-year seizure remission after surgery, 129 reduced from two to one or from one to no AEDs after achieving remission, and 162 did not reduce drugs. Ten patients who stopped all AEDs before attaining remission were excluded from analysis. In all, 114 (39%) patients relapsed: 73 (45%) of 162 in the nonreduction group and 41 (32%) of 129 in the reduction group (p = 0.02). Patients who reduced drugs were more likely to have remitted immediately after hospital discharge (p<0.0001). After adjustment for this factor, little or no apparent impact of drug reduction on the rate of relapse was noted [rate ratio (RR), 1.1; 95% CI, 0.72-1.71; p=0.64 for reducing from two to one AED, and RR, 0.85; 95% CI, 0.50-1.45; p=0.56 for reducing from one to no AEDs]. Within the 129 patients who reduced AEDs, only delayed remission after hospital discharge was significantly associated with an increased rate of relapse (RR, 2.26; 95% CI, 1.15- 4.48; p=0.02). Continued auras had a marginally significant association with relapse (RR, 2.06; p=0.07) CONCLUSIONS: Although many relapses in this cohort of postsurgical patients who achieved remission occurred in the context of reducing or completely eliminating AEDs, the risk was no higher than in those who continued AEDs. Randomized studies are needed to test the impact of drug reduction in seizure-free postsurgical patients.

Adult↗

PubMed2003

Desmoplastic infantile ganglioglioma.

BACKGROUND: Desmoplastic infantile gangliogliomas are rare intracranial tumors that mostly occur in the first 2 years of life. They are exclusively supratentorial, generally have a voluminous size, and are partially cystic. Histologically they are characterized by a divergent astrocytic and ganglionic differentiation and a prominent desmoplastic stroma; more primitive cells may be observed, which present a higher number of mitoses and these areas can mimic the features of malignant astrocytomas. Surgery is the treatment of choice. Data available from the literature suggest that no complimentary treatment is needed in cases of complete tumor resection. Chemotherapy is an option in infants with infiltration of eloquent CNS structures and progressive disease after surgery. DIGs have generally a good prognosis: recurrence-free intervals of up to 14 years have been reported and spontaneous disappearance of tumor residuals has also been described. CASE REPORTS ND DISCUSSION:We report two cases of DIGs. The first child underwent a staged partial removal of a huge right fronto-temporo-parietal tumor when she was 2 months old. At that time histological diagnosis was anaplastic astrocytoma and on these grounds she underwent six chemotherapy cycles, with a partial reduction of the tumor residual. When she was 16 months old a new operation and complete removal of the tumor residual was performed; histological diagnosis was DIG. A review of the initial histological samples confirmed this diagnosis. Twenty-two months after surgery no tumor recurrence has been documented. This case is an example of a difficult differential diagnosis, which can lead to incorrect management choices. The second patient was operated on when he was 9 months old for a mostly cystic right temporo-parieto-occipital DIG. At surgery a deep nodule, strictly adherent to the Galen and internal cerebral veins, was not removed. MRI control 9 months after surgery showed the disappearance of the tumor residual. Eleven years after surgery no tumor recurrence has been documented. The history of this patient confirms that tumor residuals do not need complimentary treatment; indeed they do not usually grow and, as in our patient, they can spontaneously disappear.

Astrocytes↗