Biomedical subjects

D Hasboun

Publications and source records attributed to D Hasboun.

At least 19 recordsLinked to original sources

PubMed2006

A volumetric MRI study of the hippocampus and the parahippocampal region after unilateral medial temporal lobe resection.

Segmentation guidelines on high-resolution MRI designed to assess remaining volumes of the hippocampus and the parahippocampal cortices after medial temporal lobe (MTL) surgery could provide a useful tool to investigate the involvement of these anatomical regions in surgical outcomes and in human memory. For this purpose, we implemented an MRI volumetric analysis, already applied to healthy population or epileptic patient before surgery, to quantify the volume of the hippocampus, the temporopolar cortex and the regions of the parahippocampal gyrus (perirhinal, entorhinal and parahippocampal cortices) spared after unilateral MTL resection carried out to treat medically uncontrolled temporal lobe epilepsy (TLE). Based on the locations of remaining anatomical landmarks, we quantified the volume of these regions in 24 patients after MTL resection and in 16 control participants. Our results show that (1) mean volumes of these regions contralateral to the epileptic focus were similar to those of normal subjects, (2) volumetric measures obtained from the resected side were much smaller than those from the non-resected side or from normal values and (3) the extent of MTL resection was comparable in right or left MTL surgery. Individual analysis of patients showed that the parahippocampal cortex, as opposed to the other regions, was not systematically removed across patients. As a post-operative MRI-based method, it therefore proves valuable to assess group data as well as to explore differences between individual patients.

Adult↗

PubMed2005

Parkinson disease, brain volumes, and subthalamic nucleus stimulation.

BACKGROUND: High-frequency stimulation of the subthalamic nucleus (STN) is an effective treatment for advanced Parkinson disease (PD). The clinical and preoperative predictive factors of the best postoperative outcome have been identified. Radiologic predictive factors were investigated. METHODS: Forty patients with PD underwent surgery for bilateral STN stimulation. MRI was performed in stereotactic conditions before surgery. Brain parenchyma, caudate nucleus, putamen, pallidum, and red nucleus volumes and the surface of the mesencephalon were measured and normalized as percentages of the intracranial volume. Clinical evaluation was performed 1 month before and 6 months after surgery. RESULTS: The normalized brain parenchyma volume was lower in patients who were older and had a longer disease duration or a lower frontal score and was not predictive of the postoperative outcome. The residual scores for activities of daily living and parkinsonian motor disability were higher in patients with a smaller normalized mesencephalon. The normalized caudate nucleus volume was predictive of the pre- and postoperative levodopa-equivalent dosage. CONCLUSIONS: Brain atrophy is not an exclusion criterion for neurosurgery, indicating that patients' neurologic, psychiatric, and neuropsychological characteristics are the best predictive factors for neurosurgery. The fact that a smaller normalized mesencephalon surface was associated with a lower beneficial effect of the subthalamic nucleus stimulation on the parkinsonian motor disability suggests that the normalized mesencephalon surface is a predictive factor of the postoperative outcome.

Activities of Daily Living↗

PubMed2005

[Chordomas of the base of the skull and upper cervical spine. 100 patients irradiated by a 3D conformal technique combining photon and proton beams].

OBJECTIVE: To define prognostic factors for local control and survival in 100 consecutive patients treated by fractionated photon and proton radiation for chordoma of the skull base and upper cervical spine. PATIENTS AND METHODS: Between December 1995 and August 2002, 100 patients (median age: 53 years, range: 8-85, M/F sex-ratio: 3/2), were treated by a combination of high-energy photons and protons. The proton component was delivered by the 201 MeV proton beam of the Centre de Protonthérapie d'Orsay (CPO). The median total dose delivered to the gross tumour volume was 67 Cobalt Gray Equivalent (CGE) (range: 60-71). A complete surgery, incomplete surgery or a biopsy was performed before the radiotherapy in 16, 75 and 9 cases, respectively. RESULTS: With a median follow-up of 31 months (range: 1-87), 25 tumours failed locally. The 2 and 4-year local control rates were 86.3% (+/-3.9%) and 53.8% (+/-7.5%), respectively. According to multivariate analysis, less than 95% of the tumour volume encompassed by the 95% isodose line (P=0.048; RR: 3.4 IC95% [1.01-11.8]) and a minimal dose less than 56 CGE (p=0.042; RR: 2.3 IC95% [1.03-5.2]) were independent prognostic factors of local control. Ten patients died. The 2 and 5-year overall survival rates were 94.3% (+/-2.5%) and 80.5% (+/-7.2%). According to multivariate analysis, a controlled tumour (P=0.005; RR: 21 IC95% [2.2-200]) was the lonely independent favourable prognostic factor for overall survival. CONCLUSION: In chordomas of the skull base and upper cervical spine treated by surgical resection followed by high-dose photon and proton irradiation, local control is mainly dependent on the quality of radiation, especially dose-uniformity within the gross tumour volume. Special attention must be paid to minimise underdosed areas due to the close proximity of critical structures and possibly escalate dose-constraints to tumour targets in future studies, in view of the low toxicity observed to date.

Adolescent↗

PubMed2004

[Results of salvage stereotactic radiosurgery in 14 patients with grade III or IV gliomas].

AIMS: To determine local control and overall survival rates of 14 patients treated for a grade III or IV glioma relapsing in a previously irradiated area and re-irradiated by stereotactic radiosurgery. PATIENTS AND METHODS: From January 1997 to October 2001, 14 patients (median age 52 Years, age range 49-58 Years, Karnofski performance score 80 to 100) received radiosurgery for a relapse of grade III (3 patients) and or grade IV (10 patients) malignant gliomas. Before relapse, all patients had undergone surgery and had been given with a classical radiation protocol. Median maximum diameter and Volume of the tumors were 38.5mm (24-86mm) and 7cm3 (2-35cm3), respectively. RESULTS: Median maximal dose at the isocenter and median minimal dose at the periphery of the lesion were 21Gy (16-38Gy) and 13Gy (9-17Gy), respectively. Mean follow-up was 8.5 Months (1-29). Median overall survival was 11.6 Months; 6-Month, 1- and 2-Year overall survival rates were 85p.100, 36p.100 and 12p.100, respectively. At univariate analysis, only histological grade was a significant prognostic factor of overall survival (p=0.03). Median disease-free survival was 8.2 Months while 6-Month and 1-Year disease-free survival rates were 69p.100 and 14p.100, respectively. According to univariate analysis, histological grade (p=0.033) and minimal dose delivered at the margin of the target Volume (p=0.02) were prognostic factors for disease-free survival. Two patients developed a symptomatic radionecrosis. CONCLUSION: Radiosurgery of relapsed primitive high-grade brain tumors is efficient and overall survival rates were encouraging.

Brain Neoplasms↗

PubMed2004

Memory for visuospatial location following selective hippocampal sclerosis: the use of different coordinate systems.

This study addressed the role of the medial temporal lobe regions and, more specifically, the contribution of the human hippocampus in memory for body-centered (egocentric) and environment-centered (allocentric) spatial location. Twenty-one patients with unilateral atrophy of the hippocampus secondary to long-standing epilepsy (left, n = 7; right, n = 14) and 15 normal control participants underwent 3 tasks measuring recall of egocentric or allocentric spatial location. Patients with left hippocampal sclerosis were consistently impaired in the allocentric conditions of all 3 tasks but not in the egocentric conditions. Patients with right hippocampal sclerosis were impaired to a lesser extent and in only 2 of the 3 tasks. It was concluded that hippocampal structures are crucial for allocentric, but not egocentric, spatial memory.

Adult↗

PubMed2003

Functional anatomy of the insula: new insights from imaging.

Little is known about the functional anatomy of the insula. Several experimental data suggest that the organization of the insular connections from the different insular cytoarchitectonic regions is related to different functional domains within the insula, and recent electrophysiological and neuroimaging studies have shown the existence of an anterior-posterior organization within the insular cortex. To further investigate this point, we carried out a positron emission tomography (PET) study using fluorodeoxyglucose ((18)F-FDG) in patients with medial temporal lobe epilepsy who experienced emotional or visceral symptoms that are supposed to be elicited in the insula. The aim of our study was to assess the existence of a functional insular somatotopic organization. FDG-PET studies were carried out in 18 epileptic patients. Data were analyzed using statistical parametric mapping (SPM96). The results showed that the emotional symptoms were correlated with hypometabolism in the anterior part of the ipsilateral insular cortex, while visceral symptoms were correlated with hypometabolism in the posterior part ( p=0.001). This neuroimaging study demonstrates that the anterior part of the insular cortex corresponding to the agranular cortex subserves emotional functions while the posterior part of the insular cortex corresponding to the granular cortex subserves ascending visceral symptoms.

Adolescent↗

PubMed2002

[Comparison with dose-volume histograms of two conformal irradiation techniques used for the treatment of T2N0M0 nasopharyngeal cancer, one with association of photons and protons and another with photons alone].

Purpose- There is a relationship between the local control rate of the nasopharyngeal cancer and the total dose delivered within the tumoral volume. In contrast, the relation between the dose and the irradiated volume and the risk of complication is not clearly defined. That is why, in patients presenting with a locally advanced nasopharyngeal cancer, we compared the dose-volume distribution of irradiated tissues, obtained from two 3D conformal irradiation techniques. Patients and methods- Between January 2000 and June 2001, 5 patients, 3 males and 2 females, with a median age of 32 years and presenting with a T4N0M0 nasopharyngeal cancer received a chemoradiotherapy. Radiotherapy combined photons and protons beams and the platin-based chemotherapy was delivered in three intravenous injections at d1, 22, 43 of the irradiation. To calculate the dosimetry, a CT scan and a MRI were performed in all the patients. The gross tumor volume (GTV) was delineated from the imagery, three clinical tumor volumes were defined, the CTV1 was the GTV and the whole nasopharynx, the CTV2 was the CTV plus a 10 mm-margin and the CTV3 was the CTV2 and the nodes areas (cervical and subclavicular). Prophylactic dose within node areas was 44 Gy. Prescribed doses within CTV2 and GTV or CTV1 were 54 Gy/CGE (Cobalt Gy Equivalent, for an EBR = 1,1) and 70 Gy/CGE, respectively. Irradiation was delivered with fractions of 1.8 or 2.0 Gy/CGE, with 44 Gy or 54 Gy by photons and with 16 or 26 CGE by protons. According to dose-volume histograms obtained from the dosimetry planning by protons and photons and from the theoretical dosimetry by photons lonely, for the different volumes of interest, GTV, CTV2, and organs at risk (optic nerves, chiasm, internal ears, brainstem, temporal lobes), we compared the averages of the maximum, minimum and mean doses and the averages of the volumes of organs of interest encompassed by different isodoses.Results- Calculated averages of minimum, maximum and mean doses delivered within GTV were superior for the treatment with combined photons and protons than with photons alone. The average GTV encompassed by the 70 Gy/CGE isodose was larger by 65% with the association compared to photons alone. The conformation ratio (tissue volume encompassed by the 95% isodose/GTV encompassed by the 95% isodose) was 3.1 with the association compared to 5.7 with photons alone. For the CTV2, there were no differences in different criteria according to the both irradiation techniques. For the critical, radiosensitive organs, the comparison of the majority of the criteria was in favour of the association of protons and photons. Overall, 78% of the criteria were in favour of the association.Conclusion- For locally advanced nasopharyngeal cancer without clinical adenopathy, irradiation by photons and protons increases the tumor volume irradiated at the prescribed dose and decreases the volume or critical organs irradiated and the total dose delivered within them.

Adult↗

PubMed2002

Bilateral hemispheric alteration of memory processes in right medial temporal lobe epilepsy.

OBJECTIVE: Functional MRI (fMRI ) was used to investigate right medial temporal lobe epilepsy (RTLE) effects on verbal memory. METHODS: BOLD fMRI data were collected from seven right sided MTLE patients (RTLE) and compared with the data previously acquired from seven left sided MTLE patients (LTLE) and 10 control subjects. Twenty two contiguous images covering the whole brain were acquired using an EPI echoplanar sequence. Subjects were instructed to learn a list of 17 words, and to recall it immediately and at 24 hours interval. Group analyses were performed using SPM96. RESULTS: RTLE patients retrieval performances were significantly impaired as compared with the performance of control subjects. As compared with control subjects and LTLE patients, RTLE patients exhibited a different pattern of hemispheric activations and a global decrease in left hemisphere functional activity. CONCLUSION: MTLE cannot be considered as a model of pure well lateralised hippocampal dysfunction. The verbal memory impairment depicted in RTLE patients may be considered as the witness of a bilateral impairment of the neuroanatomical circuits subserving memory.

Adolescent↗

PubMed2001

Combination of photon and proton radiation therapy for chordomas and chondrosarcomas of the skull base: the Centre de Protonthérapie D'Orsay experience.

PURPOSE: Prospective analysis of local tumor control, survival, and treatment complications in 44 consecutive patients treated with fractionated photon and proton radiation for a chordoma or chondrosarcoma of the skull base. METHODS AND MATERIALS: Between December 1995 and December 1998, 45 patients with a median age of 55 years (14-85) were treated using a 201-MeV proton beam at the Centre de Protonthérapie d'Orsay, 34 for a chordoma and 11 for a chondrosarcoma. Irradiation combined high-energy photons and protons. Photons represented two-thirds of the total dose and protons one-third. The median total dose delivered within the gross tumor volume was 67 cobalt Gray equivalent (CGE) (range: 60-70). RESULTS: With a mean follow-up of 30.5 months (range: 2-56), the 3-year local control rates for chordomas and chondrosarcomas were 83.1% and 90%, respectively, and 3-year overall survival rates were 91% and 90%, respectively. Eight patients (18%) failed locally (7 within the clinical tumor volume and 1 unknown). Four patients died of tumor and 2 others of intercurrent disease. In univariate analysis, young age at time of radiotherapy influenced local control positively (p < 0.03), but not in multivariate analysis. Only 2 patients presented Grade 3 or 4 complications. CONCLUSION: In skull-base chordomas and chondrosarcomas, the combination of photons with a proton boost of one-third the total dose offers an excellent chance of cure at the price of an acceptable toxicity. These results should be confirmed with a longer follow-up.

Adolescent↗

PubMed2001

Radiosurgery for re-irradiation of brain metastasis: results in 54 patients.

PURPOSE: To evaluate in terms of probabilities of local-regional control and survival, as well as of treatment-related toxicity, results of radiosurgery for brain metastasis arising in previously irradiated territory. PATIENTS AND METHODS: Between January 1994 and March 2000, 54 consecutive patients presenting with 97 metastases relapsing after whole brain radiotherapy (WBRT) were treated with stereotactic radiotherapy. Median interval between the end of WBRT and radiosurgery was 9 months (range 2-70). Median age was 53 years (24-80), and median Karnofski performance status (KPS) 70 (60-100). Forty-seven patients had one radiosurgery, five had two and two had three. Median metastasis diameter and volume were 21 mm (6-59) and 1.2 cc (0.1-95.2), respectively. A Leksell stereotactic head frame (Leksell Model G, Elektra, Instrument, Tucker, GA) was applied under local anesthesia. Irradiation was delivered by a gantry mounted linear accelerator (linacs) (Saturne, General Electric). Median minimal dose delivered to the gross disease was 16.2 Gy (11.8-23), and median maximal dose 21.2 Gy (14- 42). RESULTS: Median follow-up was 9 months (1-57). Five metastases recurred. One- and 2-year metastasis local control rates were 91.3 and 84% and 1- and 2-year brain control rates were 65 and 57%, respectively. Six patients died of brain metastasis evolution, and three of leptomeningeal carcinomatosis. One- and 2-year overall survival rates were 31 and 28%, respectively. According to univariate analysis, KPS, RPA class, SIR score and interval between WBRT and radiosurgery were prognostic factors of overall survival and brain free-disease survival. According to multivariate analysis, RPA was an independent factor of overall survival and brain free-disease survival, and the interval between WBRT and radiosurgery longer than 14 months was associated with longer brain free-disease survival. Side effects were minimal, with only two cases of headaches and two of grade 2 alopecia. CONCLUSION: Salvage radiosurgery of metastasis recurring after whole brain irradiation is an effective and accurate treatment which could be proposed to patients with a KPS>70 and a primary tumour controlled or indolent. We recommend that a dose not exceeding 14 Gy should be delivered to an isodose representing 70% of the maximal dose since local control observed rate was similar to that previously published in literature with upper dose and side effects were minimal.

Adult↗

PubMed2001

Is amygdalohippocampectomy really selective in medial temporal lobe epilepsy? A study using positron emission tomography with (18)fluorodeoxyglucose.

PURPOSE: Selective amygdalohippocampectomy (SAH) is a surgical technique effective for the treatment of medial temporal lobe epilepsy, which selectively removes the epileptogenic hippocampus and amygdala but spares the temporal neocortex. However, the benefit of SAH in terms of functional outcome is debated. In this study, we aimed to assess the metabolic consequences of SAH. METHODS: Volumetric magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (PET) studies were performed in nine patients with medial temporal lobe epilepsy associated with hippocampal sclerosis before and after SAH. Regions of interest were delineated on MRIs and then replaced on PET images using an automatic 3D image registration. We calculated absolute metabolic rates of glucose and normalized metabolic values in each region of interest. RESULTS: The comparison between preoperative and postoperative metabolic values showed a statistically significant worsening of the hypometabolism on the ipsilateral temporal pole on the superior and the hippocampal levels (p < 0.05 and 0.0045, respectively). A postoperative increase of the metabolic activity also was noted in the contralateral anterior hippocampus (p < 0.05) and the orbitofrontal cortex bilaterally (p < 0.002 and 0.001, respectively) CONCLUSIONS: SAH functional benefit is controversial. SAH worsened significantly the hypometabolism of a temporal structure that was not surgically removed (i.e., the temporal pole), and it improved postoperatively the metabolic activity in the contralateral hippocampus and the orbitofrontal cortex. Whether this postoperative improvement is linked to the selectivity of the surgical procedure must be further clarified.

Adult↗

PubMed2001

[Use of multimodality imagery in radiotherapy].

The quality of treatment that one can realize today in conformal radiotherapy, can be reached only if one has access to 3D imaging allowing a precise determination of the volume of the organs at risk and of the GTV. For this reason, one has access to anatomical imaging, CT or MRI, and functional and metabolic imaging, PET or SPECT imaging. CT gives the electronic density of the tissues, which is essential to ensure a very precise calculation of dose distribution. Its insufficiency in the visualization of the tumor and some anatomical structures makes necessary the registration of these images with MRI of which distortions are sufficiently weak to be usable in radiotherapy. The registration will be usable only if images of each modality are realized with the patient in treatment position, except for brain, where only CT, on which is based the registration, must be done in treatment position. At least, if one wants to visualize the active parts of a tumor or to make the difference between fibrosis and tumor left or recurrence after radiotherapy or chemotherapy, it is necessary to use PET or SPECT. To define correctly the CTV using these images, one must realize the anatomical localization of the metabolic abnormalities, which they highlight with a registration based on CT or MRI. The difficulties to obtain the registration of these images led the manufacturer to propose mixed machines allowing to realize, at the same time, a CT imaging and a PET or a SPECT imaging with the patient in treatment position.

Diagnostic Imaging↗

PubMed2000

Magnetic resonance-guided stereotactic biopsies: results in 100 consecutive cases.

BACKGROUND: We present the results of 100 consecutive magnetic resonance (MR)-guided biopsies in cases where computerised tomography (CT) guiding was considered dangerous or impossible. METHOD: MR guiding was preferred to CT guiding for cases where lesions were located in the central area, or were not clearly visible on CT scan, or where the visualization of vessels was considered necessary. For most of the patients, calculation of target co-ordinates was performed using dedicated software enabling trajectory previsualization. There were 62 cases of contrast enhanced lesions, 32 cases of lesions without contrast enhancement, and 6 cases of very small lesions appearing hyperintense on T2-weighted images. FINDINGS: Biopsies allowed a histological diagnosis in 92 cases. In 8 cases, the biopsy was negative (necrosis, gliosis or normal brain tissue). Three patients had a transient worsening of their neurological disturbances. Two patient had a non-regressive loss of motor function. No patient died. INTERPRETATION: MR guiding for stereotactic biopsies was effective for CT-invisible or ill-defined lesions, lesions located in functional or densely vascularized areas and in the brain stem. The rate of postoperative complications was equivalent to or less than that reported in series of CT-guided biopsies.

Adult↗

PubMed2000

Hemispheric asymmetry and corpus callosum morphometry: a magnetic resonance imaging study.

Previous post-mortem studies (Aboitiz, F., Scheibel, A.B., Fisher, R.S., Zaidel, E., 1992. Brain Res. 598, 154-161 and Aboitiz, F., Scheibel, A.B., Zaidel, E., 1992. Brain 115, 1521-1541) have shown an inverse association between asymmetry in perisylvian areas and the size of a specific segment, the isthmus, of the corpus callosum (CC) in males. The purpose of this work was to study in vivo the association between hemispheric asymmetry and the total size of the CC in 35 right-handed subjects (16 males, 19 females; mean age 24.9 +/- 3.9). An MRI scan was performed for each subject. The area of the right (RH) and left (LH) hemispheres were measured from images in the sagittal plane and the area of the CC from images in the mid-sagittal plane. The index of hemispheric asymmetry was absolute value((LH - RH)/[(LH + RH)/2]). There was a negative correlation between the absolute value of hemispheric asymmetry and the size of the CC in males (r = -0.55, P = 0.03) but not in females (r = -0.20, P = 0.42). These findings, like those of Aboitiz et al. (Aboitiz, F., Scheibel, A.B., Zaidel, E., 1992. Brain 115, 1521-1541), suggest a sex-dependent decrease in interhemispheric connectivity with increasing hemispheric asymmetry.

Adult↗

PubMed2000

A quantitative study of gamma-band activity in human intracranial recordings triggered by visual stimuli.

This paper studies gamma-band responses from two implanted epileptic patients during a simple visual discrimination task. Our main aim was to ascertain, in a reliable manner, whether evoked (stimulus-locked) and induced (triggered by, but not locked to, stimuli) responses are present in intracranial recordings. For this purpose, we introduce new methods adapted to detect the presence of gamma responses at this level of recording, intermediary between EEG-scalp and unicellular responses. The analysis relies on a trial-by-trial time-frequency analysis and on the use of surrogate data for statistical testing. We report that visual stimulation reliably elicits evoked and induced responses in human intracranial recordings. Induced intracranial gamma activity is significantly present in short oscillatory bursts (a few cycles) following visual stimulation. These responses are highly variable from trial to trial, beginning after 200 ms and lasting up to 500 ms. In contrast, intracranial-evoked gamma responses concentrate around 100 ms latencies corresponding to evoked responses observed on the scalp. We discuss our results in relation to scalp gamma response in a similar protocol [Tallon-Baudry et al. (1996) J. Neurosci., 16, 4240-4249] and draw some conclusions for bridging the gap between gamma oscillations observed on the scalp surface and their possible cortical sources.

Adolescent↗

PubMed2000

Episodic memory in left temporal lobe epilepsy: a functional MRI study.

Left medial temporal lobe epilepsy (MTLE) is associated with verbal memory impairment usually related to hippocampal damage. We used functional MRI (fMRI) to investigate the patterns of functional activity in healthy volunteers and MTLE patients engaged in verbal episodic memory tasks to look for evidence of a reallocation of verbal memory in epileptic patients. fMRI data were collected from seven MTLE patients with left-sided hippocampal sclerosis and 10 healthy right-handed control subjects on a 3T scanner. Subjects were instructed to learn a list of 17 words (encoding) and then to recall them (retrieval) on successive trials. Healthy volunteers and patients both exhibited bilateral activation (right higher than left) of the parahippocampal gyrus during the retrieval. This effect was more marked in the control subjects. In contrast to the control subjects, patients exhibited consistent and extensive left prefrontal activations in all the memory tasks. These findings show that verbal memory tasks did not involve the same functional patterns in patients and healthy volunteers. This may be interpreted as a dysfunctional response due to the epilepsy and left hippocampal sclerosis, and could reflect the early onset and progressive course of the disease.

Adolescent↗

PubMed2000

[MRI of drug-resistant epilepsies: contribution of FLAIR sequence in a series of 150 patients].

We studied the usefulness of the Fluid-Attenuated Inversion-Recovery (FLAIR) pulse sequence for patients with intractable seizures by reviewing the MR images of 150 consecutive patients including a standard imaging protocol and a FLAIR sequence. FLAIR images revealed a cortical lesion in 8 of the 81 patients with no lesion detected on the standard MR imaging protocol. In addition, FLAIR images provided additional informations for 13 patients of the 69 patients for whom a lesion was already detected on the standard MR imaging protocol. Therefore, our results indicated that FLAIR sequences were a useful imaging tool for patients with intractable seizures since it improved the MR diagnosis in 21 of 150 patients (14%).

Adolescent↗

PubMed1999

Is there a negative correlation between explicit memory and hippocampal volume?

The aim of this research was to study the relationship between explicit memory and hippocampal volume. Seventy healthy adults were administered one implicit memory test and one explicit memory (EM) test and underwent magnetic resonance imaging. The major finding was a negative correlation between the EM test and the right hippocampus/brain volume ratio (t = -0.25, P = 0.03) and the left hippocampus/brain volume ratio (t = -0.27, P = 0.02). This finding is not consistent with pathologic findings, which tend to show a relationship between decrease in memory performance and hippocampal atrophy. This discrepancy is discussed.

Adolescent↗