Bernard Giusiano

Craniopharyngioma in children: Marseille experience

ObjectivesThe management of craniopharyngioma in children represents a challenging problem. If radical excision is recommended by many authors as the initial treatment, in some cases, particularly in recurrent tumours, other methods (gamma knife surgery and intracystic bleomycin) can be very useful. Even if craniopharyngioma is a benign tumour, recurrences are frequent, and the aim of our study was to analyse our results, to try to determine some prognostic factors of recurrences and to discuss about a new strategy concerning the initial management of these tumours.MethodsForty-seven children with craniopharyngioma were treated in the Department of Pediatric Neurosurgery. All of the patients, but five children treated by intracystic bleomycin, underwent a surgical resection of the tumour as initial treatment with the goal of achieving gross total removal (GTR) of the tumour. Two children had radiotherapy and gamma knife treatment, respectively, following surgery for a tumoural residue. All the children had a magnetic resonance imaging (MRI) study 3 months after surgery to evaluate the results of the initial treatment. Using statistical analysis, some prognostic factors (age, sex, location, aspect, size of the tumour and result of the first MRI) have been studied.ResultsForty-two children were operated on, but one died in the immediate postoperative period from a major stroke due to carotid spasm. GTR, defined as the absence of residue on the first MRI control, was achieved in 27 children (65.8%), but 7 patients (25.9%) presented recurrence. Subtotal removal (STR) was obtained in 14 children (34.2%), but 9 patients (64.3%) developed a recurrence defined as the growth of the residual tumour with or without clinical symptoms. Five children having a small- or moderate-size cystic craniopharyngioma were treated using one-stage (three cases) or two-stage (two cases) intracystic bleomycin and any presented recurrence. All the prognostic factors studied, except one (presence of a residue on the first MRI control), do not have a statistical significance.ConclusionCraniopharyngioma in children remains a formidable tumour, and regardless of whatever progress made in their management, the incidence of recurrences is still elevated and severe sequelae can be observed. There are no prognostic factors among those studied concerning the recurrences of these tumours except the quality of the exeresis confirmed by the first postoperative MRI.

Frontal lobe seizures: From clinical semiology to localization

Frontal lobe seizures are difficult to characterize according to semiologic and electrical features. We wished to establish whether different semiologic subgroups can be identified and whether these relate to anatomic organization.

Optic Aphasia: Evidence of the Contribution of Different Neural Systems to Object and Action Naming*

Visual stimulus naming was studied in a 66-year-old male patient with optic aphasia subsequent to left occipito-temporal infarction. While having difficulty in naming objects perceived visually, he was able to name objects by viewing gestures illustrating their use, and to name actions shown in pictures. These results suggest that naming performance depends on the kind of stimulus that is visually presented (object vs. action). The present findings lend support to congnitive models which postulate the existence of visual and functional semantic systems.

Category specificity in object agnosia: preservation of sensorimotor experiences related to objects

We report a case of semantic agnosia, characterized by category specificity. Object recognition, mainly involving visual representation, was severely impaired, whereas object recognition involving both visual and sensorimotor representations, was relatively well preserved. His ability to recognize gestures and produce appropriate gestural responses to objects was remarkable. These two factors lead the authors to form a hypothesis, in an attempt to explain the mechanisms involved in object recognition. It has been argued that manipulation of an object may give access to a certain amount of knowledge about it, and that preservation of sensorimotor experiences of objects might be important in recognizing some of them. This could account for the category specificity, described in object agnosia.

Separate visual pathways for perception of actions and objects: evidence from a case of apperceptive agnosia

Recognition of different kinds of visual stimuli was studied in a patient who acquired apperceptive visual agnosia after a bilateral occipitotemporal lesion which partially spared the primary visual cortex. Impairment in recognising static objects perceived visually sharply contrasts with the relatively well preserved ability to recognise objects from gestures illustrating their use, and to recognise actions shown in line drawings. It is suggested that the occipitoparieto-frontal pathway is involved in the recognition of actions, and in the recognition of objects when sensorimotor experience is evoked.

Seizure-onset patterns in focal cortical dysplasia and neurodevelopmental tumors: Relationship with surgical prognosis and neuropathologic subtypes.

The study of intracerebral electroencephalography (EEG) seizure‐onset patterns is crucial to accurately define the epileptogenic zone and guide successful surgical resection. It also raises important pathophysiologic issues concerning mechanisms of seizure generation. Until now, several seizure‐onset patterns have been described using distinct recording methods (subdural, depth electrode), mostly in temporal lobe epilepsies or with heterogeneous neocortical lesions.

Anti–tumor necrosis factor alpha therapy (adalimumab) in Rasmussen's encephalitis: An open pilot study

Rasmussens encephalitis (RE) is a severe chronic inflammatory brain disease affecting one cerebral hemisphere and leading to drug‐resistant epilepsy, progressive neurologic deficit, and unilateral brain atrophy. Hemispherotomy remains the gold standard treatment but causes permanent functional impairment. No standardized medical treatment protocol currently exists for patients prior to indication of hemispherotomy, although some immunotherapies have shown partial efficacy with functional preservation but poor antiseizure effect. Some studies suggest a role for tumor necrosis factor alpha (TNF‐α) in RE pathophysiology.

High‐frequency oscillations are not better biomarkers of epileptogenic tissues than spikes

High‐frequency oscillations (HFOs) in intracerebral EEG (stereoelectroencephalography; SEEG) are considered as better biomarkers of epileptogenic tissues than spikes. How this can be applied at the patient level remains poorly understood. We investigated how well HFOs and spikes can predict epileptogenic regions with a large spatial sampling at the patient level.

Difference in imaging biomarkers of neurodegeneration between early and late-onset amnestic Alzheimer’s disease

Neuroimaging biomarkers differ between patients with early-onset Alzheimers disease (EOAD) and late-onset Alzheimers disease (LOAD). Whether these changes reflect cognitive heterogeneity or differences in disease severity is still unknown. This study aimed at investigating changes in neuroimaging biomarkers, according to the age of onset of the disease, in mild amnestic Alzheimers disease patients with positive amyloid biomarkers in cerebrospinal fluid. Both patient groups were impaired on tasks assessing verbal and visual recognition memory. EOAD patients showed greater executive and linguistic deficits, while LOAD patients showed greater semantic memory impairment. In EOAD and LOAD, hypometabolism involved the bilateral temporoparietal junction and the posterior cingulate cortex. In EOAD, atrophy was widespread, including frontotemporoparietal areas, whereas it was limited to temporal regions in LOAD. Atrophic volumes were greater in EOAD than in LOAD. Hypometabolic volumes were similar in the 2 groups. Greater extent of atrophy in EOAD, despite similar extent of hypometabolism, could reflect different underlying pathophysiological processes, different glucose-based compensatory mechanisms or distinct level of premorbid atrophic lesions.

How functional coupling between the auditory cortex and the amygdala induces musical emotion: a single case study.

Music is a sound structure of remarkable acoustical and temporal complexity. Although it cannot denote specific meaning, it is one of the most potent and universal stimuli for inducing mood. How the auditory and limbic systems interact, and whether this interaction is lateralized when feeling emotions related to music, remains unclear. We studied the functional correlation between the auditory cortex (AC) and amygdala (AMY) through intracerebral recordings from both hemispheres in a single patient while she listened attentively to musical excerpts, which we compared to passive listening of a sequence of pure tones. While the left primary and secondary auditory cortices (PAC and SAC) showed larger increases in gamma-band responses than the right side, only the right side showed emotion-modulated gamma oscillatory activity. An intra- and inter-hemisphere correlation was observed between the auditory areas and AMY during the delivery of a sequence of pure tones. In contrast, a strikingly right-lateralized functional network between the AC and the AMY was observed to be related to the musical excerpts the patient experienced as happy, sad and peaceful. Interestingly, excerpts experienced as angry, which the patient disliked, were associated with widespread de-correlation between all the structures. These results suggest that the right auditory-limbic interactions result from the formation of oscillatory networks that bind the activities of the network nodes into coherence patterns, resulting in the emergence of a feeling.