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P Krolak-Salmon

Publications and source records attributed to P Krolak-Salmon.

12 recordsLinked to original sources
PubMed2006

[Part I: Face recognition].

Faces represent a crucial vector of interhuman communication. The message transmitted by the face has multiple features. Recognition of each feature can be impaired independently or in combination with others. In order to understand the behavioral consequences of such impairments, which can be a major social handicap, we first must specify the neural networks involved in face recognition. We propose in this first part to present the systems involved in face recognition, in particular the question of identity and prosopagnosia. Different neural networks are indeed implicated in the recognition of invariant facial features such as identity, gender, ethnicity, and recognition of variant features like facial expression and eye gaze. This paper is illustrated by some of our scalp and intracranial electrophysiological studies performed in humans allowing us to describe some aspects of face recognition dynamics combining an excellent spatial and temporal resolution. Intracranial recordings were performed in drug refractory epileptical patients implanted with depth electrodes. These studies demonstrate that numerous deep brain and cortical structures participate early and sometimes in a sustained manner in face recognition.

Face↗
PubMed2006

[Part II: Recognising facial expressions].

In this second part, we address particularly the question of the neural mechanisms and structures involved in the recognition of facial emotional expressions that are crucial in social cognition. Emotion recognition in others can be critically impaired in some neurodegenerative and neurovascular diseases. That dysfunction sometimes correlated to disabling behavioural disorders and interpersonal communication impairment must be further understood. The results of a series of scalp and intracranial event related potential recordings, as well as recent advances in the literature, are reported. ERPs to facial emotional expressions were thus recorded in multiple subcortical and cortical areas in drug refractory epileptical patients implanted with depth electrodes. The roles of amygdala, insula and prefrontal cortex located at crossroads between perceptive analysis and emotional conceptual knowledge are particularly underlined. Altogether, these studies demonstrate that facial expressions are widely processed in space and time, some structures reacting very early and automatically, others providing a sustained reaction depending on the attention.

Amygdala↗
PubMed2005

[Rhinocerebral mucormycosis].

INTRODUCTION: Mucormycosis is a rare and acute fungal infection which is frequently lethal. The rhinocerebral form is usually seen in diabetics, but other localizations may occur in severely immunocompromised subjects. OBSERVATION: We report the case of a sphenoidal sinusitis associated with a probable cavernous sinus thrombosis and carotid artery thrombosis with middle cerebral artery territory infarction. Diagnosis was made on histological examination following sphenoidotomy. Early medical and surgical treatment led to a good outcome. CONCLUSION: The diagnosis of rhinocerebral mucormycosis should be considered in the clinical setting of necrotic sinusitis and acute neurologic deficit in diabetic patients. Early diagnosis and treatment are crucial factors leading to a good outcome.

Aged↗
PubMed2005

[Heidenhain's variant of Creutzfeldt-Jakob's disease].

INTRODUCTION: Creutzfeldt-Jakob's disease has various anatomoclinical presentations including a rare form with preponderant visual signs described by Heidenhain. In this form, the visual symptoms may be isolated for a few weeks, leading to multiple ophthalmological examinations. OBSERVATION: We report the case of a 75-year-old woman who developed isolated visual disorders which rapidly increased over a period of two months. Addition of neurological symptoms, abnormalities of EEG and positivity of 14-3-3 protein led to the diagnosis of Creutzfeldt-Jakob's disease. The patient died 14 months after the first neuroophthalmologic signs. The diagnosis was established by post-mortem examination and immuno-electrophoretic demonstration of type 1 prion protein. CONCLUSION: Heidenhain's form of Creutzfeldt-Jakob's disease highlights the importance of general rules for prevention of iatrogenic hazard during ophthalmological examinations.

14-3-3 Proteins↗
PubMed2002

Thalamic venous infarction as a cause of subacute dementia.

The clinical picture of deep cerebral vein thromboses (DCVT) usually is acute, combining vigilance disorders, headaches, and focal neurologic deficit. The authors describe a patient who presented with isolated subacute dementia as the sole manifestation of DCVT. In the setting of subacute cognitive deficit, the diagnosis of DCVT must be considered when neuroimaging shows bilateral thalamic changes. Enhanced venous MR angiography is the noninvasive method of choice to ascertain the diagnosis.

Brain Infarction↗
PubMed2001

[Inflammatory optic neuropathies].

Diagnosis of inflammatory optic neuropathy is very likely in a young adult presenting acute, unilateral and painful visual loss. Relative afferent pupillary defect is a very sensitive and specific sign of optic neuropathy. Ophthalmological exam is mandatory to estimate severity of visual loss, appearance of optic disks and check for another eye disease. Magnetic resonance imaging is indicated to rule out a compressive optic neuropathy and to quantify the inflammatory lesion index, which is the best prognostic indicator of multiple sclerosis development (MRI is abnormal at entry in about 50% of patients with isolated optic neuritis). Spontaneous outcome of optic neuropathies is favourable. Corticosteroids have demonstrated efficacy only in shortening length of evolution and by using parenteral high doses. Clinical benefit from introducing beta-interferons treatment after a first episode of isolated optic neuritis remains to be evaluated. Secondary inflammatory optic neuritis (infection, vasculitis, sarcoïdosis) are rare and usually present atypical evolution or other symptoms.

Adjuvants, Immunologic↗
PubMed2001

Processing of facial emotional expression: spatio-temporal data as assessed by scalp event-related potentials.

Event-related potentials (ERPs) were recorded in 10 adult volunteers, who were asked to view pictures of faces with different emotional expressions, i.e. fear, happiness, disgust, surprise and neutral expression [Ekman, P. & Friesen, W.V. (1975). Pictures of Facial Affect. Consulting Psychologist Press, Palo Alto, CA]. ERPs were recorded during two different tasks with the same stimuli. Firstly, subjects were instructed to pay attention to the gender of the faces by counting males or females. Secondly, they had to focus on facial expressions by counting faces who looked surprised. The classical scalp 'face-related potentials', i.e. a vertex-positive potential and a bilateral temporal negativity, were recorded 150 ms after the stimulus onset. Significant differences were found, firstly between late-latency ERPs to emotional faces and to neutral faces, between 250 and 550 ms of latency and, secondly, among the ERPs to the different facial expressions between 550 and 750 ms of latency. These differences appeared only during the expression discrimination task, not during the gender discrimination task. Topographic maps of these differences showed a specific right temporal activity related to each emotional expression, some particularities being observed for each expression. This study provides new data concerning the spatio-temporal features of facial expression processing, particularly a late-latency activity related to specific attention to facial expressions.

Adult↗
PubMed2000

Anatomy of optic nerve radiations as assessed by static perimetry and MRI after tailored temporal lobectomy.

AIMS: To determine the course of optic nerve radiations in the temporal lobe, especially their retinotopic organisation and the anterior limit of the Meyer's loop. METHODS: 18 adult patients who had undergone a tailored temporal lobectomy for epilepsy were included in this study between 1994 and 1998. The rostrocaudal extent of the lateral temporal lobe resection assessed intraoperatively by the surgeon and by postoperative MRI was compared with the postoperative visual fields determined by automated static perimetry (ASP). RESULTS: 15 patients (83%) presented a postoperative visual field deficit (VFD) confined to the superior homonymous field contralateral to the side of the resection. All degrees from a minimal upper field loss to a complete quadrantanopia were observed. The VFDs were somewhat stereotyped, predominating along the vertical meridian. The smallest anteroposterior resection resulting in a VFD was limited to 20 mm from the tip of the temporal lobe. A relation was observed between the extent of the lateral resection in front of the second and third convolutions and the occurrence and extent of postoperative VFDs. No patient reported persisting subjective visual impairment. CONCLUSION: The high frequency of postoperative VFDs appears to be due to the greater sensitivity of ASP. The characteristics of the stereotyped VFDs allow new conclusions about the course and retinotopy of optic nerve radiations. The anterior limit of Meyer's loop is likely to be located more rostrally than previously believed.

Adult↗
PubMed2000

Total recovery after bilateral paramedian thalamic infarct.

Bilateral paramedian thalamic infarcts are characterised initially by the association of acute vigilance disorders and vertical gaze palsy, followed by persisting dementia with severe mnemic disturbance, global aspontaneity and apathy. We describe a patient with a dramatic neuropsychological recovery, confirmed by testing examination and completed by a cerebral metabolism study. The pathophysiology of this type of cognitive deficit is discussed.

Akinetic Mutism↗
PubMed1999

MRI assessment of the anatomy of optic radiations after temporal lobe epilepsy surgery.

OBJECTIVE: The aim of this study was to determine the course of the temporal optic radiations. MATERIAL AND METHODS: Eighteen patients were included in this prospective study. All of them underwent a temporal lobectomy for epilepsy, including the mesial temporal structures and a variable extent of lateral neocortex (from 2 to 7 cm behind the temporal tip). An MRI was performed 2 months postoperatively, allowing assessment of the extent of lateral resection. Postoperative visual fields were determined by automatic static perimetry (ASP). RESULTS: (1) No patient complained of a disabling visual field deficit. (2) ASP, a highly sensitive technique, however, detected postoperative visual field deficits in 83% of patients, confined to the superior homonymous field contralateral to the resection. (3) A strong correlation was found between the presence of a visual field deficit and the extent of laterotemporal resection. (4) The smallest anteroposterior resection resulting in a field defect was limited to 20 mm from the temporal tip. CONCLUSION: (1) This study confirms a strong correlation between postoperative visual field deficits and the extent of lateral neocortical temporal resection. (2) The anterior limit of Meyer's loop is likely to be located more rostrally than previously believed. (3) Despite this, lateral resection remains useful in some cases for seizure control.

Adult↗