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P Verstichel

Publications and source records attributed to P Verstichel.

At least 19 recordsLinked to original sources
PubMed2005

[False recognition of faces associated with fronto-temporal dementia with prosopagnosia].

INTRODUCTION: The association of prosopagnosia and false recognition of faces is unusual and contributes to our understanding of the generation of facial familiarity. METHOD: A 67-year-old man with a left prefrontal traumatic lesion, developed a temporal variety of fronto-temporal dementia (semantic dementia) with amyotrophic lateral sclerosis. Cerebral imagery demonstrated a bilateral, temporal anterior atrophy predominating in the right hemisphere. The main cognitive signs consisted in severe difficulties to recognize faces of familiar people (prosopagnosia), associated with systematic false recognition of unfamiliar people. RESULT: Neuropsychological testing indicated that the prosopagnosia probably resulted from the association of an associative/mnemonic mechanism (inability to activate the Face Recognition Units (FRU) from the visual input) and a semantic mechanism (degradation of semantic/biographical information or deconnexion between FRU and this information). At the early stage of the disease, the patient could activate residual semantic information about individuals from their names, but after a 4-year course, he failed to do so. This worsening could be attributed to the extension of the degenerative lesions to the left temporal lobe. Familiar and unfamiliar faces triggered a marked feeling of knowing. False recognition concerned all the unfamiliar faces, and the patient claimed spontaneously that they corresponded to actors, but he could not provide any additional information about their specific identities. The coexistence of prosopagnosia and false recognition suggests the existence of different interconnected systems processing face recognition, one intended to identification of individuals, and the other producing the sense of familiarity. Dysfunctions at different stages of one or the other of these two processes could result in distortions in the feeling of knowing. CONCLUSION: From this case and others reported in literature, we propose to complete the classical model of face processing by adding a pathway linked to limbic system and frontal structures. This later pathway could normally emit signals for familiarity, essentially autonomic, in response to the familiar faces. These signals, primitively unconscious, secondly reach consciousness and are then integrated by a central supervisor system which evaluates and verifies identity-specific biographical information in order to make a decision about the sense of familiarity.

Aged↗
PubMed2004

[Type II split cord malformation of late clinical onset].

A 68-year-old patient suffered for 8 years from radicular S1 pain on the left side, which was aggravated by walking. After an increased effort, he experienced a violent dorsal pain and sensitive troubles in the left T1 and T2 territories. Low back pain and painful paresthesiae of right leg came on next. Physical examination revealed proprioceptive symptoms on the left, a left pyramidal syndrome and a sacral pilonidal sinus. MRI showed on level of L2 vertebra, a spinal cord duplication in a unique dural tube, corresponding to diplomyelia or split cord malformation (SCM) type II. The patient had low conus medullaris anchored on L3-L4 level. A syringomyelia surmounted this medullar dysraphia. Split cord malformations, SCM type I (diplomyelia) or SCM type II (diastematomyelia), are usually revealed in infancy or early childhood. They are very rarely discovered late in the life. With progress in noninvasive spinal cord imaging, such diagnoses will undoubtedly be made more often in adults.

Age of Onset↗
PubMed2003

["Progressive acalculia": a variety of focal degenerative atrophy affecting number processing].

A 72-year-old man experienced increasing difficulties in calculating and processing numbers. He made many syntactic errors when he read and wrote numbers, both in arabic and number-word forms. Transcoding between arabic numerals and number-words was severely impaired. His calculation abilities were grossly impaired. He could not perform even simple multiplications, but additions and subtractions were preserved. He was unable to recite multiplication tables or the alphabet. In contrast, numerosity judgment, magnitude comparisons,and semantic evaluation of numbers were intact. The patient's deficit could be summarized as an Impairment in all tasks involving numbers in a verbal format, corresponding to the so-called "verbal anarithmetia'." It was noteworthy that verification of operations, including multiplications, was accurately performed. For example, the patient could not solve a multiplication like 8 x 9, but could estimate that 9 x 2=1 1 was closer to the exact result than 9 X 2=17, or could state that 8 x 2=16 was exact even though, at the same time, he expressed verbally the terms of the corresponding addition "eight plus two is ten." Other cognitive deficits were detected by neuropsychological tests which demonstrated mainly anomic aphasia, dysorthographic agraphia without alexia, impairment of short term and episodic memory, digital agnosia. However, the patient could not be considered to have demon-eti due to preserved self-sufficiency, except for tasks requiring calculation abilities. During the two years of follow-up, the impairment in processing numbers and calculation remained predominant over other deficits. Cerebral MRI showed an atrophy of the left temporal and parietal lobes, and SPECT study showed a reduction of regional cerebral blood flow of the left hemisphere. This original clinical presentation of a cerebral degenerative disease could be described as "primary progressive acalculia" whatever the underlying primary pathological process.

Aged↗
PubMed2001

[Impaired recognition of faces: implicit recognition, feeling of familiarity, role of each hemisphere].

We report three observations of patients who suffered from impaired face recognition following cerebral lesions. Two had classical prosopagnosia, resulting from bilateral in one case and right unilateral occipito-temporal in the other. They could not differentiate famous face from unknown ones, and did not feel any familiarity. The third patient has a normal feeling of knowing, could distinguish between familiar and unfamiliar faces, but was unable to evoke any biographical information about the personalities. Prosopagnosic patients demonstrated, in an experimental condition of learning face-name pairs, implicit knowledge. We assume that these capacities were dependent of the activation of networks coding familiar faces in memory. Mental imagery of faces were normal in theses two cases. In addition, stimulation of mental imagery in the first patient improved implicit knowledge in forced choice tasks. These cases throws a light on the respective role of each hemisphere in face recognition. The right hemisphere is advantaged in perceptual analysis, and activates, from the perceived faces, mnestic systems which codes for previously encountered faces. It generates feeling of familiarity, probably by the way of specific systems which differs from, and completes, those allowing identification. The left hemisphere enable access to semantic-biographic knowledge in a conscious, verbal and explicit way.

Aged↗
PubMed2000

[Korsakoff amnesia syndrome].

PATHOLOGY CORRELATIONS: The Korsakoff syndrome results from cerebral lesions due to thiamine depletion, usually of alcoholic etiology. Other nutritional, or genetic factors, could be implicated. Exceptionally, it results from thalamic disease or a tumor of the third ventricle floor. PATHOPHYSIOLOGICAL CONSIDERATIONS: Anterograde and retrograde aspects of episodic memory are principally impaired, contrasting with the preservation of semantic and procedural memory. Opposition between explicit (impaired) and implicit (unimpaired) memory is one of the main cognitive features of this syndrome. Several cerebral structures, components of various memory systems, are simultaneously damaged. Critical lesion sites for anterograde amnesia involve the memillary bodies, the mamillotalamic tract and the anterior thalamus. Retrograde amnesia is dependent on function abnormalities of a circuit between the dorso-median thalamus and the prefrontal cortex. Impairment of retrieval and chronological disorganization of memories contribute to this extensive retrograde amnesia, probably because of frontal dysfunction. Confabulations and false recognitions are produced in the initial stage of the disease. They are, in the same way, interpreted as the consequence of frontal desafferentation due to dorso-median thalamus damage. The impact of diencephalic destruction on the frontal lobes is evidenced clinically by behavioral changes and dysexecutive syndrome. Neuroimaging studies of the brain show a decreased regional metabolic ration in the frontal areas. PROGNOSIS: Korsakoff syndrome is a serious disorder, responsible for cognitive handicap. There is no curative treatment. Preventive measures, consisting in systematic prescription of thiamine in alcoholics, is the main effective measure.

Aged↗
PubMed2000

[Left unilateral melokinetic apraxia and left dynamic apraxia following partial callosal infarction].

A 69 year-old right-handed man suffered from an infarct in the left anterior cerebral territory's artery, involving the anterior and middle parts of the corpus callosum, and the cingulum. He had a right crural hemiparesis with a grasp reflex of the right hand, and ipsilaterally a melokinetic and a dynamic apraxia. Agility of the left fingers was lost: fast and nimble movements of theses fingers, and repetitive gestures of the left hand were defective. Execution of motor sequences with the left hand was disrupted by a lack of litheness in gesture series. By analogy with unilateral left ideomotor apraxia, we suggest melokinetic and dynamic apraxia could be symptomatic of an interhemispheric disconnection. Premotor cortex could have a dominance for both digital movements and programmation of gestual sequences. As a general rule, the left cortex could be preferentially activated by the nature of some tasks, particularly the execution of complex gestual series, which implie an internal speech. In theses conditions, an interhemispheric disconnection could lead some difficulties to make theses gestures with the left hand.

Aged↗
PubMed1999

Neuropathy in two cobalamin-deficient breast-fed infants of vegetarian mothers.

We describe the electrophysiological findings in 2 infants with deficient cobalamin intake. After normal development, psychomotor regression appeared after the 6th month, leading to severe hypotonia and apathy before the 12th month. Electrodiagnostic evaluation showed sensory neuropathy in both cases, associated with motor neuropathy in 1 case. Thus, in an acquired floppy infant syndrome, electrophysiological signs of peripheral neuropathy contributed to the diagnosis of a curable metabolic disorder.

Action Potentials↗
PubMed1999

[Difficulties in face identification after lesion in the left hemisphere].

A 82 year-old right-handed man, without any intellectual impairment, suffered from an acute neurological deficit consisting in letter-by-letter reading, right superior quadrant hemianopia with achromatopia in the lower quadrant, and anomia. Cerebral MRI showed an infarct involving the ventral structures of the left hemisphere sparing the splenium of the corpus callosum and the thalamus. Neuropsychological examination revealed that the patient easily identified the objects, the animals and the famous places he could not name: his comments attested normal visual recognition. Conversely, when he was presented with famous faces, he always had a strong feeling of familiarity, but could not provide accurate information about the corresponding individual. Biographic information about personalities was not impaired in the semantic-biographic store, because it could be accessed from the names. Activation of face recognition units (where the visual description provided by the structural encoding and the stored sets of descriptions of familiar faces are compared), was effective, since the patient could distinguish famous faces from unknown ones. In a modular-sequential model of face recognition, this deficit is interpreted as a disconnection between face recognition units and person identity nodes (which are considered to contain semantic-biographic information about individuals). This kind of disturbance differs from classic prosopagnosia in which, characteristically, the patients are unable to experience a feeling of familiarity when viewing famous faces, and to perform a categorization between famous and unknown faces. Right hemisphere has a preponderant role in structural analysis of faces and in activation of face recognition units. The integrity of this hemisphere in this patient could explain the preservation of these two steps of processing. Left-hemisphere specific function in facial recognition enabled access to semantic-biographic store in a conscious, verbal and explicit way, after the right hemisphere had achieved basic visual analysis and activation of facial representation in memory. We compare the cognitive impairment in our patient to those encountered in classical prosopagnosic patients. This case illustrates the validity of the modular-sequential model considered. In addition it throws a light on the poor-known role of the left hemisphere in face recognition.

Aged↗
PubMed1997

[Letter-by-letter alexia after left hemispheral lesion without hemianopsia nor callosal involvement. 2 cases].

We describe two patients suffering from a letter-by-letter reading following an infarct in the left posterior cerebral artery's territory. Unlike most of the verbal alexics, this strategy was particularly fast and effective. Two other features distinguished these patients from verbal alexics: the absence of hemianopia and the sparing of the corpus callosum. A study of the reading of letters and words by each hemisphere was performed. In the first case, the left hemisphere was unable to identify any letter or word. The visual stimuli did not activate the visual word form, not the system which normally recognize letters. However, this latter could be activated by the information transmitted by the right hemisphere via the corpus callosum. In the second case, the left hemisphere could, as well as the right one, identify all the letters. On the other hand, identification of words was impaired, and did not improve when the duration of the visual presentation increased. The left hemisphere, unable to access to the visual word form, could not decipher letter-by-letter. One hypothesis is that the left visual working memory was reduced, and could not store more than one letter. The right hemisphere deciphered the words sequentially, and transmitted the information to the left systems which recognize the letter. These two observations confirm that letter-by-letter alexia could result exclusively from the destruction, of the inaccessibility of the visual word-form. A lesion of the left ventral occipito-temporal structures is sufficient, and a left hemianopia, or a splenial lesion is not absolutely necessary. The sparing of the corpus callosum allows a fast transmission to the left phonological processing, if the left systems recognizing letters are efficient.

Aged↗
PubMed1996

[Traumatic spinal complications of cervical arthrosis].

OBJECTIVES: Cervical spondylotic myelopathy is usually a chronic and progressive disease. In a few cases, however, dramatic tetraplegia sometimes occurs after even minor injury. METHODS: We report seven patients (6 males, 1 female, aged from 41 to 63), who suffered from acute myelopathy after an injury. RESULTS: In 5 cases, the injury revealed the cervical spondylotic myelopathy. A hyperextension of the cervical spine was found in 5 cases. The injury was severe in only one case, but there was no bony abnormalities, except arthrosis. The most common cause was a fall. In contrast, severe tetraplegia was found in 4 cases. Spontaneous, but incomplete, recuperation occurred in 4 patients. In all 7 cases, CT scan and MRI showed congenital cervical stenosis associated with cervical spondylosis. The level of disco-osteophytic changes was mainly in C4, C5, C6. On T2-weighted spin-echo image, an increased signal intensity was present in the cord of 3 patients, but was not correlated with the severity of the symptoms, nor with improvement. Surgical treatment was performed in 6 cases: 3 laminectomies, 3 anterior or antero-lateral approaches. Improvement after operative decompression was observed in all but one case, even when the motor or sensory deficit persists for more than one year. Motricity of the inferior limbs improved better than the other deficits, perhaps because of the location of non-reversible lesions in the spinal gray matter. CONCLUSION: The acute medullary syndrome of cervical spondylotic myelopathy is serious and can cause major handicaps. This complication justifies a preventive surgical attitude when medullar signs are moderate, and cervical imagery shows a spondylotic compression of the cord with congenital stenosis.

Accidents, Home↗
PubMed1996

[Interhemispheric disconnection syndrome caused by partial infarction of the corpus callosum: neuropsychological study and MRI].

A partial syndrome of hemisphere disconnection was observed in a 63 year-old woman, following an anterior and middle corpus callosum infarct on MRI. Notably, we found left ideomotor apraxia, diagonistic apraxia, left-year extinction on dichotic listening, but no left-hand anomia nor left visual field anomia. A left tactile extinction in dichaptic condition is interpreted as resultant of a dysregulation of the attentional balance between the two hemispheres. This detailed neuropsychological study permits a correlation between the callosal syndrome and the lesion. We suggest that an occlusion of the anterior callosal artery could explain this limited ischemia.

Cerebral Infarction↗
PubMed1996

[Cerebral thrombotic complications, arterial and venous, disclosing inflammatory bowel disease].

A 40 year old woman presented successively an arterial and a venous cerebral thrombosis, revealing an inflammatory bowel disease. Digestive manifestations were very poor until then. Stroke is a rare complication of inflammatory bowel disease, and is usually correlated with and active phase of the disease. The mechanism by which the thrombogenic process occurs is unclear. The possible prothrombotic role of hemostasis disorders and the role of an angiitic process are discussed.

Adult↗
PubMed1995

Aphasia and infarction of the posterior cerebral artery territory.

Spoken language disorders are rarely mentioned in superficial infarction of the posterior cerebral (PCA) territory. Two clinical types have been reported: transcortical sensory and amnesic aphasia. Between 1979 and 1990, we studied retrospectively 76 patients suffering from an occipitotemporal infarction located in the superficial territory of the posterior cerebral artery, all well documented by CT. Aphasia was one of the first and prominent signs in 18 cases. Middle cerebral artery concomitant infarction could have been the cause of language impairment in 10. In 8 patients aphasia was only explained by a PCA territory infarct. Three patients showed features of transcortical sensory aphasia. CT localization showed internal lobe and thalamic involvement of the dominant hemisphere. Five patients exhibited word finding impairment with various degrees of amnestic syndrome. The dominant internal temporal lobe was always affected. Dominant thalamus involvement was found in one case only. Some correlations between clinical features and anatomical support (vascular supply and anatomical structure) might be suggested in our 8 cases of aphasic disorders due to PCA infarcts. They are discussed and compared with data in the literature.

Adult↗