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Objective: To investigate the clinical and anatomic correlates of a previously unreported form of chronic supernumerary phantom limb, which developed only in association with motor intent directed at a hemiplegic–anesthetic upper limb. Methods: We explored the phenomenology of the phantom illusion in the light of motor control models. Hemodynamic correlates of supernumerary phantom limb were studied with an fMRI sensorimotor paradigm consisting of finger–thumb opposition movements. Results: The kinesthetic–proprioceptive illusion of a third arm was triggered by any attempt to move the paretic limb, by bimanual actions, and by motor imagery involving the nonfunctional limb. The responsible lesion destroyed the posterior part of the posterior limb of the internal capsule on the opposite side, damaging corticospinal and thalamocortical tracts. Comparison between fMRI signals performed during virtual movement of the phantom hand vs imaginary movement of the paretic hand showed increased activation in thalamus and caudate nucleus in the first condition. Conclusions: A preserved sense of agency provided by intact premotor processes translating intention into action may lead to the vivid feeling of movement in a paralyzed limb, similar to kinesthetic illusions in amputees. The interruption of thalamic afferences may explain the persistence and stability of the phantom by preventing any correction of the mismatch between expected and effective movement. The increased blood oxygen level–dependent (BOLD) signal in the basal ganglia–thalamus–cortex pathway during movement of the supernumerary hand may reflect an abnormal closed-loop functioning of the thalamocortical system underlying the phantom phenomenon.

Auditory recognition and auditory spatial functions were studied in four patients with circumscribed left hemispheric lesions. Patient FD was severely deficient in recognition of environmental sounds but normal in auditory localisation and auditory motion perception. The lesion included the left superior, middle and inferior temporal gyri and lateral auditory areas (as identified in previous anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the thalamus. Patient SD had the same profile as FD, with deficient recognition of environmental sounds but normal auditory localisation and motion perception. The lesion comprised the postero-inferior part of the frontal convexity and the anterior third of the temporal lobe; data from non-human primates indicate that the latter are interconnected with lateral auditory areas. Patient MA was deficient in recognition of environmental sounds, auditory localisation and auditory motion perception, confirming that auditory spatial functions can be disturbed by left unilateral damage; the lesion involved the supratemporal region as well as the temporal, postero-inferior frontal and antero-inferior parietal convexities. Patient CZ was severely deficient in auditory motion perception and partially deficient in auditory localisation, but normal in recognition of environmental sounds; the lesion involved large parts of the parieto-frontal convexity and the supratemporal region. We propose that auditory information is processed in the human auditory cortex along two distinct pathways, one lateral devoted to auditory recognition and one medial and posterior devoted to auditory spatial functions.

Two patients with severe and lasting prosopagnosia were studied for visuo-cognitive functions and anatomo-clinical correlations. Both patients were deficient in recognizing familiar faces and items of previously well known categories (plants and fish for patient 1, mountains for patient 2). Patient 2, but not patient 1, was also deficient for matching of unknown faces. Patient 1, but not patient 2, was achromatopsic. Both patients had bilateral symmetrical lesions. Patient 1 had a lesion of the inferior occipitotemporal cortex, including inferior parts of early stage visual areas. Patient 2 had a lesion of the inferior temporal and fusiform gyri anterior to the early stage visual areas. When compared in Talairach space, the lesions of both patients had minimal overlap. Thus, severe and lasting prosopagnosia was associated with two almost exclusive lesion sites in the postero-inferior part of the hemispheres. Comparison between activation studies of face processing (by others) and our lesion study uncovered several paradoxes. Lesions of regions involved in a given task in normal subjects do not produce a deficit in this task, as shown here for gender discrimination and partially for face matching. Conversely, lesions of a region not specifically involved in a given task in normal subjects can produce a deficit in the task, as shown here for face identification.

Three different aptitudes involved in sound object recognition were tested in 60 normal subjects and 20 brain-damaged patients: (i) capacity to segregate sound objects on different cues (intensity steps, coherent temporal modulations or signal onset synchrony); (ii) asemantic recognition of sounds of real objects by judging whether two different sound samples belonged to the same object; and (iii) semantic identification of sounds of real objects as judged by means of a multiple choice response test. In 12 patients, different aptitudes involved in auditory recognition were disrupted separately and in a way which speaks in favour of parallel rather than hierarchical processing. There was no strong association between deficits in non-verbal auditory recognition and aphasia or the side of lesion.

Article abstract-We describe a patient who had sequential strokes in both hemispheres with a severe unilateral spatial neglect after a first right-sided parietal infarct and abrupt disappearance of the neglect after a second left-sided frontal infarct. The first lesion involved the caudalmost right angular gyrus (area 39), whereas the second lesion involved the left frontal eye field (area 8) and surrounding cortex. Those two cortical areas are assumed to have a pivotal role in modulating both shifts of attention within extrapersonal space and saccadic eye movements through their connections with subcortical structures, in particular, superior colliculi and thalamic nuclei. Our case supports the existence of a distributed anatomic-functional network in subserving directed spatial attention.NEUROLOGY 19;: 184-189

We report a patient with complete callosal disconnection syndrome after severe closed head injury. MRI showed a complete destruction of the corpus callosum throughout its length. Although traumatic callosal lesions are a frequent finding in autopsy studies, as well as in some recent MRI studies, clinical signs of callosal disconnection are rarely observed after head injuries and a complete disconnection syndrome has not been reported yet. This case study and the review of other reported cases suggest that posttraumatic callosal disconnection is probably often overlooked. Our patient had also a severe memory disorder that might be partly related to the bilateral involvement of the fornix, as this structure is closely adjacent to the posterior corpus callosum, and was also shown by MRI to be very probably damaged.

A 70-year-old right-handed woman developed a complete Klüver-Bucy syndrome including psychic blindness, aberrant sexual behavior, hypermetamorphosis, aphasia and visual agnosia following left anterior temporal lobectomy for an anaplasic oligodendroglioma. MRI showed no argument for a contralateral ischemic infarct, tumoral growth or white matter damage. Thus the possibility that a unilateral anterior temporal lesion can cause the whole picture of Klüver-Bucy syndrome must therefore be considered.

Gottlieb Burckhardt, a Swiss psychiatrist who practiced in the late 19th century, was the founder of modern psychosurgery. In 1891 he reported the results of cortical extirpations on six patients who evidently suffered from intractable psychiatric disease; two of these cases are discussed here to illustrate how Burckhardt employed contemporary brain models of language and cognition as the basis for removing specific areas of the cerebral cortex with the intention of ameliorating his patients' disturbed behavior.

In March 1841, the year before he died of acute stroke, Stendhal, one of the most famous French novelists of the 19th century, developed a series of short-lived speech impairments which he precisely r

Two patients with bilateral thalamo-mesencephalic infarct in the paramedian territory developed vertical gaze dysfunction and marked behavioural changes, in the absence of significant motor inability and formal neuropsychological impairment. While they were physically and emotionally active before stroke, they became apathetic, aspontaneous, indifferent, and seemed to have lost motor and affectic drive, as well as the need itself for any psychic activity. However, this mental and motor inertia was reversible when the patients were repeatedly stimulated by another person. This need for constant external programming, together with a lack of emotional reactivity, made the patients resemble robots. CT and MRI suggested involvement of the dorsomedial and midline nuclei of the thalamus, and SPECT showed remote frontomesial hypoperfusion. A disturbance of the striatal-ventral pallidal-thalamic-frontomesial limbic loop is suggested by previous reports of a similar "loss of psychic self-activation", "pure psychic akinesia", or "athymhormia" with bipallidal, bistriatal, or subcortical bifrontal lesions.

The acclaimed Italian directors Luchino Visconti and Federico Fellini had very different life trajectories that led them to become major figures in the history of cinema. Similarities, however, can be found in their debuts with the neorealist genre, their personalities, creative styles and politicocultural involvement, and ultimately in the neurological disease that struck them at the end of their careers. Both suffered a right-hemispheric stroke that left them hemiplegic on the left side. We review their life and career to put that event into perspective, and then discuss its aftermath for both artists in the light of our current knowledge of right-hemispheric functions. Visconti showed a tremendous resilience following the accident and managed to direct several films and plays as an infirm, whereas Fellini had to put an end to his career but still was able to display his talents to the neuropsychologists that treated him. A speculative account is given of the links between right-hemispheric symptomatology and the premorbid personality of these highly prolific patients.

What about artistic creativity following a cerebral lesion? We studied the case of a prominent right-handed Swedish painter and sculptor who suffered a cerebral hemorrhage at the age of 55 years. Th

Patients' opinions about the aetiology of their disease and the implications for compliance have not been well documented at this time.To investigate prospectively aetiological beliefs of a cohort of neurological inpatients.Within two days of admission, patients orally answered a short questionnaire regarding their beliefs about the aetiology of their disease and the possible influence of psychological factors, stress, fatigue, excessive work or other activities, poor lifestyle, conflict with another person, a tragic event, chance, and destiny.Of the 342 patients who participated in the study, 49% spontaneously said that they had no idea of what could have caused their disease, 15% gave a congruent medical explanation, 11% mentioned stress and fatigue as a precipitating factor, and 6% evoked a non-congruent medical explanation. Thirty six per cent thought that psychological factors had triggered their disease; such factors being blamed by a higher proportion of young patients and patients with chronic central nervous system diseases. The triggering factors most often blamed were stress (48%, especially by patients with headache), fatigue (51%), chance (54%), and destiny (43%).Patients' aetiological beliefs only partially concur with medical opinion and this may influence compliance with treatment. This statement should be explored and confirmed by further studies-for example, in cerebrovascular risk factor follow up.

Interhemispheric transfer of visual information was investigated behaviourally and with functional magnetic resonance imaging (fMRI) 6 months after a lesion of the posterior two-thirds of the corpus callosum. On tachistoscopical left hemifield presentation, the patient was severely impaired in reading letters, words and geographical names and moderately impaired in naming pictures and colours. In contrast, interhemispheric transfer of visual motion information, tested by verbal report of the direction of short sequences of coherent dot motion presented within the left hemifield, was preserved. The pattern of cerebral activation elicited by apparent motion stimuli was studied with fMRI and compared to that of normal subjects. In normal subjects, apparent motion stimuli, as compared to darkness, activated strongly striate and extrastriate cortex. When presented to one hemifield only, the contralateral calcarine region was activated while regions on the occipital convexity, including putative area V5, were activated bilaterally. A similar activation pattern was found in the patient with a posterior callosal lesion; unilateral left or right hemifield stimulation was accompanied by activation in the contralateral and ipsilateral occipital convexity. Ipsilateral hemifield representation in the extrastriate visual cortex is believed to depend on callosal input. Our observation suggests that this is not the case for visual motion representation and that other, probably parallel, pathways may mediate visual motion transfer after posterior callosotomy.

Short-term memory for colour was studied in five patients with circumscribed posterior hemispheric lesions. It was impaired independently of colour discrimination in one and more than colour discrimination in two patients. Two patients were normal in colour short-term memory, one with normal and one with deficient colour discrimination performance. Deficient performance in colour short-term memory was associated with bilateral lesions of the inferior occipitotemporal junction including the lateral part of the fusiform gyrus or with a unilateral lesion of the left parieto-occipital convexity. An additional colour constancy deficit was found in the former but not the latter condition. Thus, colour short-term memory can be affected independently of colour discrimination or colour constancy, and may depend on at least two distinct neural circuits.

Colour matching and colour constancy were studied in seven patients and 46 control subjects. Subjects were required to match Munsell Colour Chips presented under either identical or different illumination. Three of the patients had deficits in colour constancy, i.e. failure to compensate for the change in the wavelength composition of the illumination. Two of the patients with defective constancy had suffered bilateral cortical damage to the posterior lingual and fusiform gyri, and one patient had a lesion restricted to the same regions of the right hemisphere. Our observations indicate that these cortical areas, which include part of putative human area V4, play an important role in colour constancy.

We report a 65-year-old man with a post-anoxic encephalopathy who showed compulsive sniffing at available objects. This stereotyped environment-driven behaviour has not been previously described. Other compulsive environment-driven responses, such as manipulation and utilization of tools and hyperlexia, were also present. The disorder shared several features with the Kluver-Bucy syndrome where mouthing of objects, rather than smelling them, is common. The patient had a severe dementia, with amnesia, anomia, apraxia, and visual agnosia. Whereas he could not recognize very familiar objects on sight, he could in contrast correctly identify several familiar odours. Although sniffing was a compulsive and purposeless environment-driven behaviour, the question may be asked whether a relatively preserved olfactory recognition, in the presence of a severe disorder of visual recognition and knowledge, could have favoured a stereotyped exploration of objects by smelling.

A patient in whom mandibular and maxillary parts of right trigeminal ganglion were removed experienced referred sensations after stimulation of the right hand and right forehead. She described them either as parallel to the perception at the actual stimulation site or as coming uniquely from a (non-existent) stimulation of denervated territory. The latter occurred in 6-19% of stimulations performed on the right forehead and on digits 1, 3 and 4 of the right hand. Thumb stimulations were localized on the right side of the face, stimulations of right forehead, middle and ring fingers more precisely on right cheek. Referred sensations were present on postoperative day 7 and had a more real-like quality than 5 days later.

Three patients developed a striking visual and motor behaviour in the acute phase of a stroke involving the territory of the right anterior parietal artery (postcentral gyrus, parts or upper and middle temporal gyri, anterior part of inferior parietal gyrus, and supramarginal gyrus). The patients concentrated on the left side of their bodies, looking at it for long periods and relentlessly rubbing, touching, pinching, pressing, lifting, and manipulating parts of the left arm, trunk, and leg with their right hand or foot. They all had severe loss of elementary sensation on the left (touch, pain, temperature, vibration, position). The behaviour was not associated with overinterest in the left hemispace apart from their own bodies. It lasted no more than a few days, disappearing when left sided sensation improved. The findings suggest an association between sensory dysfunction and this "acute hemiconcern". None of 13 patients with a mirror infarct in the left hemisphere and none of 38 patients with acute hemisensory loss due to thalamic capsular or brainstem stroke showed hemiconcern behaviour. This behaviour may result from a feeling of strangeness critically associated with hemisensory loss without hemispatial neglect, due to involvement of the right anterior parietotemporal region.

Two patients with bilateral thalamo-mesencephalic infarct in the paramedian territory developed vertical gaze dysfunction and marked behavioural changes, in the absence of significant motor inability and formal neuropsychological impairment. While they were physically and emotionally active before stroke, they became apathetic, aspontaneous, indifferent, and seemed to have lost motor and affectic drive, as well as the need itself for any psychic activity. However, this mental and motor inertia was reversible when the patients were repeatedly stimulated by another person. This need for constant external programming, together with a lack of emotional reactivity, made the patients resemble robots. CT and MRI suggested involvement of the dorsomedial and midline nuclei of the thalamus, and SPECT showed remote frontomesial hypoperfusion. A disturbance of the striatal-ventral pallidal-thalamic-frontomesial limbic loop is suggested by previous reports of a similar "loss of psychic self-activation", "pure psychic akinesia", or "athymhormia" with bipallidal, bistriatal, or subcortical bifrontal lesions.

Case report. A 50-year-old, right-handed, French-speaking, Spanish worker was admitted 3 weeks after an acute right hemiparesis with"hyperproductive" global aphasia. He produced meaningless nonphonemic sounds("brr," "prck," "pfft"), accompanied by an emotional display of unmotivated laughing, crying, childish behavior, and transient anger, lasting for hours, in a pseudo-hebephrenic manner. He also hummed "Gregorian chants." He could not follow simple commands, imitate gestures, read, or write. He showed utilization behavior, manipulation of objects, and an inappropriate tendency to attempt to undress the examiner, but no grasping or cephalic frontal reflexes. On neurologic examination, severe right sensorimotor flaccid hemiparesis was found, with corticobulbar signs and left Horner's sign. On MRI, a subacute infarct was found in the deep territory of the left middle cerebral artery (MCA) and bilateral anterior cerebral arteries (ACAs)(figure), with hypoplasia of the A1 segment on the right. Doppler ultrasound of precerebral vessels was normal. On transthoracic echocardiography, atrial septal aneurysm was …

Four of 1,200 consecutive patients with their first stroke showed acute transcortical mixed aphasia (TMA) characterized by nonfluent speech with impaired naming, semantic paraphasias, echolalia, impaired comprehension, good repetition, reading, and writing on dictation. All 4 had left internal carotid artery (ICA) occlusion with ipsilateral anterior pial territory infarction (precentral-central sulcus artery territory) and watershed infarction between the middle and posterior cerebral artery territories, which spared and 'isolated' the perisylvian speech areas. Although rare, acute TMA is highly suggestive of infarction due to ICA occlusion, in that it is probably related to simultaneous embolism (anterior pial infarction) and haemodynamic insufficiency (posterior watershed infarction).

The study of 3 personal cases and 5 published cases of unilateral infarct limited to the territory of the tuberothalamic artery suggests that this syndrome should be differentiated from the other thalamic syndromes. The onset is usually sudden, with moderate contralateral weakness. Sensory changes may be present but remain mild. The patients are apathetic, show perseveration and may be disoriented. In left-sided infarcts, transcortical aphasia, verbal and visual memory impairment and sometimes acalculia are found. In right-sided infarcts, hemispatial neglect, visual memory impairment and disturbed visuospatial processing are common. A decreased level of consciousness, disturbed ocular movements, severe motor weakness and delayed abnormal movements do not occur. Involvement of the ventral lateral and dorsomedial nucleus with sparing of the intralaminar nuclei, posterolateral formation and upper midbrain may explain this picture. The fact that the tuberothalamic artery arises from the posterior communicating artery, which often receives its supply from the carotid system, further justifies considering unilateral tuberothalamic infarcts as a syndrome.

A disinhibition syndrome affecting speech (with logorrhoea, delirium, jokes, laughs, inappropriate comments, extraordinary confabulations), was the main manifestation of a right-sided thalamic infarct involving the dorsomedian nucleus, intralaminar nuclei and medial part of the ventral lateral nucleus. Resolution of conflicting tasks was severely impaired, suggesting frontal lobe dysfunction. These abnormalities correlated with the finding on SPECT of a marked hypoperfusion in the overlying hemisphere predominating in the frontal region. We suggest that this behavioural syndrome was produced by disconnecting the dorsomedian nucleus from the frontal lobe and limbic system.

Resume Une observation d'alexie pure sans hemianopsie survenue au cours d'un hematome intra-cerebral est presentee.

The essential aim of this study was to evaluate the contribution of elements of “programmation” on tasks of copying in apraxics with right or left hemispheric lesions. Thirty-two patients (14 with left-sided and 18 with right-sided lesions) have been examined with tests including direct copying of designs by drawing (cube, house, bicycle), varied copies of a cube with guiding landmarks previously given (programmation), and the reproduction of figurative and non-figurative models with small sticks. The subjects in the two test groups were clearly distinguished by the elements of “programmation” which facilitated the copying in patients with left-sided lesions while the patients with right-sided lesions were hampered in their performances. The effects of the “programmation” were observed regardless of the clinical conditions seen. These results point out the difficulties of establishing a program of actions to accomplish in apraxics with left-sided lesions.

Resume On presente les resultats obtenus a une epreuve de discrimination de phonemes chez des malades avec lesions cerebrales unilaterales droite ou gauche. On releve en particulier la possibilite de mauvais resultats lors de lesions anterieures gauches.

A patient with atrial fibrillation and internal carotid artery occlusion developed mixed transcortical aphasia. The CT scan showed two recent distinct infarcts in the dominant hemisphere, one in the precentral artery area (pial artery infarct) and one in the borderzone area between the posterior and middle cerebral arteries territories (watershed infarct). The perisylvian speech areas were spared, but probably disconnected from other areas by the infarcts. The syndrome of isolation of speech area may be caused by vascular conditions which are able to produce simultaneous pial artery and watershed infarcts, and is not necessarily related to more extensive processes of the brain.

The authors report six children with acquired aphasia of unknown etiology. The clinical picture was clearly different from that seen in the usual childhood aphasias and resemble other cases initially reported as "syndrome of acquired aphasia with convulsive disorder". All had associated paroxysmal EEG abnormalities, and 5 have had clinical seizures. The language disorder has improved or remained stationary and no other neurological signs have developed. Our review of the literature and the study of our personal cases show no uniform clinical picture in these children. Three different clinical patterns seem to emerge. The first group show rapid onset and recovery of aphasia, frequent fluctuations in the severity of the language deficit typical of so-called epileptic aphasia. These children appear to have a better prognosis. The second group show worsening of the aphasic deficit after repeated seizures or episodes of aphasia. In the third group progressive deficit in language comprehension (auditory agnosia) with a variable degree of recovery and rare or no clinical seizures. The possible significance of the EEG abnormalities has been discussed and the importance of the aphasia on general behavior and the problems of differential diagnosis have been stressed.

The ambiguity in the literature concerning cerebral dominance for voice recognition, has been investigated with a monaural go-no-go task, using male and female voices. A left ear advantage for the male, and a right ear advantage for the female voice was found, suggesting that both hemispheres can perform voice recognition. A monaural word recognition test showed the expected left hemisphere dominance.

Neurochemistry.- Stoffwechselpathologie der Zyklothymie und Schizophrenie.- Elektroenzephalographie und Psychiatrie.- Psychopharmacology: Basic Aspects.- Psychopharmakotherapie.- Convulsive Therapy.- Psychosurgery.- Soziobiologie der Primaten.- Psychiatrische Genetik.- Konstitution.- Deprivationsforschung und Psychiatrie.- Neurophysiologie und Psychiatrie.- Namenverzeichnis - Author Index.- Sachverzeichnis - Subject Index.

A macular-sparing superior altitudinal hemianopia with no visuo-psychic disturbance, except impaired visual learning, was associated with bilateral ischaemic necrosis of the lingual gyrus and only partial involvement of the fusiform gyrus on the left side. It is suggested that bilateral destruction of the lingual gyrus alone is not sufficient to affect complex visual processing. The fusiform gyrus probably has a critical role in colour integration, visuo-spatial processing, facial recognition and corresponding visual imagery. Involvement of the occipitotemporal projection system deep to the lingual gyri probably explained visual memory dysfunction, by a visuo-limbic disconnection. Impaired verbal memory may have been due to posterior involvement of the parahippocampal gyrus and underlying white matter, which may have disconnected the intact speech areas from the left medial temporal structures.

• A right-handed man with a global aphasia and a left hemiparesis was examined after a cerebrovascular accident. Three weeks later, oral language was only mildly impaired but writing disorders were still severe. At autopsy, there was an infarction of the territory supplied by the right middle cerebral artery. There was no lesion in the left hemisphere.

Studies dealing with memory loss in patients having undergone surgery of the temporal lobes, usually demonstrate an interaction between the nature of the task and the side of the lesion. In this study we investigated the specificity of the deficit for verbal and non-verbal material in a population of patients with unilateral cerebral lesions (mostly vascular). 39 of them had a left hemispheric lesion (LHL), 30 a right hemispheric one (RHL). Two tests were presented to the patients. Each test was composed of 100 cards presenting either faces (test 1) or words (test 2). Word length, frequency and imagery were controlled. Full-face photographs with identical centering were drawn from press-books. The cards were presented successively for 2 seconds each, each item (of 30) appearing twice, according to the following pattern: 10 after 5 other items (I), 10 after 15 items (II), 10 after 30 items (III) and the 10 which come after 5, appear a third time after 30 other cards (IV). Patients had to point to the card seen for the second time. In order to take errors into account in the same analysis, an index (good answers-false recognitions + 20) was used for global results. An ANOVA performed on these data showed an effect of the task (WORDS>FACES, p

We have recently observed 11 cases of thalamic hematomas. 5 of them (3 left and 2 right) were submitted to a detailed neuropsychological examination. All hematomas were mainly limited to the thalamus and the internal capsula without significant invasion or compression of surrounding structures. The level of consciousness was usually good. 4 of the 8 patients with left-sided hematomas showed dysphasia and the 3 patients submitted to a detailed neuropsychological examination suffered also severe and persistent mnesic disturbances (verbal and non-verbal). On the other hand, the two patients with right thalamic hematomas presented on neuropsychological testing non-verbal mnesic disturbances and features indistinguishable from right parietotemporal cortical lesions. Vital outcome was highly favourable since no patient died. Functional recovery was also rather satisfactory but formal neuropsychological testing of memory, language and right cortical functions showed significant persistent deficits at time of follow-up in most cases examined. Relevant literature is reviewed and possible pathogenetic mechanisms are discussed. Among various hypothesis concerning neuropsychological impairments, dysfunction of a specific alerting system appears the most seducing possibility but does not explain all observed deficits.

In 2 patients with infarction in the territory of the right anterior choroidal artery, hemiparesis, hemihypesthesia (in 1), and hemianopia or superior quadrantanopia were associated with severe multimodal hemineglect, without anosognosia, disorientation, or asomatognosia. Single-photon emission tomography showed that marked hypoperfusion was not limited to the right posterior capsular region, but also involved the overlying parietal cortex, and to a lesser extent the frontal cortex. At autopsy in 1 patient, the infarct was nearly limited to the deep white matter of the temporal isthmus and the retrolenticular part of the internal capsule; only minute lesions were present in the globus pallidus, body of caudate, and amygdala. These findings are consistent with a disconnection phenomenon as the basis for subcortical neglect with ipsilateral deactivation of the parietofrontal cortex.

Summary A case of agraphia is presented of a patient who did not reveal any significant difficulties in oral language, reading, praxis or gnosia. The agraphia mainly involved written spelling. Forming words with alphabet blocks was relatively preserved whereas oral spelling was perfect. This disorder involves the final process of coding, in which the act of writing plays an important role.

STUDIES of patients with unilateral cerebral lesions1 or surgically disconnected hemispheres2 suggest a functional asymmetry in processing visual information by the two hemispheres. The right hemisphere (RH) seems to favour matching of pictures of objects by similarity of shape (apperceptive matching), whereas the left hemisphere (LH) favours matching by similarity of meaning or conceptual category (associative matching). As, on the other hand, considerable recent experimental evidence supports the hypothesis that the RH might have a distinct role in processing emotional information3–8, it would be surprising if the RH lacked the capacity of associative processing which is important in emotional communication. Using tachistoscopic half-field presentation the present study produces evidence for a RH superiority for associative processing in response to adequate stimuli such as emotional facial expressions, whereas the LH is more efficient in detecting similarity of function between objects whose shapes are very different.