Parieto-occipital Lesions Research Articles

Homonymous hemianopia following yellow fever vaccination: a case of acute disseminated encephalomyelitis.

A 42-year-old Caucasian man developed left homonymous hemianopia sixteen days after receipt of a live-attenuated 17D-204 yellow fever virus vaccine. MRI imaging of the brain revealed right occipital and left parieto-occipital lesions with marked hyperintensity consistent with demyelination, and a diagnosis of yellow fever vaccine-associated acute disseminated encephalomyelitis was made.

Frontal allographic agraphia in a patient with behavioral variant frontotemporal dementia

ABSTRACT We report a patient with behavioral variant frontotemporal dementia who developed agraphia, irritability, perseverative and stereotyped behavior, and dietary changes. MRI revealed bilateral frontal convexity atrophy. Neuropsychological examination showed fluent aphasia with perseverative allographic agraphia, mild semantic impairment, and dysexecutive syndrome. Allographic agraphia featured unidirectional conversion from hiragana (cursive form of Japanese phonograms) and kanji (Japanese morphograms) to katakana (square form of Japanese phonograms), as opposed to mutual (bidirectional) conversion between hiragana and katakana in parieto-occipital gyri lesions. Furthermore, all letters of the word were converted and this whole-word conversion may be characteristic of perseverative behavior in frontotemporal dementia.

NCMP-18. ENDOVASCULAR TREATMENT OF SYMPTOMATIC TUMORAL VENOUS SINUS STENOSIS: COMPARATIVE ANALYSIS OF CORONARY BALLOON-MOUNTED STENTS AND CONVENTIONAL TECHNIQUES

Abstract Meningiomas may lead to symptomatic papilledema due to elevated intracranial pressure (ICP) from venous sinus compression. While venous sinus stenting has proven effective for treating elevated intracranial pressure, evidence for its application in tumoral-induced stenosis and acquired intracranial hypertension is limited. This study presents an institutional series of symptomatic tumoral venous sinus stenosis cases and compares the technical considerations of endovascular treatment using a coronary balloon-mounted stent to conventional venous sinus stenting. Three patients with meningioma-induced, bilateral papilledema received treatment with venous sinus stenting between 2019-2022. Presentation, stenosis severity, venous manometry, ophthalmologic findings, procedural techniques, and post-operative outcomes were retrospectively analyzed. Three patients (mean age: 59 years, 2 out of 3 male) presented with worsening blurry vision, diplopia, and persistent headaches. Bilateral papilledema was observed (median optic nerve sheath distension=0.48mm). Pre-procedure measurements showed elevated ICP with opening pressures ranging from 37-38 cmH2O. Imaging revealed extra-axial parieto-occipital lesions with significant mass effect, and MR venograms confirmed severe stenosis of the superior sagittal sinus (SSS). Venous angiography (DSV) demonstrated median venous sinus pressures of 32-mmHg proximal to the stenosis with a 4-mmHg pressure gradient across the stenosis. During the procedure, balloon-mounted Onyx coronary stents or a self-expanding PrecisePro carotid stent were deployed successfully. Post-stenting, papilledema resolved completely in two patients, while one patient experienced partial symptom resolution. Proximal SSS pressures decreased by a mean of 46.8%, and trans-stenotic pressure gradients were reduced to ≤1 mmHg. Stent patency without complications was maintained throughout the 2 to 5-month follow-up in all patients. Adjacent meningiomas were subsequently monitored for observation or stereotactic radiosurgery. Small extra-axial lesions causing symptomatic venous sinus compression can be endovascularly treated using balloon-mounted cardiac stents. Non-surgical meningioma patients, symptomatic for intracranial hypertension and lesions proximal to venous sinuses, should be assessed with DSV for potential management with endovascular interventions.

A CASE ILLUSTRATION AND LITERATURE REVIEW OF THYROID CANCER METASTASIS TO THE PITUITARY FOSSA

Abstract AIMS To understand the clinico-radiological and histopathological features, treatment strategies and outcomes of patients with thyroid cancer metastasis to the pituitary fossa. METHOD A 71-year-old man presented with a few months’ history of headaches, blurred vision, diplopia and right sided ptosis. MRI head revealed a 2.5cm pituitary fossa lesion distorting the optic chiasm with right sided cavernous sinus invasion. It also showed frontal, temporal and parieto-occipital lesions. CT thorax, abdomen and pelvis found a retrosternal thyroid goitre. An open biopsy of the occipital lobe lesion revealed a metastatic papillary adenocarcinoma from the thyroid gland. An ultrasound-guided fine needle aspiration of the goitre and abnormal level IV lymph nodes revealed Thy5. The patient subsequently underwent an endoscopic transsphenoidal resection of the pituitary tumour which was confirmed to be a carcinoma. A date and language unrestricted literature search was performed across the MEDLINE, Embase (via Ovid) and Scopus databases using keywords relating metastasis, the pituitary & thyroid glands, and the brain. Citations reporting patients with thyroid metastasis to the pituitary fossa were included. A predetermined proforma was used to extract and store data from the included citations. RESULTS After de-duplication, 2,833 citations were screened for eligibility and 42 citations met the inclusion criteria. CONCLUSIONS We present a rare case illustration and literature review of patients with thyroid cancer metastasis to the pituitary fossa.

Differential outcomes for frontal versus posterior demyelination in childhood cerebral adrenoleukodystrophy.

In the most common variant of childhood cerebral adrenoleukodystrophy (cALD), demyelinating brain lesions are distributed predominately in parieto‐occipital white matter. Less frequently, lesions first develop in frontal white matter. This matched cohort study examined whether outcomes after standard treatment with hematopoietic cell transplantation (HCT) differ in patients with early stage frontal lesions as compared to parieto‐occipital lesions. Retrospective chart review identified seven pediatric patients with frontal cALD lesions and MRI severity score < 10 who underwent a single HCT at our center between 1990 and 2019. Concurrent MRI, neurocognitive and psychiatric outcomes at last comprehensive follow‐up (mean 1.2 years; range 0.5‐2.1 years) were compared with a group of seven boys with the parieto‐occipital variant matched on pre‐HCT MRI severity score. Both groups showed similar rates of transplant complications and radiographic disease advancement. Neurocognitive outcomes were broadly similar, with more frequent working memory deficits among individuals with frontal lesions. Psychiatric problems (hyperactivity, aggression, and atypical behavior) were considerably more common and severe among patients with frontal lesions. Aligned with the critical role of the frontal lobes in emotional and behavioral regulation, functional disruption of self‐regulation skills is widely observed among patients with frontal lesions. Comprehensive care for cALD should address needs for psychiatric care and management.

Neurodevelopmental Outcome in Patients with Typical Imaging Features of Injury as a Result of Neonatal Hypoglycemia.

Previous reports described a pattern of hypoglycemia-induced damage predominantly affecting the parieto-occipital regions. The long-term neurological sequelae of severe neonatal hypoglycemic encephalopathy include developmental delay, poor head growth, learning or behavioral difficulties, visual impairment, and epilepsy. This study reports neurodevelopmental outcome of children with neonatal hypoglycemia-associated parieto-occipital brain injury who were evaluated in our pediatric neurology outpatient clinic for different neurological complaints. We retrospectively reviewed patients who were followed at Kocaeli University Hospital, Pediatric Neurology Department between 2007 and 2015. Patients (n=42) with predominately parieto-occipital lesions on magnetic resonance imaging (MRI) with the typical pattern of neonatal hypoglycemia were evaluated. Patients with documented hypoglycemia (n=21) were included in this study. Patients (n=9) with recurrent episodes of hypoglycemia longer than 12 hours were evaluated as prolonged hypoglycemia. Eleven patients (52.4%) experienced seizures in the neonatal period. Eighteen patients (85.7%) developed epilepsy during the follow-up. Refractory seizures were observed in 8 patients (38.1%). Nine patients (42.9%) manifested microcephaly, seven patients (33.3%) manifested cerebral palsy. Parieto-occipital involvement and the spasticity rate were statistically high in patients with prolonged hypoglycemia (p<0.01). Two patients had autistic features and four patients (19%) had attention deficit hyperactivity disorder. VEP studies could be performed in 18 of 21 patients. All patients had abnormal VEP results. We are of the opinion that most patients of neonatal hypoglycemia are not always documented. Patients under risk and patients with symptoms of hypoglycemia should be vigorously screened and treated to prevent neurologic impairments including cerebral palsy, epilepsy and visual disturbance.

Clinical evaluation of childhood cerebral adrenoleukodystrophy with balint’s symptoms

BackgroundChildhood cerebral adrenoleukodystrophy (CCALD) is the most common phenotype of adrenoleukodystrophy (ALD) and is characterized by the progression of intellectual, psychic, visual, and gait disturbances. Progression of this intractable disease can only be prevented by hematopoietic stem cell transplantation during the early stages of the disease. The aim of this study was to clinically evaluate children with CCALD who have visual symptoms to enable early diagnosis. MethodsWe enrolled 41 Japanese children with CCALD who had visual symptoms. We retrospectively analyzed age of onset, past medical history, initial symptoms, visual symptoms and findings on brain magnetic resonance imaging. ResultsThe median age of disease onset was 7 years (range 5–10 years). The most common visual symptom was strabismus (n = 22). There was only one patient with the triad of symptoms of Balint’s syndrome. Seventeen patients had incomplete Balint’s syndrome and showed one or two of the triad of symptoms. Almost all patients with complete or incomplete Balint’s syndrome showed bilateral parieto-occipital white matter lesions. ConclusionsCCALD could develop into Balint’s syndrome, especially the incomplete form. Therefore, CCALD should be considered when boys show new symptoms, including lack of eye contact or bumping into objects.

Optical coherence tomography in adult adrenoleukodystrophy: a cross-sectional and longitudinal study.

Adrenoleukodystrophy (ALD) encompasses different neurological phenotypes, ranging from the most severe cerebral forms (C-ALD) to the less severe adrenomyeloneuropathy (AMN). As visual system can be varyingly involved, we aimed at exploring whether optical coherence tomography (OCT) may detect retinal abnormalities and their longitudinal changes in adult ALD patients. In this cross-sectional and longitudinal study, we measured the thicknesses of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell complex (mGCC), and segmented inner and outer macula at baseline and their changes over time in 11 symptomatic adult ALD males and 10 age- and sex-matched healthy controls. Statistical analyses were performed for the patients as complete group, and splitting them into two subgroups, one (C-ALD) with and the other (AMN) without cerebral parieto-occipital white matter (WM) lesions. In the complete ALD group and in the C-ALD subgroup, the average pRNFL, mGCC, and inner macula were significantly thinner than in controls (p ≤ 0.01), whereas in the AMN subgroup, they were constantly, though non-significantly, thinner. Significant outer macula thinning was also observed (p < 0.01). In the complete ALD group, follow-up assessment (mean 26.8months, range 8-48) showed mildly progressive thinning of inferior pRNFL, average mGCC, and inner macula. In adult ALD patients, OCT can reveal retinal abnormalities which are prominent in the more compromised patients, namely those with parieto-occipital WM lesions. The inferior pRNFL, average mGCC and inner macula thicknesses might be sensitive-to-change OCT parameters, but their utility and consistency for short-term longitudinal studies deserve further investigations.

Constructional Apraxia in Older Patients with Brain Tumors: Considerations with an Up-To-Date Review of the Literature.

Constructional apraxia (CA) is a neuropsychological impairment of either basic perceptual and motor abilities or executive functions, in the absence of any kind of motor or perceptual deficit. Considering patients with focal brain tumors, CA is common in left or right parietal and parieto-occipital lesions. In neuropsychology, the Rey-Osterrieth Complex FigureTest (ROCFT; or parallel forms) is commonly used for the assessment of CA. This study stems from a clinical observation of a difficulty with CA tests for the majority of older neurosurgical patients without occipitoparietal lesions. Patients were tested at 3 points: before surgery, 3 months after surgery, and 12 months after surgery. Thirty patients (15 meningiomas and 15 glioblastomas) were studied retrospectively. Older patients with focal brain lesions, regardless of the nature of the tumor, performed poorly at CA tests. More than 50% of patients obtained pathologic results at all 3 times considered. Our findings suggest that as CA complex tests involve multiple domains, poor results in copy task may reflect a global cognitive deficit of older patients with tumors, without a specific constructional praxis deficit. CA complex tests (such as the ROCFT) do not give significant informations about visuo-constructional abilities.

Visual and cross-modal cues increase the identification of overlapping visual stimuli in Balint’s syndrome

ABSTRACTIntroduction: Cross-modal interactions improve the processing of external stimuli, particularly when an isolated sensory modality is impaired. When information from different modalities is integrated, object recognition is facilitated probably as a result of bottom-up and top-down processes. The aim of this study was to investigate the potential effects of cross-modal stimulation in a case of simultanagnosia. Method: We report a detailed analysis of clinical symptoms and an 18F-fluorodeoxyglucose (FDG) brain positron emission tomography/computed tomography (PET/CT) study of a patient affected by Balint’s syndrome, a rare and invasive visual–spatial disorder following bilateral parieto-occipital lesions. An experiment was conducted to investigate the effects of visual and nonvisual cues on performance in tasks involving the recognition of overlapping pictures. Four modalities of sensory cues were used: visual, tactile, olfactory, and auditory. Results: Data from neuropsychological tests showed the presence of ocular apraxia, optic ataxia, and simultanagnosia. The results of the experiment indicate a positive effect of the cues on the recognition of overlapping pictures, not only in the identification of the congruent valid-cued stimulus (target) but also in the identification of the other, noncued stimuli. All the sensory modalities analyzed (except the auditory stimulus) were efficacious in terms of increasing visual recognition. Conclusions: Cross-modal integration improved the patient’s ability to recognize overlapping figures. However, while in the visual unimodal modality both bottom-up (priming, familiarity effect, disengagement of attention) and top-down processes (mental representation and short-term memory, the endogenous orientation of attention) are involved, in the cross-modal integration it is semantic representations that mainly activate visual recognition processes. These results are potentially useful for the design of rehabilitation training for attentional and visual–perceptual deficits.

Abnormal center-periphery gradient in spatial attention in simultanagnosia.

Patients suffering from simultanagnosia cannot perceive more than one object at a time. The underlying mechanism is incompletely understood. One hypothesis is that simultanagnosia reflects "tunnel vision," a constricted attention window around gaze, which precludes the grouping of individual objects. Although this idea has a long history in neuropsychology, the question whether the patients indeed have an abnormal attention gradient around the gaze has so far not been addressed. Here we tested this hypothesis in two simultanagnosia patients with bilateral parieto-occipital lesions and two control groups, with and without brain damage. We assessed the participants' ability to discriminate letters presented briefly at fixation with and without a peripheral distractor or in the visual periphery, with or without a foveal distractor. A constricted span of attention around gaze would predict an increased susceptibility to foveated versus peripheral distractors. Contrary to this prediction and unlike both control groups, the patients' ability to discriminate the target decreased more in the presence of peripheral compared with foveated distractors. Thus, the attentional spotlight in simultanagnosia does not fall on foveated objects as previously assumed, but rather abnormally highlights the periphery. Furthermore, we found the same center-periphery gradient in the patients' ability to recognize multiple objects. They detected multiple, but not single objects more accurately in the periphery than at fixation. These results suggest that an abnormal allocation of attention around the gaze can disrupt the grouping of individual objects into an integrated visual scene.

Atypical Presentation of Posterior Reversible Encephalopathy: In a Child with Bilateral Grade IV Vesicoureteric Reflux

Posterior reversible encephalopathy, better known as potential reversible encephalopathy syndrome (PRES), is a clinicoradiological entity mostly described in adult populations manifesting predominantly as bilateral symmetrical diffuse white matter vasogenic oedema in parieto-occipital regions. Rarely it may also present as patchy reversible areas of involvement in the basal ganglia, brainstem and deep white matter. It is reported scarcely in childhood populations. Frequent association with acute hypertension (67-80%) is reported in many studies. Involvement of the brainstem and cervical cord (apart from the typical parieto-occipital lesions) is an extremely rare imaging manifestation of PRES and its recognition is important to avoid misdiagnosis as myelitis or acute disseminated encephalomyelitis by proper clinical correlation. We hereby report a case of PRES in a 7-year-old child showing an uncommon pattern on imaging study involving the brain as well as the brainstem and cervical spinal cord.

Optic Ataxia: From Balint’s Syndrome to the Parietal Reach Region

Optic ataxia is a high-order deficit in reaching to visual goals that occurs with posterior parietal cortex (PPC) lesions. It is a component of Balint's syndrome that also includes attentional and gaze disorders. Aspects of optic ataxia are misreaching in the contralesional visual field, difficulty preshaping the hand for grasping, and an inability to correct reaches online. Recent research in nonhuman primates (NHPs) suggests that many aspects of Balint's syndrome and optic ataxia are a result of damage to specific functional modules for reaching, saccades, grasp, attention, and state estimation. The deficits from large lesions in humans are probably composite effects from damage to combinations of these functional modules. Interactions between these modules, either within posterior parietal cortex or downstream within frontal cortex, may account for more complex behaviors such as hand-eye coordination and reach-to-grasp.

Brain vascular lesions: a clinicopathologic, immunohistochemistry, and ultrastructural approach.

Brain vascular malformations are relatively common lesions that cause serious neurologic disability or death in a significant proportion of individuals bearing them. The purpose of this study was to analyze the clinicopathologic and immunohistochemistry these lesions, looking for common antibodies expressed such as CD31, CD34, CD15, factor VIII, nestin, vimentin, vascular endothelial grow factor (VEGF), vascular endothelial grow factor receptor-2 (VEGF-R2), glial fibrillar acidic protien (GFAP), and fibroblastic grow factor β (β-FGF) and ultrastructure in endothelial cells as well as in vessel walls. Fifty cases of vascular lesions were included in this study: 29 (58%) of them were arteriovenous malformations and 21 (52%) were brain cavernomas. Twenty-six (52%) patients were women and 24 (48%) men. The age range was from 13 to 68 years (mean age, 35.86 ± 15.19 years). The size of the lesions ranged between 1 and 8 cm (3 ± 1.65 cm), and parieto-occipital lesions had a bigger size. Evolution time varied from 1 month to 1 year (mean, 7.5 months). There was a significant statistical correlation between age and sex (P = -035), rupture of lesion (P = .015), brain hemorrhage (P = .033), necrosis (P = .011), hemosiderin deposit (P = .042), VEGF (P = .015), and VEGFR (P = .037), as well as localization of rupture (P = .017), loss of consciousness (P = .000), visual deficit (P = .026), hyaline vessels (P = .000), and CD31 (.009). Interactions between endothelial cells and mural cells (pericytes and vascular smooth muscle cells) in blood vessel walls have recently come into focus as central processes in the regulation of vascular formation, stabilization, remodeling, and function in brain vascular lesions. However, the molecular mechanisms that underlie the formation and growth of brain arteriovenous malformations are still poorly understood.

Eyeing the eyes in social scenes: Evidence for top-down control of stimulus selection in simultanagnosia

Simultanagnosia is a disorder of visual attention resulting from bilateral parieto-occipital lesions. Healthy individuals look at eyes to infer people's attentional states, but simultanagnosics allocate abnormally few fixations to eyes in scenes. It is unclear why simultanagnosics fail to fixate eyes, but it might reflect that they are (a) unable to locate and fixate them, or (b) do not prioritize attentional states. We compared eye movements of simultanagnosic G.B. to those of healthy subjects viewing scenes normally or through a restricted window of vision. They described scenes and explicitly inferred attentional states of people in scenes. G.B. and subjects viewing scenes through a restricted window made few fixations on eyes when describing scenes, yet increased fixations on eyes when inferring attention. Thus G.B. understands that eyes are important for inferring attentional states and can exert top-down control to seek out and process the gaze of others when attentional states are of interest.

Living with Balint's: A Descriptive, Narrative Account of Two Patients' Adaptations to Living with a Rare and Disabling Visuoperceptual Disorder (P02.036)

Objective: To provide a descriptive, narrative account of two patients9 own experiences with Balint syndrome due to bilateral posterior hemispheric ischemic strokes, and to familiarize clinicians and therapists with the functional impairments and subsequent adaptations. Background Balint syndrome is a rare and debilitating neurological disorder characterized by optic ataxia, ocular apraxia, and simultanagnosia. It is typically caused by bilateral parieto-occipital lesions in the convexity of the hemispheres. Design/Methods: We examine the progression from onset to diagnosis and finally ongoing adaptation to the daily difficulties of living with Balint syndrome for two patients (AS, female, age 68; and JD, male, age 66). Results: AS initially believed her symptoms were due to an ocular problem, prompting her to seek first consultation with an ophthalmologist. After subsequent neurological consult resulted in proper diagnosis and patient education, AS began to implement a variety of environmental home adaptations. She maintained spatial awareness by keeping in constant contact with bathroom fixtures while attending to her activities of daily living, and by eating with her hands in place of utensils. AS also compensated for her simultanagnosia by placing colored tape around household objects to indicate object type, and for her ocular apraxia by listening to books on tape. Soon after receiving his diagnosis of Balint syndrome, JD began to relearn basic tasks such as dressing himself and brushing his teeth. Unable to track moving objects, JD performs horizontal pursuit by rotating his head. As his strokes were more recent than AS9s, most of JD9s practical adaptations are still caretaker-centered. JD is also struggling with labile and depressed moods. Conclusions: We report two cases of Balint syndrome from the patients9 perspective and describe the impairments and ongoing adaptations accompanying the disorder. The patient9s perspective is critical in terms of developing specific rehabilitation research strategies of the visuo-perceptual disorders in Balint syndrome. Disclosure: Dr. Cuomo has nothing to disclose. Dr. Flaster has nothing to disclose. Dr. Biller has nothing to disclose.

Posterior reversible encephalopathy syndrome as a revealing manifestation of Guillain-Barré syndrome

We report a patient with a Guillain-Barré syndrome (GBS) revealed by a posterior reversible encephalopathy syndrome (PRES). The PRES is typically associated with bilateral parieto-occipital T2 and FLAIR hyperintense MRI lesions and observed in various etiologic conditions leading to acute arterial hypertension. PRES results from a breakdown of the circulatory autoregulation, many in the posterior cerebral territories. GBS can be considered as an independent risk factor of PRES, due to acute dysautonomia and pain with consecutive arterial hypertension, as well as to cytokine production changing capillary permability. Such patients with PRES-revealed GBS may be treated with intravenous immunoglobulin therapy only after exclusion of any ischemic or hemorrhagic cerebral complications, and after control of the blood pressure and of the encephalopathic signs and symptoms.

Congruence and discrepancy of interictal and ictal EEG with MRI lesions in focal epilepsies

To compare the occurrence and localization of interictal epileptiform discharges (IEDs) and epileptic seizure patterns (ESPs) with the localization of MRI lesions. We retrospectively analyzed the EEG and MRI data of a series of patients with focal epilepsies that had been studied from 1991 to 2009. In patients with temporal lesions, the localization of IEDs was most congruent (58.6% with IEDs exclusively over the lesional lobe and 29.7% with a majority of temporal IEDs). This differed (p < 0.001) from frontal lesions (27.5% with exclusively frontal IEDs, 24.6% with a majority of frontal IEDs). In parieto-occipital lobe lesions, only 12.1% had IEDs exclusively over the lesional lobe compared to 48.5% with no parieto-occipital IEDs at all. Patients with central lesions often lacked any IEDs (54.5%, p < 0.001). The occurrence and localization of ESPs also differed between the regions. They were most congruent in temporal lesions (63.5% of patient had ESPs only over the lesional lobe, 23.4% had the majority of ESPs over the lesional lobe), which differed from frontal and parieto-occipital lesions (37.7% and 30.3% of patients with ESPs only over the lesional lobe). Patients with central lesions had ESPs very frequently only outside the lesional lobe (63.6%). Surgery outcome did not differ between the regions. The occurrence and localization of interictal and ictal EEG findings differs vastly for lesions in different brain regions. These findings should be used to carefully weigh the results from EEG studies particularly in patients with extratemporal epilepsies considered for epilepsy surgery.

Posterior Reversible Encephalopathy Syndrome Presenting as Balint Syndrome

Balint syndrome is a disorder of inaccurate visually guided saccades, optic ataxia, and simultanagnosia that typically results from bilateral parieto-occipital lesions. Visual perception disturbances in the posterior reversible encephalopathy syndrome (PRES) include hemianopia, visual neglect, and cerebral blindness, but Balint syndrome had not been recognized. We report Balint syndrome associated with PRES in a 37-year-old woman with acute hypertension and systemic lupus erythematosus. Balint syndrome can be an initial presentation of PRES.

Impaired delayed but preserved immediate grasping in a neglect patient with parieto-occipital lesions

Patients with optic ataxia, a deficit in visually guided action, paradoxically improve when pantomiming an action towards memorized stimuli. Visual form agnosic patient D.F. shows the exact opposite pattern of results: although being able to grasp objects in real-time she loses grip scaling when grasping an object from memory. Here we explored the dissociation between immediate and delayed grasping in a patient (F.S.) who after a parietal-occipital stroke presented with severe left visual neglect, a loss of awareness of the contralesional side of space. Although F.S. had preserved grip scaling even in his neglected field, he was markedly impaired when asked to pretend to grasp a leftward object from memory. Critically, his deficit cannot be simply explained by the absence of continuous on-line visual feedback, as F.S. was also able to grasp leftward objects in real-time when vision was removed. We suggest that regions surrounding the parietal-occipital sulcus, typically damaged in patients with optic ataxia but spared in F.S., seem to be essential for real-time actions. On the other hand, our data indicates that regions in the ventral visual stream, damaged in D.F but intact in F.S., would appear to be necessary but not sufficient for memory-guided action.