Left Parieto-temporal Regions Research Articles

Challenges in Intraventricular Meningiomas Surgery, Case Presentation and Review of the Literature

Objectives: Review on the management of meningiomas of the ventricular atrium according to what has been reported in the literature and in the experience of our institution. Background: Intraventricular meningiomas represent 1 to 5% of meningiomas. Approaches are suggested depending on tumor location and extension, proximity to eloquent areas or pathways (motor, sensory, optic radiation, language), vascular pedicles. In this case, it is a 41-year-old female patient who presents a stabbing headache in the left parieto-temporal region with an intensity of 7/10. Clinically mental functions with impaired retrograde memory and anterograde, acalculia, preserved judgment and abstraction, bradilalia, bradypsychia, for which he went for evaluation and a cranial tomography study with contrast was carried out, evidencing intraventricular extra axial tumor lesion, for which he underwent surgical procedure through excision of a probable left intraventricular extra axial lesion meningioma vs choroid plexus papilloma.

Occult Pheochromocytoma and Acute Ischaemic Stroke in Young Adult: Cause or Association

Pheochromocytoma is a rare catecholamine-secreting tumours of chromaffin tissues that cause a constellation of symptoms. It is closely associated with endocrine hypertension that can be masked, sustained or paroxysmal leading to hypertensive crisis, resulting in vascular and non-vascular complications and rarely cerebral ischaemia and stroke. A healthy 22 year old male reported with acute Right upper limb(RUL) monoplegia and Motor aphasia for five days with raised blood pressure levels. hypertonia was present, deep tendon reflexes were exaggerated in RUL and Right Plantar was extensor. General and systemic findings were nonsignificant . Routine investigations showed thrombocytosis and M.R.I. Brain was suggestive of acute infarction of Left Parieto-Temporal region. Renal doppler, Carotid Intima Media Thickness, Cerebral Angiogram, 2D-E.C.H.O. and Fundoscopy were normal. AntinuclearAntibody was negative. Contrast CT of abdomen revealed right adrenal mass suggestive of isolated Pheochromocytoma. Vanyl-Mandelic Acid was positive. Patient was stabilised and managed conservatively for 4 weeks followed by adrenalectomy and appropriate medical therapy. Patient is on regular followup and does not seem to require any antihypertensives or any other intervention. Pheochromocytoma is a notorious tumor and a great masquerader specially in young adults. A keen eye, routine checkups and evaluation is the key to detecting and preventing its associated morbidity and mortality.

Takotsubo cardiomyopathy associated with Herpes simplex encephalitis: A case report and literature review

Takotsubo cardiomyopathy (TCM) is a stress-induced cardiomyopathy characterized by transient left ventricular dysfunction. It can be triggered by various central nervous system pathologies including status epilepticus (SE) and N-methyl-d-aspartate receptor (NMDAr) encephalitis. Herpex simplex encephalitis (HSE) is a life-threatening, sporadic, encephalitis associated with focal or global cerebral dysfunction caused by herpes simplex viruses type 1(HSV-1), or less commonly, type 2(HSV-2). While approximately 20% of patients with HSE develop NMDAr antibodies, not all manifest with encephalitis clinically. We present here a 77-year-old woman admitted with HSV-1 encephalitis who presented with acute encephalopathy and seizure-like activity. Continuous EEG monitoring (cEEG) showed periodic lateralized epileptiform discharges (PLEDs) involving the left parietotemporal region but no evidence of electrographic seizures. Her early hospital course was complicated by TCM which subsequently resolved on repeat TTE. She demonstrated initial neurological improvement. However, five weeks later her mental status declined. Again, no seizures were appreciated on cEEG. Unfortunately, repeat studies including lumbar puncture and magnetic resonance imaging (MRI) of the brain were consistent with NMDAr encephalitis. She was treated with immunosuppression and immunomodulation therapies. To our knowledge we report the first case of TCM secondary to HSE without comorbid status epilepticus. However, further studies are needed to better understand the correlation between, and underlying pathophysiology of HSE and TCM, as well as any potential association with this presentation and subsequent development of NMDAr encephalitis.

Гемодинамическая асимметрия и альфа-асимметрия полушарий головного мозга человека при различных положениях тела

Hemispheric asymmetry has been intensively studied by psycho- and neurophysiology mostly using electroencephalography (EEG) and functional magnetic resonance imaging. However, there is little data available on the characteristics of bioelectrical and haemodynamic asymmetry of the human brain during postural changes. This pilot study introduces a combined technique of simultaneous recording of brain haemodynamic and bioelectric asymmetry in different body positions. The aim of the paper was to compare asymmetry coefficients in three different body positions and to establish cortex areas with the most active shift in blood flow and alpha power in response to postural changes. The research involved 12 healthy volunteers aged between 20 and 25 years (mean age 21.4 ± 1.5 years) evenly distributed by sex. Materials and methods. Bioelectric and haemodynamic activity of the brain was assessed by means of rheoencephalography and EEG, respectively. Rheographic index and spectral power of alpha waves were recorded in three body positions (sitting, supine and 45° head-down tilt), followed by the calculation of haemodynamic asymmetry (Khda) and alpha asymmetry (Kαa) coefficients. Results. Statistical analysis of Khda showed no sex differences or significant differences in this parameter between the body positions, which can be explained by direct effects of baroreflex and cerebrovascular autoregulation. Statistical comparison of Kαa of EEG signals from all electrode leads with each other and in each position demonstrated significant changes in Kαa of P3/P4, T5/T6 and F3/F4 pairs in male subjects. These findings can indicate that posterior parietal cortex of both hemispheres and left parietotemporal region, which play an important role in spatial perception, as well as dorsolateral prefrontal cortex, which participates in muscle tone regulation for posture correction, are actively involved in bioelectrical response to postural changes.

Combination of phage therapy and cefiderocol to successfully treat Pseudomonas aeruginosa cranial osteomyelitis.

Background Pseudomonas aeruginosa has the ability to exhibit resistance to a broad range of antibiotics, highlighting the importance of identifying alternative or adjunctive treatment options, such as phages.Patients and methodsWe report the case of a 25-year-old male who experienced an accidental electrocution resulting in exposed calvarium in the left parieto-temporal region, complicated by a difficult-to-treat P. aeruginosa (DTR-P. aeruginosa) infection. Cefiderocol was the sole antibiotic with consistent activity against six bacterial isolates obtained from the infected region over a 38 day period.ResultsWGS analysis identified a blaGES-1 gene as well as the MDR efflux pumps MexD and MexX in all six of the patient’s ST235 DTR-P. aeruginosa isolates, when compared with the reference genome P. aeruginosa PA01 and a P. aeruginosa ST235 isolate from an unrelated patient. After debridement of infected scalp and bone, the patient received approximately 6 weeks of cefiderocol in conjunction with IV phage Pa14NPøPASA16. Some improvement was observed after the initiation of cefiderocol; however, sustained local site improvement and haemodynamic stability were not achieved until phage was administered. No medication-related toxicities were observed. The patient remains infection free more than 12 months after completion of therapy.ConclusionsThis report adds to the growing literature that phage therapy may be a safe and effective approach to augment antibiotic therapy for patients infected with drug-resistant pathogens. Furthermore, it highlights the importance of the GES β-lactamase family in contributing to inactivation of a broad range of β-lactam antibiotics in P. aeruginosa, including ceftolozane/tazobactam, ceftazidime/avibactam and imipenem/relebactam.

Convulsive Seizures Revealing Hashimoto’s Encephalopathy

Introduction: Hashimoto encephalopathy (HE) is an autoimmune disease with different neurological and psychiatric characteristics. It is associated with increased thyroperoxidase autoantibodies. The diagnosis of HE is clinical and involves the detection of serum thyroperoxidase (TPO) antibodies and the exclusion of other etiologies. A clinical response to corticosteroid therapy supports the diagnosis. We report a case of HE revealed by convulsive seizures and cognitive and behavioral disorders. Observation: She is a 7-year-old child followed in a neurology unit for convulsive seizures for one year. Clinical examination performed in the endocrinology unit later found tachycardia without goiter, behavioral disorders, difficulties to concentrate as well as psychomotor agitation. Biological work up revealed subclinical hypothyroidism, positive anti-TPO antibodies with normal thyroid ultrasound and brain MRI. The cerebrospinal fluid was clear, normotensive and absence of pleocytosis. The sleep-wake electroencephalogram was well organized for her age with a paroxysmal discharge in the left parieto-temporal region. Based on these clinical, biological and morphological data, the diagnosis of HE was retained. Corticosteroid therapy with prednisone at 1 mg/kg/day was initiated for 6 weeks while reducing the dose progressively. There was a good clinical and biological progress under treatment. Conclusion: Hashimoto’s encephalopathy is a rare, but probably unrecognized entity. Over the past decades, knowledge about thyroid, brain, immunity interactions has increased. This indicates the importance of a multidisciplinary approach of endocrinologists, neurologists, psychiatrists and pediatricians for early recognition and treatment.

Identification of the main components of spontaneous speech in primary progressive aphasia and their neural underpinnings using multimodal MRI and FDG-PET imaging

BackgroundPrimary progressive aphasia (PPA) is a clinical syndrome characterized by gradual loss of language skills. This study aimed to evaluate the diagnostic capacity of a connected speech task for the diagnosis of PPA and its variants, to determine the main components of spontaneous speech, and to examine their neural correlates. MethodsA total of 118 participants (31 patients with nfvPPA, 11 with svPPA, 45 with lvPPA, and 31 healthy controls) were evaluated with the Cookie Theft picture description task and a comprehensive language assessment protocol. Patients also underwent 18F-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging studies. Principal component analysis and machine learning were used to evaluate the main components of connected speech and the accuracy of connected speech parameters for diagnosing PPA. Voxel-based analyses were conducted to evaluate the correlation between spontaneous speech components and brain metabolism, brain volumes, and white matter microstructure. ResultsDiscrimination between patients with PPA and controls was 91.67%, with 77.78% discrimination between PPA variants. Parameters related to speech rate and lexical variables were the most discriminative for classification. Three main components were identified: lexical features, fluency, and syntax. The lexical component was associated with ventrolateral frontal regions, while the fluency component was associated with the medial superior prefrontal cortex. Number of pauses was more related with the left parietotemporal region, while pauses duration with the bilateral frontal lobe. The lexical component was correlated with several tracts in the language network (left frontal aslant tract, left superior longitudinal fasciculus I, II, and III, left arcuate fasciculus, and left uncinate fasciculus), and fluency was linked to the frontal aslant tract. ConclusionSpontaneous speech assessment is a useful, brief approach for the diagnosis of PPA and its variants. Neuroimaging correlates suggested a subspecialization within the left frontal lobe, with ventrolateral regions being more associated with lexical production and the medial superior prefrontal cortex with speech rate.

Penetran Travmaya Bağlı İnternal Karotis Arter Diseksiyonu ile İlişkili İskemik İnme Olgusu: Nedensellik Bağı İçin Adli Tıbbi Değerlendirme

İskemik inme, önemli bir morbidite ve mortalite nedenidir. Ancak travmatik internal karotis arter diseksiyonuna bağlı iskemik inme nadir görülen bir durumdur.
 Bu olgu sunumunda, 35 yaşında erkek hasta boynundan kesici-delici alet ile yaralanmış ve hastada total afazi ve sağ hemiparezi meydana gelmişti. Radyolojik incelemelerde sol parieto-temporal bölgede beyin enfarktüsü ve bıçaklama sonrası internal karotis arter diseksiyonu tanısı konuldu.
 Bu olgunun adli tıp anabilim dalında yapılan adli tıbbi değerlendirmesinde, başka travmatik veya patolojik bir durumun varlığını dışlamak ve “kesici-delici alet yaralanmasına bağlı internal karotis arter yaralanması” ile “iskeminin neden olduğu inme ve afazi” arasında nedensellik bağı kurulması için nöroşirürji anabilim dalı ile işbirliği yapıldı.
 Bu makalede sunulan olgu nedeniyle literatür gözden geçirilmiş, adli tıp uygulamalarında nedensellik kavramı ve prosedürü ele alınmış ve bu gibi durumlarda multidisipliner yaklaşımın önemini vurgulanmıştır.

Regional dissociation between the cerebral blood flow and gray matter density alterations in idiopathic normal pressure hydrocephalous: results from SINPHONI-2 study.

The purpose of this study was to elucidate the specific regional cerebral blood flow (rCBF) alterations for idiopathic normal pressure hydrocephalus (iNPH) by comparing the proportional rCBF and gray matter change from those of a normal database at the same point of SPECT and MRI examinations. Thirty subjects with iNPH underwent both CBF SPECT and MRI. After normalization, voxel-wise two-sample t tests between patients and 11 normal controls were conducted to compare the regional alteration in the gray matter density and rCBF. The rCBF reduction and the gray matter decrease were seen in almost similar regions surrounding Sylvian fissure, the left parietotemporal region and frontal lobes, whereas we did not find rCBF increase at the top of the high convexity, where the increase of the gray matter density was the highest (p < 0.05). Our study showed regional associations and dissociations between the relative gray matter density and rCBF in patients with iNPH.

Reading difficulties in primary progressive aphasia in a regular language-speaking cohort of patients.

Reading impairment is an important feature in Primary Progressive Aphasia (PPA). The Spanish orthography entails completely regular spelling to sound correspondences, so reading disorders may be different to English. In the current study, reading, phonological and semantic abilities of 35 patients with the three variants of PPA, and 13 healthy volunteers were assessed. Brain metabolism was concomitantly obtained from each participant using 18F-fluorodeoxyglucose positron emission tomography imaging. Two main patterns of impairment were identified: difficulties in nonwords reading with preservation of exception words in agrammatic and logopenic aphasia, and the inverse pattern in semantic dementia. Left frontal and left parietotemporal regions were associated to nonwords reading, while the anterior temporal lobe was related to reading of exception words. These results support the usefulness of examining reading abilities in the differential diagnosis of PPA variants, and suggest potential types of words that could be used in Spanish to assess these patients.

Dissecting Cellulitis of the Scalp Early Diagnosed by Color Doppler Ultrasound.

Dissecting cellulitis of the scalp (DC) is a chronic inflammatory condition of the scalp that ultimately leads to scarring alopecia. A healthy 19-year-old male presented with a solitary, soft, alopecic nodule that had appeared 1 year before. A color Doppler ultrasound examination showed a hypodermal anechoic fluid collection in the left parietotemporal region of the scalp, connected to the base of widened hair follicles, and presented inner echoes suggestive of debris, as well as several fragments of hair tracts. A diagnosis of DC was made and an epidermal or trichilemmal cyst was ruled out. This case shows the importance of color Doppler ultrasound for supporting the diagnosis at an early stage or with an unusual presentation of DC.

Atypical Sulcal Pattern in Children with Developmental Dyslexia and At-Risk Kindergarteners.

Developmental dyslexia (DD) is highly heritable and previous studies observed reduced cortical volume, white matter integrity, and functional alterations in left posterior brain regions in individuals with DD. The primary sulcal pattern has been hypothesized to relate to optimal organization and connections of cortical functional areas. It is determined during prenatal development and may reflect early, genetically influenced, brain development. We characterize the sulcal pattern using graph-based pattern analysis and investigate whether sulcal patterns in parieto-temporal and occipito-temporal regions are atypical in elementary school-age children with DD and pre-readers/beginning readers (preschoolers/kindergarteners) with a familial risk (elementary school-age children: n [males/females], age range = 17/11, 84-155 months; preschoolers/kindergarteners: 16/15, 59-84 months). The pattern of sulcal basin area in left parieto-temporal and occipito-temporal regions was significantly atypical (more sulcal basins of smaller size) in children with DD and further correlated with reduced reading performance on single- and nonword reading measures. A significantly atypical sulcal area pattern was also confirmed in younger preschoolers/kindergarteners with a familial risk of DD. Our results provide further support for atypical early brain development in DD and suggest that DD may originate from altered organization or connections of cortical areas in the left posterior regions.

P 61. Is high frequency rTMS a new tool in remediating dyslexia?

Introduction Evidence from functional neuroimaging has reported hypoactivation of the left parieto-temporal regions in children and adults with dyslexia when they engage in reading-related tasks (Shaywitz et al., 2002; Richlan et al., 2011). Studies on the remediation of dyslexia have consistently found that remedial treatment improves reading ability and increases activation in critical brain areas (Temple et al., 2003; Hoeft et al., 2011). Objectives We wanted to determine whether high frequency repetitive trancranial magnetic stimulation (hf-rTMS) over areas that are underactive in dyslexics during reading, such as the left superior temporal gyrus (STG) and the left inferior parietal lobe (IPL), would improve the reading performance of dyslexic adults. Materials and methods Ten dyslexics performed three reading tasks (reading aloud words, non-words and text) in seven experimental conditions: following 5Hz-rTMS over the IPL and STG (target sites) bilaterally (left and right hemisphere); following 5Hz-rTMS over the vertex (control site); in two conditions without rTMS (no-TMS or baseline). Reading accuracy (number of errors) and speed (onset reaction times-RTs-for word and non-word reading; number of syllables read in the text per second-syll/sec) were calculated. Stimulus consisted of seven sets of 30 words (15 trisyllabic and 15 disyllabic) with high frequency in Italian written texts, 30 non-words (15 trisyllabic and 15 disyllabic), and texts over 600 syllables long. Brain stimulation consisted of ten rTMS trains of 50 stimuli at 5-Hz frequency (stimulation time, 10s); stimuli were delivered at 100% of the motor threshold. The coil was placed tangential to the skull over P3, P4, P5 and P6 of the 10–20 EEG system and over the vertex. Results Non-word reading errors after both left and right IPL stimulations were significantly fewer than all other conditions. Text reading errors following L-STG stimulation were fewer than all other conditions. Word-reading RTs after left STG stimulation were shorter than all other conditions. Furthermore, non-word reading RTs after left IPL stimulation were shorter than Vertex and Baseline, but not than other conditions. Notably, no differences emerged between the Vertex and mean Baseline thus indicating the absence of unspecific effects related to rTMS per se. Conclusion The study shows that hf-rTMS is effective in improving the reading accuracy and speed of dyslexics and that the effect is strictly task-related and site-specific. To the best of our knowledge, this is the first study which demonstrates that distinctive facilitation of neural pathways known to be underactive in dyslexics improves their reading performance. Although preliminary, these findings could suggest new treatment perspectives for the development of long-term specific treatments for dyslexia.

EEG abnormalities in psychopath and non-psychopath violent offenders

Previous EEG studies attempted to examine violent behavior as homogeneous construct. Up to date, there is no other research studying Low-Resolution Brain Electromagnetic Tomography (LORETA) technique in psychopath offenders. ObjectiveTo find electrophysiological differences specifically related to the psychopathy construct and independent of the violent behavior. The current investigation compares the QEEG and the current source density measures of violent psychopath offenders to a non-psychopath violent group. MethodsThe resting EEG activity and LORETA for the EEG spectral fast bands were evaluated in 58 violent offenders, 31 with and 27 without psychopathy according to the Hare Psychopathy Checklist – Revised. All subjects were assessed using the DSM IV-R criteria. The EEG visual inspection characteristics and the use of frequency domain quantitative analysis techniques (Narrow band spectral parameters) are described. ResultsQEEG analysis showed a pattern of excess of beta activity on the left parieto-temporal regions and bilateral occipital areas and decrease of alpha band on the left centro-temporal and parieto-central derivations in the psychopath group. LORETA signified an increase of beta activity (17.18 Hz) in psychopath group relative to a non- psychopath group within fronto-temporo-limbic regions. ConclusionsThese findings indicate that QEEG analysis and techniques of source localization may reveal differences in brain electrical activity among offenders with psychopathy, which was not obvious to visual inspection. Taken together, these results suggest that abnormalities in a fronto-temporo-limbic network play a relevant role in the neurobiological basis of psychopathy.

Parieto-temporal alpha EEG band power at baseline as a predictor of antidepressant treatment response with repetitive Transcranial Magnetic Stimulation: A preliminary study

The aim of this preliminary study was to determine the predictive value of absolute alpha band power measured during the rest EEG eyes closed task for responses to 20 sessions of high frequency repetitive transcranial stimulation (rTMS) in the left dorsolateral prefrontal cortex in patients with pharmacoresistant major depressive episode. 13 major depressive disorders (8 males) and 8 bipolar disorders (6 males) were included (mean age 58years). Spearman correlations between pretreatment alpha band power in height regions of analysis and absolute improvement in Beck Depression Inventory Short Form (ΔBDI-SF) were analyzed. The predictive value of alpha band power for classifying patients as responders and non-responders to rTMS was determined using Receiver Operating Characteristic (ROC) curve. Spearman correlation analysis revealed that ΔBDI-SF correlated significantly and negatively with alpha band power on the right (r=-.673, p=.001) and left parieto-temporal regions (r=-.638, p=.002). The area under the ROC curve for the right parieto-temporal was .815, p=.0037. The cut-off point that maximized both sensitivity and specificity was 1.49μV. Sensitivity, specificity, positive and negative predictive values were 100, 66, 80, 100% respectively. The population was small and lacked homogeneity concerning affective disorders (unipolar and bipolar disorder). The use of a self-rating subjective scale (BDI-SF) to measure the severity of depression could be criticized. Pretreatment alpha band power on parieto-temporal regions could be a predictor for response to rTMS in patients with homogenous demographic/clinical features. The association between electrical activity and the perfusion under each electrode need to be examined.

AS21-02 - Bulimia nervosa and impulsiveness: electrophysiological evidence of hyperarousal-related impairment of inhibitory processes

Objectives Bulimia nervosa (BN) is associated with a deficit of self-regulatory control and impulsivity. The present study was aimed to clarify, using electrophysiological techniques, whether impulsivity in BN subjects is related to hyperarousal, which impairs inhibitory control. A poor modulation of emotional arousal might induce impulsive behaviors through this mechanism favoring binge eating as well as comorbidity with substance abuse. Methods Event-related potentials were recorded in 17 female patients with BN and 17 healthy controls, during a three-tone oddball task. ERP components related to response inhibition, effortful and automatic processing were analyzed. ERP topography and tomography were analyzed by means of the microstate and LORETA techniques. Results BN patients showed reduced amplitude and shorter latency of the N200; increased amplitude and shorter latency of the target SW; higher activity of the distracter P300 generators in left fronto-parietal-temporal cortex and bilateral cingulate; lower activity of the target SW generators in right frontal gyrus, left parieto-temporal regions, and bilateral cingulate. Discussion The observed electrophysiological abnormalities suggest a condition of hyperarousal, with impaired suppression of irrelevant stimuli due to abnormal cortical activation and reduced signal-to-noise ratio. Our findings point to functional abnormalities within a neural system that subserves self-regulatory control and reward, which may contribute to binge-eating and other impulsive behaviors in women with BN.

P-566 - Electrophysiological investigation of impulsiveness in patients with bulimia nervosa: evidence of reduced inhibitory control

Bulimia nervosa (BN) has been previously associated with impulsivity and a deficit of self-regulatory control. However, the pathophysiological mechanisms underlying such behaviors have not been clarified. The present study was aimed to investigate, using electrophysiological techniques, whether impulsivity in BN subjects is related to hyperarousal, which might impair inhibitory control. Event-related potentials were recorded in 17 female patients with BN and 17 matched healthy controls, during a three-tone oddball task. ERP components related to response inhibition, effortful and automatic processing were analyzed. ERP topography and tomography were analyzed by means of brain electrical microstate and LORETA techniques. With respect to healthy controls, BN patients showed reduced amplitude and shorter latency of the N200; increased amplitude and shorter latency of the target SW; higher activity of the distracter P300 generators in left fronto-parietal-temporal cortex and bilateral cingulate; lower activity of the target SW generators in right frontal gyrus, left parieto-temporal regions, and bilateral cingulate. The electrophysiological abnormalities correlated positively with the BIS scores for impulsiveness. The observed electrophysiological abnormalities suggest a condition of hyperarousal, with impaired suppression of irrelevant stimuli due to abnormal cortical activation and reduced signal-to-noise ratio. Our findings point to functional abnormalities within a neural system that subserves self-regulatory control and reward, which may contribute to binge-eating and other impulsive behaviors in women with BN.

The Brain Basis of the Phonological Deficit in Dyslexia Is Independent of IQ

Although the role of IQ in developmental dyslexia remains ambiguous, the dominant clinical and research approaches rely on a definition of dyslexia that requires reading skill to be significantly below the level expected given an individual’s IQ. In the study reported here, we used functional MRI (fMRI) to examine whether differences in brain activation during phonological processing that are characteristic of dyslexia were similar or dissimilar in children with poor reading ability who had high IQ scores (discrepant readers) and in children with poor reading ability who had low IQ scores (nondiscrepant readers). In two independent samples including a total of 131 children, using univariate and multivariate pattern analyses, we found that discrepant and nondiscrepant poor readers exhibited similar patterns of reduced activation in brain areas such as left parietotemporal and occipitotemporal regions. These results converge with behavioral evidence indicating that, regardless of IQ, poor readers have similar kinds of reading difficulties in relation to phonological processing.

Sellar Fracture Followed by Sudden Death

The authors describe a case of sellar fracture followed by sudden death. The victim was involved in a wrangle. The autopsy revealed facial damage and sellar fracture and no evidence of cerebral damage, except for a mild subarachnoid hemorrhage in the left parietotemporal regions and undersurface of both frontal lobes. Sellar fracture is a rare and severe entity, associated with serious complications, which is frequently diagnosed postmortem. In any case, death is rarely a direct consequence of the sellar fracture itself and is usually considered to be the result of associated cerebral trauma. This case prompted us to screen the literature on sellar fracture to gain a better understanding of the mechanism of death.

A Mirror in the Mind: A Case of Visual Allaesthesia in Homonymous Hemianopia

We report the case of a 61-year-old female patient with intracranial bleeding in left parietal and parieto-temporal regions and a history of epilepsy and migraine. MR images showed lesions of the optic radiation, but primary visual cortical areas were intact. Perimetric testing revealed an incomplete right hemianopia. The patient claimed that visual percepts from her intact field were projected as “mirror images” into the hemianopic field. The illusory images were weak and sometimes difficult to detect, but focusing spatial attention on the “mirror” image increased its saliency. Drawings the patient made of her pseudo-hallucinations revealed that the illusions were lateral transpositions instead of mirror images of real objects. The illusions were tilted in clockwise direction and were never colored, although color discrimination was unimpaired in the patient's left hemifield. We quantified the characteristics of the pseudohallucinations in several experiments: The patient was asked to adjust the position, rotation angle, and size of a white test card in her blind field so that it corresponded with the illusory projection of a card of standard size and position that was presented in the intact field. The test card was compressed in horizontal size by 20% and positioned 17° visual angle to the right of the standard, shifted 1.5° upward or downward, and rotated in clockwise direction by 22.6° on average. Large objects in the intact field were projected incompletely into the blind area. Our patient's symptoms are similar to those reported in earlier case studies of visual allaesthesia. We hypothesize that the “mirror image” is induced by sparse input from contralesional V1 via the corpus callosum upstream of the lesion site and a lack of inhibition or hyperexcitability of ipsilesional early visual areas after deafferentation. The rotation of the illusions may be induced by the parietal lesions causing faulty co-ordinate computations, e.g., an inability to integrate visual and otholitic input. We would like to thank Prof. Dr. H. Schwegler (Department of Anatomy, Otto-von-Guericke University in Magdeburg, Germany) for his support in finding the anatomical information, Prof. Dr. D. Petersen (Radiology UKSH, Luebeck, Germany) for the MRT scans, Dr. E. Schreier (Ophthalmologist, Luebeck, Germany) for performing the perimetry and Imelda Pasley as English speaker for her corrections of this article.