Remarkable Clinical Improvement Following Microsurgical Resection of Left Lingual Gyrus Cerebral Cavernous Malformation: A Case Report

Moyamoya disease is a chronic and unusual cerebrovascular disorder characterized by progressive stenosis and occlusion of the distal portions of internal carotid arteries and its main branches within the circle of Willis. Posterior circulation (vertebral and basilar arteries) may also be affected; however, this presentation is uncommon. As well as stenosis of the terminal portion of intracranial arteries, it is seen the development of a network of collateral vessels abnormally dilated at the base of the brain with an aspect of a "puff of smoke," whose term in Japanese is described as "moyamoya." The present study aims to report two consecutive cases of patients who presented to our service with different clinical manifestations. Further investigation with digital subtraction angiography showed a moyamoya pattern.

Brain Abscess Caused by Nocardia: Case Report and Literature Review

Nocardia brain abscess is a rare clinical entity, accounting for 2% of all brain abscesses, associated with high morbidity and amortality rate 3 times higher than brain abscesses caused by other bacteria. Proper investigation and treatment, characterized by a longterm antibiotic therapy, play an important role on the outcome of the patient. The authors describe a case of a patient without neurological comorbidities who developed clinical signs of right occipital lobe impairment and seizures, whose investigation demonstrated brain abscess caused by Nocardia spp. The patient was treated surgically followed by antibiotic therapy with a great outcome after 1 year of follow-up.

Growing up with Bilateral parieto-occipital injury: over ten years of clinical observation and neuropsychological follow-up.

This paper presents a follow-up of a child with Balint's syndrome over more than a decade. The patient experienced traumatic brain injury before age 12, resulting in bilateral occipito-parietal infarctions and a clinical presentation of Balint's syndrome. Neuropsychological assessments at three time points showed average verbal abilities alongside persistent difficulties in visual orientation, mirrored in the patient's daily life. Her outstanding compensatory abilities in the face of these impairments are discussed with respect to the recruitment of the ventral visual stream and the role of top-down processing. This profile may help to determine interventions for younger patients with similar lesions.

Evaluation of a fluidised positioner to reduce occipital pressure injuries in intensive care patients: A pilot study.

This pilot study aimed to evaluate the clinical efficacy and feasibility of a fluidised positioning device to reduce occipital pressure injuries (PIs). A post-test design with a historical control group was used in a 54-bed intensive care unit between September 2017 and August 2018. Patients who were receiving either extracorporeal membrane oxygenation, were mechanically ventilated, or had raised intracranial pressure (≥20) were recruited. The intervention consisted of a fluidised positioning device under the patient's head, and a skin assessment every 8 h. Outcome measures included the occurrence of occipital PIs and registered nurses (RNs)' perspectives of the intervention. Data collected from patients in the intervention group were compared with data obtained from the historical control group between May 2016 and April 2017. Sixty-four patients were recruited in the intervention phase and 63 were in the historical control group. Results showed a statistically significant reduction in occipital PIs by 87.7% (16/63; 25.4% historical control vs 2/64; 3.13% interventional group). Bedside RNs provided positive evaluation of the fluidised positioning device. The findings demonstrate that the fluidised positioning device is a feasible and effective intervention in reducing the risk of occipital PIs in intensive care patients, which merits the continuation of use and further evaluation through a larger-scale study.

More than blindsight: Case report of a child with extraordinary visual capacity following perinatal bilateral occipital lobe injury.

Injury to the primary visual cortex (V1, striate cortex) and the geniculostriate pathway in adults results in cortical blindness, abolishing conscious visual perception. Early studies by Larry Weiskrantz and colleagues demonstrated that some patients with an occipital-lobe injury exhibited a degree of unconscious vision and visually-guided behaviour within the blind field. A more recent focus has been the observed phenomenon whereby early-life injury to V1 often results in the preservation of visual perception in both monkeys and humans. These findings initiated a concerted effort on multiple fronts, including nonhuman primate studies, to uncover the neural substrate/s of the spared conscious vision. In both adult and early-life cases of V1 injury, evidence suggests the involvement of the Middle Temporal area (MT) of the extrastriate visual cortex, which is an integral component area of the dorsal stream and is also associated with visually-guided behaviors. Because of the limited number of early-life V1 injury cases for humans, the outstanding question in the field is what secondary visual pathways are responsible for this extraordinary capacity? Here we report for the first time a case of a child (B.I.) who suffered a bilateral occipital-lobe injury in the first two weeks postnatally due to medium-chain acyl-Co-A dehydrogenase deficiency. At 6 years of age, B.I. underwent a battery of neurophysiological tests, as well as structural and diffusion MRI and ophthalmic examination at 7 years. Despite the extensive bilateral occipital cortical damage, B.I. has extensive conscious visual abilities, is not blind, and can use vision to navigate his environment. Furthermore, unlike blindsight patients, he can readily and consciously identify happy and neutral faces and colors, tasks associated with ventral stream processing. These findings suggest significant re-routing of visual information. To identify the putative visual pathway/s responsible for this ability, MRI tractography of secondary visual pathways connecting MT with the lateral geniculate nucleus (LGN) and the inferior pulvinar (PI) were analysed. Results revealed an increased PI-MT pathway in the left hemisphere, suggesting that this pulvinar relay could be the neural pathway affording the preserved visual capacity following an early-life lesion of V1. These findings corroborate anatomical evidence from monkeys showing an enhanced PI-MT pathway following an early-life lesion of V1, compared to adults.

Childhood Falls With Occipital Impacts.

OBJECTIVES: Falls are commonly reported in children who present with both accidental and inflicted brain injuries. Short falls rarely result in serious or life-threatening injuries. Our purpose is to describe a series of cases of short falls with occipital impact leading to subdural hemorrhage (SDH). METHODS: We present a series of 8 witnessed accounts of young children diagnosed as having SDHs after striking the back of their heads during a short fall. Child-abuse physicians were surveyed to determine if they had evaluated a child younger than 24 months diagnosed as having SDH, with or without retinal hemorrhages, following a witnessed fall with occipital impact. Submitted cases were analyzed. RESULTS: The median age of the children was 12.5 months. All fell backward from a standing or seated position onto a hard surface and immediately developed symptoms. There was an average of 4 witnesses per case. Physical examinations were normal; however, the majority of children had enlarged head circumferences. All were previously healthy. Six of 8 children had unilateral convexity SDH. All children had varying degrees of retinal hemorrhage but no retinoschisis. The majority of children had returned to their baseline within 24 hours of hospitalization. CONCLUSIONS: Although a larger study is needed to identify the full spectrum of injuries, we postulate that, if a history of a fall with an occipital impact is elicited during a trauma workup, accidental injury should be considered.

Prevention of postoperative visual field defect after the occipital transtentorial approach: anatomical study.

OBJECTIVE A postoperative visual field defect resulting from damage to the occipital lobe during surgery is a unique complication of the occipital transtentorial approach. Though the association between patient position and this complication is well investigated, preventing the complication remains a challenge. To define the area of the occipital lobe in which retraction is least harmful, the surface anatomy of the brain, course of the optic radiations, and microsurgical anatomy of the occipital transtentorial approach were examined. METHODS Twelve formalin-fixed cadaveric adult heads were examined with the aid of a surgical microscope and 0° and 45° endoscopes. The optic radiations were examined by fiber dissection and MR tractography techniques. RESULTS The arterial and venous relationships of the lateral, medial, and inferior surfaces of the occipital lobe were defined anatomically. The full course of the optic radiations was displayed via both fiber dissection and MR tractography. Although the stems of the optic radiations as exposed by both techniques are similar, the terminations of the fibers are slightly different. The occipital transtentorial approach provides access for the removal of lesions involving the splenium, pineal gland, collicular plate, cerebellomesencephalic fissure, and anterosuperior part of the cerebellum. An angled endoscope can aid in exposing the superior medullary velum and superior cerebellar peduncles. CONCLUSIONS Anatomical findings suggest that retracting the inferior surface of the occipital lobe may avoid direct damage and perfusion deficiency around the calcarine cortex and optic radiations near their termination. An accurate understanding of the course of the optic radiations and vascular relationships around the occipital lobe and careful retraction of the inferior surface of the occipital lobe may reduce the incidence of postoperative visual field defect.

Significance of the Tentorial Alignment in Protecting the Occipital Lobe with the Poppen Approach for Tentorial or Pineal Area Meningiomas.

OBJECTIVE: We aimed to identify the factors that can predict the risk of occipital lobe damage preoperatively when resecting tumors located at the tentorial or pineal regions with the occipital-transtentorial approach (Poppen approach). METHODS: In 27 consecutive patients who underwent tumor resection with the Poppen approach for tentorial or pineal region meningiomas, the following morphologic parameters were assessed on a preoperative magnetic resonance imaging: (1) tentorial angle, (2) tentorial length, and (3) the shortest distance from the confluence of the sinus to the tumor. These parameters, together with tumor size, texture, and resection extent, were correlated with occipital lobe damage by using the one-way analysis of variance, χ2, or Fisher's exact tests. RESULTS: The mean value was 55.3° ± 5.6° (range, 45°-66°) for the tentorial angle, which was significantly associated with the occipital lobe damage grades (P = 0.008), but this was not the case for the tentorial length (P = 0.802) and the shortest distance from the confluence of the sinus to the tumor (P = 0.695). Interestingly, age was also strongly associated with occipital lobe damage risk (P = 0.020). The patients in the subgroup with no occipital damage (grade 4) were the youngest (aged 47.3 years), compared with other grades, with age of 58.0 years for grade 1, 54.3 years for grade 2, and 58.6 years for grade 3. These 2 parameters were also significant after multivariate analysis. No correlation was observed between either tumor nature or the extent of resection and damage grades. CONCLUSIONS: The risk of occipital lobe damage increases in the presence of a steep tentorial angle during the Poppen approach for tentorial or pineal area tumors. Awareness of such anatomic features preoperatively is important for minimizing operative complications.

[Brodmann Areas 17, 18, and 19 in the Human Brain: An Overview].

Brodmann areas 17, 18, and 19 in the human brain are visual cortices of the occipital lobe. Each area has its own retinotopic representations, particulary area 19, which has many small retinotopic areas representing half or all of the contralateral visual field, several functional areas, and nine cytoarchitectonic areas. Several fasciculi are known as occipital fiber connections, but their precise endpoints are not clear. Lesions in the visual cortices cause several visual disorders including visual field defect, visual hallucinations, metamorphopsia, and different kinds of visual agnosia.

Trans-synaptic Retrograde Degeneration in the Human Visual System: Slow, Silent, and Real.

Degeneration of neuron and axons following injury to cells with which they synapse is termed trans-synaptic degeneration. This phenomenon may be seen in postsynaptic neurons (anterograde) or in presynaptic neurons (retrograde). Retrograde trans-synaptic degeneration (RTSD) of the retinal ganglion cells and retinal nerve fiber layer following injury to the occipital lobe has been well documented histologically in animal studies, but its occurrence in the human retina was, for many years, felt to be limited to cases of neonatal injury during a critical period of neuronal development. Over the last decade, imaging techniques such as MRI and optical coherence tomography have allowed us to visualize and quantify RTSD and analyze its time course and relationship to degree of vision loss and age of cortical injury. A deeper understanding of RTSD in the human visual system may allow us to interfere with its occurrence, potentially allowing for greater recovery following visual cortex injury.

Neural correlates of face detection.

Although face detection likely played an essential adaptive role in our evolutionary past and in contemporary social interactions, there have been few rigorous studies investigating its neural correlates. MJH, a prosopagnosic with bilateral lesions to the ventral temporal-occipital cortices encompassing the posterior face areas (fusiform and occipital face areas), expresses no subjective difficulty in face detection, suggesting that these posterior face areas do not mediate face detection exclusively. Despite his normal contrast sensitivity and visual acuity in foveal vision, the present study nevertheless revealed significant face detection deficits in MJH. Compared with controls, MJH showed a lower tolerance to noise in the phase spectrum for faces (vs. cars), reflected in his higher detection threshold for faces. MJH's lesions in bilateral occipito-temporal cortices thus appear to have produced a deficit not only in face individuation, but also in face detection.

Perinatal occipital lobe injury in children: analysis of twenty-one cases.

This study used magnetic resonance imaging to analyze causes and clinical courses of pediatric occipital lobe injury. Patients undergoing magnetic resonance imaging for suspected bilateral occipital lobe injury at our Neurodevelopmental Department between July 2007 and June 2011 were included. We evaluated magnetic resonance imaging characteristics, clinical courses, electroencephalogram monitoring, and Denver Development Screen Test scores. Twenty-one infants were examined. Of these, 10 had been born preterm. Thirteen patients demonstrated hypoglycemia. Perinatal period hypoglycemia comprised the most common cause (71.4%) of occipital brain injury. Visual abnormalities were evident in 18 patients. Seventeen (80.9%) patients manifested epilepsy. Infantile spasms were observed in 13 cases (76.5%). According to Denver Development Screen Test assessment, 17 patients demonstrated delayed motor development. Motor function and language improved in 10 patients after effective control of their seizures. Hypoglycemia constitutes the most common cause of occipital injury in infants. Visual impairment, startle episodes, infantile spasms, and motor developmental delay comprise the most common complications, whereas language function is usually spared.

The time course of retrograde trans-synaptic degeneration following occipital lobe damage in humans.

Following damage to the human post-geniculate visual pathway retrograde trans-synaptic degeneration of the optic nerve fibres occurs. It has been known for some time from investigations carried out in primates that a decline in the number of retinal ganglion cells follows occipital lobectomy. However, this is not detectable in all species studied and whether this occurs in humans was controversial until recent studies that have shown that following lesions of the occipital lobe, the retinal nerve fibre layer thickness measured by optical coherence tomography is reduced and corresponding shrinkage of the optic tract can be demonstrated by magnetic resonance imaging. The time course of the degeneration in humans is, however, unknown. In the present study, we have used optical coherence tomography to demonstrate for the first time progressive thinning of the retinal nerve fibre layer following occipital lobe/optic radiation damage due to stroke. First, in a group of 38 patients the measurement was taken on a single occasion at a known time interval since the stroke, ranging from 6 days to 67 years. Here, a negative straight line relationship (linear regression r = 0.54, P < 0.001) was found between nerve fibre layer thickness and elapsed time since injury in log years, giving a rate of decline of 9.08 µm per log year after adjusting for age. This indicates a decelerating rate of loss that differs from the rate of decline found with chronological age in this same group, which shows a steady rate of thinning by 0.4 µm per year (P = 0.006) after adjusting for duration of the disease. In a second study serial measurements were taken following the acute event in a group of seven patients with homonymous hemianopia; here a negative straight line relationship was found between time and nerve fibre layer thickness in micrometres over a period of data collection beginning at a mean of 36.9 days post-stroke (range 5-112) and ending at a mean of 426.6 days post-stroke (range 170-917). Evidence from clinical observation (funduscopy) suggested that retrograde trans-synaptic degeneration occurred in humans only where the damage to the post-geniculate pathway occurred prenatally. The results reported herein add weight to the previous demonstration that this type of degeneration does indeed occur in the human visual system by showing that it can be monitored over time and hence may provide a model for trans-synaptic degeneration in the human central nervous system.

Post-traumatic frontal and parieto-occipital extradural haematomas: a retrospective analysis of 41 patients and review of the literature.

BACKGROUND: The purpose of this study was to analyse the differences between patients with frontal (FEDH) or parieto-occipital (POEDH) epidural haematomas and evaluate possible statistically significant prognostic factors. MATERIAL AND METHODS: In this retrospective study of a group of 41 patients with a FEDH (17) or POEDH (24 individuals), the authors analysed the influence of gender, age, type of injury, clinical presentation, Glasgow coma scale (GCS) score on admission, radiological findings, and time interval from trauma to surgery on outcomes. A good recovery and moderate disability were considered a "good" or "favourable outcome", whereas severe disability, a vegetative state or death was a "poor outcome". RESULTS: In the POEDH subgroup, a higher GCS score on admission and a younger age were statistically significant prognostic factors for a better outcome (p=0.006, rs=0.702). In the subgroup of patients with FEDHs, the results were not significant. However, patients with FEDHs more frequently had "good outcomes" than members of the POEDH subgroup (88.2 vs. 70.9%). Children (≤ 18 years old) constituted a smaller portion of the POEDH subgroup (12.5%) than those in the FEDH subgroup (41.2%). The evaluation of time intervals between the accident and surgery (≤ 24 h vs. > 24 h) showed no significant influence on outcomes in any of the studied subgroups. However, patients undergoing surgery within 24 h of their injury had a less favourable GCS score on admission than those operated on more than 24 h after their injury. Subacute and chronic clinical courses predominated in patients with a FEDH (10/17 FEDH vs. 11/22 POEDH). Different accompanying intradural lesions occurred in 12 patients of the POEDH subgroup, but only in 2 of the FEDH subgroup (50 vs. 11.8%). However, the presence of such lesions did not significantly deteriorate surgical outcomes in either of the subgroups.

Spatial and temporal aspects of navigation in two neurological patients.

We present two cases (A.C. and W.J.) with navigation problems resulting from parieto-occipital right hemisphere damage. For both the cases, performance on the neuropsychological tests did not indicate specific impairments in spatial processing, despite severe subjective complaints of spatial disorientation. Various aspects of navigation were tested in a new virtual reality task, the Virtual Tübingen task. A double dissociation between spatial and temporal deficits was found; A.C. was impaired in route ordering, a temporal test, whereas W.J. was impaired in scene recognition and route continuation, which are spatial in nature. These findings offer important insights in the functional and neural architecture of navigation.