Neurorehabilitation of saccadic ocular movement in a patient with a homonymous hemianopia postgeniculate caused by an arteriovenous malformation: A Case Report.

RATIONALE: Visual therapy, which includes a restorative and compensatory approach, seems to be a viable treatment option for homonymous defects of the visual field in patients with postgeniculate injury of the visual pathway, due to occipital arteriovenous malformation (AVM). Until now, the Mexican population suffering from homonymous hemianopia did not have health services that provided any type of visual therapy for their condition. PATIENT CONCERNS: A 31-year-old patient, who underwent a surgical procedure for resection of the AVM, was referred with posterior low vision on the left side. DIAGNOSES: The patient was diagnosed with left homonymous hemianopia. INTERVENTIONS: Visual neurorehabilitation therapy (NRT), which integrated restorative and compensatory approaches, was administered for 3 hours each week. NRT included fixation, follow-up, search, peripheral vision, and reading. OUTCOMES: The NRT did not change visual field defects and, retinotopocally, the same campimetric defects remained. However, after training the tracking ocular movements improved to standard values on the ENG, further, the visual search became more organized. The reading reached a level without mistakes, with rhythm and goog intonation. The Beck test demostrated an improvement in depression symptoms. Regarding the daily life activities, the patient reported significant improvements. LESSONS: Visual NRT can significantly improve eye movements, as well as the quality of life and independence of the patient. This integral approach could be an effective therapeutic option for homonymous defects of the visual field.

From EEG to BOLD: brain mapping and estimating transfer functions in simultaneous EEG-fMRI acquisitions.

Simultaneous acquisition of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) aims to disentangle the description of brain processes by exploiting the advantages of each technique. Most studies in this field focus on exploring the relationships between fMRI signals and the power spectrum at some specific frequency bands (alpha, beta, etc.). On the other hand, brain mapping of EEG signals (e.g., interictal spikes in epileptic patients) usually assumes an haemodynamic response function for a parametric analysis applying the GLM, as a rough approximation. The integration of the information provided by the high spatial resolution of MR images and the high temporal resolution of EEG may be improved by referencing them by transfer functions, which allows the identification of neural driven areas without strong assumptions about haemodynamic response shapes or brain haemodynamic's homogeneity. The difference on sampling rate is the first obstacle for a full integration of EEG and fMRI information. Moreover, a parametric specification of a function representing the commonalities of both signals is not established. In this study, we introduce a new data-driven method for estimating the transfer function from EEG signal to fMRI signal at EEG sampling rate. This approach avoids EEG subsampling to fMRI time resolution and naturally provides a test for EEG predictive power over BOLD signal fluctuations, in a well-established statistical framework. We illustrate this concept in resting state (eyes closed) and visual simultaneous fMRI-EEG experiments. The results point out that it is possible to predict the BOLD fluctuations in occipital cortex by using EEG measurements.

Bilateral occipital infarcts associated with carotid atherosclerosis and a persistent hypoglossal artery.

The persistent hypoglossal artery (PHA) is the second most common persistent embryological carotid-basilar connection and usually represents an incidental finding in cerebral arteriograms. The hypoglossal artery connects the primordial carotid artery with the longitudinal neural arteries, which later form the basilar artery. The PHA leaves the internal carotid artery as an extracranial branch, enters the skull through the anterior condyloid foramen, the hypoglossal canal and joins the caudal portion of the basilar artery. We report magnetic resonance and digital subtraction angiography findings in the first case of bilateral occipital infarctions associated with PHA and carotid atherosclerosis. The probable mechanism underlying bilateral occipital infarcts was embolism from the carotid territory to the posterior cerebral arteries. PHA may present a challenge in diagnosis and management of patients with carotid atherosclerosis and vertebrobasilar ischemia.

Localized cerebral blood flow reductions in patients with heart failure: a study using 99mTc-HMPAO SPECT.

BACKGROUND AND PURPOSE: Reduced resting global cerebral blood flow has been previously detected in association with heart failure (HF), but it is not clear whether there are brain regions that could be specifically affected by those brain perfusion deficits. The authors used a fully automated, voxel-based image analysis method to investigate, across the entire cerebral volume, the presence of resting regional cerebral blood flow (rCBF) abnormalities in HF patients compared to healthy controls. METHODS: rCBF was evaluated with 99mTc-single-photon emission computed tomography in 17 HF patients (New York Heart Association functional class II or III) and 18 elderly healthy volunteers. Voxel-based analyses of rCBF data were conducted using the statistical parametric mapping software. RESULTS: Significant rCBF reductions in HF patients relative to controls (P<.05, corrected for multiple comparisons) were detected in 2 foci, encompassing, respectively, the left and right precuneus and cuneus and the right lateral temporoparietal cortex and posterior cingulated gyrus. In the HF group, there was also a significant direct correlation between the degree of cognitive impairment as assessed using the Cambridge Mental Disorders of the Elderly Examination and rCBF on a voxel cluster involving the right posterior cingulate cortex and precuneus, located closely to the site where between-group rCBF differences had been identified. CONCLUSIONS: These preliminary findings indicate that posterior cortical areas of the brain may be particularly vulnerable to brain perfusion reductions associated with HF and suggest that functional deficits in these regions might be relevant to the pathophysiology of the cognitive impairments presented by HF patients.

Visuographemic alexia: a new form of a peripheral acquired dyslexia.

We report a single-case study of peripherally acquired dyslexia that meets the clinical criteria of "alexia without agraphia." The patient, AA, has a large infarct involving the left posterior cerebral artery. The most striking feature is a severe impairment in recognizing single visually presented letters that precludes explicit or implicit access to reading, even in a letter-by-letter fashion. AA can, however, differentiate letters from similar nonsense characters and digits, and he is also able to identify alphanumeric signs when the visual channel is bypassed (through somesthesic or kinesthesic presentation). Spelling tasks are also well performed. Since there is a breakdown in mapping a visually presented letter to its abstract graphemic representation, we propose the term "visuographemic alexia" for this kind of reading disorder. The pattern of deficits is interpreted following theoretical models previously developed in cognitive neuropsychology. An alexia for arabic numerals with preserved comprehension lends additional support for the crucial processing of different notational systems (e.g., phonographic vs logographic). More general perceptive disorders do not seem to account for these patterns; they are material-specific. Finally, we attempt to specify functional correlations with the implied neural networks.

Radiographic aspects and angioarchitectural arrangements in corrosion casts of the blood supply to the human sternocleidomastoid muscle by the sternocleidomastoid branch of the occipital artery

A contribuicao do ramo esternocleidomastoideo da arteria occipital para a irrigacao do musculo esternocleidomastoideo foi avaliada em cadaveres humanos nao fixados, atraves da injecao de contraste radiografico e de resina polimerizavel para estudo da microvasculatura. O musculo foi dividido nos tercos superior, medio e inferior, a partir da sua insercao no processo mastoideo do osso temporal. Na maioria dos musculos, o pediculo superior apresentou-se formado por dois ramos paralelos longitudinais. Em todos os casos, o contraste radiografico atingiu ou ultrapassou a parte media do musculo. Na parte mais distal do terco inferior, ha pouca ou nenhuma contribuicao do pediculo superior para a irrigacao dessa regiao muscular sugerindo...

Radiographic aspects and angioarchitectural arrangements in corrosion casts of the blood supply to the human sternocleidomastoid muscle by the sternocleidomastoid branch of the occipital artery.

The contribution of the sternocleidomastoid branch of the occipital artery (superior arterial pedicle-SAP) to the irrigation of the sternocleidomastoid muscle (SCM) was evaluated in fresh human cadavers by injecting radiological dye and a resin for microvasculature corrosion casts. From its insertion in the mastoid process of the temporal bone, the SCM was divided into superior, medium, and inferior thirds. In most of the SCM, The SAP are formed by two longitudinal parallel branches. In all specimens, the radiological dye injected into the SAP reached or trespassed the middle part of the studied SCM. The SAP was poorly distributed in the lowermost region of the inferior third of the SCM, suggesting the contribution of other arteries or pedicles. The corrosion casts of the microvasculature showed a profuse network of microscopic vessels in those levels where the SAP was detected.

Vascularização arterial do músculo esternocleidomastóideo pelo pedículo superior: análise dos segmentos músculos-vasculares: estudo topográfico e estrutural no homem / Arterial supply of the human sternocleidomastoid muscle through the occipital artery branch: a segmentary musculo-vascular analysis

A irrigação do músculo esternocleidomastóideo atravésdo ramo da artéria occipital (pedículo superior) foi estudada em espécimes obtidos de 41 cadáveres formolizados e frescos, com auxílio de injeção de neoprene-látex, métodos radiológicos e corrosão. Foram também tomadas medidas antropométricas do tipo altura do indivíduo, comprimento do músculo esternocleidomastóideo e distâncias do processo mastóideo à incisura jugular, à incisura tireóidea superior, à cartilagem criocóidea e ao mento. O músculo esternocleidomastóideo foi dividido em seis porções iguais em sua linha longitudinal, denominadas respectivamente níveis 1, 2, 3, 4, 5 e 6, a partir da sua inserção. Verificou-se que em todos os espécimes estudados a irrigação atingiu o nível 3. Em 56,66(per cent) dos espécimes a irrigação atingiu ou superou o nível 4. Em nenhum espécime o nível 6 foi atingido. Isto permite inferir que a utilização do retalho do pedículo superior do músculo esternocleidomastóideo é segura quando utilizados 50(per cent) de seu comprimento. A partir desta extensão sua irrigação declina rapidamente e conseqüentemente sua utilização em reparações perde, portanto, sua margem de segurança. A porção extrema distal não apresentou irrigação pelo pedículo superior, fato este que deve ser levado em consideração no planejamento de reparações que necessitem de maior extensão do músculo. Foi encontrada correlação positiva entre o comprimento do músculo esternocleidomastóideo à distância mastóidea-mento e a altura. Não houve correlação entre o comprimento do músculo esternocleidomastóideo a extensáo irrigada. (au)

Accidentes vasculares encefálicos del territorio cortical de la arteria cerebral posterior: infartos occipitales / Encephalic vascular accidentes within the cortical territory of the posterior cerebral artery: occipital infarction

Los defectos del campo visual constituyen la presentación clínica más frecuente de los infartos occipitales. Su presencia en forma aislada, no asociada a otros defectos neurológicos, es la clave para el diagnóstico de un accidente vascular encefálico del territorio cortical de la Arteria Cerebral Posterior. El mecanismo implicado muy frecuentemente es embólico. Se analizan 7 casos de infartos occipitales que se presentan clínicamente con defectos en el campo visual(AU)

Accidentes vasculares encefálicos del territorio cortical de la arteria cerebral posterior: infartos occipitales / Encephalic vascular accidentes within the cortical territory of the posterior cerebral artery: occipital infarction

Los defectos del campo visual constituyen la presentación clínica más frecuente de los infartos occipitales. Su presencia en forma aislada, no asociada a otros defectos neurológicos, es la clave para el diagnóstico de un accidente vascular encefálico del territorio cortical de la Arteria Cerebral Posterior. El mecanismo implicado muy frecuentemente es embólico. Se analizan 7 casos de infartos occipitales que se presentan clínicamente con defectos en el campo visual