Bilateral Occipital Lobe Infarction Presenting as Bilateral Inferior Altitudinal Defects

PURPOSE: Horizontal visual field defects are generally caused by lesions before the optic chiasm, but we report a case with bilateral inferior altitudinal defects secondary to bilateral occipital lobe infarction. CASE SUMMARY: A 57-year-old male with a history of diabetes and hypertension presented with a month of blurring in the inferior visual field. His corrected visual acuity was 1.0 in the right eye and 0.63 in the left eye, and the intraocular pressure was normal in each eye. Pupillary response, ocular movement, and color vision tests were normal in both eyes. There was no specific finding of the optic disc and macula on fundus examination. Visual field examination revealed an inferior congruous homonymous hemianopia with horizontal meridian sparing and a left incongruous homonymous quadrantanopia. Optical coherence tomography for peripapillary retinal nerve fiber layer thickness revealed a mild decrease in the inferior disc of both eyes. Brain magnetic resonance imaging confirmed the presence of an acute infarction confined with upper medial calcarine fissures of bilateral occipital lobe and the right splenium of the corpus callosum, which were consistent with inferior altitudinal hemianopia and left superior incongruous quadrantanopia, respectively. Brain magnetic resonance angiography showed multiple stenosis of bilateral posterior cerebral arteries. CONCLUSIONS: The altitudinal visual field defects could be caused by the occipital lesion medial to the calcarine fissure, and unusual visual defects could be due to a combination of multiple lesions.

Functional connectivity analysis of different subtypes of Parkinson′s disease / 中华神经科杂志

Objective To investigate the changed brain areas of functional connectivity ( FC ) patterns of subthalamic nucleus ( STN) between different subtypes of Parkinson′s disease ( PD) and healthy controls and their clinical significance .Methods Twenty-three PD patients and 12 health controls were enrolled, and PD patients were divided into 11 tremor dominant PD patients and 12 postural instability and gait disorder (PIGD) dominant PD patients.The difference of whole-brain resting-state FC with STN among the three groups was investigated and the relationship between the changed areas and clinical symptoms was calculated.Results Compared with healthy controls , PIGD dominant group showed increased FC between STN and right calcarine and decreased FC between STN and right precuneus , and tremor dominant PD patients showed decreased FC between STN and precuneus , right angular gyrus and left middle frontal gyrus , while the FC strength between the STN and left middle frontal gyrus showed positive relationship with MMSE scores ( r=0.64, P=0.034 ) .Compared with tremor dominant PD patients , PIGD dominant patients showed increased FC in the area of left calcarine .Conclusions Decreased FC between STN and precuneus was gained in different subtypes of PD , and PIGD dominant patients showed increased FC between STN and calcarine.Changed areas based on the FC of STN in different subtypes of PD were found related with cognition and mood control .

Three-dimensional MRI study on the morphology and lateral asymmetry of Chinese female calcarine sulcus / 解剖学报

ObjectiveTo study the morphology, normal values and lateral asymmetry of Chinese calcarine sulcus on MRI. Methods High-resolution and transverse MRI were obtained from 40 female volunteers. Brainvisa software was used to reconstruct the calcarine sulcus and measure its average length, depth and width automatically. Results The posterior branch of calcarine sulcus showed six types in the median sagittal plane: bifurcation(32.50%), single peak(25.00%), flat (16.25%), S-shaped (15.00%), double peak(7.50%) and other shape (3.75%); its location had three types: inferior(72.50%), middle(21.25%)and superior(6.25%). The depth of left calcarine sulcus was (15.24±2.67)mm, and the right one was (16.97±3.25)mm, which revealed great statistical significance (P＜0.000 1). The width of left calcarine sulcus was (3.14±0.91)mm, and it was (3.19± 0.83)mm in the right side. The bottom length of calcarine sulcus: the left was (86.47±16.85)mm, the right was (83.62±17.10)mm. The top length of calcarine sulcus: the left was (70.52±12.40)mm, the right was (64.90±15.17)mm. There were not statistical significance in width, bottom length and top length between left and right calcarine sulci. More than half of the end part of calcarine sulci turned to the lateral surface of cerebral hemisphere.Totally 63 cases (78.75%) were found with prominent calcar avis. Conclusion Significant difference of depth between left and right calcarine sulcus of female was found. Three-dimensional reconstruction is an effective method to study the anatomy of calcarine sulcus.

ANGIOARCHITECTURE OF HUMAN VISUAL CORTEX / 解剖学报

In order to observe the pial and intracortical vessels in the upper and lower lips of calcarine sulcus, the normal human visual cortex of 15 brains (30 sides) were studied with scanning electron microscope (SEM), staining for alkaline phosphatase activity, continuous arterio-venous perfusion and clearing of thick sections according to Malligan's procedure. The results are: (1) Superficial pial arteries on visual cortex originate from calcarine artery, parieto-occipital artery, and inferior posterior temporal artery. Their branches destribute on the surface of the upper and lower lips of the calcarine sulcus resembling a comb. Two types of arterial anastomoses were found. The pial veins of the upper lip of the calcarine sulcus empty into the medial parieto-occipital vein, while those of the lower lip empty mostly into the medial occipital vein. (2) Intracortical arteries might be divided into five groups, i.e, short cortical artery, middle cortical artery, long cortical artery, subcortical artery and medullary artery. In general, they send out forward and recurrent branches. Veins might also be classified into five groups accordingly. There are four layers of vascular network within the striate cortex. The 3rd layer was clearly divided into sublayer 3a, 3b, 3c. The capillary density of the sublayer 3b is with lower density, which is just situated in Gennari's band. Angioarchitecture in the unstriate cortex is loosely arranged. The vascular density of each layer has been measured. The relationship between the blood supply of visual cortex and its clinical significance has been discussed as well.