Homonymous hemianopsia.

Homonymous hemianopia (HH) is a visual field defect involving either two right or the two left halves of the visual field of both eye. It results from the damage of the visual pathway in its suprachiasmatic part. The causes of HH include stroke, brain tumors, head injuries, neurosurgical procedures, multiple sclerosis and miscellaneous conditions. HH result in a severe visual impairment and affect a variety of cognitive visual functions. Patients with HH frequently have difficulties with reading and scanning scenes in sufficiently rapid fashion to make sense of things as a whole. They stumble, fall or knock objects in their surroundings, since they cannot see them and they are frequent surprised that somebody or something suddenly appeared in their visual field. The prognosis of visual field deficit recovery is highly variable and depends on the cause and severity of brain nd optic pathway injury. The fundamental method in the management of HH patients is rehabilitation. Rehabilitation techniques used in HH include three groups of methods: optical therapies, eye movement-based therapies, and visual field restitution therapies.

A congruous superior quadrantanopsia following a junctional scotoma induced by asperogillosis.

A 69-year old man presented to us with decreased vision in his right eye and a relative afferent pupillary defect. Under the presumption that he was suffering from retrobulbar optic neuritis or ischemic optic neuropathy, visual field tests were performed, revealing the presence of a junctional scotoma. Imaging studies revealed tumorous lesions extending from the sphenoid sinus at the right superior orbital fissure, with erosion of the right medial orbital wall and optic canal. Right optic nerve decompression was performed via an endoscopic sphenoidectomy, and histopathologic examination confirmed the presence of aspergillosis. The patient did not receive any postoperative antifungal treatment; however, his vision improved to 20 / 40, and his visual field developed a left congruous superior quadrantanopsia 18 months postoperatively. A junctional scotoma can be caused by aspergillosis, demonstrating the importance of examining the asymptomatic eye when a patient is experiencing a loss of vision in one eye. Furthermore, damage to the distal optic nerve adjacent to the proximal optic chiasm can induce unusual congruous superior quadrantanopsia.

Bilateral homonymous superior quadrantanopia after traumatic attempts to remove a cockroach impacted in the external auditory canal.

Visual field defects typically caused by lesions in the optic nerve or optic chiasm may be caused indirectly by subdural haematomas. A 61-year-old man survived transtentorial herniation caused by subdural haematomas that resulted from shaking his head in an attempt to remove a cockroach impacted in his external auditory canal. Bilateral incomplete posterior cerebral artery infarction of both inferior tips of the occipital lobe resulted in bilateral superior quadrantanopia. There are no previous reports of tentorial herniation causing this permanent outcome.

[Emphasize the importance of study on treatment and visual restoration related to impairment of retro-chiasmal visual pathway].

Homonymous visual field defect which is usually caused by stroke, brain tumor and trauma, is common. In spite of partial spontaneous recovery, homonymous hemianopia still causes serious disability. Visual restoration therapy (VRT) based on the residual visual capability and brain plasticity theory was reported effectively enlarged visual field caused by impairment of visual pathway. Controversy still exits on the efficacy of these procedures. However, due to the high prevalence and poor outcome of visual pathway impairment, it is important to initiate multiple disciplinary co-operative study on VRT and other procedures for visual function rehabilitation to improve life quality of patients with retro-chiasmal visual pathway impairment.

Stroke rehabilitation 2009: old chestnuts and new insights.

The past year has continued to see growth in stroke rehabilitation literature, ranging from important insights into the basic science of stroke recovery to broader multidisciplinary aspects aimed at improving global quality of life in stroke survivors. The areas that particularly stand out include 1) new evidence on old treatment strategies in clinical rehabilitation; 2) developments in the treatment of "neglected" impairments, such as hemianopia and sensory loss; 3) evaluation of the use of technology in stroke rehabilitation; and 4) advances in neurorestorative treatments after stroke.

[Arachnoid cyst as the differential diagnosis of ischemic optic neuropathy in type-II diabetes]. / Arachnoidalzyste als Differentialdiagnose der ischämischen Opticusneuropathie bei Typ-II-Diabetes.

HISTORY AND CLINICAL FINDINGS: A 71-year-old woman, a diabetic (type IIb) for 27 years, developed bilateral hemianopsia over a period of about 2 years. A few weeks before hospital admission the defect in her visual fields increased more rapidly and double vision occurred intermittently. The hemianopsia was demonstrated by finger perimetry. There was no evidence of heart failure or peripheral vascular disease. Muscle reflexes were normal, but there was a decrease in vibratory sensation in both feet. The cause of the visual disturbance was at first thought to be an ischaemic optic neuropathy. INVESTIGATIONS: Biochemical tests showed an HbA1 of 12.8%, blood sugar levels were between 230 and 359 mg/dl, and there was increased intravascular platelet activation. Ophthalmological examination confirmed bitemporal hemianopsia and early retinopathy. Magnetic resonance imaging of the skull revealed an intra- and suprasellar cystic space-occupying lesion extending to the right optic chiasma. These findings, taken together, indicated an arachnoidal cyst. TREATMENT AND COURSE: After the diabetic metabolic state had been normalized with insulin treatment (average of 30 IU of an intermediary insulin) and dietary measures, the cyst was evacuated stereotactically. The hemianopsia quickly improved markedly and the patient was discharged 4 days after the operation with her vision nearly fully restored.

Visual evoked potential in the management of pituitary tumor during pregnancy.

We examined a pregnant woman with chiasmal syndrome in the late stage of pregnancy. Her vision was determined to be seriously threatened after 31 weeks' gestation. Study of the latency of preoperative visual evoked potentials (VEPs) in other patients with pituitary tumor showed that insofar as latency is not delayed, surgical decompression is expected to be followed by functional improvement of the optic pathway. We monitored optic nerve function by serially recorded VEPs, and labor was induced at 38 weeks because there had been no delayed response up to that time. After a decompressive operation, visual field and visual acuity recovered normally. Serially recorded VEPs can provide a useful monitor along with visual field and acuity tests in guiding therapy for a patient with threatened vision in late pregnancy and in determining whether or when to induce labor.

Restitution of visual field in patients with damage to the geniculostriate visual pathway.

Previous experiments have investigated the effect of specific practice on partially blinded monkeys after striate cortex lesions. Similar procedures were adapted for patients suffering homonymous field defects due to geniculostriate damage. Both methods, light detection and saccadic localization, led to an enlargement of the visual field. The amount of this enlargement depended on the eccentricity of the field border as well as on the level of light sensitivity in the region between the intact field and the scotoma. Recovery of visual field included the reappearance of various visual functions (e.g. visual acuity, color identification). In periods without training visual field did not recover. It is hypothesized that recovery can take place at the level of the striate cortex, and is mediated by structures interacting with the striate cortex, e.g. the superior colliculus.