Sleep apnea: encompasses a heterogeneous group of sleep-related breathing disorders in which there is repeated intermittent episodes of breathing cessation or hypopnea, when breathing is shallower or slower than normal. Sleep apnea is a common finding in stroke patients but recent research suggests that it is even more prevalent in silent stroke and  chronic microvascular changes in the brain. In the study presented at the American Stroke Associations International Stroke Conference 2012 the higher the apnea-hypopnea index, the more likely patients had a silent stroke. Neuropsychological deficits
Individuals who have had silent strokes often have various neuropsychological deficits and have significant impairment in multiple areas of cognitive performance. One study has shown an association between silent stroke and a history of memory loss and lower scores on tests of cognitive function. In a second study, individuals who have a had a silent stroke scored lower on the mini–mental state examination (MMSE) and on Ravens Colored Progressive Matrices—a test designed for children aged 5 through 11 years, mentally and physically impaired individuals, and elderly people. In children
Children who have suffered silent strokes often have a variety of neuropsychological deficits. These deficits may include lowered I.Q., learning disabilities, and an inability to focus. Silent strokes are the most common form of neurologic injury in children with sickle cell anemia, who may develop subtle neurocognitive deficits in the areas of attention and concentration, executive function, and visual-motor speed and coordination due to silent strokes which may not have been detected on physical examination.
Fourth cranial nerve palsy or trochlear nerve palsy, is a condition affecting cranial nerve 4 (IV), the trochlear nerve, which is one of the cranial nerves. It causes weakness or paralysis of the superior oblique muscle that it innervates. This condition often causes vertical  or near vertical double vision as the weakened muscle prevents the eyes from moving in the same direction together. Because the trochlear nerve is the thinnest and has the longest intracranial course of the cranial nerves, it is particularly vulnerable to traumatic injury. To compensate for the double-vision resulting from the weakness of the superior oblique, patients characteristically tilt their head down and to the side opposite the affected muscle. When present at birth, it is known as congenital fourth nerve palsy. See also
Harada–Ito procedure

References


== External links ==