|
Chiari malformation, also known as Arnold–Chiari malformation, is a condition affecting the brain. It consists of a downward displacement of the cerebellar tonsils through the foramen magnum (the opening at the base of the skull), sometimes causing non-communicating hydrocephalus as a result of obstruction of cerebrospinal fluid (CSF) outflow. The cerebrospinal fluid outflow is caused by phase difference in outflow and influx of blood in the vasculature of the brain. It can cause headaches, fatigue, muscle weakness, difficulty swallowing (sometimes accompanied by gagging), choking and vomiting, dizziness, nausea, tinnitus, impaired coordination, neck pain, unsteady gait (problems with balance), poor hand coordination (fine motor skills), numbness and tingling of the hands and feet, and speech problems (such as hoarseness). Less often, people with Chiari malformation may experience ringing or buzzing in the ears (tinnitus), weakness, slow heart rhythm, curvature of the spine (scoliosis) related to spinal cord impairment, abnormal breathing, such as central sleep apnea, characterized by periods of breathing cessation during sleep, and, in severe cases, paralysis. 〔(【引用サイトリンク】 Chiari malformation: Symptoms )〕 ==Signs and symptoms== *Headaches aggravated by Valsalva maneuvers, such as yawning, laughing, crying, coughing, sneezing or straining, bending over, or getting up suddenly *Tinnitus (ringing in the ears) *Lhermitte's sign (electrical sensation that runs down the back and into the limbs) *Vertigo (dizziness) *Nausea *Nystagmus (irregular eye movements; typically, so-called "downbeat nystagmus") *Facial pain *Muscle weakness *Impaired gag reflex *Dysphagia (difficulty swallowing) *Restless leg syndrome *Sleep apnea *Sleep disorders〔http://abcnews.go.com/GMA/OnCall/story?id=6711810〕 *Impaired coordination *Severe cases may develop all the symptoms and signs of a bulbar palsy *Paralysis due to pressure at the cervico-medullary junction may progress in a so-called "clockwise" fashion, affecting the right arm, then the right leg, then the left leg, and finally the left arm; or the opposite way around. *Papilledema on fundoscopic exam due to Increased intracranial pressure *Pupillary dilation *Dysautonomia: tachycardia (rapid heart), syncope (fainting), polydipsia (extreme thirst), chronic fatigue 〔 〕 The blockage of cerebrospinal fluid (CSF) flow may also cause a syrinx to form, eventually leading to syringomyelia. Central cord symptoms such as hand weakness, dissociated sensory loss, and, in severe cases, paralysis may occur. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Arnold–Chiari malformation」の詳細全文を読む スポンサード リンク
|