Chiari 1.5 is a term used when both brainstem and tonsillar herniation through the foramen magnum are present.The diagnosis of a Chiari II malformation can be made prenatally, through ultrasound. Classification
In the late 19th century, Austrian pathologist Hans Chiari described seemingly related anomalies of the hindbrain, the so-called Chiari malformations I, II and III. Later, other investigators added a fourth (Chiari IV) malformation. The scale of severity is rated I – IV, with IV being the most severe. Types III and IV are very rare. Since Dr. Chiaris original descriptions Chiari 0, 1.5, 3.5, and 5 have been described in the medical literature. Types of Chiari malformation
Other conditions sometimes causally associated with Chiari malformation include hydrocephalus, syringomyelia, spinal curvature, tethered spinal cord syndrome, and connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome. Chiari malformation is the most frequently used term for this set of conditions. The use of the term "Arnold–Chiari malformation" has fallen somewhat out of favor over time, although it is used to refer to the type II malformation. Current sources use "Chiari malformation" to describe its four specific types, reserving the term "Arnold-Chiari" for type II only. Some sources still use "Arnold-Chiari" for all four types.Chiari malformation or Arnold–Chiari malformation should not be confused with Budd-Chiari syndrome, a hepatic condition also named for Hans Chiari. In Pseudo-Chiari Malformation, leaking of CSF may cause displacement of the cerebellar tonsils and similar symptoms sufficient to be mistaken for a Chiari I malformation.
Weak crying
Facial weakness
Aspiration
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)
Lhermittes sign (electrical sensation that runs down the back and into the limbs)
Vertigo (dizziness)
Nausea
Schmahmann syndrome
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
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
Apnea: Sudden pause of breathing, usually during sleep. Opisthotonos: Spasm of the head which causes head to arch backwards. More common in infants than adults. StridorThe 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. Syringomyelia
Syringomyelia is a chronic progressive degenerative disorder characterized by a fluid-filled cyst located in the spinal cord. Its symptoms include pain, weakness, numbness, and stiffness in the back, shoulders, arms or legs. Other symptoms include headaches, the inability to feel changes in the temperature, sweating, sexual dysfunction, and loss of bowel and bladder control.