1. Show your best 3 Karl Clebak

2. Case Presentation  75 year old with rt shoulder numbness, lest sided trapezius muscle soreness fasciculation in left biceps. No headaches, dysphagia, dysphonia.

4. Read  There are low lying cerebellar tonsils, with protrusion approximately 11 mm below the basion-opisthion line. The posterior fossa is small. There is a large syrinx in the visualized portion of the cervical spine extending from the mid body of C2 inferiorly. The syrinx is incompletely imaged on this study. These findings are consistent with Chiari I malformation.

5. Chiari Malformation  Type I - fourth ventricle above foramen magnum, upper part of cervical cord displaced caudally, seen in pediatrics  Type II - most common; cerebellar vermis (+ cerebellar tonsils), medulla + fourth ventricle herniated into upper cervical canal; described here  Type III - cerebellar vermis, medulla + fourth ventricle protrude exteriorly as occipital encephalocele  types III + IV - progressive caudal displacement of cerebellar vermis, pons + medulla below foramen magnum

6.  Age affected 40-60 years symptoms in adolescence or adult life; apparent at birth for types II and III  Associated Symptoms syringomyelia, syringobulbia, deformities of vertebrae, cranial nerve palsies, hydrocephalus and hydromyelia associated with lumbosacral meningomyelocele obstructive sleep apnea  related to loss of pharyngeal sensation

7. Presentation  Chief Concern cough-induced headache and neck pain, nausea, vomiting; occasionally transient hydrocephalus, unsteadiness of gait, dysarthria, dysphagia, syncope (compromised medullary function)  History of Present Illness pain at cranial-cervical junction aggravated by head movement or Valsalva  General Physical:  rapidly increasing head circumference, lethargy, irritability

8. More Physical  HEENT:  bulging fontanelles  scalp vein dilatation  ocular findings  decreased upward gaze  Parinaud's syndrome - light-near dissociation  light reflex may be disrupted in midbrain pretectal region without damage to more ventral near reflex fibers; anatomic lesion is pretectal internuncial neurons serving reflex pupil constriction to light  Parinaud's syndrome is usually caused by pinealomas or other dorsal midbrain lesions  pupils are relatively large, often slightly unequal; convergence- retraction nystagmus on attempted upgaze; constriction to light is absent or very weak, but response to near stimulus is normal  papilledema  occasionally downbeat nystagmus accentuated on lateral gaze  Neuro: well compensated, progressive ataxia, peripheral neuropathy (tethered cord)

9. Surgery  Surgery: shunt to direct ventricular fluid  most commonly ventriculoperitoneal shunt  absorptive surface of peritoneum may be inadequate in very small infants - ventriculoatrial shunt  CSF may need to be shunted to pleural space

10. Bonus Case  Hip Pain

12. References  Arnold-Chiari malformation. Dynamed. Updated 2007 Jul 05 02:25 PM. Accessed 31 March 2008.