Central Nervous System
Cervical syringomyelia all are seen except (AIPG 2011)
|A||Burning sensation in hands|
|B||Hypertrophy of abductor pollicis brevis|
|C||Extensor plantar response is present|
|D||Absent biceps reflex.|
The basics of CSF production and drainage
CSF production (Occurs by choroid plexus of lateral and lllrd ventricle)
Foramen of Monro
Aqueduct of Sylvius
Foramen of Magendie and Lushka
Subarachnoid space (lt is absorbed here, by arachnoid villi)
Both Aqueductal stenosis and Dandy Walker syndrome cause non-communicating hydrocephalus but the site of obstruction is different.
• Let us see the causes of hydrocephalus in
aqueductal stenosis and Dandy-Walker malformation'
• In aqueductal stenosis the aqueduct connecting the 3"t and 4th ventricle is stenosed which leads to hydrocephalus with the dilatation of ventricular system prior of the aqueduct, i.e. lateral ventricles and third ventricle.
Dandy Walker Malformation
• In Dandy Walker malformation there is cystic dilatation of the fourth ventricle in the posterior fossa with obstruction at the formation of Lushka and Magendie.
• So the ventricular system in this condition, will also be dilated as in aqueductal stenosis but here the posterior fossa is also enlarged (in contrast to normal posterior fossa size in aqueductal stenosis).