Flashcards in Workbook questions 1 - The brain Deck (21):
Absence or loss of power of voluntary
Loss of purposeful movements despite
the preservation of muscular power,
sensation and co-ordination
Impaired communication by speech
Absence of reflexes
Loss of muscular co-ordination.
Slowness of movement
Difficulty in swallowing
Slowing or slurring of speech
due to loss of co-ordination of
muscles of speech.
Any disorder of voice production
Difficulty in doing
Showing a level of
expected for measured IQ
What is anencephaly? How does it arise?
Due to its complex embryology, abnormal development of the brain is common (about 3 in 1000 births) most result from a failure of the rostral neuropore to close. In the most serious congenital abnormality, anencephaly, there is a more or less complete absence of the brain.
What would be the consequences of a failure of the neural fold to fuse in the lumbosacral region of spinal cord? What is this condition called?
Most congenital abnormalities of the spinal cord arise from a failure of the caudal neuropore to close. The commonest condition is called spina bifida when the vertebral arch fails to grow normally and to fuse.
What condition arises if (a) the meninges herniate through the unfused region of the lumbar spine?
spina bifida meningocele
What condition arises if (b) the cord and meninges herniate through the unfused region of the lumbar spine?
Spina bifida myelomeningocele or simply myelomeningocele
What condition arises if too much cerebrospinal fluid accumulates in the ventricles of the brain?
An imbalance between the production and absorption of the CSF leads to an accumulation of fluid in the ventricles of the brain. This accumulation of fluid may cause a significant expansion of the head - hydrocephalus.
How is hydrocephalus corrected after birth?
Normally a drain is inserted - a shunt - which shifts CSF into the jugular vein or peritoneum
Identify vertebrae L3 & L4 on a skeleton - why is this an important landmark when planning a lumbar puncture?
•L3 & L4 is defined by the supracristal plane, an imaginary line joining the crests of both hips
• This is palpable as the top of the hips
•The spinal cord is shorter than the vertebral canal. The cord ends at vertebral level L2/L3 (or L1/2 in some texts) whilst the vertebral canal, now called the lumbar cistern and containing fibres of the corda equina extends to S2/S3. In a lumbar puncture a sample of CSF is drawn from the lumbar cistern by inserting a needle between L3 & L4 where there is no danger of damage to the spinal cord.
•To give an epidural block an anaesthetic agent is introduced into the lumbar cistern to block sensation in structures innervated by the cordal equina.
Would you use a different landmark to give a lumbar puncture in a baby? Why?
•In the early foetus the spinal cord fills the vertebral canal.
•As growth proceeds the vertebrae grow faster than the cord so that at birth the spinal cord ends at L3
•As most neural tissue is laid down at birth, during growth, neural tissue only matures .
• Differential growth through adolescence brings the cord to its adult position i.e. ending at the level L1/L2 or L2/3, bearing in mind inter-individual variation.
vertebral fracture at T12 may paralyse the bladder. Why is this, bearing in mind that the bladder is innervated by nerves arising from spinal cord segments S2 - S4?
Because the spinal cord is shorter than the vertebral column, the correspondence between the origin of the spinal nerves and their entry/exit to the vertebral column is progressively lost toward the caudal end. Therefore spinal nerves entering/leaving through foramen in lumbar and sacral vertebrae, enter the spinal cord at positions equivalent to vertebral level T11 - to L1. Fractures in this region may affect structures innervated by lower spinal cord segments