Neurosurgery Flashcards
(30 cards)
What two intracranial areas/structures commonly calcify (can be seen on CT)?
pineal gland, choroid plexuses (in lateral ventricles)
What pathology/variation is commonly found on the roof of the third ventricle? what can it cause?
colloid cyst; CSF obstruction –> hydrocephaly
What is a Berg (BBS)?
Berg Balance Scale: functional scale; rates 14 items 0-4 (total /56) such as standing, sitting, transfers, sit-stand, and picking up items. 0-20: wheelchair, 41-56 independent.
What is the link between aneurysms and hydrocephalus?
Ruptured aneurysms bleed; blood can interfere with CSF production and clearance – notably blood can ~clog arachnoid granulations
What are major features of glioblastoma multiforme?
Very aggressive primary CNS tumour. Median survival w/o treatment a few months; with treatment under 2y. Rare cases have made it several years.
Why is glioblastoma multiforme so difficult to treat, and what are recommended treatments?
Tumour cells progress along tracts in brain so it’s hard (impossible) to achieve totally clear margins. Treatment involves tumour resection but also adjuvant radiation and chemo; resection removes large masses of cells, but more general therapy aims to damage remaining cells that are less localized/concentrated.
Why does resection of temporal lobe cause visual impairment, and what kind of impairment would it cause?
Optic tracts travel through either temporal lobe or parietal to occipital (primary visual); damage to temporal lobe can cause contralateral superior homonymous quandrantanopsia (? – “pie in the sky”, w/ same quadrant of each visual field affected; side missing is opp as side of damage)
What are the outlets of CSF from the 4th ventricle?
there are 3:
- two lateral foramina (of Luschke), which go to the superior cistern (of the great cerebral vein)
- one medial foramen (of Magendie), which goes to the cisterna magna
What is a mega cisterna magna (aside from a weird mix of dead languages)?
as it sounds: v large cisterna magna – space in posterior fossa, posterior to cerbellum. Filled with CSF normally. V large: often a normal variant, or an arachnoid cyst.
How do you distinguish L5 from S1 radiculopathy?
Same: 45% of lumbar disc syndromes. Sciatic pattern of pain.
L5:
- Sensory (impairment?): dorsal foot to hallux.
- Motor: Extensor hallucis longus
- Reflex: medial hamstrings
S1:
- No sensory changes
- Motor: gastrocnemius, soleus (plantar flexion)
- reflex: achilles
Pattern of L4 radiculopathy
<10% of lumbar disc syndromes. Pain: femoral Sensory: medial leg Motor: tibialis anterior (dorsiflexion) Reflex: patellar
Pattern of L5 radiculopathy
45% of lumbar disc syndromes. Pain: sciatic. Sensory: dorsal foot to hallux. Motor: ext. hallucis longus (hallux extension ... dorsiflexion) Reflex: Medial hamstrings
Pattern of S1 radiculopathy
45% of lumbar disc syndromes. Pain: sciatic. Sensory: none. Motor: gastrocnemius, soleus (plantar flexion) Reflex: Achilles
What is nerve claudication?
Discomfort/pain/numbness/weakness in one or both legs. precipitated by walking and prolonged standing. Classically relieved by a change in position or flexion of the waist (as well as rest). Common symptom of lumbar spinal stenosis.
myelopathy
Any neurologic deficit related to the spinal cord.
- trauma: (acute) spinal cord injury
- inflammatory: myelitis.
- vascular: vascular myelopathy
- arthritic changes: spondylotic
What is the most common myelopathy?
cervical spondylotic myelopathy (CSM): arthritic changes (spondylosis) of cervical spine –>spinal stenosis –> compression of the spinal cord.
Presentations of cervical spondylotic myelopathy
- weakness (upper>lower extremity)
- decreased dexterity, loss of fine motor
- sensory changes
- UMN findings (hyperreflexia, clonus, babinski)
- funicular pain, characterized by burning and stinging +/- Lhermitte’s sign
What is Lhermitte’s sign?
lightning-like sensation down the back with neck flexion. Seen in MS, cervical spondylotic myelopathy
What is Spurling’s test?
Compression test of cervical nerve root. Rotation & lateral bending with vertical compressive force; radiation along affected dermatome is positive test.
What are the approximate survival rates for acute epidural hematoma?
1/3 don’t make it to hospital, 1/3 don’t make it out, 1/3 survive
Definitions of Chiari I & II malformations, & age of presentation
Chiari I: cerebellar tonsils lie below the level of the foramen magnum. Avg age at presentation: 15y.
Chiari II: part of cerebellar vermis, medulla, and 4th ventricle extent through foramen magnum, often to midcervical region. Present in infancy.
How are Chiari malformations definitively diagnosed?
MRI
What are clinical features of Chiari I malformations?
Many are asymptomatic. If symptomatic:
pain, weakness, numbness, central cord syndrome,
loss of temp sensation, foramen magnum compression syndrome, cerebellar syndrome, syringomyelia, hydrocephalus
What are clinical features of Chiari II malformations?
Findings due to CN and brainstem compression.
Dysphagia, apnea, stridor, aspiration, arm weakness, downbeat nystagmus
Respiratory arrest is most common cause of mortality
Myelomeningocele and hydrocephalus v commonly associated.
