neuro Flashcards
what nerve palsy causes diplopia worse going down stairs of reading?
fourth CN
- usually after bang to head
- classically noticed when reading a book or going downstairs
- vertical diploplia
- tilt head to make vision seem more natural
- otherwise well
what is the clinical purpose of the corneal reflex?
check integrity of CN5 (sensory) and CN7 (motor)
when corneal is touched sensory fibres -> spinal trigeminal nucleus -> facial motor nucleau bilaterally -> orbicularis oculli muscles bilaterally -> blink
what nerve palsy causes horizontal diplopia with the distance between the objects being greater when looking at things far away. and the inability to abduct the eye?
CN6
- no ptosis
what symptoms does 3rd nerve palsy cause?
ptosis, diplopia (horizontal), and dilated pupil
what clinical signs suggest damage to the common peroneal nerve (L4-S2)?
pt cannot evert, dorsiflex at the ankle joint or extend the digits of the foot
- common injury if fracture head of fibula or use of a tight plaster cast
- pt present with footdrop and associated characteristic gait
- loss of sensation over the dorsum of the foot, and lateral side of the leg.
- Innervation is preserved on the medial side of the leg (supplied by the saphenous nerve, a branch of the femoral), and the heel and sole (supplied by the tibial nerve, a branch of the sciatic).
what is the underlying molecular pathology behind the different types of dementia?
- alzheimer’s:
- most common!
- cortical plaques due to deposition of type A-Beta-amyloid protein and intraneuronal neurofibrillary tangles caused by abnormal aggregation of the tau protein
- reduction of Ach reduces neuronal signalling
- insidious onset, with steady progression
- loss of short term memory usually early symptom
- slow disintegration of personality and intelect, eventually affecting all aspects of corticol function
- decline in language (understanding what is being said), visuospacial skills, apraxia (cant carry out skilled motor tasks) and agnosia (cant recognise objects) - vascular:
- second most common
- atherosclerosis in the cerebral arteries
- stepwise deterioration and decline followed by short periods of stability
- hx of TIAs and/or other CVD
- less insidious onset, emotional lability (amygdala), preserved personality - dementia with lewy body:
- presence of LB
- fluctuating cognition with pronounced variation in attention and alertness
- prominent or persistent memory loss may not occur in early stages
- impairment in attention, frontal, subcorticol and visuospacial ability
- depression and sleep disorders
- visual hallucinations, parkinisonism, delusion and transient LOC
* DON’T GIVE ANTI-PSYCHOTICS* - fronto-temporal dementia:
- personality changes
- behavioural changes
- language problems
- memories relatively preserved (no hipocampus involvement)
- younger onset
* ACHEi are not effective
night terrors, nocturnal enuresis, sleepwalking occur during what stage of sleep?
Non-REM stage 3
posterior communicating artery stroke can cause what nerve palsy?
third (diabetes mellitus, vasculitis, posterior communicating artery aneurysm, cavernous sinus thrombosis)
bilateral acoustic neuromas are associated with what genetic condition?
neurofibromatosis type 2
chiari malformations (where lower part of the brain pushes into the spinal cord) are associated with what kind of spinal pathology?
syringomyelia -> a fluid filled cavity, called a syrinx develops in the spinal cord. if not treated can lead to SCI/damage
transient loss of function of a nerve is know as what?
neuropraxia
Nerve intact but electrical conduction is affected Myelin sheath integrity is preserved Full recovery Autonomic function preserved Wallerian degeneration does not occur
what are the muscles that attach to the greater trochanter?
Mnemonic for muscle attachment on greater trochanter is POGO:
- Piriformis
- Obturator internus
- Gemelli
- Obturator externus
what do the following fibres transmit?
C fibres.
A α fibres
A β fibres
Slow transmission of mechanothermal stimuli is transmitted via C fibres.
A α fibres transmit information relating to motor proprioception, A β fibres transmit touch and pressure and B fibres are autonomic fibres
Peripheral nociceptors are innervated by either small myelinated (hence fast) fibres (A-gamma) fibres or by unmyelinated (hence slow) C fibres.
The A gamma fibres register high-intensity mechanical stimuli. The C fibres usually register high-intensity mechanothermal stimuli.
after confirmed epilepsy Dx (>2 seizures), what are the treatment options?
focal:
- 1st line = carbamazepine (strong sedating effect and will affect CONTRACEPTION) or lamotrigine
- 2nd line = sodium valproate or levetiracetam
tonic clonic:
- 1st = sodium valproate
- 2nd = lamotrigine or carbamazepine
absent:
- 1st = sodium valproate or ethosuxamide
atonic:
- 1st sodium valproate
- 2nd lamotrigine
myotonic:
- 1st sodium valporate
- 2nd lamotrigine, levetiracetam, topiramate
infantile spasms:
- 1st line prednisolone and vigabatrin
- adjuncts: relaxation/CBT/surgical intervention (if epileptogenic focus like hippocampal sclerosis or small low-grade tumour)/ vagal nerve stimulation
- start with monotherapy and increase to max dose before switching drug. dual therapy if all appropriate drugs have been tried
- stopping can be considered if seizure free for >2years. decreased slowly over 2-3months
what seizure type may be a sign of lennox-gastaut syndrome
atonic seizure
LGS = usually begins between 3 and 5, but can start as late as adolescence. Children may have several different types of seizure with this syndrome. These include tonic (where the muscles suddenly become stiff), atonic (where the muscles suddenly relax), myoclonic, tonic clonic and atypical absences. Atypical absences often last longer than normal absences and are different as a child may be responsive and aware of their surroundings.
