Neurology Flashcards
Causes of bilateral facial palsy
Lyme’s disease
Guillain Barré
Sarcoidosis
What is synkinesia?
In Parkinson’s exam, whilst examining tone, getting them to tap their leg and it accentuating the cogwheel rigidity
What are the causes of a combined upper and lower motor deficit
Fred’s Tabby Cat Seeks Mice
Freidrich's Ataxia Taboparesis (syphillis) Cervical spondylosis Subacute degeneration of the cord Motor neurone disease
If a nystagmus is worse when looking to the left side, where is the lesion site if:
A. It is caused by a cerebellar lesion
B. It is caused by vestibular nerve/nuclear lesion (CN VIII)
A. Left (ipsilateral)
B. Right (contralateral)
Patient has ataxic gait and trunk but limbs have normal tone, coordination and no dysmetria evident. Where is the site of the lesion?
Cerebellar vermis (a central part) (Often alcohol may causes vermis atrophy)
Causes of unilateral cerebellar syndrome (DASHING SYMPTOMS)
Demyelination (MS) or brain stem stroke on ipsilateral side
Rarely: posterior fossa tumour, abscess
Causes of bilateral cerebellar syndrome
DADS HAR Drugs (anticonvulsants) Alcohol Demyelination (MS) Stroke (brain stem)
Hypothyroid
Antineuronal antibodies (paraneoplastic syndrome)
Rare- Freidrich’s, Ataxic telangiectasia
What is internuclear opthalmaplegia and which condition does bilateral opthalmaplegia occur in?
Inability to adduct eye when looking to opposite side, contralateral eye gets a nystagmus.
In MS due to demyelinating lesion of the medial longitudinal fasciculus
Young woman has pain on eye movement and rapid reduction in central vision, with tingling in her right arm. What is the diagnosis?
Multiple sclerosis- unilateral optic neuritis is often the first sign
Ishihara plates might show a reduction in red colour vision
What objective imaging or tests support a clinical diagnosis of MS?
Based on the McDonald criteria:
MRI plaques disseminated in time and space
Oligoclonal IgG bands in CSF (not serum)
Delayed evoked potentials- normal amplitude
Neuromyelitis Optica IgG antibodies (Devic’s syndrome)
Medications used in MS:
All the medications reduce relapses in relapsing and remitting MS but do not alter progression of the disease ultimately.
Relapse reducing:
Immunomodulation- IFN B + Glatiramer
Monoclonal antibodies: Alemtuzamab (anti-T cell) + Natalizumab (anti VLA-4 R that allows Abs to cross the BBB)
Symptomatic: Methylprednisolone reduces length of short relapses Baclofen- spasticity Botox- tremors Carbamezepine- seizures
How can Devic’s syndrome be distinguished from MS?
Devic’s syndrome- Anti-aquaporin 4 antibodies in CSF (60%)
Also known as neuromyelitis optica antibodies
Both may get transverse myelitis- loss of motor, sensory, autonomic, reflex + sphincter function below lesion
Both may get optic atrophy (pale disc, altered acuity)
Rx: for Devic’s is plasma exchange
Difference between decorticate and decerebrate posturing and their cause?
No-one celebrates in decerebrate posturing (hands by sides, no clapping) and means brain stem is affected ?vegetative state
If somone goes from decorticate to decerebrate = pontine tonsils at risk of herniation
In decorticate posturing, they look meek like they’re in court, arms bent up (cerebrum, internal capsule and thalamus may be involved)
In a stroke patient with decorticate posturing, which muscle groups would you expect to be stronger in upper and lower limbs?
Decorticate (not decerebrate where no one is celebrating because brain stem is involved)
Is extended legs and flexed arms, so on examination
Flexors stronger in upper limb
Extensors stronger in lower limb
Young patient (in 30s) presents with stroke-like findings, acute onset of focal neurological deficit. What other causes of stroke need to be considered?
Blood perfusion:
Sudden BP drop (ie sepsis, affects watershed zone)
Carotid artery dissection
Subarachnoid haemorrhage
Vessel changes:
Vasculitis (check ESR)
Blood components:
Venous sinus thrombosis
Thrombophilia (like antiphospholipid syndrome)
Inherited- Fabry’s (lysosomal storage), CADASIL
In Fabry disease, which parts of the body may there be problems with and what are the problems?
X linked lysosomal storage disease due to a-galactosidase A Skin- angiokeratoma (burgundy moles) Eyes- lens opacities Heart- MI, syncope, arrhythmia Kidneys- failure CNS- stroke Nerves- neuropathy
What is CADASIL?
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts + Leucoencephalopathy
Main genetic cause of strokes due to Notch3 gene mutation (19q) affecting vascular smooth muscle
PC: Migrane, TIA, mood disorders, dementia ± psuedobulbar palsy
IHx: MRI
Nme 5 types of lacunar infarct:
- Pure motor
- Ataxic hemiparesis (cerebellar signs + weakness)
- Pure motor
- Dysarthria/clumsy hand
- Mixed sensorimotor
What are the 3 H’s of a total anterior circulation stroke?
Hemiparesis
Homonymous hemianopia
High cortical deficit (dysphasia, visual inattention, dyspraxia)
When would a UMN lesion mimic a LMN lesion?
In the first few hours, before the spasticity and hyper-reflexia develop. This occurs from ‘spinal shock’- not well understood
Patient has hemiparesis of the right leg and reduced cognition- broadly where is the site of the lesion?
Left cerebral hemisphere
If hemiparesis with epilepsy, reduced cognition or a homonymous hemianopia it is in the cerebral hemispheres
Cranial nerve palsy in CN 3-8 with contralateral hemiplegia means the site of the stroke is where?
Brainstem on the side of the cranial nerve deficit
Where does pain, temperature, proprioception and vibration sense travel in the spinal cord?
Pain + Temp- raise ALert = Anterolateral (immediate decussation to get away from danger)
Vibration + Proprioception = Dorsal columns (ring the DOORbell, open the door)
How does the side of sensory loss differ if the lesion is in the brainstem or above it?
In the brainstem- lesion is ipsilateral to cranial nerve sensory loss and contralateral to arm + leg
Above- contralateral for both (sensory nerves have all decussated by then)