Neurology Flashcards
xWhat is the treatment for Trigeminal neuralgia?
Carbamazepine
If no improvement - refer to neurology
What are the branches of the Trigeminal nerve?
- Ophthalmic
- Maxillary
- Mandibular
What is a marcus gunn pupil?
- found in MS
- a.k.a relative afferent pupillary defect (RAPD)
- Constriction of pupils of both eyes when the light stimulus is applied to the normal eye
2. Dilatation of pupils of both eyes when the light stimulus is rapidly transferred from the normal eye to the affected eye.
Foot drop is caused by compression of which nerve?
common peroneal nerve
Loss of sensation of big toe is caused by which nerve root being affected?
L5
What nerve is mainly responsible for tongue movements?
Hypoglossal nerve
Where is Broca’s area located and what is its function?
Frontal lobe - usually left
Motor function of speech
How does a lesion in Broca’s area present?
BROKEN speech of Broca aphasia (speaks in short meaningful phrases)
Where is Wernicke’s area located?
Temporal lobe - usually left side
(95% of people have a left dominant hemisphere)
How does a lesion in Wernicke’s area present?
Long WORDY speech of Wernicke’s with no meaning
A lesion in the cerebellum leads to symptoms on which sides of the body?
Lesions of the cerebellum affect the ipsilateral side of the body.
What are the clinical features of idiopathic intracranial hypertension?
- young obese females
- headache - worse in the morning and at night - improved by standing
- nausea and vomiting.
- may also complain of pulsatile tinnitus (described as whooshing or buzzing)
- diplopia and deteriorating vision, eventually leading to blindness if not treated.
- On funduscopy- papilledema.
- Computed tomography (CT) scans will reveal no mass, but sometimes small slitlike ventricles and an empty sella sign can be seen.
- Diagnosis is usually made by measuring the opening lumbar puncture (LP) pressure, which is high
What is the treatment for idiopathic intracranial hypertension?
LP to drain excess CSF
Acetazolamide may help to reduce CSF production
Weight loss
What is the defect that leads to neurofibromatosis type 1?
Autosomal dominant mutation of neurofibromin (NF1 gene) on chromosome 17, which is a tumor suppressor gene (that inhibits p21 ras oncoprotein). This mutation leads to uncontrolled cell pro- liferation.
NF1 is more common (90% of all neurofibromatosis is type 1)
What are the main clinical features of NF1?
- Neurofibromas - skin lumps - can be small or large
- axillary and groin freckling
- café au lait spots - flight, light brown patches usually seen from birth
- Lisch nodules - iris hamartomas - lumps on the iris that don’t affect vision
- optic gliomas - can affect vision
- epilepsy
- learning difficulties
What is the defect that causes neurofibromatosis type 2?
Autosomal dominant mutation of merlin on chromosome 22, which is also a tumor suppressor gene.
What are the main clinical features of neurofibromatosis type 2?
Bilateral acoustic neuromas (schwannomas)
Think NF type 2, on chromosome 22, leads to 2 acoustic neuromas
What is the cause of an extradural haematoma?
Associated with temporal bone skull fracture
typically due to direct trauma to the pterion - the weakest part of the skull located on the temporal bone - resulting in rupture of the middle meningeal artery
This could happen for example in an RTA
What are the classic features of extradural haematoma?
TALK AND DIE
- lucid period followed by rapid deterioration as the bleeding expands and can lead to transtentorial herniation
- CT: “Biconvex” lens that does not cross suture lines
What is a subdural haematoma?
Venous bleeding between the dura and arachnoid membrane due rupture of small bridging veins
Subdural haematoma is seen more commonly in which groups of people?
babies (shaken baby syndrome)
Alcoholics
Elderly following a fall
What are the clinical features of subdural haematoma?
due to it being a slow venous bleed the onset of symptoms can be delayed and go on for longer before they present
- headache
- confusion
- drowsiness
- limb weakness or speech disturbance
CT head shows crescent shaped appearance of the bleeding, DOES cross suture lines
What is the cause of a subarachnoid haemorrhage?
- rupture of cerebral aneurysms, especially berry aneurysms, causing bleeding into subarachnoid space
- can be due to aneurysm that has spontaneously developed in the person’s life) or associated with underlying conditions such as
polycystic kidney disease or connective tissue diseases like Marfan’s syndrome or Ehler Danlos syndrome - Increased risk in smokers and hypertension
How does SAH present?
- sudden onset severe headache - thunderclap headache
- typically occipital
- worst headache I’ve ever had
- there may be a history of recent headache “sentinel headache”- warning leak
- vomiting, collapse
- seizures, coma
- CT head: blood in the cisterns and filling of blood along the sulci and fissures.
- If CT is negative you need to do LP - positive for xanthochromia (bilirubin breakdown from RBCs)
What are upper motor neurone signs
- hypertonia
- spastic paralysis
- hyperreflexia
- Babinski positive
(reflexes are uninhibited by UMNs)
what are lower motor neurone signs?
- hypotonia
- flaccid paralysis
- hyporeflexia
- muscle atrophy
- fasciculations
What is the most common type of motor neurone disease (MND)?
ALS amyotrophic lateral sclerosis
What are the clinical features of MND?
- rapidly progressive, fatal disease
- mixture of upper motor AND lower motor signs
- autonomic nervous system and cognition are spared
- muscle weakness
- muscle wasting/atrophy - thenar eminence wasting, tongue wasting
- fasciculations
- spasticity (hyperreflexia)
- dysphagia
- dysarthria
- most common cause of death is respiratory depression
what is the cause of subacute combined degeneration of the cord
B12 deficiency causing demyelination
Affects the dorsal column and lateral corticospinal tracts
(dietary, pernicious anaemia)
What are the clinical features of subacute combined degeneration of the cord?
mixture of UMN + LMN + sensory signs
- symmetrical
- Romberg’s positive (loss of proprioception and position sense)
- sensory ataxia (gait)
- brisk knee reflexes
- absent ankle reflexes
- babinski positive (upgoing planters)
-
What is a positive Babinski sign?
positive = abnormal
Big toe bends towards the face (dorsiflexion) and other toes fan out
also called “extensor plantar response”
Normal response: big toe should flex down (plantar flexion)
What is Romberg’s test?
Patient closes their eyes for at leats 60 seconds
Romberg’s test is positive if they are unable to maintain their balance
Indicates a problem with proprioception and usually a problem with dorsal columns
Positive in
- tabes dorsalis
- subacute combined degeneration of the cord
- brown-sequard syndrome
what is the pathophysiology of Huntington’s disease
- Autosomal dominant
- Mutation of Huntingtin gene on chromosome 4
- trinucleotide repeat disorder - CAG is repeated an abnormal number of times
- exhibits anticipation
What is the triad of Huntington’s disease?
- early onset dementia
- behaviour changes - depression, aggression, hypersexuality
- choreiform movements
What are the differences between Huntington’s and ALS?
Huntington’s affects cognition whereas ALS usually doesn’t
Hungtinton’s gives you chorea which is characteristic
Huntington’s is inherited while ALS is usually not
What is the pathophysiology of Parkinson’s disease
Degeneration of dopaminergic neurones in the substantial nigra (in the basal ganglia) - not sure why these neurones die.
Dopamine needed in these nerves for control of motor movements
presence of Lewy bodies
Parkinson’s = low dopamine in the brain
What are the tetrad of symptoms in Parkinson’s?
- Bradykinesia - slowness of initiating and executing movements
- resting tremor - unilateral (pill-rolling tremor at rest)
- rigidity - cog wheel
- postural instability - poor balance and frequent falls
Other features
- Shuffling gait
- loss of facial expression - mask like face (hypomimia)
- hypophonia (weak, soft voice)
- dysphagia
- difficulty with fine motor skills - doing up buttons, writing (micrographia)
- difficulty turning over In beed
- sleep disturbance
Can develop dementia in the advanced stages
Parkinson’s plus syndrome - multi system atrophy - what are the key features
- parkinsonism
- ataxia
- autonomic dysfunction
- difficult to distinguish from PD in the early stages but it progresses more rapidly
- unlike PD - does not respond to levodopa/carbodopa
Parkinson’s plus syndrome - progressive supranuclear palsy (PSP) - what are the key features
- parkinsonism
- EYE PROBLEMS - cannot move the eyes vertically
- recurrent falls - they typically fall backwards due to “axial rigidity” (where in PD they fall forwards)
- less likely to have a tremor
- speech and swallowing are affected more commonly than PD
- progresses more rapidly than PD
What are the extra-pyramidal symptoms that can be caused by anti-psychotics?
These extrapyramidal symptoms (EPS) include
- acute dystonic reac- tions (muscle spasms, especially those of the neck [torticollis] and eyes [oculogyric crisis])
- akathisia (restless legs)- pseudoparkinsonism (bradykinesia, resting tremor etc)
- tardive dyskinesia (involuntary movements such as tongue dart- ing out of the corner of the mouth or lip smacking).
What is tardive dyskinesia?
extra-pyramidal symptoms typically caused by dopamine receptor antagonist drugs such as: metoclopramide, anti-psychotics - symptoms persist despite stopping medications for at least 1 month
Involuntary movements of tongue, lips, neck, trunk and limbs e.g. tongue smacking, tongue protrusion
What are the features of Lewy body dementia and how can you distinguish it from Parkinson’s disease?
- visual hallucinations
- parkinsonism
- sleep disturbance
- dementia and extrapyramidal symptoms come on within 12 months of each other (unlike in PD when cognitive decline happens at least 12 months after and can happen many years later)
what is Friedreich’s ataxia?
A trinucleotide repeat disorder
autosomal recessive mutation of frataxin gene on chromosome 9 - impairs the mitochondria
Affects the spinal columns and also the cerebellum
What are the clinical features of FA?
- muscle weakness
- staggering gait
- frequent falls
- loss of proprioception and vibration
- loss of deep tendon reflexes
- nystagmus
- dysarthria
- kyphoscoliosis
- pes cavus (high arch of the foot that does not flatten with weight bearing)
- cardiomyopathy
- diabetes
What is Lhermitte’s sign?
Bending the head forward triggers an electric shock sensation down the neck and spine
What is Uhthoff phenomenon?
Worsening of neurological symptoms in MS in a warmer environement such as
- warm bath
- warm weather
- exercise - increases body temperature