Week 12 Flashcards
Where can cranial nerve abnormalities arise from?
communicating pathways to and from the cortex, cerebellum and other parts of brainstem nerve nucleus nerve neuromuscular junction disorders muscle
What are the mnemonics for cranial nerves?
On old olympus towering tops a frenchman and german viewed some hops.
some say marry money but my brother says bug business makes money
What are the 12 cranial nerves?
olfactory optic oculomotor trochlear trigeminal abducens facial vestibulocochlear glossopharyngeal vagus spinal accessory hypoglossal
Describe the olfactory nerve
sensory
smell
olfactory cells of nasal muscosa - olfactory bulbs - pyriform cortex
Describe the optic nerve
sensory
vision
retinal ganglion cells - optic chiasm - thalamus- primary visual cortex in occipital cortex
How do you examine the optic nerve?
optic discs with opthalmascope
pupillary responses
visual acuity
visual fields and blind spot (tested by confrontation)
Describe the oculomotor nerve
motor midbrain movement of eyeball, lens accommodation inferior oblique, superior, middle and inferior recti muscles levator palpeerde superiores
part 2 - parasympathetic
midbrain *Edinger_westphal)
pupil constriction
ciliary muscle and pupillary constrictor muscles
Describe the appearance of an oculomotor palsy
eye turns down and out - superior oblique and lateral rectus are the only muscles active
ptosis
involvement of pupil only if complete palsy
Describe the trochlear nerve
motor
moves eyeball
midbrain (inferior colliculus)
superior oblique muscles
depresses the adducted eye and introits the abducted eye
longest intracranial course
II and IV are only nerves to decussate to contralateral side
Describe the abducens nerve
motor
eyeball movement
pons
lateral rectus muscles
Describe an abducens nerve palsy
most common CN palsy
lateral rectus
double vision when looking to affected side - horizontal diplopia
Describe internuclear opthalmoplegia
disorder of conjugate gaze
failure of adduction of affected eye with nystagmus on lateral gaze in contralateral eye
can be unilateral or bilateral
results from lesion of medial longitudinal fasiculus (connects III and iV nerve nuclei)
commonly seen in MS
What does horner’s system consist of?
miosis
ptosis
apparent enopthalmos
anhidrosis
What can cause horner’s syndrome?
results from ipsilateral disruption of cervical/thoracic sympathetic chain congenital brainstem stroke cluster headache apical lung tumour MS carotid artery dissection cervical rib syringomyelia
Describe the trigeminal nerve
1 - sensory input from face
pons and medulla
face (opthalmic, mandibular and maxillary divisors) and anterior 2/3 of tongue
2 - motor
mastication
pons
masseter, temporalis, medial and lateral pterygoids
Describe the facial nerve
1 - motor
pons
muscles of expression
2 - sensory
medulla
taste
anterior 2/3 of tonguw
3 - parasympathetic
medula
salivation and lacrimation
Describe the corneal reflex
useful in patients with reduced conscious level lightly touch cornea with cotton wool afferent - V efferent - VII test of pontine function
Describe the vestibulocochlear nerve
1 - sensory
balance
pons and medulla
nerve endings within semi-circular canals - cerebellum and spinal cord
2 - sensory
hearing
pons and medulla
cochlear - auditory cortex in the temporal lobes
Describe the glossopharangeal nerve
1 - sensory
medulla
taste, proprioception for swallowing, blood pressure receptors
posterior 1/3 of tongue, pharyngeal nerve and carotid sinuses
2 - motor
medulla
swallow and gag reflex
pharyngeal muscles and lacrimal glands
3 parasympathetic
saliva production
parotid glands
In a glossopharyngeal palsy, in what direction does the uvula deviate to?
away from the side of the lesion
Describe the vagus nerve
1 - sensory
medulla
chemorecptors, pain receptors, sensation
blood oxygen concentration, carotid bodies, respiratory and digestive tracts, external ear, larynx and pharynx
2 - motor
medulla
hert rate and stroke volume, peristalsis, air-flow, speech and swallowing
pacemaker and ventricular muscles, smooth muscles of GI tract, smooth muscles of bronchial tube, muscles of larynx and pharynx
3 - parasympathetic
smooth muscles and glands of the same areas innervated by motor component as well as the thoracic and abdominal areas
Describe the spinal accessory nerve
motor
head rotation and shoulder shrugging
medulla
sternocleidomastoid and trapezius muscles
Describe the hypoglossal nerve
motor
speech and swallowing
medulla
tongue
In what direction does a hypoglossal nerve palsy cause the tongue to deviate?
towards the affected side
What cranial nerves would be affected if there was a lesion in the cavernous sinus?
III, IV, V (1st and 2nd divisions), VI, horner’s syndrome
What cranial nerves would be affected if there was a lesion in the superior orbital fissure?
III, IV, V(1st division), VI
What cranial nerves would be affected if there was a lesion in the cerebellopontine angle?
V, VII, VIII
What cranial nerves would be affected if there was a lesion in the jugular foramen?
IX, X (and XI)
What cranial nerves would be affected if there was a lesion in the bulbar /pseudobulbar palsy?
IX, X, XI (and XII)
Describe a pseudo bulbar palsy?
upper motor neurone lesion
spastic dysarthria, slow and limited tongue movements
lesions involving descending corticobulbar pathways cause pseudo bulbar palsy
stroke, MS, space occupying lesion
Describe a bulbar palsy
lower motor neurone lesion
nasal dysarthria, dysphagia with nasal regurgitation, wasted tongue with fasciculations
lesions of nuclei, cranial nerves or muscles can cause bulbar palsy
brainstem stroke, guillain barre syndorme, myasthenia gravis
What makes up the basal ganglia?
striatum; both dorsal striatum (caudate nucleus and putamen) and ventral striatum (nucleus accumbens and olfactory tubercle), globus pallidus, ventral pallidum, substantia nigra, and subthalamic nucleus.
What are the basal ganglia loops?
motor - movement
oculomotor - eye movement control
lateral orbito-frontal - social behaviour
dorsolateral prefrontal loop - executive functions / working memory
Describe the pathology of Parkinson’s disease
loss of dopaminergic neurones within the substantia nigra
surviving neurones contain lewy bodies
PD manifests clinically after loss of approximately 50% of dopaminergic neurones
What protein are lewy bodies made from?
alpha synuclein
What are the suggested mechanisms of LB formation
oxidative stress mitochondrial failure excitotoxicity protein aggregation interference with DNA transcription nitric oxide inflammation apoptosis trephine deficiency infection
Describe the pathological progression of PD
1-2 = medullary / pons and olfactory nucleus - asymptomatic
3-4 = midbrain - substantially nivea pars compacts - parkinsonism after extensive damage
5-6 - development of PD dementia
What are the features of parkinson’s disease?
bradykinesia
muscular rigidity
4-6Hz rest tremor
postural instability
What is the definition of bradykinesia?
slowness of initiation of voluntary movement with progressive reduction in speed and amplitude of repetitive actions
What are the non-motor symptoms of parkinson’s disease?
neuropsychiatric - dementia, depression, anxiety
sleep - REM sleep behaviour disorder
restless leg syndrome
daytime somnolence
autonomic - constipation urinary urgency / nocturia erectile dysfunction excessive salivation / sweating postural hypotension
other - reduced olfactory function
fatigue
pain and sensory symptoms
Describe the differential diagnosis of PD>
diagnosis improves with follow up other disorders mistaken for PD benign tremor disorders dementia with lewy bodies vascular parkinsonism parkinson plus disorders drug induced tremor
What are the investigations for PD?
bloods - if tremor present, TFTs, copper, caeroplasmin
Structural imagine - CT MRI brain normal
functional imaging - presynaptic dopaminergic function using DAT SPECT is abnormal
What drug classes are there in PD?
L-DOPA
dopamine agonists
MAO-B inhibitors
COMT inhibitors
Describe L-dopa
taken up by dopaminergic neurones and decarboxylated to dopamine within presynaptic terminals
prescribed with dopa-decarboxylase inhibito
half life about 90 minutes
What are the 2 common preparations of L dopa?
sinemet - Ldopa and carbidopa
Madopar - Ldopa and benserazide
What are the peripheral side effects of Ldopa?
nausea, vomiting, postural hypotension
What are the central effects of Ldopa?
confusion and hallucinations
What are the longer term complications after 5 years of Ldopa?
fluctuation in motor response
dyskinesia - most commonly chorieform movements at peak dose
Give examples of dopamine agonists
ropinirole
pramipexole
rotigotine
amomorphine
Describe Mao-B inhibitors
selegiline, rasagiline
prevents dopamine breakdown by binding irreversible to monoamine oxidase
can be prescribed as mono therapy in early disease or as adjunct in later disease
well tolerated
Describe COMT inhibitors
entacapone, tolcapome
inihibitng catechol - o-methyltransferase results in longer L-DOpa half life / duration of action
co-prescribe with Ldopa
side effects - dopaminergic and diarrhoea
What are the problems in advanced PD?
motor complications on/off fluctuations L-dopa induced dyskinesia poor balance / falls speech / swallowing disturbances cognitive -dementia
What are other degenerative causes of parkinosonism?
dementia with lewy bodies
progressive supranuclear palsy
multisystem atrophy
corticobasal degeneration
What are secondary causes of parkinsonism?
Drug induced - chronic use of dopamine antagonists
cerebrovascular disease
toxins - CO, organophosphates, MPTP
post infectious
Describe the fibre types in peripheral nerves
large fibres (myelinated)
motor nerves
proprioception, vibration and light touch
thinly myelinated fibres
light touch, pain, temperature
small fibres (unmyelinated) light touch, pain, temperature
Describe length dependent axonal nuropathy
diffuse involvement of peripheral nerves age >50 years length dependent; starts in toes/feet symmetrical slowly progressive no significant sensory ataxia any weakness distal and mild glove and stocking distribution
What are the causes of length dependent axonal neuropathy?
diabetes
alcohol
nutritional (folate, B12, thiamine, B6 deficiency)
immune mediated - RA, SLE, vasculitis, PAN
metabolic - renal failure , hypothyroidism
drugs -isoniazid, cisplatin, amioderone, gold
infectious - HIV, hepatitis
inherited -
neoplastic - myeloma
paraneoplastic
critical illness
Describe guillain_barre syndrome
acute inflammatory demyelinating neuropahy
post infectious autoimmune aetiology
progressive ascending weakness over days
flaccid, quadriparxsis with areflexia
respiratory / bulbar/ autonomic involvement
treated with IV immunoglobulin or apheresis
CIDP - chronic h form
What are the symptoms of muscle disease?
proximal limb weakness facial weakness eyes bulbar - dysarthria, dysphagia neck and spine respiratory myocardial
What are some causes of muscle disease?
muscular dystrophies metabolic muscle disorders mitochondrial siders myotonic dystrophies inflammatory muscle disorders neuromuscular junction disorders
Describe the pathogenesis and presentation of myasthenia gravis
autoimmune disorder 0 antibodies to acetylcholine receptor and post synaptic NMJ
association with other AI conditions
may be associatied with thymoma
affects young women and older men
fatiguable weakness of ocular, bulbar, neck, respiratory and/or limb muscles
what is the investigation and management of myasthenia gravis?
antibodies to AChR present in 85% of cases
single fibre EMG and repetitive nerve stimulation also abnormal
managed with pyridostigmine (anti-acetylcholine esterase) and immunosuppressive therapies
What is the definition of dementia?
progressive cognitive decline
interfere with the ability ti function at work or at squall activiities
a decline from previous levels of functioning and performing
not explained by delirium or major psychiatric disorder
the cognitive or behavioural impairment involves a minimum of 2 of the following domains - memory, executive function, language, apraxia / visuospatial
What is asked about memory in a cognitive assessment?
impaired ability to acquire and remember new information - symptoms include: repetitive questions or conversations, misplacing personal belongings, forgetting events or appointments, getting lost on a familiar route
What is asked about executive function in a cognitive history?
impaired reasoning and handling of complex tasks, poor judgement -symptoms include: poor understanding of safety risks, inability to manage finances, poor decision making ability, inability to plan complex or sequential activities
What is asked about visuospatial awareness in a cognitive history?
impaired visuospatial abiltiies - symptoms include: inability to recognise faces or common objects or to find objects in direct view despite good visual acuity, inability to operate simple implements or orient clothing to body
Describe what is asked about language in a cognitive history
impaired language functions (speaking, reading, writing) symptoms include: difficulty thinking of common words while speaking, hesitations: speech, spelling and writing errors
What does the addenbrookes cognitive assessment examine?
memory attention / concentration language visuospatial executive function purpose - severity, pattern of impairment
Describe attention / concentration / orientation
component of consciousness which allows filtering of information to allow one to focus on a particular stimuli
essential for all aspects of cognitions
pathological process - delirium (depression)
How are attention, concentration and orientation assessed?
orientation
serial 7s
working memory facet of attention/concentration e.g digit span
Describe executive function
facet of frontal lobe function
behaviour, social awareness (orbitofrontal)
working memory, cognitive estimates planning (dorsolateral prefrontal cortex)
motivation (anterior cingulate)
How do you test executive function?
proverbs
verbal fluency
estimates
planning
What is the dorsal stream involved in?
position of object in space (dyspraxia) picking an object from a scene
What is the ventral stream involved in?
object recognition (visual gnosis)
facial recognition
(prosopagnosia)
How do you test visuospatial parietal lobe function?
pentagons cubes 3-D letters dots counting assess higher motor control, deficits result in impairment of purposeful motor skills pantomime gestures to command use of everyday objects copying of meaningless gestures
How can language be assessed?
naming
repetition
3 stage command (comprehension)
reading
what are the 3 patterns of aphasia?
semantic variant
logopenic variant
non-fluent aphasia variant
Describe the semantic variant
poor confrontation naming
impaired single word comprehension
poor object / person recognition, surface dyslexia, spared repetition
semantic dementia
Describe logopenic varient
impaired single word retreival
impaired repetition, speech sound errors
spared object / person recognition, single word recognition
Alzheimer’s dementia
Describe non fluent variant aphasia
effortful, halting speech
phenomic errors
spared object / person recognition, single word recognition
progressive non-fluent apahsia
What is the “cut off” score in the addenbrookes cognitive assessment?
88
What does a deficit in episodic memory suggest?
alzheimers
What does a deficit in semantic memory suggest?
semantic dementia
What does a deficit in attention / concentration suggest?
delirium
What does a deficit in naming and fluency suggest?
progressive non fluent dementia
What does a deficit in visuospatial abilities suggest?
PD plus syndrome
or variants of AD
What leads to aneurysm formation?
haemodynamic stress
extensive inflammatory and immunological reactions are common in enraptured intracranial aneurysms and may be related to aneurysm formation and rupture
What are the predisposing factors for aneurysmal SAH?
smoking female hypertension positive family history ADPCK, Ehlers dan lose, coarctation of the aorta
Describe the history which is common in SAH
sudden onset headache
LOC, seizures, visual, speech and limb disturbance
sentinel headache
Describe the clinical examination of SAH
photophobia meningism subhyaloid haemorrhages vitreous haemorrahges (Terson's syndrome) speech and limb disturbance pulmonary oedema
how is SAH graded?
By GCS 15 - grade 1 13-14 - grade II 13-14 with deficit grade III 7-12 - grade IV 3-6 grade V
Describe the use of CT in SAH
confirms diagnosis
clues to aetiology
identifies complications: infarction, haematoma, hydrocephalus
prognostic - fisher grade
Describe the investigations in SAH
LP - xanthochromia - bilirubin vs oxygen Hb CTA MRA DSA: stroke, diabetics hyponatraemia ECG changes elevated troponin echocardiography - tako tsubo cardiomyopathy
Describe the resuscitation in SAH
bed rest fluids 2.5-3.0 L normal saline anti-embolic stockings nimodipine: 60mg 4 hourly oral? NG or 2.5-10ml/hr IV via central line analgesia doppler studies
What are the management options for SAH?
surgical clipping
endovascular (coils, stents and glue)
conservative
What are the potential complications of SAH?
rehaemorrhage delayed ischaemia hydrocephalus hyponatraemia ECG changes, LVF LRTI, PE, UTI
Describe delayed ischaemia
day 3-10
progressive deterioration in LOC associated with new deficit
angiographic spans
What is the treatment of delayed ischaemia?
fluid management
nimodipine
inotropes
angioplasty
Describe hyponatraemia in SAH
CWS vs SIADH
establish volume status
hypertonic saline
fludrocortisone
Describe the cardiopulmonary complications associated with SAH
sympathetic stimulation and catecholamine release can lead to myocardial injury elevations of troponin can occur arrhythmia wall motion abnormality sudden death normally normal within 3 days
What factors can affect consciousness?
trauma elevated ICP fever hypothermia seizure hypotension severe hypertension hypoxia hypercapnia sepsis metabolic medications etc....
What are the three sub scales in GCS?
eye
verbal
motor
Describe eye opening in GCS
- spontaneous
- to verbal command
- to pain
- none
N.B cannot be assessed if eyes are swollen
Describe verbal response in GCS
- orientated (T/P/P)
- confused
- inappropriate
- incomprehensible sounds
- none
append T to score if patient is intubated
Describe motor in GCS
- obeys commons
- localises pain
- normal flexion
- abnormal flexion
- extension
- none
N.B cannot be assessed if patient has received muscle relaxants
also spinal injury?
What is a coma?
inability to obey commands, speak, open eyes to pain
How is the best verbal response modified for young children?
- none
- restless, agitated
- persistently irritable
- consolable crying
- appropriate words, smiles, fixes/follows
How is head injury classified?
GCS
14-15 = minor
9-13 = moderate
severe <8
Describe MS
idiopathic inflammatory demyelinating disease of the CNS
acute episodes of inflammation are associated with focal neurological deficits
demyelination results in loss of neurological function - weak leg, visual loss, urinary incontinence
deficits usually develop gradually, last more than 24 hours and may gradually improve over days to a week.
Late in untreated disease patients may become progressively more disabled
What are the subtypes of MS?
relapsing remitting MS
primary progressive MS
secondary progressive MS
benign MS
Describe relapsing remitting MS
unpredictable attacks which may or may not leave permanent deficits followed by periods of remission
Describe primary progressive MS
steady increase in disability without attacks
Describe secondary progressive MS
initial relapsing-remitting MS that suddenly begins to decline without periods of remission
What are examples of symptoms that may develop into MS?
optic neuritis
clinically isolated syndromes
transverse myelitis
radiologically isolated syndromes
Describe optic neuritis
painful visual loss that comes on over a few days
may resolve after a few weeks
many will go on to develop MS
Describe transverse myelitis
inflammation of the spinal cord weakness sensory loss incontinence may be only symptom many causes other than MS
Describe clinically isolated syndromes in MS
single episode of neurological disability due to focal CNS inflammation
can include optic neuritis and transverse myelitis
may be first attack of MS
can happen after infection and not be related to MS
When is MS diagnosed?
When there is evidence of 2 or more episodes of demyelination disseminated in space and time
What are thought to contribute to the development of MS?
genetic factors
sunlight / vitamin D exposure
viral trigger - EBV?
multifactorial - smoking
When should MS be suspected?
neurological symptoms that develop over a few days
a history of transient neurological symptoms that have lasted for more than 24 hours and spontaneously resolved
How can relapses of MS be “hidden”
optic neuritis / visual disruption Bell's palsy "Labyrinthitis" sensory symptoms bladder symptoms in man/woman without children
What are the main symptoms of MS?
fatigue cognitive impairment depression unstable mood nystagmus optic neuritis diplopia dysarthria dysphagia weakness spasms ataxia pain hypoesthesias paraesthesias incontinence diarrhoea/constipation frequency or retention of urine
When to suspect symptoms may not be caused by MS?
sudden onset peripheral signs - areflexia, glove and stocking distribution, muscle wasting, fasciculations major cognitive impairment reduced level of consciousness prominent seizures pyrexia/ evidence of infection normal MRI scan
Describe MRI scan in diagnosis of MS
MRI brain and cervical spine with gadolinium contrast
possible to diagnose with one scan
evidence of demyelination in 2 regions can indicate dissemination in space
If enchanting and non-enchanting areas of demyelination are seen this can indicate dissemination in time
What additional investigations can be carried out for MS?
lumbar puncture
bloods - exclude other conditions
visual evoked potentials
CXR - exclude sarcoidosis
What is examined in a lumbar puncture for MS?
CSF oligobands (need matched blood sample)
CSF cell counts - exclude mimics
CSF glucose (matched blood sample)
CSF protein
Describe oligoclonal bands in MS LP
immunoglobulin bands seen in blood and spinal fluid after protein electrophoresis
presence of bands in CSF but not blood suggests immunoglobulin production in CNS
supports diagnosis of MS but can be seen in other conditions
What blood tests should be carried out to exclude other causes of MS?
B12/folate serum ACE lyme serology ESR/CRP ANA/ANCA/rheumatoid factor aquaporin-4 antibodies (if transverse myelitis / optic neuritis)
Describe visual evoked potentials
measure conduction of nerve signals in optic nerve to look for subclinical optic neuritis
conduction will be slower if a patient has had optic neuritis in the past
Describe relapse vs pseudo-relapse in MS
a relapse usually involved a new neurological deficit that lasts for more than 24 hours in the absence of pyrexia or infection
a pseudo-relapse is the reemergence of previous neurological symptoms or signs related to an old area of demyelination in the context of heat or infection
if evidence of infection this should be treated
Describe the steroid regime for a relapse of MS
1g of IV methylprednisalone for 3 days
or
500mg of oral methylprednisalone for 5 days
and PPI for gastroprotection
ideally prescribe at 9am to avoid sleep disruption
What are 2 powerful drugs that can be used to treat MS?
alemtuzumab
natalizumab
What are examples of oral treatments of MS?
fingolimod
dimethyl fumarate
Describe cladribine
old chemo drug
two short courses of tablets over two years
targets B cells
may stop MS activity for many years
What is the definition of a stroke?
central nervous system infarction (which includes brain, spinal cord and retinal cells attributable to ischaemia), based on objective evidence of focal ischaemic injury in a defined vascular distribution or clinical evidence of the form with other aetiologies excluded
In what artery is there most likely to be an infarction if there is leg weakness?
anterior cerebral arteries
In what artery is there most likely to be an infarction if there is weakness of the trunk and hands?
middle cerebral artery
What blood vessel supplies the main language areas of the brain?
middle cerebral artery
What is the definition of an ischaemic stroke?
an episode of neurological dysfunction caused of focal cerebral, spinal, or retinal infarction
Describe TACS
total anterior circulation syndrome
hemiparesis and higher cortical dysfunction and hemianopia
proximal MCA or ICA occlusion
Describe PACS
partial anterior circulation syndrome
isolated higher cortical dysfunction or any 2 of hemiparesis, higher cortical dysfunction or hemianopia
usually branch MCA occlusion
Describe POCS
posterior circulation syndrome
isolated hemianopia or brainstem syndrome
can include perforating arteries, PCA or cerebellar arteries
Describe LACS
lacunar syndrome
pure motor stroke or pure sensory stroke or sensiromotor stroke or ataxic hemiparesis or clumsy hand dysarthria
perforating artery / small vessel disease
What is the definition of an intracerebral haemorrhage
A focal collection of blood within the brain parenchyma or ventricular system not caused by trauma
What is the definition of a stroke caused by intracerebral haemorrhage?
Rapidly developing clinical signs of neurological dysfunction attributable to a focal collection of blood within the brain parenchyma or ventricular system which is not caused by trauma
What can cause an intracerebral bleed?
hypertension trauma blood clotting deficiencies abnormalities in blood vessels haemorrhage transformation of an infarct tumours drug usage
What is the management of an ischaemic stroke?
IV thrombolysis thrombectomy +/- IV thrombolysis aspirin stroke unit hemicranectomy
What is the management of a haemorrhagic stroke?
blood pressure control
stroke unit
neurosurgical evacuation
What are the cerebrovascular risk factors for stroke?
hypertension obesity sedentary lifestyle high cholesterol smoking alcohol diabetes heart disease poverty
Describe secondary prevention in stroke management
smoking cessation aspirin for first 2 weeks then clopidigrel antihypertensives statins diabetes control endarterectomy if stenosed carotids
Describe mononeuropathy of the radial nerve
entrapment at spinal groove "saturday night palsy" presenting symptoms wrist and finger drop usually painless
Describe the muscles supplied by the radial nerve and what weakness of them effects
extensor carpi radialis longus - wrist extension
extensor digitorum communis - finger extension
brachioradialis - elbow flexion in mid-pronation
Where would the sensory change occur in radial nerve damage?
the dorsal aspect of the hand - thumb, index and half of middle finger
Describe palsy of the ulnar nerve
entrapment at ulnar groove (medial epicondyle of humerus)
may be history of trauma at elbow
sensory disturbance and weak grip
usually painless
Describe the muscles supplied by the ulnar nerve and what weakness of them effects
1st dorsal interosseus - index finger abduction
abductor digiti minimi - pinkie abduction
flexor carpi ulnari - wrist flexion
adductor pollicis - thumb adduction
Describe the sensory change in ulnar nerve palsies
medial aspect of the hand
Describe palsy of the median nerve
entrapment within carpal tunnel at wrist
history of intermittent nocturnal pain, numbness and tingling - often relieved by shaking hand
patient may complain of weak grip
positive tine’s sign/phalen’s test
Describe the muscles supplied by the median nerve and what weakness of them effects
lumbricals I+II - flexion at MCP joints
opponens pollicis - thumb opposition
abductor pollicis brevis - thumb abduction
flexor pollicis brevis - thumb flexion
Describe the sensory change in a median nerve palsy
lateral aspect of the palm
tips of index, middle and half of ring finger
Describe mononeuropathy affecting the median nerve II anterior interosseus branch
trauma to forearm
history of forearm pain
patient may complain of weak grip of keys
can’t make OK sign
Describe the muscles supplied by themedian nerve II anterior interosseus branch and what weakness of them effects
pronator quadratura - flexion at MCP joints
flexor pollicis longus - thumb flexion
flexor digitorum - thumb flexion
Describe palsy of the femoral nerve
haemorrhage or trauma
weakness of quadriceps
weakness of hip flexion
numbness in medial shin - saphenous branch
Describe the motor weakness in female nerve palsy
quadriceps - knee extension
illiopsoas - hip flexion
adductor magnus - hip adduction
Which nerve supplies the back of the lower leg and what muscles are involved?
tibial
gastrocnemius, soleus
Which nerve supplies the front of the lower leg and what muscles are involved?
peroneal
TA, peroneii
Describe peroneal nerve palsy
entrapment at fibular head
may be history of trauma, surgery or external compression
acute onset of foot drop and sensory disturbance in the lateral aspect of the shin
usually painless
What muscles does the perineal nerve supply and what would be the effect of a palsy?
tibialis anterior - ankle dorsiflexion
extensor hallicus longs - great toe extensinon
How can you distinguish between a common peroneal nerve palsy and L5 distribution?
L5 damage would also affect foot inversion
What is mono neuritis multiplex?
simultaneous or sequential development palsies of 2 or more nerves
What are some common causes of mononeuritis multiplex?
diabetes vasculitic - Churg strauss, polyarteritis nodosa Rheumatological - RA, SLE etc infective - hep C, HIV sarcoidosis lymphoma
What is primary headache?
headache and its associated features is the disorder
e.g. migraine, tension-type headache, cluster headache
What is a secondary headache?
secondary to underlying cause
e.g Subarachnoid haemorrhage, space occupying lesion, meningitis, temporal arteritis, high/low intracranial pressure, drug-induced
What is important to ask about in the history of headache
onset severity and pain quality location/radiation presence of aura / prodrome periodicity associated features age of onset triggering / exacerbating / relieving factors family history social / employment history medication history co-morbid depression / sleep disturbance
What are the red flag features suggesting secondary headache ?
age >50 years
thunderclap headache
focal/non-focal neurological deficit
worsening of symptoms with posture, valsalva or physical exertion
early morning headaches
systemic symptoms - fever, weight loss
seizures, meningism
temporal artery tenderness/ jaw claudication
specific situations - cancer, pregnancy, post partum, HIV, immunosuppression
Describe the clinical examination of the patient with headache
general reduced conscious level BP/pulse pyrexia meningism skin rash temporal artery tenderness
cranial nerve pupillary responses visual fields +/- blind spots eye movements fundoscopy
What are upper motor neurones signs in a neurological examination?
pronator drift
increased tone
brisk reflexes
extensor plantar response
What are cerebellar signs in neurological examination?
nystagmus
past-pointing
dysdiagochokinesis
broad based ataxic gait
Describe the epidemiology of migraine
female > male 12-16% general population prevalence highest aged 25-55 years positive family history most patients report triggers without aura - 70%
Describe the pathophysiology of migraine
primary dysfunction in brainstem sensory nuclei (V, VII-X)
pain results from pain sensitive cranial blood vessels and their innervating trigeminal fibres
Describe migraine prodrome
up to 48 hours before headache
variable symptoms - mood disturbance, restlessness, hyperosmia, photophobia, diarrhoea
Describe migraine aura
recurrent reversible focal neurological symptoms (visual , sensory, motor)
develops over 5-20 minutes and lasts <60 minutes
visual aura is most common
sensory aura often starts in hand and migrates up arm
Give examples of visual aura
zigzag fortification spectrum
visual field loss
negative scotoma
positive scotoma
Describe a migraine headache
character commonly throbbing or pulsatile moderate - severe gradual onset, duration 4-72 hours unilateral in 60& can radiate aggravated by routine physical activity nausea and vomiting photophobia phonophobia osmophobia mood disturbance diarrhoea autonomic disturbance - lacrimation, conjunctival infection, nasal stiffness
Describe the investigation of migraine
good history and normal clinical examination does not require further investigaion
cranial imagine advised if red flag features present or aura >24 hours
Describe the complications of migraine
medication overuse headache: headache >15 days per month associated with frequent use of acute relief medications - NSAIDs, paracetamol, opioid medications, triptans
patients advised to take acute treatments more than 2-3 times per week to prevent this
Describe the management of migraine
lifestyle
avoid triggers
reduce caffeine / alcohol
encourage regular meals and sleep patterns
acute management
simple analgesia
triptans (sumatriptan)
antiemetics (domperidone, metoclopramide)
prophylaxis
beta blockers (propanalol)
tricyclic antdepressants (amitriptyline)
anti-epilepsy drugs (topiramate, sodium valproate)
Describe a thunderclap headache
definition - abrupt onset of severe headache which reaches maximum intensity <5mins
should be considered as SAH until proven otherwise
What are the causes of thunderclap headache?
SAH
intracerebral haemorrhage
arterial dissection
bacterial meningitis
rare - spontaneous intracranial hypotension, pituitary apoplexy
primary headaches - diagnosis of exclusion
Describe the investigation of thunderclap headache
bloods
U&Es, LFT, glucose, full blood count, coagulation screen, CRP, cultures if pyrexial
12 lead ECG
urgent CT brain
LP after 12 hours to look for xanthochromia
What is the cerebral perfusion pressure equation?
CPP = mean arterial pressure - ICP
What types of cerebral herniations are there?
uncal central (transtentorial) cingulate transcalvarial upward transtentorial tonsillar
Describe the history in raised pressure headaches
worse on lying flat worse in the morning persistent nausea/vomiting worse on valsalva worse with physical exertion transient visual obscurations with change in posture
What are the examination findings in a raised pressure headache?
optic disc swelling impaired visual acuity/colour vision restricted visual fields/ enlarge blind spot III nerve palsy VI nerve palsy (false localising sign) focal neurological signs
What are the causes of raised ICP?
mass effect - tumour, infarction with oedema, subdural/extradural/intracerebral haematoma, abscess
Increased venous pressure
cerebral venous sinus thrombosis, obstruction of jugular venous system
obstruction to CSF flow / absorption
hydrocephalus, meningitis
idiopathic
What are the features of low CSF pressure headache?
headache worse on sitting/standing
results from CSF leakage
What are the causes of low CSF headache?
post LP
spontaneous intracranial hypotension
What is a seizure?
episode of neuronal hyperactivity
What is epilepsy ?
at least two unprovoked episodes of seizure
Describe focal epilepsy
localised, partial onset
area of abnormality in otherwise normal brain
trauma, infection, abscess
more likely in elderly
transient injuries may lead to focal injuries
Describe generalised epilepsy
where someone is born with a problem in the way they process neurotransmitters, channels, receptors etc
innate responsiveness in CNS that leaves them more prone to seizures
more likely in children
What should you do if you see someone having a seizure?
keep them out of harm’s way
recovery position
if movements stop, not impairment of ABCS, does not need hospitalisation once recovers awareness
Describe the features of focal epilepsy
history of trauma/birth injury focal aura / sequelae post attack confusion/drowsiness automatisms nocturnal events
Describe GGE features
photosensitivity age of onset 8-26 alcohol or sleep deprivation myoclonus (AM) lack of aura seizures within 2 hours of awakening family history EEG abnormal
What investigations are needed for epilepsy ?
brain imaging
EEG
systemic provocations
Describe the EEG
test takes C 1 hour observe activity on EEG lying at rest hyperventilation drowsiness photic stimulation
What is the differential for epilepsy ?
first seizure vs syncope
multiple seizures vs syncope vs NEAD
rarer - migraine, narcolepsy, transient global amnesia, panic attacks
What is status epillepticus
repetitive or prolonged epileptic seizures
medical emergency
may cause profound systemic/neuronal damage
recognised mortality
What is the clinical definition of status epilepticus?
> 2 seizures without full recovery or neurological function between seizures
or continuous seizure activity >30 minutes
What is the normal treatment of focal epilepsy?
lamotrigine, carbamazepine, levetirecetam
What is the normal treatment of generalised epilepsy?
valproate
levetiracetam
lamotrigine
What are the different anatomical classifications of CNS infection?
meningitis
(meningo) encephalitis
mass lesion
myelitis
What are the main bacteria that cause meningitis and encephalitis?
meningococcus, pneumococcus, listeria
What are the main viruses that cause meningitis and encephalitis?
HSV, VZV, enterovirus, HIV, Mumps
What is a common fungal infection that can cause meaning-encephalitis and mass lesions?
crytococcosis
What is a common protozoal infection that can cause CNS mass lesions and eosinophils-meningitis?
toxoplasmosis
Describe meningitis
inflammation of meninges (and sometimes cerebrum)
acute- bacterial or viral
sub-acute - bacterial (listeria, TB)
What are the signs and symptoms of meningitis?
95% will have 2 of headache, neck stiffness, reduced GCS or fever
confusion indicative of celebrities/encephaltis
Rash - purpuric or petechial but macular early on
What are the risk factors for pneumococcal meningitis?
middle ear injury head injury neurosurgery alcohol immunuosuppresion
What are risk factors for listeria?
immunosuppresion
pregnancy
What are signs of pneumococcal meningitis?
focal neuro signs
seizures
VIII palsy
other signs of pneumococcal infection - CAP, ENT, endocarditis
What indicators are associated with adverse outcomes in bacterial meningitis?
pneumococcus reduced GCS CNS signs older than 60 CN palsy bleeding
Describe the investigations for suspected meningitis
history and exam - throat and examine for cervical lymph nodes
blood cultures (PCR)
throat culture, viral gargle
FBC, UEs, LFTs, CRO
lumbar puncture 0 cell count, gram stain, culture and PCR
protein and glucose, viral PCR
When to do a CT in suspected meningitis?
CT to exclude mass session /effect, gross cerebral oedema doesn't exclude RICp CT before LP if GCS < 12 CNS signs papilloedema immunocompromised seizure
ANTIBIOTICS PRE CT SCAN
When is LP contraindicated in bacterial meningitis investigation?
brain shift, rapid GCS reduction, response/cardiac compromise, severe sepsis, rapidly evolving rash, infection at LP site, coagulopathy
How should a possible bacterial meningitis be treated?
IV ceftriaxone 2 g 12 hourly
Add amoxicillin 2g 4 hourly if suspicion of listeria
Add dexamethasone if bacterial meningitis strongly suspected (10mg 6 hourly for 4 days)
Describe the definitive antibiotic therapy for meningococcal meningits
IV ceftriaxone or benzyl penicillin
5-7 days
Describe the definitive antibiotic therapy for pneumococcal meningitis
IV ceftriaxone or benzyl penicillin
14 days
Describe the definitive antibiotic therapy for listeria meningitis
IV amoxicillin
21 days
Describe special cases of bacterial meningitis
travel to sub-saharan africa and other high prevalence areas - ACWY recommended
asplenia, complement deficiency, Men boosters with men B and ACWY, HIB and pneumothorax
cochlear impants - pneumococcal booster
Describe viral meningits
usually only diagnosed after exclusion of BM no confusion enterovirus HIV mumps unidentifed supportive therapy aciclovir only in immunocompromised
Describe viral encephalitis
confusion, fever and seizures HSV encephalitis - lymphocytic CSF, PCR EEG - temporal lobe MRI that with aciclivir 2-3 weeks
Describe intra-cerebral TB
sub acute often associated with other sites may be unmasked during TB Rc CN lesions usual (II,IV, VI, IX) sample widely CSF may be normal steroid paradoxical worsening usual treat for one year steroids
Describe HIV brain disease
consequence of unrecognised/untreated infection and marked immunodeficiency or life-style
encephalitis
dementia
neuro-syphilis
opportunistic (tuberculosis, cryptococcus, toxoplasmosis, JCV - progressive multi-focal leuco-encephalopayh
Describe progressive multifocal leucoencephalopthhy
progressive motor dysfunction immunocompromsied HIV, anti-TNF, transplant JC virus no specific Rx ARVs if HIV may occur as part of immune reconstitution
Describe intra-cerebral toxoplasmosis
toxoplasma gonii headache, seizures, focal CNS signs immunocompromised multiple enhancing ;lesions IgG and IgM (blood) PCR (CSF) Rx sulphadiazine + pyramethamine restore immune function
Describe cryptococcal meningits
immunodeficiency SOL or meningo-encepahlitis CSF - india ink, cryptococcal antigen treatment with amphotericin B and flucytosone and fluconazole raised IPC (shunt) paradoxical worsening with ARVs in HIV
