Nervous System Diseases Flashcards
how is hydrocephalus classified?
- communicating hydrocephalus
- non-communicating hydrocephalus
what is the pathology behind hydrocephalus?
excess CSF in ventricles
what is the difference between communicating and non-communicating hydrocephalus?
communicating - CSF pathway not affected
non-communicating - obstruction of the CSF pathway
what are the physiological processes behind production and absorption of CSF in the brain?
production: Na-K ATP-ase activity
absorption: pressure gradient between CSF and venous pressure
where is CSF produced?
in choroid plexus of ventricles
where is CSF reabsorbed from subarachnoid space into the venous sinuses?
at arachnoid villi protruding into the sinuses
where is CSF drained from the ventricles to the subarachnoid space?
through foramina at 4th ventricle
what are the names of the foramina in the 4th ventricle through which CSF drains into the subarachnoid space?
Laterally: foramen Lushka (x2)
Medially: foramen Magendie (x1)
what is usually the pathology behind communicating hydrocephalus?
impairment of CSF resorption
what are the common causes of communicating hydrocephalus?
- infection (eg meningitis)
- subarachnoid haemorrhage
- post-operative
- post-trauma
what is a common sign of hydrocephalus in young children? what is the reason for this?
enlarged head and failure to thrive - cranial sutures haven’t fused yet, so enlarged ventricles expand the skull
what are common symptoms of hydrocephalus in older children and adults?
raised ICP symptoms:
- nausea and vomiting
- headache
- papilloedema
- visual disturbance/upgaze difficulty
- balance problems
- cranial nerve palsy
- drowsiness
what is the pathology behind non-communicating hydrocephalus?
obstruction of CSF pathway
what are common causes of non-communicating hydrocephalus?
- acqueductal stenosis (most common!)
- tumours
- cysts
- infection
- haemorrhage
- congenital abnormalities
what is the imaging investigation and immediate treatment for acute hydrocephalus?
imaging: CT head
immediate intervention: external ventricular drain (EVD) - to drain excess CSF
what is the gold standard treatment for communicating hydrocephalus?
shunt - normally ventriculo-peritoneal
what disadvantages are associated with shunts used to treat hydrocephalus?
- high failure rate after 1 year
- disconnection/occlusion
- under/overdrainage
- migration
- infection
what are treatment options in non-communicating hydrocephalus, other than shunting?
- surgical removal of obstruction
- 3rd ventriculostomy
what is among the first symptoms a patient will experience if their hydrocephalus-treating shunt fails?
headache
what measures are used to diagnose hydrocephalus on radiological imaging?
- ventricular index (>50%)
- Evans ratio (>30%)
how is normal pressure hydrocephalus treated?
by using a programmable ventriculo-peritoneal shunt to control the drainage of CSF
what is normal pressure hydrocephalus commonly misdiagnosed as?
dementia/Alzheimer’s
what is the symptom triad for normal pressure hydrocephalus?
Wet - urinary incontinence
Wobbly - gait and balance difficulty
Wacky - fast progressive dementia
which symptoms of normal pressure hydrocephalus are more or less likely to improve once the hydrocephalus is treated?
likely to improve: incontinence, memory and gait
less likely to improve: dementia
what is likely to happen to a patient’s symptoms if they have normal pressure hydrocephalus and they receive a lumbar puncture?
their symptoms improve
why is normal pressure hydrocephalus important?
because it may be the reason for a patient presenting with dementia - can be reversed if treated early
what are the indications for a lumbar puncture?
diagnostic: meningitis, meningoencephalitis, cancer, neurological disease, inflammation, subarachnoid haemorrhage, idiopathic ICP
- therapeutic: contrast, intrathecal chemotherapy
what are the contraindications for a lumbar puncture?
- raised ICP
- suspicion of intracranial mass
- patient cardiovascular/respiratory unstable
- skin infection over area to puncture
- clotting abnormality
why should a lumbar puncture not be carried out on a patient with raised ICP because of a lesion?
because the change in pressure from the puncture could cause coning of the cerebellar tonsils
what are the two positions a patient can be in for a lumbar puncture to be carried out? in which cases is each position used?
- decubitus position (most patients)
- sitting position (obese and infants)
which position used for a lumbar puncture also allows to measure the ICP of the CSF? what is the tool used to do this?
decubitus position (by using manometer)
at which level should a lumbar puncture be carried out and why?
between L3/4 or L4/5 - because that sits sufficiently below the conus medullaris
what layers does a lumbar puncture needle pierce before entering the dural space?
- skin
- subcutaneous tissue
- supraspinous ligament
- interspinous ligament
- ligamentum flavum
- dura mater
what piece of equipment should always be attached to the needle when piercing the interspace and coming out of it again during a lumbar puncture?
the stylet
why should the bevel of the needle be parallel to the fibres in the cauda equina?
so that the fibers are separated rather than cut through
after a lumbar puncture, three samples are sent to labs to test what?
- culture/gram stain
- glucose/proteins
- cell count
what are possible complications of a lumbar puncture?
- headache
- back pain
- bleeding from site or into dural space
- nerve damage/irritation
- transient abducens palsy
- coning
what are the indications for a paramedian approach in a lumbar puncture?
if there is fibrosis in interspace due to previous LP’s, or to avoid site of previous lumbar surgery
why is there less incidence of spinal headache with a paramedian approach to a lumbar puncture?
because the needle goes through the erector spinae muscles - CSF can’t leak through the muscle, and the holes made by the needle don’t overlap because of the angle of insertion
what position should patients adopt during a lumbar puncture and why?
ideally decubitus position with back flexed - maximise space between spinous processes of vertebrae
what is the purpose of a blood patch in lumbar punctures?
it stops leakage of CSF into the epidural space following a lumbar puncture
what are solutions to spinal headaches after lumbar punctures?
- lying flat
- consuming caffeine/IV caffeine
- hydration
- blood patch
what immediate steps should be taken if a patient experiences coning following a lumbar puncture?
remove needle immediately raise backrest to 45 degrees give mannitol/3% saline intubate/hyperventilate get urgent neurosurgery consultation
what is a common cause of an epidermal inclusion cyst after a lumbar puncture?
the use of a needle without a stylet
what steps should be taken if a lumbar puncture fails?
ask someone else to try
guided LP with use of USS, CT or fluoroscopy
how can a spinal headache from a lumbar puncture be avoided?
- using smaller diameter needles
- always using the stylet
- ensuring bevel of needle is parallel to nerve roots
What are the three main causes of localised cerebrovascular disease?
- Atheroma/thrombosis
- Thromboembolism
- Haemorrhage
What are the three factors contributing to cerebrovascular disease? What are they called collectively?
Virchow’s Triad:
- changes in blood vessel wall
- changes in blood flow/pressure
- changes in blood components
What is the pathological presentation of an ischaemic stroke on a brain specimen?
Wedge shaped lesion in area supplied by blocked artery
Tissue loss, yellow discolouration, cyst formation
How does a haemorrhagic stroke cause ischaemia?
Distal ischaemia - causes by spasm of ruptured artery in attempt to stop bleeding. Protective mechanism
What are the most common regions in the brain for haemorrhagic strokes to occur?
- basal ganglia, around internal capsule
- circle of Willis, berry aneurysms
what are three common presentations of syncope?
- cardiogenic (MI, arrhythmia)
- reflex (vasovagal reaction)
- orthostatic (hypotension, endocrine)
with which type of seizure are tongue biting at tip or lateral side of tongue associated respectively?
tip - syncopal seizure
lateral side - epileptic seizure
what are the two main criteria for diagnosing epilepsy?
- at least 2 seizures more than 24hrs apart
- one seizure with high risk of recurrence
what are the two main classifications of seizures?
generalised and partial seizures
what do absent seizures, myoclonic seizures and tonic/clonic seizures have in common?
they are all generalised seizures
in which age group are absent seizures common?
in children
list some of the signs of a tonic/clonic seizure
groaning sounds stiff limbs followed by jerking foaming at mouth eyes open/rolling back drowsy/no recollection afterwards
list some risk factors for seizures
sleep deprivation/fatigue drug and alcohol use stress/anxiety hormone changes missed medications
what is status epilepticus?
one continuous seizure or multiple seizures with no recovery time, lasting >30mins
how is status epilepticus treated?
benzodiazepines + phenytoin/sodium valproate
what is the mortality of status epilepticus due to?
normally due to underlying condition (eg stroke, tumour, trauma)
what is the first line treatment for partial seizures, generalised seizures and status epilepticus respectively?
partial seizures - carbamazepine
generalised seizures - sodium valproate
status epilepticus - benzodiazepines
what are DVLA regulations for epilepsy in case of one-off seizures and diagnosed epilepsy?
one-off seizure - no driving for 6 months
epileptic patients - after seizure no driving for 1 year, HGV drivers no driving for 10 years
what are some of the reversible causes for dementia-like symptoms?
b12 deficiency
thyrotoxicosis
HIV
tertiary syphilis
is frontotemporal dementia normally early or late onset?
early onset
list some common forms of dementia
Alzheimer’s
vascular dementia
Lewy body dementia
frontotemporal dementia
what is the pathogenesis behind vascular dementia?
multiple very small strokes
what are common features of Alzheimer’s?
loss of skills, speech, memory, executive decision making, visuo-temporal impairment
what drugs can help to relieve Alzheimer’s symptoms?
acetylcholinesterase inhibitors (rivastigmine) glutamate inhibitors (memantine) antipsychotics
list some of the differences between frontotemporal and temporoparietal dementia
- frontotemporal dementia has earlier loss of personality compared to temporoparietal
- frontotemporal retains visuo-spatial awareness until late disease, temporoparietal loses it sooner
- frontotemporal has earlier speech/auditory impairment compared to temporoparietal
what is the pathology behind alzheimer’s disease?
beta amyloid build up tau protein build up neurofibrillary tangles brain tissue shrinkage enlarged ventricles
what is the pathology behind parkinson’s disease?
dopaminergic cell loss in substantia nigra
what are the common symptoms of parkinson’s disease?
TRAP - tremor, rigidity, akinesia/bradykinesia, postural instability
urinary frequency/retention
list some complications of parkinson’s disease
depression
dementia
bowel/bladder problems
speech impediments
name some features of parkinsonian gait
shuffling
hunched over
arm swing absent
head down
list some of the drug treatments used in parkinson’s
levodopa (+ COMT/MAO-B inhibitors)
carboxylase inhibitors - carbidopa, madopar
dopamine agonists
if a dementia has fast progression, what underlying cause should be considered?
Creutzfeld-Jakob Disease
what is the characteristic of vascular parkinsonianism?
only lower half of body affected
name some of the possible aetiologies and risk factors of multiple sclerosis
EBV vitamin D deficiency/temperate climate genetics (HLA) autoimmune (MBP) female early 20's caucasian
name some investigations carried out to diagnose MS
MRI scan
lumbar puncture - oligoclonal IgG bands
bloods - look for infection or other inflammatory cause
visual evoked potentials
what are the three management principles for MS
- treat symptoms
- manage relapses
- disease modifying treatments
name some common presentations of MS
optic neuritis
limb weakness
sensory disturbance
ataxia/diplopia/vertigo
how is neuromyelitis optica treated?
with immunosuppression
what is the variant of MS which immunosuppressed patients are more at risk of developing?
progressive multifocal leukencelopathy
what are the three main causes of ischaemia in the brain?
- atheroma/thrombosis
- thromboembolus
- ruptured aneurysm
in a brain specimen, what would an ischemic stroke caused by thrombosis look like?
wedge shaped area, soft and later cystic
name the common point of origin of an thromboembolus causing an ischemic stroke, and where in the brain it’s most likely to end up
origin: left atrium
often gets stuck in middle cerebral artery
a wedge shaped area of soft and cystic brain tissue is indicative of what?
ischaemic stroke
which two types of ischaemic stroke are likely to cause a wedge shaped area of neuronal damage?
thromboembolic
thrombotic
what is the most common cause of a haemorrhagic stroke?
rupture of aneurysm
what causes the hypoxia in haemorrhagic strokes?
distal vasospasm of ruptured artery in attempt to stem bleeding
name two common areas in the brain where aneurysms are found, and what kind of aneurysms are likely to form there
circle of willis - berry aneurysms
basal ganglia - microaneurysms
through which three mechanisms could generalised ischaemia in the brain occur?
- reduced oxygen in blood
- reduced blood flow
- reduced ability to use O2 in cells
name a few common causes of generalised ischaemia in the brain
cardiac arrest
respiratory arrest
hypotension
haemorrhage
what are watershed zones in the brain, and what causes ischaemia in those areas?
junctions between areas of brain tissue supplied by different arteries
ischaemia at these junctions is caused by generalised hypotension, causing adequate perfusion in main arteries but less in peripheral arteries
what type of ischaemia pattern is visible in the brain, when the cause of ischaemia is a generalised lack of perfusion?
cortical necrosis
what is cortical necrosis in the brain often due to?
generalised hypoxia/lack of perfusion
an epidural haematoma is most likely caused by rupture of what?
middle meningeal artery
a subdural haematoma is most likely caused by rupture of what?
bridging veins
a subarachnoid haemorrhage is most likely caused by rupture of what?
aneurysm (berry or microaneurysm)
haemorrhagic and ischaemic strokes are better visualised which which imaging techniques respectively?
haemorrhagic - CT scan
ischaemic - MRI scan
during a stroke, the area of brain affected by ischaemia is divided in two zones. what are they called?
ischaemic core
ischaemic penumbra
what is the radiological appearance of an epidural haematoma?
lens shaped
what is the radiological appearance of a subdural haematoma?
crescent shaped
what is small vessel lipohyalinosis, what causes it and what can it lead to?
it’s thickening and narrowing of small arteries in the brain
it’s often caused by hypertension, and can lead to lacunar strokes
what is a stroke of the anterior cerebral artery likely to affect?
lower limbs - motor and sensory input
gait
what is a stroke of the middle cerebral artery likely to affect?
face, arm and leg paralysis/sensation
speech affected - aphasia
vision affected - homonymous hemianopia, gaze paralysis to opposite side
sensation affected - one-sided neglect
what is a stroke in the posterior cerebral artery likely to affect?
vision
balance
breathing/HR control
name the arteries that supply the basal ganglia, and what artery they are branches of
lenticulostriate arteries, branches of MCA
name some contraindications to using thrombolysis for stroke treatment
> 3hrs since onset
any cause of potential bleeding
high blood pressure
glucose too low or too high
what are the two main treatments for acute ischaemic stroke?
- tPa (thrombolysis)
- thrombectomy
what percentage of TIA patients go on to have a larger stroke within 2 weeks?
10%
name the common investigations carried out to confirm stroke diagnosis
bloods
ECG
CT scan
carotid doppler ultrasound
name two common causes for young onset ischaemic stroke
arterial dissection
cardioembolic
arteriovenous malformation
what are the signs of an upper motor neuron lesion?
muscle weakness increased reflexes increased tone muscle wasting (only if lack of use) positive Babinski sign
what are the signs of a lower motor neuron lesion?
decreased reflexes
decreased tone
muscle weakness
fasciculations
name some common surgical causes of myelopathy
tumour
vascular abnormalities
trauma
degenerative spine disorders
name some common medical causes of myelopathy
spinal cord stroke
demyelination
inflammation
B12 deficiency
what is the area of the spinal cord most vulnerable to spinal cord strokes, and why?
thoracic spinal cord
because it’s in a watershed zone between two joining blood supply regions
which spinal artery is most commonly affected in a spinal cord stroke?
anterior spinal artery
name some symptoms of a spinal cord stroke
onset over hours back pain increasing limb weakness increasing sensory loss urinary retention/incontinence
name some of the causes of a spinal cord stroke
atherosclerosis thromboembolism vasculitis/inflammation hypotension venous occlusion hypercoagulability
how is a spinal cord stroke treated?
same as a normal stroke: address risk factors, anticoagulate, thrombolysis
define Brown-Sequard syndrome
myelopathy that only affects one half of the spinal cord
which imaging technique is normally used to diagnose a spinal cord lesion?
MRI scan
what kind of lesion does MS related spinal cord myelopathy often present as?
transverse myelitis
what is the treatment for myelopathy caused by B12 deficiency?
intramuscular B12 injection
where is the junction between the UMN and LMN?
when the fibres from the descending tract synapse with a second neuron
define myelopathy
injury to spinal cord due to compression causing UMN deficits
define radiculopathy
injury to spinal nerve root causing dermatome and myotome LMN deficits
what is the management of a disc prolapse?
discectomy
rehabilitation
what are is the classic symptom triad of Cauda Equina Syndrome?
- saddle anesthesia
- bilateral sciatica
- urinary problems
how is Cauda Equina Syndrome diagnosed?
clinical diagnosis radiological diagnosis (MRI)
what is the management of Cauda Equina Syndrome?
emergency discectomy
where are the majority of cord-compressing tumours located?
intradural/extramedullary
extradural
what is the triad of symptoms to help diagnose a spinal abscess?
- pyrexia
- focal symptoms
- back pain
name two types of degenerative conditions which may require surgery for myelopathy or radiculopathy
cervical spondylosis
spinal stenosis
what characterises lumbar spinal stenosis?
bilateral claudication
how is a spinal abscess managed?
- decompression
- antibiotics
how is a spinal abscess diagnosed?
urgent MRI
list some risk factors which may contribute to spinal infections
- immunocompromised
- diabetes
- CKD
- alcoholism
name three common causes of myelopathy that require surgery, with examples of each type
infection - osteomyelitis, spinal abscess
degenerative - disc prolapse, spondylosis, stenosis
tumour - intra/extradural, intramedullary
how is lumbar spinal stenosis treated if it’s causing neurological symptoms?
surgical laminectomy
how is cervical spondylosis treated if it’s causing neurological symptoms?
conservative if mild, decompression surgery if severe
how are spinal tumours investigated and treated if causing neurological symptoms?
urgent MRI
surgical decompression and radiotherapy
name three common organisms to cause epidural spinal abscesses
E coli
staph aureus
streptococci
what is a common cause of oculomotor (CNIII) palsy and why?
diabetes, microvascular changes affect nerve function
how is trigeminal neuralgia treated?
with carbamazepine or surgery
how is Bell’s palsy treated? what is an important consideration in terms of the eyes?
with steroids
give eye drops as palsy causes inability to close eye, drying it out and risking damage
what causes Horner’s syndrome?
damage to sympathetic nerves to the face
list the three main symptoms of Horner’s syndrome
ptosis
constricted pupil (miosis)
lack of sweating (anhydrosis)
describe the main presentation of CNIII (oculomotor) palsy
unilateral dilated pupil
impaired adduction of affected eye - “down and out” gaze
ptosis
describe the main presentation of CNVI (abducens) palsy
impaired abduction of affected eye
what is a common disorder affecting CNV (trigeminal), what can cause it and how is it treated?
trigeminal neuralgia
can be caused by nerve compression by an artery
treated with carbamazepine
what disease presents when the facial nerve (CNVII) be affected? how is it treated?
Bell’s palsy
treated with steroids
how can a patient’s ability to lift their eyebrows determine whether they have an UMN or LMN lesion?
UMN - forehead spared
LMN - unilateral forehead paralysis
what happens as a result of inflammation to the vestibular nerve?
labyrinthitis/vestibular neuritis
what does bulbar refer to?
anything related to the medulla
what is bulbar palsy?
damage to LMN in medulla related to CNVIII, CNIX, CNX and CNXI
what is pseudobulbar palsy?
bilateral damage to UMN coming from the cortex
name some symptoms which can occur in bulbar and pseudobulbar palsy
dysarthria
dysphagia
dysphonia
what signs are found in bulbar but not pseudobulbar palsy? why is that?
tongue fasciculations
tongue wasting
LMN lesion signs, fasciculations and wasting not present in UMN lesions
which cranial nerves are affected in bulbar palsy?
CNIX (glossopharyngeal), CNX (vagus), CNXII (hypoglossal)
in general terms, what does a cranial nerve palsy present with?
impaired function of that nerve
name a common disorder affecting the optic nerve (CNII) and what disease it’s associated with
optic neuritis, commonly affects patients with multiple sclerosis
name a few causes of dilated pupils
young age dark lighting amphetamines anxiety CNIII palsy coma
name a few causes of narrowed pupils
old age
bright light
opiates
Horner’s syndrome
where is the cause of the problem likely to be if CNIII, CNIV and CNVI are all affected?
superior orbital fissure
how can a subarachnoid haemorrhage lead to communicating hydrocephalus?
breakdown blood products can block the arachnoid granulations into the venous sinuses
what are two commonest organisms causing meningitis?
strep pneumoniae (pneumococcus) neisseria meningitidis (meningococcus)
what is the first line treatment for meningitis?
ceftriaxone
list some features of meningitis
meningism (photophobia, stiff neck) fever headache seizures raised ICP focal symptoms cranial nerve palsy
what investigations are done to diagnose meningitis?
bloods
blood cultures
lumbar puncture: CSF culture (bacterial) and PCR (viral)
which viral organisms may be involved in meningitis?
enteroviruses
what is the most common organism causing encephalitis?
HSV virus
what is the treatment of viral encephalitis?
aciclovir
name some organisms which may be involved in encephalitis
HSV
enteroviruses
arboviruses
which receptors are affected in auto-immune encephalitis?
NMDA receptors
VGKC receptors
list some common features of encephalitis
preceding flu symptoms headache seizures focal signs raised ICP
list the investigations done to diagnose encephalitis
bloods blood cultures LP: CSF cultures (bacterial) and PCR (viral) CT/MRI EEG
what investigations are done for brain abscesses?
bloods
LP
CT/MRI
aspirate biopsy
how is a brain abscess/empyema treated?
drainage
antibiotics - penicillin/ceftriaxone/metronidazole
what is the aetiology of Guillain-Barre syndrome?
post-infectious neuropathy - autoimmune reaction to neurons a few weeks after an infection
does Guillain-Barre syndrome present with ascending or descending paralysis?
ascending paralysis
does botulism present with ascending or descending paralysis?
descending paralysis
when should botulism be suspected?
IVDA
dilated pupils
descending paralysis
how are diseases like polio, rabies, tetanus and botulism treated?
vaccination
antibodies
antibiotics
how does tetanus present, and why?
presents with rigidity and spasticity, due to blockage of NMJ
how does botulism present, and why?
presents with flaccid paralysis, stops ACh release at NMJ
how is neurosyphilis treated?
with penicillin
how is lyme disease treated?
with ceftriaxone and doxicycline
what organism is responsible for syphilis?
treponema pallidum
what organism is responsible for lyme disease?
borrelia burgdorferi
what organism is responsible for leptospirosis?
leptospira interrogans
what class of bacteria do the organisms causing lyme disease and syphilis belong to?
spirochaetes
what is a common sign found on imaging in patients with variant CJD?
pulvinar sign
what causes CJD?
prions (eg misfolded proteins) causing other proteins to misfold
when should CJD be borne in mind as a differential?
when a patient presents with rapidly progressing dementia
what investigations are done for CJD?
bloods
LP - CSF culture/PCR
MRI
EEG
name a few possible types of CJD
sporadic CJD
familiar CJD
variant CJD
neurotropic infections from which organisms are more likely to present in immunocompromised patients?
toxoplasmosis gandii cryptococcus neoformans cytomegalovirus aseptic meningitis/encephalitis progressive multifocal leukoencelopathy (PML) cerebral abscess
list a few types of skull fracture
linear fracture depressed fracture mosaic fracture ring fracture basal skull fracture
which types of brain haemorrhage are not associated with skull fractures?
subdural hematoma
subarachnoid hematoma
in subarachnoid, subdural and epidural haemorrhages, which vessels are most likely affected?
subarachnoid - circle of Willis (berry aneurysms)
subdural - bridging veins
epidural - middle meningeal artery
why is it important to perform a head CT after an event which may have caused head trauma, even if the patient feels fine?
because the patient might be experiencing a lucid interval, before the haemorrage builds up and causes raised ICP
how does a patient present who has diffuse axonal injury (DAI)?
usually comatose
explain the term “one punch killer”
it’s the term for punches which cause the head to suddenly swing upwards, causing a laceration of the vertebral artery and resulting in a traumatic basal subarachnoid haemorrhage
what is a contre-coup brain contusion?
damage to the brain surface caused by trauma to the opposite side of the brain
what is normally responsible for scalp lacerations vs incise injuries?
laceration injury - often blunt force trauma
incise injury - normally sharp object eg knife
what is the physiological activity in vegetative state?
brainstem recovery post injury, but no recovery from cortex
what can cause “locked-in” syndrome, and what does it result in?
stroke in pons
causes all nerve activity below CNIII to cease, so no motor or sensory activity
what GCS score counts as comatose?
GCS 8 or less
what needs to be looked for specifically when someone presents with a coma, to work out a possible differential?
- meningism
- focal symptoms/lateralising
if a comatose patient presents with no meningism or focal symptoms/lateralising, what are some of the likely causes?
hypoxia/hypercapnia
metabolic causes
alcohol/drug intoxication
hypo/hyperthermia
if a comatose patient presents with meningism but no focal symptoms/lateralising, what are the likely causes?
meningitis
encephalitis
subarachnoid haemorrhage
if a comatose patient presents with focal symptoms and lateralising to one side (with or without meningism), what are the likely causes?
stroke (haemorrhage or infarct)
tumour
cerebral abscess
how is brainstem function assessed in comatose patients?
cranial nerve reflexes
name a few examples of metabolic causes which may result in a coma
hypoglycaemia diabetic ketoacidosis hepatic failure renal failure sepsis
what is the system called that determines being awake?
ascending reticular activating system
name the three initial neurological assessments carried out if someone presents in a coma
GCS
brainstem function
motor function and reflexes
which muscle disease can present with a rash, an what type of condition is it?
dermatomyositis - an inflammatory muscle condition
how are inflammatory muscle conditions investigated?
bloods: CK, ESR, AST, LDH levels
electromyography
serology for autoantibodies
muscle biopsy
how are inflammatory muscle conditions treated?
with steroids/immunosuppression
name two examples of similar NMJ diseases and explain the difference between them
myasthenia gravis
lambert-eaton syndrome
what is the pathophysiology behind myasthenia gravis and lambert-eaton syndrome?
myasthenia gravis - ACh antibodies blocking post-synaptic ACh receptors
lambert-eaton syndrome - Calcium channel antibodies blocking vesicle exocytosis from pre-synaptic terminal
how does myasthenia gravis present?
fatiguability - symptoms worse as day goes on ptosis lid lag diplopia slurred speech swallowing problems respiratory problems muscle weakness
how can lambert-eaton syndrome be differentiated from myasthenia gravis in terms of symptoms?
in lambert-eaton syndrome, symptoms improve after exercise
in myasthenia gravis, symptoms get worse throughout the day
how are NMJ disorders investigated?
serology - autoantibodies
bloods - CK, AST, LDH
muscle biopsy
EMG
what imaging test is always done in myasthenia gravis, and why?
CT chest to look for thymus abnormalities - can cause myasthenia gravis-like symptoms
what structural abnormality is associated with myasthenia gravis?
thymus hyperplasia or thymoma
how is myasthenia gravis treated?
acetylcholinesterase inhibitors (pyridostigmine) immunosuppression immunoglobulins plasmapheresis thymectomy
name the types of nerve fibres found in a peripheral nerve
motor fibres sensory fibres (pain/temp and touch/pressure./vibration) autonomic fibres (symp and parasymp)
list a few common causes of peripheral neuropathy
diabetes
alcohol
drugs
inflammatory (guillain-barre syndrome)
what are the two most common pathophysiological processes behind peripheral neuropathy?
axonal damage
demyelination
list some investigations that are done for nerve diseases
bloods genetic testing nerve conduction tests nerve biopsy lumbar puncture
what characterises motor neuron disease symptoms?
they have both UMN and LMN features
list some features of motor neuron disease
weakness increased reflexes increased tone fasciculations muscle wasting
in which order are motor neurons often affected in motor neurone disease?
limbs first
bulbar next
respiratory last
how is MND investigated?
examination - UMN and LMN signs
nerve conduction studies
genetic testing
how is MND treated?
supportive and palliative care
list some of the types of brain herniation which can occur
cingulate central uncal transcalvarial cerebellotonsillar
name two common symptoms/signs found in raised intracranial pressure due to a tumour
morning headache + vomiting
papilloedema
name a common malignant brain tumour in children
medulloblastoma
why are all glial brain tumours classed as malignant?
because they can cause significant damage even if slow growing
what is an unusual characteristic of malignant gliomas?
they can’t metastasise outside CNS despite aggressiveness, because they can’t cross BBB
where are the majority of brain tumours found in adults and children?
adults - cerebrum
children - cerebellum and brainstem
are meningiomas slow or fast growing?
slow growing
name a few common tumours which metastasise in the brain
breast lung melanoma renal colorectal
what is an acoustic neuroma?
shwannoma of CNVIII (vestibulocochlear)
why are CNS lymphomas difficult to biopsy?
because they often sit in a deep central area of the brain
list some presenting symptoms of brain tumours
morning headache nausea and vomiting vision problems drowsiness reduced conscious level seizures focal symptoms
list some presenting signs of brain tumours
papilloedema CNIII and CNVI palsy reduced GCS altered consciousness focal signs
what investigations should be done if a brain tumour is suspected
identify lesion: CT/MRI scan
find out if primary or met: chest/abdo or pelvic XR
characterise lesion: biopsy
what are the management options for brain tumours?
treat symptoms: mannitol, steroids, antiemetics, anticonvulsants
surgery: remove tumour or debulk
medical: radiotherapy/chemotherapy
what drugs are sometimes used to alleviate cluster headaches?
with the use of triptans
how is paroxysmal hemicrania treated?
with indomethacin
