Neurology 3 Flashcards
What is the presentation of an intracerebral space occupying neoplasm?
presentation is dependent on the rate of growth of the tumour and its anatomical position:
S/s of raised ICP
headache, nausea and vomiting, papilloedema
more common in rapidly growing tumours
malignant glioma, metastatic deposits
Epileptic seizures - adults with epileptic fit have brain tumour until proven otherwise
progressive neurological deterioration
What ‘neurological deterioration’ signs might be seen for Brain neoplasm?
increasing weakness
sensory loss
cranial nerve palsies: 6th
Dysphasia - if involving the dominant hemisphere (left Dom in 98% right hand Dom and also most left hand Doms too)
hat is the management of space occupying neoplasm?
Dexamethasone 4-6mg QDS if any neurological deterioration or drowsiness
anti-convulsants: if presented with epilepsy
refer to neuro-oncology MDT: neurosurgical interventions accessible, often with adjunctive radiotherapy
What is paraneoplastic syndrome?
Cluster of symptoms that occur in patients with cancer, that cannot be explained by the tumour, metastases or the hormones normally secreted by the primary tissue from which the tumour arose
Give examples of paraneoplastic syndromes?
Myasthenia gravis
Lambert-Eaton myasthenic syndrome
paraneoplastic sensory neuropathy
paraneoplastic cerebellar degeneration
What are the three most common adult primary brain tumours?
malignant glioma, meningioma and astrocytoma
What is a malignant glioma? prognosis?
Most common adult primary malignancy, originating from astrocytes
rapidly growing, thus present with signs of raised ICP
Poor prognosis, with death often within 6 months of diagnosis
What is meningioma?
Most common overall cerebral neoplasm
generally benign, slowing tumours arising from the meninges
surgical excision and debunking is undertaken wherever possible
What is an astrocytoma?
benign slow growing tumour that occurs in young people
can turn malignant in later life
Name the other important cerebral tumours
ependymomas (originate from ependymal cells. most common in young people/children). usually malignant, but do not tend to recur
pituitary adenomas: 10% of all diagnosed intracranial neoplasms
Acoustic neuroma: Schwann cells of the acoustic nerve.
more common in neurofibromatosis type II
What tumours most commonly metastasise to the brain?
Bronchus Breast Kidney Colon Thyroid Malignant melanoma
What is meningitis?
Inflammation of the leptomeninges
i.e. arachnoid and pia mater and underlying CSF
What organisms cause meningitis?
70% = neisseria meningitides (classical petechial rash)
streptococcus pneumonia (more common if skull fractures, ear disease or those with congenital CNS lesions)
Other 30% = listeria monocytogenes, haemophilus influenza, staph aureus and TB
Viral: enteroviruses, HSV, VZV
What are the symptoms of meningitis?
Headache
Neck stiffness
Fever
In acute bacterial - high fever with rigors, photophobia, vomiting, intense malaise coming on over hours. Confusion and seizures in more serious cases
What are the signs of meningitis?
Kernig’s sign positive: knee flexed, extend at the knee to cause pain
Brudzinski’s sign positive: passive flexion of the neck leads to flexion of the knees/hip
signs of raised ICP and/or cranial nerve palsies
What is the presentation of meningococcal meningitis?
petechial rash, erythematous, non blanching purpura
How does TB meningitis present?
As per acute bacterial meningitis, but more commonly as an insidious illness with fever, weight loss and progressive confusion/cerebral irritation, eventually leading to coma
What is the management of TB meningitis?
RIPE for 12 months
corticosteroids early on to decrease risk of cerebral oedema
What is the presentation of epidural spinal abscess?
Patient presents with fever, back pain and later spinal root lesions
ddx osteomyelitis
What is encephalitis?
Inflammation of the brain parenchyma, usually viral
similar organisms to viral meningitis
What are the clinical features of encephalitis?
normally mild, headache, drowsiness, fever, malaise, confusion
rarely - serious illness can occur with high fever, mood change and progressive drowsiness over hours / days leading to seizures and comas
What is the cause of severe encephalitis?
HSV-1
HSV1: causes necrotising encephalitis, affecting the temporal lobes
HSV2: causes meningitis in adults
What ix should be done for encephalitis?
Head CT/MRI
diffuse oedema, classically in the temporal lobes
LP: raised opening pressure, raised lymphocytes, raised protein and normal glucose with a positive viral PCR
viral serology: blood and CSF culture
What is the management of HSV encephalitis?
IV acyclovir >10 days
What is the cause of TB meningitis?
blood Bourne spread of M.tuberculosis to the brain, following primary infection of miliary TB
What are the risk factors of TB meningitis?
immunosuppression, malnourishment, multiple co-morbidities and recent contact with TB
What investigations should be done for meningitis?
Bloods: FBC, U+Es, LFTs, clotting, glucose, lactate
Serum PCR for pneumococcal and meningococcal antigens
Blood cultures: prior to Abx if possible, but do not delay
LP: if no clinical suspicion of a mass lesion (send for MCS protein, glucose and meningococcal / pneumococcal / viral PCR)
CT prior to LP (if suspected raised ICP)
Throat swabs: 1 for virology, one for bacteriology
What CSF stains are there and which organisms do they show are present?
Gram +ve intracellular diplococci: pneumococcus
gram negative cocci: meningococcus
ziehl-Neelsen stain for acid-fast bacilli: TB
indian ink: fungi
What is the normal appearance of CSF?
Crystal clear, <5 cells per mm3, low protein and glucose levels
What CSF appearance indicates bacteria?
turbid fluid with high polymorphs and low glucose
What CSF appearance indicates viruses?
clear fluid with high lymphocytes and normal glucose
What does TB do to CSF?
Both raised lymphocytes and polymorphs
What is the management of meningitis?
LP within 1 hour. give empirical abx after blood cultures
If non-blanching rash: BenPen 1.2g IM
2.4mg 4-hourly is then the treatment of choice in hospital
Cefotaxime can be used in penicillin allergic patients
If <60 and not immunocompromised, IV ceftriaxone 2g bd, IV dexamethasone 2 doses 6 hours apart
If >60 or immunosuppressed: IV ceftriaxone 2g bd
IV amoxicillin 2g 4 hourly
IV dexamethasone
ADD IV acyclovir if suspect herpes encephalitis
How should close contacts of patients with meningitis be managed?
Single dose of ciprofloxacin should be given to all close contacts as prophylaxis to eliminate pharyngeal carriage in meningococcal meningitis
What are the acute complications of bacterial meningitis?
Sepsis / DIC
Hydrocephalus
Adrenal haemorrhage: Waterhouse-Friderichsen syndrome
What are the longer term complications of bacterial meningitis?
Brain abscess
Seizure disorders
Cranial nerve palsies: sensorineural hearing loss VIII or gaze palsies
Ataxia / muscular hypotonia
What conditions can give rise to brain abscesses?
Otitis media
Paranasal sinus infections
Bacterial endocarditis
head trauma / neurosurgery
What is the presentation of a brain abscess?
expanding mass lesion, fever and possible systemic illness
What is the treatment of brain abscess?
surgical drainage, broad spectrum antibiotics, high dose corticosteroids
What are the classical features of a generalised seizure (tonic clonic)?
Aura: vague warning phase
loss of consciousness
tonic phase - body becomes rigid for up to a minute, usually falling to ground + tongue biting + incontinence
Clonic phase: generalised convulsion, with frothing of the mouth and rhythmic jerking of muscles (several minutes)
Post-ictal phase: drowsiness, confusion or coma for several hours
What are the different types of syncope?
Vasovagal/cardiogenic
Postural hypotension
Post-prandial hypotension
carotid sinus (excessive vagal response e.g. wearing tight collars), anaemic syndrome, MICTURITION syncope, coughing or exertion
What is a vasovagal / cardiogenic syncope?
‘simple faint’ due to sudden reflex bradycardia and peripheral vasodilation
occurs in response to standing, fear, venesection or pain
the patient is unconscious for less than two minutes
recovery is rapid and treatment is not necessary
What is postural hypotension?
Drop in systolic BP or 20mmHg or diastolic of 10 on standing from a sitting/lying position
Measure sitting and then at 1, 2 and 3 minutes after standing up
this occurs as blood pools in the legs due to the influence of gravity.
Risk is increased If fluid depleted, if there is age-related autonomic dysfunction and polypharmacy (vasodilating / diuretic drugs)
What is post-prandial hypotension?
Drop in systolic BP of 20mmHg (or diastolic of 10mmHg) after eating due to pooling of blood in the splanchnic vasculature.
thought to be even more common than postural hypotension
What distinguishes seizures from syncope?
Witness accounts of jerking movements, incontinence, post-episode confusion and amnesia highly suggestive of a fit
How should a recurrent syncope be investigated?
Advise against driving whilst elucidating cause
Bloods: FBC, U&Es, glucose
Lying / standing blood pressure or tilt table tests
ECG / 24-hour tape (heart block, arrhythmias, long QT)
EEG / sleep EEG
Echo / CT head
What is a seizure?
Convulsion or transient abnormal event resulting froth paroxysmal discharge of cerebral neurones
What is epilepsy?
Continuing tendency to have seizures, even if a long time separates the attacks, affecting 1% of the population
What is a partial seizure?
single focus of electrical activity - either:
SIMPLE PARTIAL:
no impairment of consciousness e.g. a single limb jerking, often associated with a sensory aura. Pattern depends on the lobe involved.
Temporal: lip smacking, chewing
Frontal: motor movements, speech arrest, Jacksonian march
Parietal: sensory disturbances, tingling / numbness
Occipital: visual disturbances
Complex partial: consciousness impaired at some stage
What is temporal lobe epilepsy?
Classical aura with a sense of fear / deja-vu and hallucinations
There is then confusion and anxiety and often automatisms e.g. lip smacking and chewing
They can also go on to become secondary generalised seizures
What are generalised seizures?
When there is a widespread focus of electrical activity across both hemispheres.
What are the categories of generalised seizures?
Absence Tonic clonic Tonic clonic myoclonic Atonic
What is an absence seizure?
‘petit mal’ seizures with classical EEG appearance, typically less than 10 seconds in 4-10 year olds, more common in girls, stimulated by hyperventilation and flashing lights
Remit by puberty
What are the secondary causes of seizures?
Structural: trauma, space occupying lesion, stroke, SLE, AVMs
Developmental (cerebral palsy)
Metabolic (hypo, hyper: glycaemia, calcaemia, natremia
Drugs: withdrawal syndrome, cocaine, TCAs, SSRIs, ciprofloxacin
Infection: Encephalitis, HIV, syphilis
What are the important history points of seizures?
risk factors for epilepsy: FH, CVD, tumours, trauma
alcohol: delirium tremens
infection: meningitis, encephalitis
psychiatric conditions: pseudoseizurs
What is the emergency management of a patient having a seizure?
Place patient in recovery position and remove harmful objects.
If seizure >3 minutes, treat as status epilepticus
A-E
IV lorazepam - 4mg bolus and repeat after 10 minutes
finger prick - glucose
IV phenytoin - 15mg/kg slow infusion
ICU if 20 minutes
In community: buccal midazolam
What are the potential causes of status epilepticus?
Epilepsy, hypoxia, stroke, brain injury, metabolic derangements, infections, eclampsia and drug withdrawal / toxicity
What is the mortality of status epilepticus?
10%, decreased according to how quickly seizure activity is initially treated
What investigations are done for epilepsy?
Bloods: FBC, U+Es, LFTs, Ca, Mg, glucose
Toxicology / drugs screen
Head CT/MRI
EEG (can be enhanced by sleep deprivation)
How is drug treatment of epilepsy initiated?
after 2 seizures after ruling out organic causes
aim of treatment is the control of seizures with lowest possible dose with fewest side-effects, starting with one drug and increasing dosage over 2-3 months until control is achieved.
Baseline bloods are taken prior to starting the drugs
Avoid triggers
What is the management for generalised seizures?
1st line = valproate or lamotrigine in females of childbearing age
Adjuncts: clozabam, carbamazepine, levetiracetam
Ethosuximide is generally first line for absence seizures
What is the management for partial seizures?
1st line = carbamazepine or lamotrigine in females of childbearing age
multiple adjuncts used
How does valproate act?
Potentiates GABA and causes Na-channel blockade
What are the side effects of valproate?
Rash, sedation, weight gain, hair loss, tremor
Associated with causing birth defects, thrombocytopenia and liver damage
How does lamotrigine act?
Blocks Na-channels and reduces glutamate relese
What are the side effects of lamotrigine?
not highly sedating , risk of bone marrow toxicity
suitable for women of childbearing age
How does carbamazepine act?
Na-channel blocker
What are the Side effects of carbamazepine?
include rashes, dizziness and double vision
cam cause agranulocytosis
induces metabolism of itself and many other drugs, associated with birth defects and liver damage
What are the difficulties with phenytoin?
Side effects: increased gum growth and nystagmus
Displays zero-order kinetics thus requires therapeutic drug monitoring
Metabolism saturates a a variable level leading to disproportionate increases in plasma concentration after this point
Enzyme inducer - can lead to failure of the COCP
What other side effects may come about from anti-epileptic drugs?
May cause leucopenia, rashes and more serious skin effects such as SJS and TEN
In refractory causes, check adherence, alcohol, drug usage or the possibility of an underlying structural lesion.
When can a patient withdraw from anti-epileptic drugs?
Seizure free from 2-4 years
Drug reduced in dose every 4 weeks, with patient stopping driving during withdrawal
How do anti-epileptic drugs affect pregnancy?
Patients should withdraw prior to conception - however treatment is preferable to hypoxic szirues during pregnancy
carbamazepine, valproate and phenytoin lead to NTD although carbamazepine has the lowest incidence
Lamotrigine = 1st line in women of childbearing age and in pregnancy for generalised seizures
Give 5mg folic acid in first trimester and vitamin k in third
What are the laws regarding epilepsy and driving?
Patients must tell DVLA immediately and stop driving if they have had a seizure.
If attack while driving and involved LOC, license revoked
6 months seizure free - can ask for license back.
In true epilepsy, need to be seizure free for a year
What is MS?
Chronic and progressive condition that involves demyelination of the myelinated neurones in the central nervous system
This is caused by an inflammatory process involving activation of immune cells against the myelin.
Describe the epidemiology of MS?
Affects 1 in 1000 UK population twice as common in females Age of onset = 20-45 years aetiology = uncertain Associated with HLA-DR2 phenotype
Where are areas of demyelination often seen in MS?
Optic nerves Angles of the lateral ventricles Cerebellar peduncles Brainstem Dorsal and corticospinal tracts
What symptoms are seen with demyelination of the optic nerve in MS?
visual disturbance:
Central scotoma
optic neuritis - blurring of vision, mild ocular pain worse on movement and loss of colour vision
decreased acuity, colour vision and a pink / swollen optic disc
diplopia also common due to brainstem involvement