Neurology Flashcards
Describe the clinical features of raised ICP? (9)
- Headache
- Altered mental state (lethargy, irritability, slow decision making, abnormal behaviour)
- Papilloedma
- Vomiting (progresses to projectile)
- Pupil changes: irregular or dilated in one eye)
- Cranial nerve palsies (esp unilateral ptosis, III or IV lesions)
- Later changes: hemiparesis, raised BP, bradycardia
- Seizures, syncope if acute rise in ICP
- Cushings reflex
- visual changes: black spots, blurring, enlarged blind spot and reduced peripheral vision (subacute) or reduced central vision and visual acuity (acute advanced)
Describe the headache of raised ICP
nocturnal, starting on waking, worse on coughing/ moving
Describe what papillodema looks like
blurring of disc margins, loss of venous pulsations, flame haemorrhages
What is the cushings reflex and why does it occur?
hypertension + bradycardia + low resp rate due to: Ischaemia at medulla causing sympathetic activation so rise in BP + tachycardia// Baroreceptors detect increase in BP causing Bradycardia// Ischemia @ pons/ medulla resp centers so low resp rate
How should raised ICP be investigated?
- CT/ MRI for underlying lesions
- blood glucose, renal function and osmolality
- check for signs of CSF leak
- ICP monitoring can be done
Give 6 causes of raised ICP
- localised mass lesions (eg traumatic haematoma)
- neoplasms (glioma, meningioma, mets)
- abscesses
- focal odema secondary to trauma, infection or infarction
- disturbance of CSF circulation
- major venous sinus thombosis/ obstruction
- diffuse brain odema/ swelling
- idiopathic intracranial hypertension
Give 5 causes of diffuse brain odema/ swelling
- meningitis
- encephalitis
- diffuse brain injury
- sub arachnoid haemorrhage
- reyes syndrome
- water intoxication
- cerebral venous thrombosis
Describe the first line steps to management of raised ICP?
- stabilise ABC
- treat seizures with lorazepam +/- phenytoin
- Head CT if meets criteria
- assess C spine, immobilise and order neck CT if not cleared
- involve neurosurgery
- head elevation to 30 degrees
When should you intubate someone with a head injury/ raised ICP?
If: - sats <92% or - hypoxic on ABG or - GCS <8
Describe the further management of someone with raised ICP
- Analgesia with morphine and sedation w/ propofol if necessary
- mannitol (risk of hypovolaemia) or hypertonic saline if cerebral odema
- barbiturate coma
- hypothermia
- decompressive craniotomy and shunts
- treat cause (anticoag if venous outflow obstuction, diuretics then shunts if increased CSF, resections/ craniotomys/ steroids for SOLs)
- hyperventilation (causes hypercapnic vasoconstriction so decreases ICP)
Describe the clinical features of a subarachnoid haemorrhage?
- Sudden onset explosive headache (often occipital) lasting a few seconds or a fraction of a second then a diffuse headache which can last a week or so
- almost always have N+V
- altered mental status
- seizures
- neck stiffness/ meningism signs sometimes present around 6 hrs after
- intraocular haemorrhages seen on fundoscopy in 15%
- other signs of raised ICP
- 10-15% die before getting to hospital
What warning symptoms may occur prior to SAH as aneurysm expands and bleeds slightly (sentinel bleeds)?
- headache
- dizziness
- orbital pain
- diplopia
- ptosis
- sensory or motor disturbance
- seizures
- dysphagia
- bruits less common
Describe the investigation findings consistent with a subarachnoid haemorrhage? (4)
- CT scan without contrast: hyperdense blood vessel in basal cisterns (98% sensitive after 2 hrs and 100% after 6, sensitivity drops after 24hrs)
- cerebral panangiography then CT or MR angiography if aneurysm found
- LP if CT scan negative but suspect SAH- spectrophotometry should be able to detect xanthochromia if SAH occured (detected from 12hrs- 2weeks after bleed)
- ECG changes inc prolonged QT, Q waves, ST elevation
Describe the urgent and supportive management of a SAH? (4)
- stabilise pt and send straight to neurosurgical unit +/- intubation, ventilation, NG tube, analgesia and antiemetics
- endovascular obliteration by platinum spirals (coiling) or direct neurosurgical clipping to prevent rebleeding
- oral nimodipine given to prevent vasospasm which leads to cerebral ischaemia/ stroke
- hydrocephalus can occur as early or late complication, many will resolve on their own but some surgeons drain immediately
Describe the further management of an SAH? (3)
- secondary prevention (stop smoking etc)
- specialist rehab if lasting impairment
- antifibrinolytics reduce rate of rebleeding but doesnt improve overall outcomes
Describe the clinical features of meningitis
- Headache
- Fever
- Photophobia
- Neckstifness
- Vomiting
- Muscle pains
- Non blanching purpuric rash
- seizures
- altered consciousness
- Fatigue, muscle pain
What signs require urgent senior review +/- critical care input when managing a meningitis pt? (9)
- rapidly progressive rash
- poor peripheral perfusion (cap refill >4/ BP >90mmhg)
- RR <8 or >30
- HR <40 or >140
- acidosis <7.3
- WBC <4
- lactate >4
- GCS <12 or drop of 2
- poor response to initial fluid resus
How should suspected meningitis (meningitis without signs of shock, severe sepsis or signs suggesting brain shift) be managed? (7)
- blood cultures
- bloods (FBC, renal function, glucose, lactate, clotting, viral PCR, blood gas)
- LP
- dexamethasone 10mg IV
- ceftriaxone IV 2g
- careful fluid resus
- throat swab for meningococal culture
- isolate until abx for 24 hrs, tell microbiology and PH
How should suspected meningitis with signs suggestive of brain shift/ raised ICP, severe sepsis or a rapidly evolving rash be managed? (9)
- critical care input
- secure airway, give O2
- take bloods, do cultures
- fluid resus (if shock/ sepsis/ rapidly evolving rash)
- ceftriaxone 2g IV
- Dexamethasone 10mg IV (omit if severe sepsis or rapdily evolving rash)
- Neuro imagine such as CT head if signs of raised ICP
- throat swab for meningococcal culture
- DELAY LP
What tests should be done on CSF when meningitis suspected? (7)
- glucose (w/ concurrent blood glucose)
- protein
- microscopy and culture
- lactate
- meningococcal and pneumococcal PCR
- enteroviral, HSV, VZV PCR
- consider investigations for TB meningitis
What are the criteria for delaying LP in meningitis?
- signs of severe sepsis
- rapidly evolving rash
- severe cario/ resp compromise
- significant bleeding rik
- signs suggestive of brain compartment shift (do CT first): focal neurosigns, presence of papillodema, continious or uncontrolled seizures, GCS <12
State 5 complications of meningitis
septic shock, DIC, septic arthiritis, haemolytic anamia, pericadial effusion, subdural effusion, SIADH, seizures, hearing loss, cranial nerve dysfunction
Describe the clinical features of encephalitis (5)
- bizarre behaviour or confusion
- decreased GCS or coma
- fever
- headache
- seizures
- focal neuro signs (weakness, visual disturbance, aphasia, cerebellar signs)
- history of travel or bite
Describe the key differenced between meningitis and encephalitis?
- Seizures uncommon in meningitis but common in encephalitis
- photophobia, rash and neck stiffness much more common in meningitis
- focal neurological signs are a hallmark feature of encephalitis, but only occur in some and later in meningitis
- mental status is almost always altered in encephalitis, however is common but less so in meningitis
How should encephalitis be investigated?
- bloods: cultures, viral PCR, malaria film biochemistry
- contrast enhanced CT
- LP (viral picture usually, if bacterial ?meningitis)
- EEG: diffuse abnormalities may help confirm encephalitis
Give 3 common viral and 3 common non viral causes of encephalitis
Viral: HSV, arbovirus, EBV, CMv, VZV, HIB, mumps (paramyxo), measles, rabies, west nile
Non viral: any bacterial meningitis, lyme disease, TB, malaria, legionella, leptospirosis
How is encephalitis managed?
- start acyclovir within 30 mins or arrival- 10mg/ kg/ 8hrs IV for 14 days as empirical treatment
- specific therapies exist for CMV and toxoplasmosis
- supportive therapy in HDU/ ITU if necessary
- symptomatic treatment with phenytoin if necessary
Define status epilepticus
seizure lasting >30 mins or repeated seizures without intervening consciousness - usually in known epilepsy, if 1st presentation then high chance of structural brain lesion
How should status epilepticus be investigated/ assesed?
- bedside glucose (dont miss this as cause) early
- pulse oximetry and cardiac monitor while its happening
After treatment started: - consider anticonvulsant levels, toxicology, LP, blood cultures, urine cultures, EEG, CT and carbon monoxide levels
- CXR to evaluate for possible asipration
- lab glucose, ABG, u&e, ca, fbc, ecg
Describe management of status epilepticus (from start of seizure) (inc paeds and adult doses)
0 mins: ABC, high flow O2, check BM, make surroundings safe- (50ml 50% dextrose if hypo)
5 mins: give IV lorazepam 0.1mg/ kg (4mg) slow bolus or rectal diazepam 10-20mg
10-15 mins: (if no response) give 2nd bolus
20-25 mins: phenytoin infusion 20mg/kg (up to 2g) at 50mg/min w/ ECG monitoring AND seek ITU help for general anaesthetic with propofol/ thiopentone if still going at 45 mins
Give 5 causes of spinal cord/ cauda equina compression?
- neoplasms (breast, kindey, thyroid, lung, prostate mets, myeloma or primary bone tumours)
- trauma
- infections; abscesses
- spinal stenosis
- transverse myelitis
- disc prolapses (rare but lumbar disc herniations typically cause CES)
- post op haematoma
- spondylolithesis
Describe the locations and functions of the 2 main ascending sensory tracts and the main motor tract within the spinal cord
Corticospinal tract- lateral cord, ipsilateral motor control
Dorsal column- posterior cord, ipsilateral vibration and proprioception
Spinothalamic tract- anterior cord, contralateral pain, temp and crude touch sensation
What are the upper motor neurone signs?
- Weakness- esp of extensors in arms and flexors in legs
- Hyperreflexia, clonus, upgoing planters
- Hypertonia which is spastic (velocity dependent)- clasp knife
What are the lower motor neurone signs
- weakness (pattern consistent with neuronal distribution)
- muscle wasting
- fasiculation
- hypotonia/ flaccidity
- reflexed reduced or absent
- flexor planter reflex
Describe the type and distribution of motor and sensory deficit seen with cord lesions
- usually bilateral motor deficit from below level of lesion down- initially LMN signs then UMN over the next hrs.
- LMN signs + loss of reflexes at the level of the lesion
- Presence of a sensory level
- autonomic features may also be present & associated w/ worse prognosis (constipation, retention, incontinence)
Describe the MRC grading of muscle weakness
0= no contraction 1= flicker of contraction 2= some active movement 3= active movement against gravity 4= active movement against resistance 5= normal power (allowing for age)
Describe the classifications of head injuries?
- Focal (slit into haematoma (sub, extra or intracerebral) or contusion (coup vs contracoup)
vs - Diffuse (concussion vs diffuse axonal injury)
AND - traumatic (split into open/ penetrating vs closed)
vs - non traumatic (axonia, infection, CVA/ TIA, tumour etc)
Describe the pathophy of a concussion
- Stretching of axons causes impaired neurotransmission, ion regulation and reduced blood flow causing temporary brain dysfunction
Describe the clinical features of post concusion syndrome
Difficulty thinking clearly, slowed down, confusion, headache, N+V, balance problems, tired, light sensitive, irritable, sad, sleep disturbance, trouble falling asleep
Describe the pathophys of diffuse axonal injury
- Shearing of grey and white matter interface following traumatic acceleration/ deceleration or rotational forces
- Leads to axonal death so cerebral odema so raised ICP and death
- they get instate LOC with few recovering- v poor prognosis
State 5 signs of a basilar skull fracture
racoon eyes, CSF rhinorrhoea, CSF otorrhoea, battle sign, haemotympanum
Describe the differences in mechanism between extradural (EDH) and subdural (SDH) haemorrhage?
EDH: almost always traumatic
SDH: usually traumatic but less major trauma, can be spontaneous also
Describe the difference in presentation between EDH and SDH
EDH: young pt, LOC followed by lucid interval then rapid decline in consciousness, signs of raised ICP etc
SDH: acute bleeds can be any age, chronic bleeds seen in elderly, reduced GCS, neuro signs, or chronic bleeds= insidious neurological decline
Where is the bleed for EDH and SDH? What is the radiological appearance?
EDH: middle meningeal artery, lentiform shape, limited by suture lines
SDH: bridging veins, cresent shaped, not bound by suture lines but unable to cross midline due to falx cerebri, chronic bleeds appear hypodense- can have acute on chronic
What is the definitive management for EDH and SDH?
EDH: urgent craniotomy to relieve raised ICP, if small can just observe
SDH: acute- surgery to relieve raised ICP, if chronic and not causing symptoms then many are left alone
What are the criteria for a head CT within 1 hr of head injury?
- GCS <13 or <15 after 2 hrs
- focal neuro deficit
- suspected skull or C spine fracture
- seizure or vomiting >1 time
What are the criteria for head CT within 8 hrs of head injury?
- LOC or amnesia AND - age >65 (or) - coagulopathy (or) - high impact injury (or) - retrograde amnesia of > 30 mins
When is a CT neck NOT required to clear the neck and allow mobilisation?
- no posterior midline cervical tenderness
- no evidence of intoxication
- pt altert and orientated to person, place, time and event
- no focal neuro deficit
- no painful distracting injuries
How do acute bulbar and pseudobulbar palsies present differently?
- A bulbar palsy is one of the nuclei of CN IX- XII (medulla)
- A true bulbar palsy= LMN lesion (, flacid fassiculating tongue, normal or decreased jaw jerk and reduced gag reflex, quiet nasal speech)
- corticobulbar palsy/ pseudobulbar palsy is UMN (hot potato speech, increased jaw and palatine reflexes, mood incontinent giggling/ weeping, spastic tongue)
List causes of bulbar and a pseudobular palsies?
Bulbar: MND, guillian barre, polio, MG, syringobulbia, brainstem tumours or central pontine demyelinolysis
Pseudobulbar: MS, MND, BILATERAL stroke or centralpontine demyelinolysis
What is epilepsy
a tendency to experience seizures- spontaneous, intermittent abnormal electrical activity within the brain
What are the major causes of epilepsy?
- 2/3 are idiopathic
- structural: scarring from previous brain injury, developmental, SOL, stroke, vascular malformation
- neurocutaneous syndromes eg. tuberous sclerosis
- sarcoidosis
- SLE
- channelopathies
What reversible factors could provoke seizures and need to be ruled out before diagnosing epilepsy
- alcohol and alcohol withdrawal
- raised ICP
- fever
- metabolic disturbance
- infection
What general advice should be given to epilepsy pts?
- avoid swimming and heights unsupervised, at least till diagnosis is known
- inform the DVLA and need to be seizure free for 1 yr until you can drive
What is the difference between generalised and focal/partial seizures?
generalised- seizure involving both sides of the brain (always lose consciousnes)
Focal/ partial- seizure activity limited to one or more areas but on one side of the brain
What is the difference between and simple and a complex partial/ focal seizure?
Simple- consciousness not lost, lasts <1 min, limited to one muscle group
Complex- consciouness lost, lasts 1-2 mins, post ictal period after, commonly affects temporal lobe
What are the different types of generalised seizures?
- Tonic- clonic
- Atonic (drop attacks)
- Myoclonic (quick movements/ sudden jerking, happen in clusters several times a day or several days in a row
- Absence (brief LOC, may maintain posture but face, eyes or mouth may move, commonest age 4-12, cant recall them)
- Infantile spasm (before 6 months, when wakening or falling asleep, brief movements in neck, trunk or legs)
Describe the phases to generalised tonic clonic seizures
- contract: body, arms, legs flex
- extend
- tremor/ shake
- contraction and relaxation of muscles, clonic period
- post ictal period: sleepy, vision problems, fatigue, ache, headache
Describe the features of a temporal lobe focal seizure
- automatisms (lip smacking, screaming, crying)
- dysphagia
- dejavu
- emotional disturbance
- hallucinations of smell, taste, sound
- delusional behaviours
Describe the clinical features of frontal lobe focal seizures
- motor features such as posturing or peddling legs
- jacksonians march (starts distal part of limb and spreads to ipsilateral side of face)
- motor arrest
- dysphagia or speech arrest
Describe clinical features of parietal and occipital lobe focal seizures
- parietal: sensory disturbance (motor if spread to precentral gyrus)
- occipital: visual phenomena such as spots, lights and flashes
What drugs are best for focal seizures
1st- carbemazepine or lamotrigine
2nd= sodium valproate
What drugs are used for generalised tonic seizures
1st= sodium valproate or lamotrigine 2nd= levetiracetam
What drugs are used for absence, myoclonic or tonic or atonic seizures?
1st- sodium valproate
2nd- lamotrigine/ levetiracetam