Neurology Flashcards
What is a TIA?
- Transient ischaemic attack.
- A transient episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischaemia.
- Symptoms resolve within 24 hours, usually within 1 hour.
What is the clinical presentation of a TIA?
- Sudden onset and brief duration of symptoms.
- Symptoms will represent a focal neurological deficit.
- Basically a shorter version of a stroke.
What are the risk factors for a TIA?
- Atrial fibrillation.
- Mitral valve stenosis.
- Carotid stenosis.
- Congestive heart failure.
- Hypertension.
- Diabtes mellitus.
- Smoking.
- Older age.
What is the pathophysiology of TIA?
- Partial blood flow restriction.
- Leads to neuronal dysfunction, but delays neuronal death (infarction) as there is still a partial supply of blood.
- If the partially occluding thrombus is autolysed quickly enough, blood flow is restored and neuronal death will be prevented.
- Causes reversal of neurological symptoms.
What are the scoring systems/investigations used in a TIA?
TIA is a clinical diagnosis primarily.
- ROSIER (ER assessment)/ FAST (outside of hospital) used to screen/diagnose TIA.
- Blood glucose levels checked (hypoglycaemia can mimic the symtpoms of a TIA/stroke).
- Non-contrast CT head not typically used. However, will be used if the patient has a bleeding disorder/ is currently taking anticoagulants (e.g. warfarin) as they are at higher risk of haemorrhage.
- ABCD2 can be used to calculate stroke risk following a TIA.
What is the ABCD2 score?
Assesses risk of stroke following a TIA:
A - Age>60? +1
B - BP>140/90? +1
C - Clinical features of TIA.
Speech disturbance without weakness? +1
Unilateral weakness? +2
D - Duration of symptoms.
>10 mins? +1
>60 mins? +2
^2 - History of diabetes? +1
6 or more is high risk.
What treatment can be given for a TIA?
- Give a loading dose of aspirin (an antiplatelet) if TIA suspected.
- When TIA confirmed, swap aspirin to clopidogrel (P2Y12 inhibitor) and continue clopidogrel as secondary prevention from this point onwards.
- Start atorvastatin immediately (and continue as secondary prevention).
What is a stroke?
- Rapid onset of either focal or global neurological deficit with no apparent cause other than that of vascular origin.
- Symptoms last MORE THAN 24 HOURS (unlike a TIA).
What are the two types of stroke?
- Ischaemic (Caused by vascular occlusion/stenosis leading to ischaemia of the brain).
- Haemorrhagic (vascular rupture causes subarachnoid or intraparenchymal haemorrhage.
What are the risk factors for stroke?
- Old age.
- FH of stroke.
- Previous stroke/TIA.
- Diabetes mellitus.
- Smoking.
- High BP.
- Atrial fibrillation (AF).
What is the general clinical presentation of a stroke?
- Unilateral weakness in face, arm, leg.
- Unilateral sensory loss.
- Extremely painful headache.
- Speech impairments (dysarthria, dysphasia etc.)
- Loss of coordination/change of gait.
- Vertigo/loss of balance.
What is the pathophysiology of an ischaemic stroke?
- Stroke is caused by either a permanent or transient occlusion of blood flow due to arterial occlusion or stenosis. There are three main mechanisms for this:
- Primary vascular pathology (e.g. vasculitis, atherosclerosis).
- Cardiac pathology (E.g. AF, patent foreamen ovale).
- Haematological pathology (e.g. sickle cell anaemia, hypercoagulapathies).
What is the pathophysiology of a haemorrhagic stroke?
- Vascular rupture with bleeding into the brain parenchyma, causing primary mechanical brain damage.
What are the two tools used to initially recognise/diagnose stroke in the community and in a hospital?
- FAST (Face, arms, speech test) is used in the community to screen for a potential stroke.
- ROSIER (Recognition of stroke in emergency room) is used in the ER to quickly diagnose stroke.
What is the initial management of a suspected stroke?
- Admit to specialist acute stroke unit.
- GCS (Glasgow coma score).
- Measure blood glucose (to exclude hypoglycaemia, which can mirror the presentation of stroke).
- Refer for urgent non-contrast CT head scan. This will determine if the stroke is haemorrhagic or ischaemic.
What is the management following confirmation a stroke is ischaemic?
- IF WITHIN 4.5 HOURS OF SYMPTOM ONSET give altepase (a thrombolytic drug).
- Aspirin ASAP (or clopidogrel if aspirin not tolerated).
- Thrombectomy if there is potential to save some of the brain tissue.
- After 48 hours, start high dose atorvastatin.
- ANTCOAGULANTS (WARFARIN, HEPARIN) ARE NOT INDICATED.
What is the treatment following confirmation a stroke is haemorrhagic?
- Supportive treatment (O2, fluids, BP monitoring, ICP monitoring etc.)
NOTE: Only give O2 if <94% - Urgent reversal of anticoagulants (warfarin is reversed using vit K/prothrombin complex concentrate.
- Immediate referral to neurosurgery.
- DO NOT START A STATIN.
What are the key symptoms suggestive of disrupted blood supply in each of the cerebral arteries?
- Anterior cerebral artery (ACA) will generally present with contralateral leg weakness.
- Medial cerebral artery (MCA) will generally with contralateral face/arm weakness.
- Posterior cerebral artery (PCA) will generally present with homonymous hemianopia and memory loss (hippocampus supplied by the PCA).
What is a subarachnoid haemorrhage?
How does it present on a CT scan?
- Spontaneous arterial bleeding into the subarachnoid space, between the pia and the arachnoid layers.
- Presents as a star pattern on a CT scan.
What is a subdural haemorrhage?
How does it present on a CT scan?
- Bleeding occurring between the dura and arachnoid layers.
- Presents as a crescent on a CT scan.
What is a extradural haemorrhage?
How does it present on a CT scan?
- Bleeding occurring in the potential space between the skull and the dura.
- Presents as a convex lens (otherwise known as lentiform) shape.
Which type of heamorrhage causes thunderclap headache?
- Subarachnoid haemorrhage.
What are the typical causes of each type of haemorrhage?
Extradural haemorrhage - Middle meningeal artery rupture due to temporal bone break.
Subdural haemorrhage - Due to bridging vein rupture (e.g. shaken baby, old, alcoholics).
Subarachnoid haemorrhage - Caused by rupture of berry aneurysms.
Which type of haemorrhage is associated with CN III palsy?
- Extradural haemorrhage.
Which type of haemorrhage is associated with Marfan’s syndrome?
Briefly, what is Marfan’s syndrome and how does it relate to brain haemorrhage?
- Subarachnoid haemorrhage.
- Marfan’s syndrome. An inherited condition that affects the connective tissues of the body. This weakens the blood vessel walls, making them susceptible to aneurysm.
What is a lucid interval and which type of cerebral haemorrhage is it associated with?
- Extradural haemorrhage.
- Patient initially is knocked unconscious.
- Then, brain compensates and the patient will appear to briefly recover. This is the “lucid recovery”.
- Then, as the haemorrhage expands and ICP builds, the patient will again be knocked unconscious.
What is epilepsy?
- Umbrella term for a condition where there is a tendancy to have seixures.
What are the 5 main types of seizures seen in epilepsy and what do they present like?
Tonic-clonic - Period of stiffness followed by period of jerking. Most common type of seizure.
Focal - Occurs in the temporal lobe. Affects emotions, memory, speech and hearing (Deja vu, hallucinations, memory flashbacks, strange actions).
Absence - Loses awareness of surrounding and becomes unresponsive for a short period of time. Most common in children and usually resolves as they get older.
Myoclonic - Period of muscles tensing, stiffness.
Atonic - Muscles relax and person goes “floppy”.
What is status epilepticus?
Management?
- A seizure that lasts over 5 minutes
OR - More than one seizure in the space of 5 mins, where consciousness is regained briefly between the seizures.
- THIS IS CONSIDERED A MEDICAL EMERGENCY.
Management:
- ABC (especially high flow oxygen, secure airway).
- Monitor GCS.
- Lorazepam (benzodiazepam)
- Dose of 1st line anticonvulsant (normally sodium valproate - a GABA receptor agonist).
What is the treatment for epilepsy?
FOR ALL TYPES EXCEPT FOCAL:
- Sodium valproate is 1st line (GABA receptor agonist).
- Carbamazepine/lamotrigine is 2nd line (Sodium channel blocker).
FOR FOCAL:
- Carbamazepine/lamotrigine is 1st line.
- Sodium valporate is 2nd line.
FOR MID-SEIZURE CONTROL:
- Lorazepam (1st line) or diazepam (2nd line) (benzodiazepam)
What are some of the most common epileptic triggers?
3 most common are:
- Alcohol.
- Lack of sleep.
- Poor adherance to treatment.
Other causes are:
- Flashing lights
What are the diagnostic tests used for epilepsy?
- EEG (+ video is GS).
- MRI brain (check for structural abnormality and cancers).
- ECG (check for cardiac abnormalities, potentially causing syncope).
What are the four categories of stroke within the Bamford classification?
- Total anterior circulation stroke (TACS).
- Partial anterior circulation stroke (PACS).
- Posterior circulation syndrome (POCS).
- Lancunar Stroke (LACS)
How is the Bamford classification used?
Anterior stroke criteria. Total anterior circulation stroke (TACS) needs 3/3, partial anterior circulation stroke (PACS) needs 2/3:
- Unilateral loss of motor and/or sensory function in face, arm and leg.
- Homonymous hemianopia.
- Higher cerebral disfunction (e.g. speech difficulty, memory loss, reasoning).
Posterior circulation syndrome criteria. POCS must meet 1 of the following criteria:
- ISOLATED homonymous hemianopia.
- Bilateral motor/sensory deficit.
- Cranial nerve palsy that is contralateral to the motor/sensory deficit.
- Cerebellar dysfunction (nystagmus, ataxia etc.)
- Conjugate gaze palsy (Inability to move both eyes in the same direction).
Lancunar stroke criteria. LACS must meet one of the following criteria:
- Purely motor and/or sensory stroke with NO LOSS OF HIGHER CEREBELLAR FUNCTIONS.
- Ataxia hemiparesis. (This is ataxia on one side of the body).
What is higher cerebral function?
Refers to conscious mental activities. For example:
- Thinking.
- Remembering.
- Reasoning.
What is the relationship between brain haemorrhage and haemorrhagic stroke?
Haemorrhage CAN cause haemorrhagic stroke, but not all haemorrhages are strokes.
Treatment for a haemorrhage refers to a haemorrhage alone, rather than a haemorrhagic stroke.
What is the management for a subarachnoid haemorrhage (non-stroke)?
- Monitor GCS.
- ABC
- Nimodipine (A CCB). Used to reduce risk of late-onset cerebral ischaemia.
- Reverse anticoagulation/antiplatelets (e.g. warfarin reversal with vit K).
- Paracetamol for analgesia (AVOID NSAIDS, can affect the clotting cascade).
What is the management of a subdural haemorrhage?
- Continue to assess GCS.
- ABC.
- Phenytoin (an anti-convulsant) should be given prophylactically to prevent seizure.
- Reversal of anticoagulation/antiplatelets (e.g. reverse warfarin with “Prothrombin Complex Concentrate” - this is vit. K).
- Raise bed to 30 degrees to lower ICP. 2nd line is mannitol.
What is huntington’s disease, including details of the genetic cause?
- Autosomal dominant neurodegenerative disorder, caused by CAG repeats.
What is the presentation of Huntington’s disease?
- Usually presents in middle-ages (slow progression).
- +ve family history is key.
- Chorea (involuntary, jerky movements).
- Cognitive impairment (concentration deficit, misjudgements etc.)
- Behaivoural changes (irritable, impulsive etc.)
What is the diagnostic investigation used for Huntington’s disease?
- CAG repeat testing.
What is the treatment for Huntington’s disease?
- Limited options.
- SSRI (e.g. fluoxitine).
- Antipsychotics.
What is Guillian-Barre Syndrome?
- An acute inflammatory neuropathy associated with progressive symmetrical muscle weakness.