Neurology Flashcards
What constitutes the CNS?
The brain and spinal cord
What constitutes the PNS?
The cranial nerves and the other nerves in the body not in the spinal cord.
What are the physiological divisions of nerves?
Somatic (sensory and motor)
Branchial (motor only)
Autonomic (sensory and motor)
Special senses (sensory only) - olfaction, vision, accelerometer etc.
What are the three different functional types of motor neurones?
Somatic, autonomic and branchial
What are the three different functional types of sensory neurones?
Somatic, autonomic and special
What is a dermatome?
An area of skin supplied by a single spinal nerve/pair of nerves
What is a myotome?
A volume of muscle supplied by a single spinal nerve
What is the spinal cord?
The pathway for motor control from the brain to the body and the pathway for sensory information from the body to the brain.
What percentage of strokes are embolic?
85%
What percentage of strokes are haemorrhagic?
10%
What are the rarer causes of strokes?
Vasculitis
What is the typical presentation of an intracerebral haemorrhage?
Sudden onset headache, drowsiness, vomiting, focal deficit
What are the primary causes of ICH?
Hypertension - Charcot-Bouchard aneurysms
Amyloid angiopathy
What are the secondary causes of ICH?
Tumour, AVM, cerebral aneurysm, haemorrhagic transformation infarct, venous infarct, anticoagulants
What locations of ICH are typical of hypertensive bleeds?
Basal ganglia
Pons
Cerebellum
What are the three complications of Charcot-Bouchard aneurysms?
Rupture, thrombosis and leakage
What complication does intraventricular extension cause?
Hydrocephalus as the brain cannot resorb CSF
What is the management of an anticoagulant-related ICH?
Discuss with haematologist
If on warfarin check INR and consider reversal with Beriplex and Vit K
If has low platelets - consider transfusion
What imaging can be used post-stroke?
CTA, MRA, catheter angiography
Why is imaging used post-stroke?
To look for causes of the ICH e.g. vascular abnormalities, tumours or microbleeds
What are the symptoms of an ACA stroke?
Leg weakness Sensory disturbance in the legs Gait apraxia - truncal ataxia Incontinence Drowsiness Akinetic Mutism - decrease in spontaneous speech - stuporous state
What are the symptoms of an MCA stroke?
Contralateral arm and leg weakness Contralateral sensory loss Hemianopia Aphasia Dysphasia Facial droop
What are the symptoms of a PCA stroke?
Contralateral homonymous hemianopia
Cortical blindness with bilateral involvement of the occipital lobe branches
Visual agnosia
Prosopagnosia - face blindness
Dyslexia, anomic aphasia, colour naming and discrimination problems
Headaches unilateral
What are the symptoms of a posterior circulation stroke?
Motor deficits such as hemiparesis or tetraparesis and facial paresis Dysarthria and speech impairment Vertigo, nausea and vomiting Visual disturbances Altered consciousness
What is the treatment for an ischaemic stroke?
Thrombolysis (up to 4.5 hours post onset of symptoms)
Clot retrieval
Intra-arterial thrombolysis
Decompressive craniectomy
What are the contraindications of thrombolysis?
Recent surgery in the last 3 months Recent arterial puncture History of active malignancy Evidence of brain aneurysms Patient on anticoagulation Severe liver disease Acute pancreatitis Clotting disorder
Name 3 types of primary headache.
Migraine
Cluster
Tension type
Name 3 types of secondary headaches.
Meningitis Subarachnoid haemorrhage Giant cell arteritis Idiopathic intracranial hypertension Medication overuse headache - caused by overuse of OTC medications
Under what circumstances would you consider immediate referral to a neurologist regarding a headache?
Thunderclap headache - ?SAH Seizure and new headache ?meningitis ?encephalitis Red eye - ?acute glaucoma Headache and new focal neurology including papilloedema
What are the red flags with headache?
New headache with a history of cancer Cluster headache Seizure Significantly altered consciousness, memory, confusion, coordination Papilloedema Other abnormal neuro exam of symptoms
What are the different types of common headache?
Migraine (episodic with and without aura; chronic migraine)
Medication overuse
Tension type headache
What is the abortive treatment for migraine?
An oral triptan and an NSAID or an oral triptan and paracetamol
Consider an anti-emetic, even in the absence of N&V.
What is the preventative treatment of migraine?
Topiramate or propanolol, amitriptyline. Advise patients to take 400 mg riboflavin OD.
What do nerve conduction studies assess?
The peripheral nervous system
What can nerve conduction studies show?
Axon loss - small responses
Myelin loss - slow responses
What is electromyography used for?
To determine whether a PNS problem is in the nervous system or muscle. The NCS is normal even though the patient is weak, the problem is with the muscle.
What are EEGs used for?
Primarily done for patients with seizures.
What do somatosensory evoked potentials examine?
Look at the integrity of the dorsal columns.
How do somatosensory evoked potentials work?
You stimulate the peripheral nerve and record a response from the somatosensory cortex using scalp electrodes, like an EEG.
What do visual evoked potentials examine?
The visual pathways
What are visual evoked potentials used for?
To look for demyelination in the optic nerve in conditions such as MS
What are somatosensory evoked potentials used for?
To diagnose MS and intraoperative monitoring e.g. in spinal cord surgery
What is transcranial magnetic stimulation?
A brief magnetic pulse induces an electric current that excites cells in the motor cortex.
What are the main uses of transcranial magnetic stimulation?
To diagnose motor neuron disease, MS and to treat severe depression.
What is meningitis?
Inflammation of the meninges; it can be bacterial, viral or fungal.
What is encephalitis?
Inflammation of the brain, it is usually viral
What is encephalopathy?
A reduced level of consciousness/diffuse disease of brain substance, usually non-infective but has multiple aetiologies.
What is neuropathy?
Damage to the peripheral nerve e.g. diphtheria, Guillain-Barre syndrome, Lyme disease and Hep A
What is polyradiculopathy?
Inflammation of the nerve roots e.g. in cauda equina, HIV + CMV/syphilis/HSV
What is myelitis?
Inflammation of the spinal cord (whole cord cross section vs. anterior horn cells)
What is meningoencephalitis?
It resembles both meningitis and encephalitis.
What are the clinical signs of meningeal irritation?
Reduced GCS
Headache
Neck stiffness
Papilloedema
Kernie’s sign (extension of the knee is painful when the hip is flexed)
Burdzinski’s sign (severe neck stiffness causes a patient’s hips and knees to flex when the neck is flexed
What are the important steps in the management of meningeal irritation?
Blood cultures before antibiotics Antibiotics Bloods: FBC, U&E, CRP, serum glucose, lactate Lumbar puncture CT head Throat swabs (bacterial and viral) Pneumococcal and meningococcal serum PCR
What are the important adverse effects of a lumbar puncture?
Headache Parasthesia CSF leak Damage to the spinal cord Cerebral herniation and death
What investigations should be performed on CSF for ?meningitis?
CSF protein and glucose MC&S Viral PCR (enterovirus, HSV/VZV) Bacterial PCR Simultaneous serum glucose
What are the common bacterial causes of meningitis in children and adults?
Neisseria meningitides
Streptococcus pneumoniae
Listeria monocytogenes
Haemophilus influenzae
What are the common bacterial causes of meningitis in neonates?
E. coli (gut flora can spread easily in a neonate)
Group B streptococci (carried by some women in the vagina)
Listeria monocytogenes
What is the management for suspected bacterial meningitis?
IV Cefotaxime (or ceftriaxone; chloramphenicol if the patient has severe anaphylaxis with beta-lactams)
Add amoxicillin IV for listeria cover if >55, immunocompromised or the patient has a Hx of alcohol excess
Add steroids
Consider vancomycin in return travellers
What forms of meningitis don’t require prophylaxis
Those caused by H. influenzae and pneumococcal bacteria if the patient has been vaccinated.
What is meningococcal sepsis?
Meningitis and septicaemia where the bacteria are in the blood; this is a medical emergency.
What is the treatment for viral meningitis?
There is no specific treatment, treatment is just supportive.
What is the management of encephalitis?
Treat empirically with IV acyclovir.
What are the symptoms of encephalitis?
Fever
Headache
Lethargy
Behavioural change
What are the symptoms of rabies?
Fever Anxiety Confusion Hydrophobia Hyperactivity/uncontrollable excitement Hallucinations Violent movements
What are the symptoms of tetanus?
Paraesthesia of the wound Lockjaw Sustained muscle contractions Involvement of the facial muscles Paroxysmal generalised spasms
What are the symptoms of Clostridium botulinum infection?
Descending paralysis with cranial neuropathy first then: Diplopia Dysarthria Dysphagia Peripheral weakness
What is the aetiology of a TIA?
It is usually embolic but it may be thrombotic. The most common source of emboli is the carotids, usually the bifurcation. It can also originate with AF and valve disease.
What is the pathophysiology involved in a TIA?
There is temporary inadequacy of the circulation in part of the brain leading to a cerebral or retinal deficit. It doesn’t last >24 hours and most last <30 minutes.
What are the risk factors associated with TIA?
HTN, smoking, DM, heart disease, peripheral arterial disease, polycythaemia vera, combined OCP, hyperlipidaemia, excess alcohol, clotting disorders
Which gender experiences more TIAs?
Males
What are the symptoms of a TIA?
Unilateral weakness, unilateral sensory loss, drooping face, confusion, difficulty with speech, amaurosis fugax (painless, fleeting loss of vision)
What are the signs of a TIA?
Dysarthria (difficulty with speech), dysphagia, loss of memory, abnormal behaviour, homonymous hemianopia, diplopia, ataxia
What tests are used to diagnose a TIA?
A TIA is a retrospective diagnosis as it is only once it’s over that it’s diagnosed as a TIA
Bloods: FBC, ESR, U&Es, fasting lipids and glucose, LFTs, TSH
ECG - may show AF, MI or evidence of myocardial ischaemia
Imaging - carotid doppler
ABCD2 score - predicts risk of a stroke
What is the treatment for a stroke?
Control cardiovascular risk factors e.g. HTN, hypercholesterolaemia, smoking cessation
Clopidogrel
Carotid endarterectomy if stenosis is >70%
What is the aetiology of a stroke?
Young patient: vasculitis, thrombophilia, SAH, venous sinus thrombosis, carotid artery dissection
Older patient: thrombosis, thromboembolism, CNS bleed, vasculitis
What is the pathophysiology of a stroke?
A stroke is due to disruption of the blood supply caused by ischaemic infarction of part of the brain or from intracranial haemorrhage
What are the risk factors for a stroke?
HTN, smoking, DM, heart disease, peripheral arterial disease, polycythaemia vera, combined OCP, hyperlipidaemia, excess alcohol, clotting disorders, post-TIA
What is the epidemiology of a stroke?
Most occur in patients >65
What are the symptoms of a stroke?
Facial drooping, weakness in a limb or side of the body, hemisensory loss, dysphagia, diplopia, ataxia, imbalance, unsteadiness, dysarthria
What are the signs of a stroke?
Nystagmus, Horner’s syndrome, hemianopia, flaccid paralysis (becomes spastic later), locked in syndrome - complete infarction affecting the pons
What tests are used to diagnose a stroke?
Bloods: FBC, ESR, glucose and lipids
Imaging - head CT, MRI head, carotid doppler, cerebral angiography
Echo if suspected cardiac emboli
ECF - AF
What is the treatment for a stroke?
Ischaemic - thrombolysis (IV alteplase, must be given <4.5 hours from onset), aspirin for 2 weeks then clopidogrel
Haemorrhagic - BP control, beta blockers, Beriplex if it’s warfarin related, clot evacuation
Risk factor management e.g. antihypertensives, statins