Neurology Flashcards
Define myasthenia gravis
A disorder of neuromuscular transmission characterised by: weakness and fatiguing of some or all muscle groups, weakness worsening on sustained or repeated exertion, or towards the end of the day, relieved by rest
Myasthenia Gravis pathophysiology
Autoimmune destruction of the nicotinic postsynaptic receptors for acetylcholine (AChR)
Clinical features of myasthenia gravis
Ptosis, muscle paresis, weakness of jaw muscles leaves mouth hanging open,, characteristic smile - myasthenic snarl, muscle wasting, hyperactive limb reflexes
Investigations for myasthenia gravis
Acetylcholine receptor antibodies (anti-AchR)
Anti-MUSK also
Anticholinesterase drugs used to confirm diagnosis - Tensilon test
CT of the thymus - thymic hyperplasia found in 70% of sufferers
Treatment for myasthenia gravis
Anticholinesterase durgs - Pyridostigmine
Muscarinic inhibitor - atropine to counter side effects
Prednisolone
Thymectomy
Define meningitis
Inflammation of the leptomeninges and underlying subarachnoid CSF
Risk factors for meningitis
Alcoholism, overcrowding, spinal procedures, diabetes mellitus, IV drug abuse, malignancy, cystic fibrosis
Causes of meningitis
Neonates= Gram -ve bacilli: E.coli, Klebsiella, H.influenzae Children= H.influenzae, Strep. pneumoniae, N.Meningitidis Adults= Strep. pneumoniae, H.influenzae,
Symptoms of meningitis
Fever, headache, stiff neck, photophobia, non-blanching petechial skin rash, Kernig’s sign, Brudzinski’s sign, seizures
Differential diagnoses of meningitis
Encephalitis, subarachnoid haemorrhage, malaria, septicaemia
Investigations for meningitis
LP - Ziehl-Neelsen stain, glucose, protein, rapid antigen screen,
U&Es, FBC, LFT
X-ray
CT scan
Treatment for meningitis
Dexamethasone + Ceftriaxone (E.Coli)/Benzylpenicillin (Pneumococcus + Meningococcus)
Define Guillain Barre syndrome
A disorder causing demyelination and axonal degeneration resulting in acute, ascending and progressive neuropathy, characterised by weakness, paraesthesiae and hyporeflexia
Causative organisms of Guillain Barre syndrome
CMV EBV Camplyobacter jejuni HIV Haemophilus influenzae
Risk factors for Guillain Barre syndrome
History of GI or respiratory infection, association with Zika virus, vaccinations, malignancies, pregnancy
Symptoms of Guillain Barre syndrome
Weakness - facial, dysphasia, dysarthria, back pain, reduced reflexes, paraesthesiae, hypotonia
Autonomic symptoms - reduced sweating, reduced heat tolerance, urinary hesitancy, tachycardia
Differential diagnosis for Guillain Barre
Stroke Encephalitis Spinal cord compression Vasculitis Myasthenia Gravis
Investigations for Guillain Barre
Confirmed with Nerve conduction studies
Electrolytes - inappropriate ADH secretion
LP - Elevated CSF: elevated protein, low WBC
ECG - T-wave abnormalities, ST depression, QRS widening
Spirometry
Management of Guillain Barre
IV immunoglobulin
Plasma exchange
Low molecular weight heparin
Define Parkinson’s disease
A progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the pars compacta of the substantia nigra - low levels of dopamine
Causes of Parkinson’s
Idiopathic Drugs - Neuroleptics, Metocloparide, Prochloperazine, sodium valproate Truma HIV Manganese/copper toxicity
Triad of symptoms of Parkinson’s
Bradykinesia - slowness of movement
Pill-rolling tremor
Cogwheel rigidity
Other symptoms of Parkinson’s
Constipation Frequency, urgency and incontinence Hallucinations Sweating Dribbling of saliva Weight loss Sleep problems Depression Anxiety
Main treatment for Parkinson’s
Levodopa (converted to dopamine)
Complications: Postural hypotension
On-off effect
What is levodopa given with?
Decarboxylase inhibitor - Carbidopa
Other treatments for Parkinson’s
Dopamine agonists - Ropinirole
MAO-B inhibitors - Rasagiline
COMT inhibitors - Tolcapone
How is meningitis spread?
By respiratory droplet
Define meningococcal septicaemia
Petechial rash + signs of sepsis
CSF findings in bacterial meningitis
Raised protein
Low glucose
CSF findings in viral meningitis
Normal protein
Normal glucose
Prophylaxis for meningitis
Rifampicin
Define TIA
Transient ischaemic attack
Sudden onset of neurological dysfunction which lasts less than 24 hours
TIA pathophysiology
Cerebral ischaemia due to arterial embolism or thrombosis in an atheromatous carotid, vertebral or cerebral artery
Risk factors for TIA
Smoking Hypertension Diabetes mellitus Increasing age Alcohol Previous TIA Hypercholesterolemia Vasculitis AF
Signs and symptoms of TIA
Hemiparesis, hemi sensory disturbance, dysphasa, amaurosis fugax
Define amaurosis fugax
Painless transient monocular visual loss - ‘a curtain coming down vertically into field of vision’
Leads to retinal hypoxia
Differential diagnosis for a TIA
Stroke
Hypoglycaemia
Migraine aura
Focal epilepsy
Diagnosis for TIA
ECG - check for AF or myocardial ischaemia
FBC, U&Es, glucose, ESR, LFTs, TSH
Echocardiogram or cardiac monitoring
Doppler ultrasound of the carotid arteries
How is risk of a stroke following a TIA assessed?
Use ABCD2 score
A - age >60
B - BP 140/90 or greater
C - Clinical features: unilateral weakness/speech disturbance without weakness
D - duration of symptoms: 60 minutes 2 points, 10-59 = 1 point
D - diabetes
High risk = 4+
Refer for specialist assessment within 24 hours. Low risk need assessment within 1 week
How is a TIA managed?
Control cardiovascular risk factors: stop smoking, improve diet, regular exercise, cut down on alcohol, lose weight Manage AF, diabetes, hypertension Aspirin Antiplatelet therapy - clopidogrel Statin - simvastatin
Define stroke
Disruption of blood to the brain lasting for more than 24 hours
Pathophysiology of a stroke
May be due to a blockage in a cerebral blood vessel leading to ischaemic infarction (70%) or due to a intracerebral haemorrhage (30%)
Causes of a stroke
Small vessel occlusion/thrombosis Cardiac emboli (AF, MI, IE) Atherothromboembolism CNS bleeds (trauma, SAH) Coronary artery dissecton Vasculitis Hyperviscosity (polycythaemia, sickle cell anaemia, myeloma)
Risk factors for a stroke
Diabetes mellitus Hypertension AF Smoker Alcohol Increasing age Previous TIA Hypercholesterolemia
Signs and symptoms of a stroke
Total anterior circulation stroke = Unilateral weakness of face, arm and leg, homonymous hemianopia, higher cerebral dysfunction (dysphagia, visuospatial disorder) Partial anterior circulation stroke: 2 of the 3 above Posterior circulation syndrome = cerebellar or brainstem syndromes, loss of consciousness, isolated homonymous hemianopia Lacunar syndrome (LACS) = unilateral weakness, pure sensory loss, ataxic hemiparesis
Diagnosis of a stroke
Urgent CT head
MRI
BP/ECG, blood glucose
Management of a stroke
ABCDE approach
Ensure hydration, keep O2 saturation >95%
Thrombolysis for ischaemic stroke = Alteplase
Antiplatelet therapy - Clopidogrel
MDT team
Define primary prevention
Risk factor control before any stroke
Define secondary prevention
Risk factor control to prevent recurrence of a stroke including lifelong antiplatelet
Define Subarachnoid haemorrhage
Bleeding into the subarachnoid space - between the arachnoid layer of the meninges and the brain parenchyma
Risk factors for a subarachnoid haemorrhage
Hypertension
Family history
Diseases which predispose to aneurysms - Polycystic kidney disease, Ehlers Danlos syndrome, coarcation of the aorta
Pathophysiology of a subarachnoid haemorrhage
Rupture of a berry aneurysm (70%), 10% are due to an ateriovenous malformation
Signs and symptoms of a subarachnoid haemorrhage
Thunder clap headache, vomiting, Kernig’s sign, neck stiffness, altered level of consciousness - drowsiness, collapse, seizures, coma, papilloedema
Diagnosis of a subarachnoid haemorrhage
CT scan
Lumbar puncture - blood xanthochromic (yellow) due to billirubin from Hb breakdown
Management of a subarachnoid haemorrhage
Dexamethasone to decrease cerebral oedema
Neurosurgery - surgical clipping or coiling of anuerysm
Nimodipine to reduce risk of vasospasm
Complications of subarachnoid haemorrhage
Rebleeding
Hydrocephalus
Hyponatraemia (SIADH)
Cerebral ischaemia due to vasospasm
Define subdural haematoma
A collection of clotting blood in the subdural space (space between the dura mater and the arachnoid mater)
Pathophysiology of subdural haematoma
Due to a rupture of a vein between the venous sinuses and the cortex, the accumulating haematoma causes raised ICP, shifting the midline structures
Risk factors for subdural haematoma
Traumatic head injury
Increasing age
Alcoholism
Anticoagulation medications
Signs and symptoms for subdural haematoma
Raised ICP - headache, nausea, vomiting, raised BP Confusion Seizure Focal neurology Alternating level of consciousness
Complications of a subdural haematoma
Death due to herniation
Raised ICP
Cerebral oedema
Coma
Differential diagnosis for subdural haematoma
EDH, SAH, meningitis, encephalitis, stroke, dementia, DKA
Investigations for a subdural haematoma
CT - gold standard = crescent shaped mass
FBCs, U&E’s, LFT’s
MRI
Management for subdural haematoma
Prioritise CT head
Surgery - evacuate the haematoma e.g. Craniotomy
Mannitol if raised ICP
Define extradural haematoma
Collection of blood between the dura mater and the bone, usually caused by head injury
Pathophysiology of an extradural haematoma
Due to fracture of the temporal or parietal bone causing laceration of the middle meningeal artery, typically after trauma to the temple
Risk factors for extradural haematoma
Young adults
Signs and symptoms for extradural haematoma
Loss of consciousness
Lucid interval
Headache, nausea and vomiting, confusion and seizures
Increased ICP
Differential diagnosis for extradural haematoma
Subdural haematoma
SAH
Meningitis
Encephalitis
Diagnosis for extradural haematoma
CT scan - gold standard = lemon shape
Management for extradural haematoma
ABCDE
Mannitol if increased ICP
Surgery - Craniotomy and clot evaculation
Define tension headache
Commonest primary headache. Can be episodic (<15 days/month) or chronic (>15 days for at least 3 months)
Risk factors for tension headaches
Stress
Anxiety
Noise
Fumes
Signs and symptoms of tension headaches
Bilateral, non-pulsatile, chronic daily headache - ‘tight band-like sensation’, pressure behind eyes, mild-moderate pain
Scalp muscle tenderness
No vomiting, no aura
Differential diagnosis for tension headache
Migraine, cluster, GCA, PMR
Diagnosis for tension headache
Clinical diagnosis
Management for tension headache
Lifestyle advice - regular exercise, avoid triggers, massage
Aspirin, paracetamol, NSAIDs
Define migraine
Recurrent throbbing headache often preceded by an aura and associated with nausea, vomiting and visual changes
Triggers for a migraine
Cheese, caffeine, alcohol, menstruation, oral contraceptives, anxiety, travel, exercise
Symptoms and signs
Aura - lasting 5-60 minutes, visual = flashing, jagged lines, hemianopia, sensory = paraesthesia, numbness, motor
Classic features - moderate to severe headache, unilateral pulsatile throbbing aggravated by movement, nausea + vomiting, photophobia
Differential diagnosis for migraine
Tension headache, cluster headache
Investigations for migraine
Clinical diagnosis
CRP, ESR,
LP
Management for migraine
Reduce triggers - e.g. dietary factors
Oral triptan - sumatriptan + NSAIDs/paracetamol
Prophylaxis for a migraine
Propanolol/topiramate
Consider amitriptyline
Define cluster headache
‘Migraineous neuralgia’ - rapid onset, excruciating unilateral pain around one eye, typically wakes the patient from sleep
Occurs in clusters of 1-2x a day, lasting 5-12 weeks, followed by pain free periods of months-years
Risk factors for cluster headache
Male: Female = 5:1
Smoking
Signs and symptoms for cluster headache
Pain around one eye
Lasts 15-60 minutes
Wakes patient from sleep
Watery and bloodshot eye, lid swelling, lacrimation, facial flushing, rhinorrhoea, miosis + ptosis
Investigations for cluster headache
Clinical diagnosis
Management for cluster headache
100% 15 O2
Sumatriptan or Zolmitriptan
Prophylaxis for cluster headache
Verapamil
Avoid alcohol
Prednisoline may help
Define trigeminal neuralgia
Paroxysms of instense, debilitating pain in the distribution of the trigeminal nerve
Pathophysiology of trigeminal neuralgia
Compression of trigeminal nerve causing demyelination and excitation of the trigeminal nerve
Risk factors for trigeminal neuralgia
Hypertension
Signs and symptoms of trigeminal neuralgia
Sudden, unilateral, paroxysms of knife-like/electric shock like pain
Starts in mandibular divison, spreading upwards to maxillary and ophthalmic divisions, lasts seconds to minutes
Triggers for trigeminal neuralgia
Shaving, eating, talking, vibration, exposure to cold wind
Differential diagnosis for trigeminal neuralgia
Temporal arteritis
Multipel sclerosis
Investigations for trigeminal neuralgia
MRI
Management for trigeminal neuralgia
Carbamazepine
Others: Gabapentin, lamotrigine, phenytoin
Percutaneous procedures: Rhizotomy
Surgical: Neurovascular decompression
Pathophysiology of Giant Cell Arteritis
Inflammatory granulomatous vasculitis of large cerebral arteries
Risk factors for giant cell arteritis
Male
>50 years
Signs and symptoms for giant cell arteritis
Temporal pulsating headache
Scalp tenderness (when combing/washing hair)
Jaw claudication (jaw pain on eating)
Amaurosis fugax (sudden blindness)
Tender, thickened, pulseless or nodular temporal artery
Fever, fatigue, breathlessness, myalgia, morning stiffness
Investigations for giant cell arteritis
ESR raised
Temporal artery biopsy
Management for giant cell arteritis
Prednisolone
Complications of giant cell arteritis
Polymyalgia rheumatica
Define encephalitis
Infection and inflammation of the brain parenchyma
Pathophysiology of encephalitis
Disease which mostly affected the frontal and temporal lobes, so causes decreased consciousness, confusion and focal signs
Causes of encephalitis
Viral infection
Herpes simplex virus
Varicella zoster virus, EBV, CMV, HIV, mumps, measles
Non viral: TB, toxoplasma, malaria, listeria
Risk factors for encephalitis
Extremes of age
Immunocompromised patients
Signs and symptoms for encephalitis
Fever, headache, myalgia, fatigue, nausea
Decreased consciousness, confusion, seizures, coma
Differential diagnosis for encephalitis
Meningitis, stroke, brain tumour
Investigations for encephalitis
Lumbar puncture + CSF studies (increase in protein level, decreased glucose) FBC Throat swabs, stool culture CT/MRI scan EEG
Management for encephalitis
Viral - Acyclovir
Define Huntington’s disease
An autosomal dominant, progressive neurodegenerative disorder
Pathophysiology of Huntington’s
Autosomal dominant
Mutation in chromosome 4, repeated expression of CAG
Cerebral atrophy with loss of neurones in the caudate nucleus and putamen of the basal ganglia
Decreased ACh synthesis and GABA in striatum
Signs and symptoms of Huntington’s
Prodrome
Chorea - jerky, explosive, figidity movements
Rigidity, writhing and abnormal posture
Dysarthria, dysphagia and abnormal eye movements
Behavioural change - aggression, addictive behaviour, depression/anxiety
Dementia
Seizures
Clonus
Investigations for Huntington’s
Diagnosis is clinical
CT/MRI
Genetic testing
Management for Huntington’s
No treatment to prevent progression
Management of chorea = benzodiazepines, valproic acid
Define motor neurone disease
A sporadic or hereditary disease affecting upper and/or lower motor neurones - characterised by progressive degeneration of motor neurone in the spinal cord (anterior horn), cranial nerve motor nuclei and within the cortex
Risk factors for motor neurone disease
Genetic
Upper motor neurone signs
Weakness
Hypertonia
Upgoing plantars (positive Babinski)
Clonus
Low motor neuron signs
Weakness Depressed/absent reflexes Decreased tone Wasting Fasciculations
Name the four types of MND
Amyotrophic lateral sclerosis (ALS)
Primary lateral sclerosis (PLS)
Progressive muscular atrophy (PMA)
Progressive bulbar palsy (PBP)
Investigations for MND
Clinical findings
Nerve conduction studies
Management for MND
Riluzole - not a cure, extends life by 3 months
MDT approach
Baclofen for spasms
Define multiple sclerosis
A chronic inflammatory disorder of the central nervous system associated with progressive disability
Risk factors for multiple sclerosis
EBV
MMR
Higher prevalence in the north and south hemispheres - lowest rates around the equator
Pathophysiology of multiple sclerosis
Immune-mediated demyelination at multiple CNS sites occurs as discrete plaques. Thought to be T-cell mediated: T-cells activate B cells to produce auto-antibodies against myelin. Repeat demyelination leads to axonal loss and incomplete recovery between attacks
Name the subtypes of multiple sclerosis
Relapsing-remitting (80%)
Secondary progressive
Primary progressive
Symptoms and signs of multiple sclerosis
Unilateral optic neuritis, diplopia, ataxia, vertigo, bladder/sexual dysfunction, fatigue, UMN signs
Symptoms worsen with heat/exercise - Uhthoff’s phenomenon
Investigations for multiple sclerosis
Electrophysiology - delayed nerve conduction studies suggests demyelination
MRI
Lumbar puncture - increased protein, OLIGOCLONAL bands of increased immunoglobulin concentration
>2 CNS lesions disseminated in time and space
Management for multiple sclerosis
Oral methylprednisolone
Natalizumab
Risk factors for brain tumours
Family history
Exposure to ionising radiation
Immunosuppression
Types of tumours
High grade - Gliomas (astrocytomas or oligodendromas)
Low grade - Meningioma (benign), neurofibromas, pituitary tumour, pineal tumour
Metastases
Where can a tumour metastasis from
lung, breast, prostate, colorectal, melanoma and kidney
Signs and symptoms of tumours
Increased ICP
Nausea and vomiting
Seizures
Personality change, confusion, papilloedema
Investigations for tumours
CT or MRI scan
Management for tumours
Neurosurgery
Where is the most common site for disc herniation
L4/L5
What is spinal cord compression
Myelopathy with UMN signs
What is spinal root compression
Radiculopathy with LMN signs
Causes of spinal cord compression
Secondary malignancy
Disc herniation
Intervertebral disc prolapse
Investigations for spinal cord compression
MRI - gold standard
Management for spinal cord compression
Neurosurgery
Epidural steroid injection
Signs and symptoms at L5/S1
SCIATICA
Sensory loss/pain - back of thigh, leg, lateral aspect of little toe
Signs and symptoms at L4/L5
Sensory loss/pain - lateral thigh/lateral leg
Pathophysiology of cauda equina syndrome
Nerve root compression caudal to the termination of the spinal cord
Usually large central disc herniation at L4/L5 or L5/S1 levels
Causes of cauda equina syndrome
Disc herniation
Tumours/metastasis
Trauma
Congenital e.g. spinal bifida
Signs and symptoms of cauda equina syndrome
Bilateral/unilateral pain in legs Vairable leg weakness Saddle anaesthesia Poor anal tone Erectile dysfunction Bladder/bowel dysfunction
Investigations for cauda equina syndrome
MRI
Management for cauda equina syndrome
Neurosurgery - MEDICAL EMERGENCY
