Neuro 2 Flashcards
What are some risk factors for meningitis?
CSF shunts/dural defects - staphylococcal
Spinal procedures (epidurals) - Pseudomonas
Splenectomy/sickle cell - encapsulated organisms
What are the main causes of bacterial meningitis per age category?
Neonates
- Group B strep
- L. monocytogenes
- E. coli
Infants
- H. influenzae
- N. meningitides
- S. pneumoniae
Adults
- same as infants
Elderly
- S. pneumoniae
- L. monocytogenes
- TB
What are the main organisms causing hospital acquired meningitis?
- Klebsiella pneumoniae
- E. coli
- S. aureus
- Pseudomonas aeroginosa
What are some non-infective causes of meningitis?
Malignant cells Drugs - NSAIDs, trimethoprim Sarcoidosis SLE Behcet's disease
What are some early features of meningitis?
Headache Fever Leg pains Cold hands and feet Abnormal skin colour
What features make up ‘meningism’?
- Neck stiffness
- Photophobia
- Kernig’s sign = pain and resistance on passive knee extension with hip fully flexed
What indicates invasive meningococcal disease?
- Petechial rash that is non-blanching (use glass test to check)
- Signs of shock: prolonged cap refill, hypotension, tachycardia
What haematological disorder can be secondary to meningitis? What blood levels would indicate this?
DIC (disseminated intravascular coagulation)
Low fibrinogen levels - used up all your fibrinogen to make many little clots
Raised D-dimer - released from the many little clots
Low platelets - used up all the platelets to make clots
What is another sign that may be positive in meningitis?
Brudzinski’s sign = hips flex on bending head forwards
What is the first line in managing meningitis?
Take blood cultures
What is the management for meningitis after taking blood cultures?
- IV antibiotics
- Dexamethasone 10mg IV to reduce meningism
- Airway support
- Fluid resuscitation
- LP (do this before IV antibiotics only if they are stable)
Describe the CSF analysis in bacterial, viral + TB meningitis
Bacterial
- Cloudy, turbid appearance
- > 1.5g/L protein (normal 0.2-0.4)
- Low glucose
- Neutrophils ++++
Viral
- Clear appearance
- Normal protein
- Normal glucose
- Lymphocytes ++++
TB
- Cob-web like appearance
- > 1.5g/L protein
- Low glucose
- Lymphocytes ++++
What antibiotic should GPs give for meningitis?
IM benzylpenicillin
What is the blind/empirical therapy for meningitis?
IV ceftriaxone (3rd generation cephalosporin)
If atypical pathogens, add IV amoxicillin
If Listeria spp, add gentamicin
Name some triggers of migraines
CHOCOLATE
Chocolate Hangovers Orgasms Cheese/caffeine Oral contraceptives Lie-ins Alcohol Travel Exercise
Who are migraines more common in?
Women - particularly of reproductive age (potential link with hormones)
How does a migraine present?
Prodromal symptoms
- Hours/days
- Yawning
- Cravings
- Sleep or mood changes
Aura
- Visual
- Somatosensory - paraesthesiae
- Motor - dysarthria, ataxia, hemiparesis
- Speech - dysphasia
Headache
- Unilateral, pulsating headache
- Can wake patient in the night
- Nausea + vomiting (only once or twice)
What is the prophylactic treatment of migraines?
- Propanolol
- Amitryptiline
- 12 weekly botulinum toxin injections in chronic migraines
How do you treat a migraine during an attack?
- Simple analgesic with anti-emetic e.g. paramax = combination preparation
of ibuprofen + prochlorperazine - Triptans = 5-HT1 (serotonin) receptor agonist
When are triptans contraindicated?
IHD Coronary spasm Uncontrolled hypertension Recent lithium SSRIs - can induce serotonin syndrome
What defines episodic and chronic tension headache?
Episodic = <15 days of each month Chronic = >15 days of each month
Describe a tension headache
Bilateral ‘tight band’ headache that comes from neck and shoulders and occurs later in the day
What usually causes a tension headache?
- Stress
- Anxiety/depression
- Poor posture
- Muscle tightness
What is a big risk factor for cluster headaches?
Smoking
Males (5:1)
Describe a cluster headache
Sudden onset of excruciating pain around one eye that lasts 15-180 min
Excessive watering, redness and swelling of the eye
Occurs at the same time each day for about 6-12 weeks
What might you see on examination of a cluster headache?
Ptosis and miosis
What is first line treatment for a cluster headache?
High flow oxygen - 100% O2 for 15min via non-rebreathe mask
Sumatriptan SC (contraindicated in coronary artery disease)
What can be given for prophylaxis of cluster headaches?
Verapamil
Corticosteroids
Lithium
List the red flags for a brain tumour
- Papilloedema
- New seizure
- Headache with cancer/neurofibromatosis/immunodeficiency - Change in consciousness/confusion
- New onset cluster headache
What is the 2nd most common neurodegenerative disorder after Alzheimer’s?
Parkinson’s disease
What is the pathophysiology of Parkinson’s disease?
Loss of dopaminergic neurons in the substantia nigra
What is the extrapyramidal triad of Parkinsonism?
- Tremor - ‘pill-rolling’, 4-6Hz resting tremor
- Hypertonia - cogwheel rigidity during pronation/supination
- Bradykinesia - slow to initiate movement, festinating gait, decreased arm swing, expressionless face
What type of dementia mimics Parkinsonism?
Lewy-body dementia
Name some differential diagnoses for Parkinsonism
- Lewy-body dementia - MMSE
- Multiple system atrophy - would have poor response to levodopa
- Progressive supranuclear palsy
- Benign essential tremor - ask them to draw something
What can cause drug-induced Parkinsonism and how can you tell difference from Parkinson’s disease?
Parkinson’s disease is asymmetrical; drug-induced more likely to be symmetrical
Psychosis tranquilisers
- Phenothiazines
- Thioxanthes
- Butyrophenones
Metoclopramide = anti-emetic
Describe a Parkinsonian gait
Hesitant - difficulty initiating + turning
Shuffling - reduced stride length
Festinating - walks faster and faster to not fall over
Lack of arm swing
Stooped posture
Unsteadiness
What signs would you see on examination of Parkinson’s disease?
- Babinski’s sign
- Hypomimia = mask like face with reduced blinking
- Glabella tap = Myerson’s sign - blinking fails to cease with tapping on forehead
- Quiet voice
- Cogwheel rigidity
- Bradykinesia - slow at opening and closing thumb + forefinger
- Postural hypotension
What investigation can you do to diagnose Parkinson’s disease?
PET scan with fluorodopa to localise dopamine deficiency in basal ganglia
What type of drug are Sinemet and Madopar?
Levodopa = dopamine precursor
With dopa-decarboxylase inhibitor (carbidopa) to prevent peripheral conversion to dopamine which reduces nausea and lowers the dose required
What are some side effects of levodopa? What does this mean in terms of prescribing it?
- Dyskinesia
- Dystonia (painful)
- Psychosis
- Nausea + vomiting
The efficacy reduces over time, which requires much larger doses –> more side effects.
Start levodopa late i.e. over 70 years old or when Parkinson’s seriously affects life
What drugs can be used earlier in life to delay starting levodopa?
- Dopamine agonists e.g. Ropinirole
- Monoamine-oxidase-B inhibitors e.g. rasagiline/selegiline
Why are Ergot-derived dopamine agonists not used as first-line treatment of Parkinson’s?
They can cause fibrotic reactions
What are some side effects of dopamine agonists?
- Compulsive behaviour e.g. gambling, hypersexuality
- Drowsiness
- Nausea
- Hallucinations
Name some inherited congenital myopathies
- Duchenne’s muscular dystrophy - X-linked recessive
- Becker’s muscular dystrophy - X-linked recessive
- Facioscapulohumeral (FSHD) - autosomal dominant
- Myotonic dystrophy - autosomal dominant
What symptoms/signs distinguish myopathy from neuropathy?
Myopathy = gradual onset of symmetrical weakness
- difficulty combing hair or climbing stairs
- preserved tendon reflexes
- no paraesthesia or bladder problems
- no fasciculations
What symptoms distinguish the different types of myopathy?
- Rapid onset = toxic, drug or metabolic myopathy
- Fatigue/increased weakness with exercise = myasthenia
- Spontaneous pain at rest = inflammatory myopathy
- Pain on exercise = metabolic myopathy
- Oddly firm muscles (due to infiltrations with fat/connective tissue) = Duchenne’s muscular dystrophy
Name an inherited metabolic myopathy
- McArdle’s = glycogen storage disorder
What can cause an acquired immunological myopathy?
- Polymyositis
- SLE
- Rheumatoid arthritis
- Polyarteritis noda
- Polymyalgia rheumatica
What kind of gait is seen in proximal myopathy?
Waddling gait = wide-based gait with toe walking. Swaying but symmetrical.
How does Duchenne’s present?
Presents around 4 years old Clumsy walking Difficulty standing Respiratory failure Pseudohypertrophy in calves (deposition of fat and connective tissue)
What are some signs of facioscapulohumeral muscular dystrophy?
- Onset at 12-14 years old
- Weakness of face - can’t puff out cheeks; ‘ironed-out’ expression
- Weak upper limbs
- Foot drop
- Winging of scapula
- Scoliosis
- Anterior axillary folds
- Horizontal clavicles
What bloods should be done in proximal myopathy?
Creatinine kinase - level may be 50-100x normal
Renal function + U&Es
Serum myoglobin
What further investigations can be done for proximal myopathy?
Muscle biopsy
Genetic testing
Electromyography to rule out neurogenic cause
What causes multiple sclerosis?
Autoimmune condition where repeated episodes of inflammation of nervous tissue in the brain and spinal cord lead to loss of the myelin sheath
What virus is multiple sclerosis sometimes linked to?
EBV - antibodies produced by B cells + T cells directed against EBV nuclear antigens may be redirected to attack CNS myelin due to molecular mimicry
Who is more likely to get MS?
Females in their 30s
Caucasians
How does MS usually first present?
Unilateral optic neuritis - pain on eye movement and rapid decrease in central vision
How are the eye movements affected by MS?
- Double vision - weakness of lateral rectus muscle
- Symmetrical horizontal jerking nystagmus
What criteria is used for diagnosing MS?
McDonald criteria
How do you describe the course of MS?
Relapsing-remitting course
Initially there is full recovery between relapses
With time, remission is incomplete so disability accumulates
If MS affects the autonomic system, how would this present?
- Loss of control over bladder
- Faecal incontinence
- Impotence
- Loss of thermoregulation - sweating, pyrexia, hypothermia
What would be seen on an MRI of MS?
- Periventricular lesions
- White matter abnormalities
MRI is sensitive but not specific for plaque detection
What would be found on CSF analysis in MS?
Increased IgG
Increased protein
How do you treat an acute flare of MS?
Prednisolone 500mg/day for 5 days (with omeprazole)
What is used in mild/moderate relapsing-remitting MS?
DMARDs e.g. dimethyl fumarate or monoclonal antibodies (alemtuzumab)
What is transverse myelitis?
Seen in MS
Loss of motor, sensory. autonomic, reflex and sphincter function below the level of a lesion
What is Uhthoff’s phenomenon?
Seen in MS
Worsening of symptoms in the heat e.g. hot bath
What is the acute management of status epilepticus?
Lorazepam, then lorazepam again, then phenytoin
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