Neurology- core conditions Flashcards
Parkinsons disease
Caused by the loss of dopaminergic neurones in the substantia nigra of the basal ganglia. The basal ganglia is essential for coordinating movement
Symptoms of parkinsons disease
• Bradykinesia- slow movement
• Tremor- rest, postural
• Rigiditity- cog wheeling, lead pipe
• Postural instability- late feature
• Early features- loss of sense of smell, REM sleep behaviour disorder, constipation, depression and anxiety
• Late complications- bladder and blood pressure problems, pyschosis and dementia
Differentials for Parkinsons disease
• Essential tremor
• Drug induced parkinsonism
• Dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration
• Alzheimer’s and multiple cerebral infarctions
Clinical examination- Parkinsonian gait
• Stooped posture
• Forward flexion of the trunk and the knees
• Arms flexed at the elbows and wrists
• Known as shuffling gait due to small and fast steps
• Difficulty initiating turning around
Clinical examination- Parkinsonian tremor
• Resting tremor
• Pill rolling, looks like the patient is trying to roll a pill between their thumb and index finger
• 4-6Hz
• Asymmetrical, worse at rest
• Improves with movement
• No change with alcohol
Clinical diagnostic criteria
Step 1- diagnosis of Parkinsonian syndrome
• Bradykinesia
• At least one of muscle rigidity, resting tremor, postural instability
Clinical diagnostic criteria
Step 2- exclusion criteria for Parkinsons disease
• History of strokes/ head injury/ encephalitis
• Oculogyric crisis
• Neuroleptic treatment at onset of symptoms
• Sustained remission
• Cerebrallar signs
• Cerebral tumour
Clinical diagnostic criteria
Step 3- supportive positive criteria for Parkinsons disease
• Three or more are required alongside step one
• Unilateral onset
• Resting tremor present
• Disease is progressive
• Good response to levodopa
Parkinsons- investigations
DAT scan- less dye is taken up. Reduced uptake in the substantia nigra, particularly in the posterior part of the putamen. Motor symptoms begin in stage 4
MRI/CT- to rule out other things
Bedside- physical examination, anosmia testing
Bloods
Management plan- Parkinsons
First line treatment- levodopa. Addition of a dopamine agonist/ MAO-B inhibitor as an adjunct if motor symptoms are not controlled
Supportive therapies- include physiotherapy/ occupational therapy/ speech and language therapy/ diet advice
Can give deep brain stimulation
Levodopa
Usually combined with carbidopa to prolong action (peripheral inhibitor of dopamine metabolism). Side effects include dyskinesia when doses are high, impulsive behaviour, NV, loss of appetite, hypotension. Becomes less effective over time
Dyskinesia with levodopa (defenitions)
• Excessive motor activity when the dose is too high
• Dystonia - excessive muscle contraction leading to abnormal postures and movements
• Chorea - abnormal involuntary movements that are jerky and random
• Athetoid - involuntary twisting or writhing movements typically of the fingers / feet / hands
Dopamine agonists
• Stimulate dopamine receptors in the basal ganglia
• Side effects include pulmonary fibrosis / dizziness / drowsiness / tachycardia / dry mouth / NV / memory, concentration and confusion problems
• Usually used to delay the use of levodopa and then used in combination with levodopa to reduce the dose needed
• They increase impulsivity, shows as disinhibited behaviours i.e. gambling and hypersexuality
• E.g. pramipexole, ropinirole, bromocriptine
Monoamine oxidase B inhibitors
• These block the affects of monoamine oxidase B (an enzyme which breaks down dopamine)
• Used to delay the use of levodopa and used to reduce the required dose
• For example, Selegiline, Rasagiline
COMT inhibitors
• COMT metabolises levodopa, the inhibitors slow this down and extends the effect of levodopa
• For example, Tolcapone, entacapone
Multiple system atrophy
• Progressive degeneration of the neurones in multiple brain areas e.g. basal ganglia, cerebellum, autonomic and peripheral nervous system
• Basal ganglia degeneration leads to parkinsonian presentation but there are also other symptoms e.g. a lot of autonomic dysfunction causing hypotension/incontinence/impotence/sexual dysfunction etc
• Also profound cerebellar dysfunction
• Parkinsons with autonomic disturbance e.g. atomic bladder/postural hypotension points towards MSA
Progressive supranuclear palsy
• Rapidly progressive neurological disease characterised by accumulation of tau protein in basal ganglia, brainstem, prefrontal cortex, and cerebellum
• Symptoms include difficulty moving eyes, mood changes, dysphagia, backwards falls, slurred speech, memory loss, apraxia, resting tremor
• Involves psudeobulbar palsy (dysarthria and dysphagia)
• Bradykinesia, Backwards falls, Slow vertical saccades, Loss of a vertical gaze
Dementia with Lewy bodies
• Dementia associated with features of Parkinson’s disease - the parkinsonian features develop after the memory loss
• Other features = visual hallucinations / delusions / disorders of REM sleep / fluctuating consciousness
Neuroleptic malgnant syndrome
Life threatening muscle rigidity, fever and rhabdomyolysis in response to antipsychotics
Stroke
A clinical syndrome of presumed vascular origin characterised by rapidly developing signs of focal or global disturbance of cerebral functions which lasts longer than 24 hours or leads to death.
Types of stroke- Haemorrhagic (15%), Ischaemic (85%)
Types of stroke
Ischaemic- due to occlusion of arteries of cerebral circulation, normally due to an embolism as a result of atrial fibrillation
Haemorrhagic- a collection of blood from a blood vessel rupture.
Stroke risk factors (conditions)
• Ischaemic heart disease
• Peripheral arterial disease
• Carotid atherosclerosis -> carotid stenosis
• TIA
• Vascular heart disease and heart failure
• Clotting disorders
• Atrial fibrillation
Stroke symptoms
• Sudden onset
• F- face may have drooped to one side
• A- weakness or numbness in one arm
• S- speech may be slurred or cant speak
• T- call 999 immediately
Diagnosing a stroke
Diagnose with ROSIER score
Exclude hypoglycaemia in people with sudden onset neurological symptoms as the cause
