Neurology Flashcards
What investigation should be urgently ordered in suspected sub-arachnoid haemorrhage?
Plain CT brain
What are the features of a headache associated with raised ICP?
- Diffuse headache of variable severity
- Often progressive
- Nausea ++
- Worse with increases in ICP (cough, straining, morning)
- Papilloedema (peripheral vision loss)
- Diplopia (6th cranial nerve palsy)
What is Todd’s paresis?
A focal weakness in a part of the body after a seizure
Besides with headache, how many a subarachnoid haemorrhage present?
- Reduced conscious state
- Coma
- Meningism
- Focal neurological signs
What are the main causes of sub-arachnoid haemorrhage?
- Ruptured cerebral aneurysm (70%)
- Ruptured AV malformation (10%)
- Undiscovered (15%)
If a CT is negative in suspected SAH, what test would you do next?
Lumbar puncture - looking for blood in the CSF that does not clear on 3 consecutive tubes
What is xanthochromia?
Yellow staining of the CSF due to breakdown of haemoglobin that occurs 6-8 hours after the SAH
What are the 2 management priorities in SAH?
- Monitor & treat the symptoms & complications of SAH
- Prevent re-bleeding
What investigations can be used to find the source of the bleed in a sub-arachnoid haemorrhage?
- CT angiogram
- MR angiogram
- Digital subtraction angiography
What are the options for treatment of an aneurysm?
- Surgical clipping of the aneurysm neck
- Endovascular coiling
What is normal intracranial pressure?
10-15mmHg
What are the signs of transtentorial herniation?
- Unilateral dilated pupil (3rd nerve palsy)
- Contralateral hemiparesis (midbrain)
- Hypertension/bradycardia (Cushing response)
- Respiratory failure
What is the treatment of raised ICP?
- Elevate head of bed
- Diuresis (mannitol)
- Hyperventilate/avoid hypoventilation
- Sedate/paralyse
- Remove mass
- Drain hydrocephalus
What is a seizure?
Abnormal, hypersynchronous neural activity
What is an ictus?
A sudden neurological event
What is epilepsy?
The tendency to repeated, spontaneous seizures
What are the 3 main generalised seizure types?
- Generalised tonic-clonic
- Absence
- Myoclonic
What are the features of a generalised tonic-clonic seizure?
- Tonic phase: arms down, eyes open, ictal cry
- Clonic phase: initially low amplitude & high frequency, progressing to high amplitude but low frequency movements
- Apnoea may occur
- Generally last 1-5 minutes
- Minor injury is common (tongue biting)
- Aftergoing confusion
What are the features of an absence seizure?
- Alteration of consciousness only
- No loss of postural tone
- No warning
- Facial twitching might occur
- Last 2-10 seconds
- Present almost exclusively in children or teenagers
What are the features of a myoclonic seizure?
- Sudden, involuntary muscle twitch
- Appear as a prodrome to GTCS
What are the features of a focal dyscognitive seizure?
- Localised region
- Affects consciousness
- Similar to absence, but: longer, less distinct offset, automatisms, less frequent, preceding simple seizure
Which is more reliable for distinguishing between GTCS and syncope - tongue-biting or urinary incontinence?
Tongue-biting - more specific to GTCS
Urinary incontinence may occur in both
What are the features of a psychogenic pseudoseizure?
- Fluctuating intensity
- Very long
- Eyes closed
- Non-anatomical tremor
- Reactive
- Consciousness retained (but usually denied)
What % of people who have a had a single seizure have another?
50%
What is the safety advice given to newly diagnosed epileptics?
- Have someone supervising you if swimming
- Do not work at heights
- Take showers not baths
- Alcohol & sleep deprivation can trigger seizures
What is the treatment of acute seizures if they are prolonged or recurrent?
- Seizure termination: benzodiazepines
- Acute prophylaxis: benzodiazepines or phenytoin
Which hand muscles does the median nerve supply?
Opponens pollicis, abductor pollicis brevis, flexor pollicis brevis + lateral 2 lumbricals
Diplopia & ptosis are common in which neuromuscular disease?
Myasthenia gravis
What investigation should be performed for a suspected myopathy?
Muscle biopsy (or MRI)
What test can distinguish neuropathy from myopathy & axonal from demyelinating?
Electrophysiology
Which nerves does motor neurone disease affect?
Both the upper & lower motor neurons
What cognitive impairment is motor neurone disease most commonly associated?
Fronto-Temporal Dementia (FTLD)
What mutation is linked to 10% of cases of motor neuron disease?
SOD1 gene on chromosome 21
What are the clinical features of motor neurone disease?
- Muscle wasting including tongue
- Fasciculations
- Tone: increased or decreased
- Generalised weakness
- Reflexes preserved until late
- Plantars may be upgoing
- NO SENSORY LOSS
- Cranial nerves spared
What is Lambert Eaton Myasthenic Syndrome (LEMS)?
A loss of pre-synaptic neurons due to antibodies against Ca2+ channels
Often associated with small cell lung cancer
What are the clinical features of myasthenia gravis?
- History of fatigueability
- Early involvement of EOM
- Dysarthria
- No muscle wasting
- Weakness increasing with repetitive exercise
- Reflexes & sensation unaffected
What causes myasthenia gravis?
Autoantibodies that cross react with the acetylcholine receptor at the neuromuscular junction
High association with thymic hyperplasia or thymoma
What tests should be ordered in suspected myasthenia gravis?
- Tensilon test
- Bloods - for autoantibodies (ACh receptor, MuSK)
- CT chect (thymoma)
What is the tensilon test?
Transient reversal of symptoms using a short-acting acetylcholinesterase antagonist
What drug is used in the tensilon test?
Edrophonium
What is mononeuritis multiplex?
Neuropathy involving multiple peripheral nerves - a medical emergency (almost always ischaemic)
What are some axonal causes of acute polyneuropathies?
- AMAN, AMSAN
- Glue sniffers neuropathy
- Vasculitis
- Thiamine deficiency
- Porphyria
What are the 4 cardinal features of Parkinson’s disease?
- Tremor
- Bradykinesia
- Rigidity
- Postural instability
What is dyskinesia?
A reversible, Levodopa-induced motor complication
What is dystonia?
Involuntary muscle contraction involving abnormal movements & postures
For which PD symptoms if levodopa most effective at treating?
Hypokinetic motor symptoms, tremor & rigidity
What drug must levodopa be combined with?
A peripheral dopa decarboxylase inhibitor (carbidopa or benserazide)
What are common adverse effects of levodopa?
- Nausea, abdominal cramping, diarrhoea
- Somnolence
- Dizziness & headache
- Confusion, hallucination, delusions, agitation & psychosis
- Orthostatic hypotension
What medications besides L-DOPA are used in Parkinson’s disease?
- COMT inhibitors
- Selective Monoamine Oxidase Type B inhibitors
- Dopamine agonists
- Anticholinergics
- Amantadine
What are the non-motor features common in Parkinson’s disease?
- Orthostatic hypotension
- Urine frequency
- Constipation
