neuro SBAs Flashcards
Immediate Rx in meningococcal septicaemia (fever, headache, non-blanching rash, neck stiffness)
Immediate IV ceftriaxone or cefotaxime
then lumbar puncture if no signs of raised ICP
Wernicke’s encephalopathy (acute/subacute delirium) causes
Vit B12 deficiency
Thiamine deficiency
Secondary to alcohol
Wernicke’s encephalopathy clinical triad
- encephalopathy
- ocular dysfunction (nystagmus)
- ataxia
±apathy, disorientation, disturbed memory. Treat urgently with thiamine or it may progress to Korsakoff’s psychosis.
Expressive dysphasia affects
Broca’s area
cortical area i.e. not internal capsule
Receptive dysphasia affects
Wernicke’s area
Anti-ganglioside antibodies present in…
Guillain-Barre syndrome
miller-fisher variant
Miller-Fisher variant of GBS (rare) clinical triad
Opthalmoplegia
Ataxia
Arreflexia
Three weeks following an illness which caused crampy abdominal pains, vomiting and diarrhoea a 26 year old presented with progressive bilateral leg weakness. Knee jerks and ankle jerks were both reduced on examination. What is the diagnosis?
Guillain-Barre syndrome (a demyelinating polyneuropathy)
Most have prior influenza-like illness or gastroenteritis.
Beware of resp muscle weakness
AST and ALT may be elevated LP = high CSF protein with normal cell count (known as albuminocytological dissociation)
Pick’s disease is also known as
Frontotemporal lobe dementia
Down’s syndrome is associated with which type of dementia
Alzheimer’s
Brown-Sequard syndrome definition
Hemi-section of the cord. Results in ipsilateral paralysis of limbs, loss of light touch and vibration sensation, contralateral loss in pain and temperature below the point of the lesion (spinothalamic tracts cross at level of cord). C3,4,5 (phrenic nerve) innervates diaphragm so lesions below this will preserve it.
Signs of increased ICP
Papilloedema
N+V
Meningism (e.g. nuchal rigidity)
Painless, unilateral visual loss of short duration described as a ‘black curtain descending’ is called…
Amaurosis fugax
Acute eye pain with blurred vision “see haloes around things”. Older patients
What is the likely diagnosis
Closed/acute angle glaucoma
Extradural haemorrhage
Fractural temporal/parietal bone damaging middle meningeal artery and occurs post-severe trauma. Lucid interval before presentations. Lens shaped
50 year old complains of slowly worsening weakness in his L leg. Started gradually 3 months ago, now making him limp. Examination reveals increased tone, brisk reflexes and weakness in L leg. What is the likely diagnosis?
Recognise these as UMN signs.
R sided brain tumour
It is slowly progressive, so a slowly growing brain tumour is likely (strokes start suddenly)
Examination of the lower limbs reveals wasting of the muscles of the left calf with arreflexia on that side. What is the likely diagnosis?
LMN problems unilaterally so the problem is pressure on a nerve below the cauda equina or damage to the spine/nerve roots.
A patient complains of a tremor when he smokes cigarettes. What is the likely cause if the tremor gets worse when he puts the cigarette into his mouth. What is the likely cause?
This is typical of the ataxia with cerebellar disease, with the past pointing getting worse as you approach the target (either nose, or in this case the mouth)
A 15 month old toddler developed a maculo-papular rash 10 days after receiving the MMR vaccine, followed by a swelling at the angle of the left jaw. His mother phoned the surgery in a state of panic one morning because he is confused, having convulsions and has a high temperature. What is the likely diagnosis?
Encephalitis - altered state of consciousness, fever, headache, seizures ± focal neurology. Rx: IV acyclovir as most are caused by HSV.
(Vesicular patterns are seen in VZV, HSV and enteroviruses; EBV is maculopapular after ampicillin; Lyme disease has erythema migrans; TB has erythema nodosum)
A 35 year old woman has suddenly developed facial palsy. 6 months before this, she had an episode of blurred vision + unsteadiness. On examination, she has mild ataxia and an afferent pupillary defect.
MS is a demyelinating CNS condition which is characterised by 2 or more episodes of neurological dysfunction which are separated in both time and space. This person has had blurred vision and now 6 months later has developed facial palsy. RAPD is present.
A 70 year old man has suddenly developed facial weakness, which was preceded by 2 days of severe left ear pain, vertigo + deafness. On examination, he has red vesicles in his ear canal and on the hard palate. What is the likely diagnosis?
Ramsay Hunt syndrome = reactivation of VZV with CNVII palsy.
There is ear pain and erythematous vesicular rash in ear canal + hard palate. CN8 palsy = vertigo and hearing loss. Rx: acyclovir.
A 45 year old man who is had a SAH 2 months ago was prescribed an anti-convulsant to reduce the risk of seizure and continued to take it. He has now become increasingly confused, lethargic + ataxic. O/E nystagmus, an intention tremor, past-pointing. What is the likely diagnosis?
Phenytoin toxicity - unpredictable pharmacokinetic behaviour with narrow therapeutic range.
Symptoms: nystagmus, confusion, headache, ataxia and vertigo. Chronic use: gum hyperplasia.
A 45 year old type 1 diabetic patient presents with a history of feeling light headed. On examination, he is noted to have a blood pressure of 150/90 lying + 125/70 on standing. What is the likely diagnosis?
This patient has postural hypotension from diabetic autonomic neuropathy. Other symptoms: resting tachycardia, impaired HR variation, erectile dysfunction, decreased libido, dyspareunia, constipation, sweating dysfunction, urinary LUTS symptoms. Rx: fludrocortisone
A 73 year old male presents with difficulty ascending stairs. O/E: weakness of knee flexion, more on the left with some wasting of quadriceps and diminished knee reflexes. He has T2DM. What is the likely diagnosis?
Diabetic amyotrophy, more common in T2DM, is an uncommon peripheral diabetic neuropathic complaint.
It presents with severe muscle weakness and pain with proximal thigh muscle atrophy. The weak knee flexion and quadriceps wasting is typical. Reduced reflexes = peripheral neuropathy.
A 62 year old male diabetic presents with a sudden onset of double vision. He has ptosis and a deviation of the right eye down and right. The pupils are equal in size and are reactive to light. What is the likely diagnosis?
A complete (or surgical) CN3 palsy = compete ptosis, a dilated pupil, eye down and out. Causes: PCA aneurysm.
A partial (medical) pupil-sparing CN3 palsy = partial ptosis without pupillary signs. Causes: infarction of the nerve i.e. mononeuritis multiplex due to DM or vasculitis like GCA.
parasympathetic nerve compressed in surgical complete so pupil dilates
Testing loss of consciousness
24 ECG/holter monitor
Treatment for unconscious diabetic man with capillary blood glucose of 1.5mmol/L
IV dextrose
Hydrocephalus (enlargement of cerebral ventricular system) leads to abnormal accumulation of CSF in the ventricles. The two types are…
Obstructive - impaired outflow of CSF from ventricles e.g. lesions of 3rd ventricle or posterior fossa, cerebral aqueduct stenosis
Non-obstructive - impaired reabsorption into subarachnoid villi e.g. in tumours, meningitis, NPH
Obstructive hydrocephalus (impaired CSF outflow) signs and symptoms
Acute impaired GCS Diplopia CN6 palsy (increased ICP signs) Papilloedema Neonates have enlarged head circumference
Normal pressure hydrocephalus is an example of non-obstructive hydrocephalus. There is idiopathic chronic ventricular enlargement. Signs and symptoms include
Chronic cognitive decline Falls Urinary incontinence Gait apraxia (shuffling) Hyper-reflexia
Stroke anterior circulation lesions
Anterior cerebral - lower limbs, confusion
Middle cerebral - facial weakness, hemiparesis, hemisensory loss, dysphasia
Stroke small vessel (lacunar) lesions
Internal capsule/pons - pure sensory or motor deficit
Thalamus - LOC, hemisensory loss
Basal ganglia - hemichorea, parkinsonism
Stroke multiple lacunar infarct lesions presents with
Vascular dementia
Urinary incontinence
Gait apraxia
