Neurology Flashcards
What is papilloedema?
- swollen optic nerve causing visual disturbances, headaches and nausea - is a ophthalmology emergency
Define Bell’s palsy.
Idiopathic lower motor neurone facial nerve palsy.
What are the risk factors for Bell’s palsy?
o IDIOPATHIC
- however, 60% are preceded by an upper respiratory tract infection -> suggests that it has a viral or post-viral aetiology
What are the presenting symptoms of Bell’s palsy?
Unilateral facial weakness and droop
50% experience facial, neck or ear pain or numbness
Hyperacuisis (due to stapedius paralysis)
Loss of taste (uncommon)
Tearing or drying of exposed eye
- some cases experience prodrome pre-auricular pain
What are the signs of Bell’s palsy on examination?
o Lower motor neurone weakness of facial muscles - affects ipsilateral muscles of facial expression
o Bell’s Phenomenon - eyeball rolls up but the eye remains open when trying to close their eyes
o Despite unilateral facial numbness, clinical testing of sensation is normal
How do upper and lower motor neurone palsy’s of CN 6 differ?
o Lower (Bell’s) does NOT spare the muscles of the upper part of the face unlike upper motor neurone facial nerve palsy
What are the appropriate investigations for Bell’s palsy?
o Usually unnecessary (except for excluding other causes)
- EMG - may show local axonal conduction block
What is the treatment for Bell’s palsy?
o 85-90% make a full recover in 2-12 weeks without treatment
- Protection of cornea with protective glasses/patches or artificial tears
- High-dose corticosteroids is useful within 72 hrs (if Ramsey-Hunt Syndrome is excluded)
- Surgery - lateral tarsorrhaphy (suturing the lateral parts of the eyelids together)
- all eye orientated
What is Ramsey-Hunt syndrome?
An acute peripheral facial neuropathy associated with erythematous vesicular rash of the skin of the ear canal, auricle (also termed herpes zoster oticus), and/or mucous membrane of the oropharynx.
What are the possible complications of Bell’s palsy?
o Corneal ulcers
o Eye infection
o Aberrant reinnervation -> blinking may cause contraction of the angle of the mouth due to aberrant sympathetic innervation of orbicularis oculi and oris
o Crocodile Tears Syndrome - parasympathetic fibres may aberrantly reinnervate the lacrimal glands causing tearing whilst salivating
Define cluster headache.
A neurological disorder characterised by recurrent, severe headaches on one side of the head typically around the eye, tending to recur over a period of several weeks.
What are the risk factors for cluster headaches?
- genetics
- being male
- 20-40 years of age
Define episodic cluster headaches.
Cluster headaches occurring in periods lasting 7 days - 1 year, separated by pain-free periods lasting a month or longer.
Cluster periods usually last between 2 weeks - 3 months.
Define chronic cluster headaches.
Cluster headaches occurring for 1 year without remissions or with short-lived remissions of less than a month.
Chronic cluster headaches can arise de novo or arise from episodic cluster headaches.
Describe the pattern of occurrence of cluster headaches.
o Headaches occur in bouts lasting 6-12 weeks - tend to occur at the same time each year
o Headaches typically occurs at night, 1-2 hours after falling asleep
o The interval between bouts tends to be the same
o 10% with episodic cluster headaches go on to develop chronic cluster headaches
What are the presenting symptoms of cluster headaches?
o Intense, sharp, penetrating pain comes on rapidly over around 10 mins
o Pain is unilateral and centred around the eye, temple or forehead
o Associated autonomic features: ipsilateral lacrimation, rhinorrhoea, nasal congestion, eye lid swelling, facial swelling, flushing, conjunctival injection, partial Horner’s syndrome
o Patients find it difficult to stay still and will pace around, occasionally banging their heads on things
What are the triggers of cluster headaches?
ALCOHOL - major precipitant
Exercise and solvents
Sleep disruption
What are the appropriate investigations for cluster headaches?
CLINICAL diagnosis based on history
Neurological examination may be useful
Define dementia.
A chronic and progressive deterioration of cognitive function due to organic brain disease. It is irreversible and consciousness is not impaired.
What are the 4 types of dementia?
Alzheimer’s disease (50%) - degeneration of the cerebral cortex, with cortical atrophy and reduction in acetylcholine production
Vascular Dementia (25%) - brain damage due to several incidents of cerebrovascular disease (e.g. strokes/TIAs)
Lewy Body Dementia (15%) - deposition of abnormal proteins (Lewy bodies) within the brain stem and neocortex
Frontotemporal Dementia - specific degeneration of the frontal and temporal lobes
Describe Alzheimer’s.
- degeneration of the cerebral cortex, with cortical atrophy and reduction in acetylcholine production
Describe vascular dementia.
- brain damage due to several incidents of cerebrovascular disease (e.g. strokes/TIAs)
Describe Lewy Body dementia.
- deposition of abnormal proteins (Lewy bodies) within the brain stem and neocortex
What are the presenting symptoms of dementia?
- a progressive loss of memory and cognitive function
How does Alzheimer’s present?
- insidious onset of memory and cognitive function decline
How does vascular dementia present?
- step-wise onset of memory and cognitive function decline
How does Lewy Body dementia present?
- fluctuating levels of consciousness, hallucinations, falls and Parkinsonian symptoms along with memory and cognitive decline
How does frontotemporal dementia present?
- behavioural changes and intellectual changes along with memory and cognitive decline
What are the appropriate investigations for dementia?
Diagnosis is based on the HISTORY
- ensure no treatable cause is missed (e.g. hypothyroidism, vitamin B12/folate deficiency, space-occupying lesion, normal pressure hydrocephalus)
Define Guillain-Barre syndrome.
Acute inflammatory demyelinating polyneuropathy.
What is the risk factors for Guillain-Barre syndrome?
o An inflammatory process where antibodies after a recent infection react with self-antigen on myelin or neurons
o 40% of cases are idiopathic
Other causes: malignancy (e.g. lymphoma) or post-vaccination
What are the presenting symptoms of Guillain-Barre syndrome?
o Progressive symptoms of ascending symmetrical limb weakness and ascending paraesthesia
o Cranial nerve involvement (dysphagia, dysarthria, facial weakness)
o Respiratory muscles may be affected in SEVERE cases
o Miller-Fisher Variant (RARE) = ophthalmoplegia, ataxia, arreflexia
What are the signs of Guillain-Barre syndrome on examination?
o General motor examination = hypotonia, flaccid paralysis, arreflexia (ascending upwards from feet to head)
o General sensory examination = impairment of sensation in multiple modalities (ascending from feet to head)
o Cranial nerve palsies = facial nerve weakness, abnormality of external ocular movements, if pupil constriction is affected consider botulism
o Type II respiratory failure = due to paralysis of respiratory muscles
o Autonomic function = assess postural blood pressure change and arrhythmias
What are the appropriate investigations for Guillain-Barre syndrome?
o Lumbar puncture = high protein with normal cell count and glucose
o Nerve conduction study = reduced conduction velocity
o Bloods = anti-ganglioside antibodies in Miller-Fisher variant + 25% of Guillain-Barre cases
o Spirometry = reduced fixed vital capacity - suggests ventilatory weakness
o ECG = arrhythmias may develop
Define Horner’s syndrome.
A condition that results from the disruption of the sympathetic nerves supplying the face resulting in a triad of:
Ptosis
Miosis
Anhydrosis
What are the causes of Horner’s syndrome?
Caused by disruption of the sympathetic nerves
- Strokes
- Multiple sclerosis
- Apical lung tumours
- Lymphadenopathy
- Basal skull tumours
- Carotid artery dissection
- Neck trauma
What are the presenting symptoms of Horner’s syndrome?
Inability to open the eye fully on the affected side
Loss of sweating on affected side
Facial flushing
Orbital pain/headache
Other symptoms based on cause
What are the signs of Horner’s syndrome on examination?
Ptosis
Miosis
Anhydrosis
Enophthalmos
What are the appropriate investigations for Horner’s syndrome?
Investigations are directed towards figuring out the underlying cause
CXR - apical lung tumour
CT/MRI - cerebrovascular accidents
CT angiography - dissection
What is the treatment for Horner’s syndrome?
Horner’s syndrome is a sign not a disease in itself
So, the management depends on the cause (e.g. management for carotid dissection is very different to management of apical lung tumours)
Define Huntington’s disease.
Autosomal dominant trinucleotide repeat disease characterised by progressive chorea and dementia, typically commencing in middle age.
What are the presenting symptoms of Huntington’s disease?
o FAMILY HISTORY
o Insidious onset in middle-age
o Progressive
o Fidgeting
o Clumsiness
o Involuntary, jerky, dyskinetic movements often accompanied by grunting and dysarthria
o Early cognitive changes = lability, dysphoria (a state of unease or generalised dissatisfaction with life), mental inflexibility, anxiety, develops into dementia
o Later stages = rigid, akinetic, bed-bound
o Enquire about drug history (especially cocaine and anti-psychotics)
What are the signs of Hungtinton’s disease on examination?
Chorea
Dysarthria
Slow voluntary saccades
Supranuclear gaze restriction
Parkinsonism
Dystonia
MMSE shows cognitive and emotional deficits
What are the appropropriate investigations for Huntington’s disease?
o Genetic analysis = diagnostic if there are > 39 CAG repeats in the HD gene and reduced penetrance leads to an intermediate number of CAG repeats
o Imaging = brain MRI or CT may show symmetrical atrophy of the striatum and butterfly dilation of the lateral ventricles
o Bloods = exclude other pathology
Define hydrocephalus.
Enlargement of the cerebral ventricular system.
- can be subdivided into obstructive and non-obstructive (aka communicating and non-communicating)
Define hydrocephalus ex vacuo.
Apparent enlargement of the ventricles as a compensatory change due to brain atrophy.
Describe the distribution of people who suffer from hydrocephalus.
YOUNG - congenital malformations and brain tumours
ELDERLY - strokes and tumours
What are the presenting symptoms of obstructive hydrocephalus?
Acute drop in conscious level
Diplopia/double vision
What are the presenting symptoms of normal pressure hydrocephalus?
Dementia
Gait disturbance
Urinary incontinence
What are the signs of obstructive hydrocephalus on examination?
o Low GCS
o Papilloedema
o 6th nerve palsy (longest CN so most susceptible to raised ICP)
o NEONATES - increased head circumference and sunset sign (downward conjugate deviation of the eyes)
What are the signs of normal pressure hydrocephalus on examination?
Cognitive impairment
Gait apraxia (shuffling)
Hyperreflexia
What are the appropriate investigations for hydrocephalus?
o CT Head = FIRST-LINE for detecting hydrocephalus -> may also pick up the cause (e.g. tumour)
o CSF/Ventricular drain/Lumbar puncture - may indicate pathology (e.g. tuberculosis),check MC&S, protein and glucose
- lumbar puncture -> contraindicated if raised ICP and therapeutic in normal pressure hydrocephalus