Neurology Flashcards
What is an acoustic neuroma?
benign tumours of the Schwann cells surrounding the auditory nerve (vestibulocochlear nerve) that innervates the inner ear.
Symptoms of acoustic neuroma
o Patient usually 40-60 yo o Vertigo (CNVIII) o Hearing loss – unilateral sensorineural hearing loss (CNVIII) o Tinnitus – unilateral (CNVIII) o Absent corneal reflex (CNV) o Facial palsy (CNVII) – if the tumour grows large enough to compress the facial nerve (NO FOREHEAD SPARING = LMN lesion) o Dizziness / imbalance o Sense of fullness in the ear
Are acoustic neuromas unilateral or bilateral?
- Usually, unilateral
- Bilateral vestibular schwannomas = neurofibromatosis type 2
What CNs are affected by acoustic neuromas?
cranial nerves V, VII and VIII
trigeminal, facial and vestibulocochlear
IX for acoustic neuroma
- Audiometry: to assess hearing loss (sensorineural pattern)
- Auditory brainstem reflexes: results will be abnormal
- Brain CT/MRI: diagnosis of tumour
Mx for acoustic neuroma and risks with the treatment
- URGENT ENT REFERRAL
- ENT management:
o Conservative – monitoring if there are no symptoms
o Surgery – to remove tumour
o Radiotherapy – to reduce tumour growth - Risks with treatment:
o Vestibulocochlear nerve injury – permanent hearing loss or dizziness
o Facial nerve injury – facial weakness
Other names for acoustic neuroma
Vestibular schwannoma
Cerebellopontine angle tumours
What is Bell’s palsy?
an acute unilateral facial nerve weakness or paralysis of rapid onset (less than 72 hours) and unknown cause.
The history and examination otherwise are unremarkable. Deficits in all facial zones equally that fully evolve within 72 hours.
Cause of Bell’s palsy
Idiopathic
Symptoms of bells palsy
- Single episode
- Unilateral lower motor neurone facial nerve palsy – involves upper and lower parts of the face
o Reduction in movement on the affected side
o Drooping of eyebrow and corner of mouth
o Loss of nasolabial fold - Rapid onset (less than 72 hours)
- Ear and postauricular region pain
- Difficulty chewing, dry mouth and change in taste
- Incomplete eye closure, dry eye, eye pain or excessive tearing
- Numbness / tingling in cheek + mouth
- Speech articulation problems, drooling
- Hyperacusis
- 3-6 months later – synkinesis (abnormal & involuntary synchronous movement of a facial region with reflex or voluntary movement in another facial region)
Diagnosis of bells palsy
clinical diagnosis of exclusion
Mx for bells palsy
• If patient presents within 72 hours of symptom onset = PREDNISOLONE:
o 60mg OD for 5 days, then reduce by 10mg daily
• Eye protection
o Lubricating eye drops
o Tape eye shut at night
o Sunglasses outdoors
• Antivirals (with prednisolone) may offer small benefit, discuss with specialist
Complications of bells palsy
- Exposure keratopathy – eye pain, requires ophthalmology review
- Eye injury, corneal ulceration, vision loss
- Synkinesis – abnormal facial muscle contraction during voluntary movements
Recovery from bells palsy
- Most patients fully recover over several weeks, can take 12 months to recover
- 1/3rd are left with some residual weakness
- Refer to a facial nerve specialist if there is no improvement after 3 weeks of treatment, there’s incomplete recovery 5 months after initial onset or there are any atypical features.
What is a brain abscess?
a suppurative collection of microbes (most often bacterial, fungal or parasitic) within a gliotic capsule occurring within the brain parenchyma. Lesions can be single or multi-focal.
It is potentially life threatening
Causes of brain abscesses
- Bacterial: strep pyogenes, strep milleri, staph aureus
- Fungal: aspergillus fumigates, candida albicans, cryptococcus neoformans
- Parasitic: toxoplasma gondii
How do brain abscesses happen?
- Haematogenous spread through bloodstream
- From an infected adjacent area e.g., ears or sinuses
Risk factors for brain abscess
- Sinusitis
- Otitis media
- Recent dental procedure or infection
- Recent neurosurgery
- Skull fracture
- Meningitis
- Congenital heart disease
- Endocarditis
- DM
- HIV or immunocompromised
- IVDU
Symptoms of brain abscess
- Seizures
- Fever
- Localising signs
- Signs of increased ICP
- Signs of infection elsewhere
Ix for brain abscess
- CT/MRI = ring enhancing lesion
- Raised WCC
- Raised ESR
Mx for brain abscess
- Neurosurgery referral
- Antibiotics: CEFTRIAXONE
- Treat raised ICP
Common cancers that metastasise to the brain
Lung
Breast
Renal cell carcinoma
Melanoma
Symptoms of brain mets
- Increased ICP o Headache worse on waking, lying down, bending forwards, coughing and straining o Vomiting o Papilloedema o Reduced GCS - Seizures - Evolving focal - Subtle personality change
Ix for brain mets
- CT/MRI brain
- Consider biopsy
What is cerebral palsy?
umbrella term referring to a non-progressive disease of the brain originating during the antenatal, neonatal or early post-natal period while brain neuronal connections are still evolving, that results in disorders of movement and posture development.
Prevalence of cerebral palsy
2 in 1000
Impairments seen in cerebral palsy
- Disorders of movement
- Disorders of posture
- Learning impairment
- Visual impairment and squint
- Hearing loss
- Speech and language difficulties
- Behavioural problems
- Epilepsy
Presentation of cerebral palsy
- Delayed motor milestones
- Abnormal tone in infancy
- Persistence of primitive reflexes
- Abnormal gait
- Feeding difficulties
- Other developmental delays e.g., language and social
What are the primitive reflexes
Moro's (startle) reflex Rooting reflex Sucking reflex Tonic neck reflex Grasping reflex Stepping reflex
Causes of cerebral palsy
• Antenatal (80%)
o Cerebral malformation
o Cerebral dysgenesis
o Congenital infection
• Intrapartum (10%)
o Hypoxic-ischaemic encephalopathy (birth asphyxia)
• Post-natal (10%) o Cerebral ischaemia o Intraventricular haemorrhage o Head trauma o Hydrocephalus o Non-accidental head injury o Hyperbilirubinaemia (severe neonatal)
What are the 3 types of cerebral palsy?
Spastic
Ataxic hypotonic
Dyskinetic
Ix for cerebral palsy
- Brain imaging – USS in neonates, CT or MRI
- Congenital infection screen
- Metabolic screen
Mx of cerebral palsy
MDT
What is hypoxic-ischaemic encephalopathy?
- Seen in neonates.
- Ischaemic damage to the brain causes a disturbance of neurological behaviour
- Areas most affected are the ‘watershed zones’ between the major arteries as they’re most susceptible to hypoperfusion.
How is hypoxic-ischaemic encephalopathy classified
mild (resolves over a few days)
moderate
severe (50% of mortality and 80% risk of cerebral palsy)
Symptoms of HIE
floppy after birth, seizures, irregular breathing, hypertonic
Ix for HIE
APGAR score fetal umbilical artery pH <7 arterial base deficit >12 MRI brain EEG presence of multisystemic organ failure
Tx of HIE
therapeutic hypothermia (33-35°C for 72 hrs within first 6hrs of life) and supportive measures
What is chronic fatigue syndrome?
4 months + of disabling fatigue affecting mental and physical function more than 50% of the time in the absence of other disease which may explain the symptoms.
risk factors for chronic fatigue syndrome
Female
Past psychiatric history
Symptoms of chronic fatigue syndrome
- Fatigue
- Sleep problems
- Muscle/joint pain
- Headaches
- Painful lymph nodes without enlargement
- Sore throat
- Cognitive dysfunction
- Physical or mental exertion makes symptoms worse
- General malaise
- Dizziness
- Nausea
- Palpitations
Ix for chronic fatigue syndrome
• Screening blood tests to exclude other pathology o FBC o U&E o LFT o Glucose o TFT o ESR o CRP o Calcium o CK o Ferritin o Coeliac screen o Urinalysis
Mx for chronic fatigue syndrome
- CBT
- Graded exercise therapy
- Pacing
- Low dose amitriptyline
- Referral to pain management clinic
What is CNI, its function and foramen?
Olfactory
smell
Cribriform plate
What is CNII, its function and foramen?
Optic
Sight
OPtic canal
What is CNIII and its function
Oculomotor
Eye movements = superior, inferior and medial rectus & inferior oblique
Pupil constriction
Accommodation
Eyelid opening
What happens in CNIII palsy?
Palsy results in
- Ptosis
- Down and out eye
- Dilated fixed pupil
CNIII foramen
Superior orbital fissure
Causes of CNIII palsy
o DM
o Vasculitis e.g., temporal arteritis, SLE
o False localising sign due to uncal herniation through tentorium if raised ICP
o Posterior communicating artery aneurysm: pupil dilated + pain
o Cavernous sinus thrombus
o Weber’s syndrome – ipsilateral third nerve palsy with contralateral hemiplegia, caused by midbrain strokes
o Amyloid
o MS
CNIV name, function, palsy symptoms and foramen
Eye movement (Superior oblique)
Palsy = defective downward gaze = vertical diplopia
Superior orbital fissure
What is CNV, its function and 3 foramen?
Trigeminal
facial sensation and mastication
V1 = superior orbital fissure V2 = foramen rotundum V3 = foramen ovale
What happens in CNV lesions?
Lesions =
- Trigeminal neuralgia
- Loss of corneal reflex (afferent)
- Loss of facial sensation
- Paralysis of mastication
- Deviation of jaw to weak side
What is CNVI, its function, symptoms of palsy and foramen?
VI = abducens
Eye movement
- Lateral rectus
Palsy = defective abduction = horizontal diplopia
Superior orbital fissure
What is CNVII, its function, symptoms of palsy and foramen?
VII = facial
Facial movement
Taste anterior 2/3rds
Lacrimation
Salivation
- Flaccid paralysis of the upper and lower face
- Loss of corneal reflex (efferent)
- Loss of taste
- Hyperacusis
Internal auditory meatus
What is CNVIII, its function, symptoms of palsy and foramen?
VIII = vestibulocochlear
Hearing
Balance
Hearing loss
Vertigo
Nystagmus
Acoustic neuroma
Internal auditory meatus
What is CNIX, its function, symptoms of palsy and foramen?
IX = glossopharyngeal
Taste (posterior 1/3rd)
Salivation
Swallowing
Mediated input from carotid body & sinus
Hypersensitive carotid sinus reflex
Loss of gag reflex (afferent)
Jugular foramen
What is CNX, its function, symptoms of palsy and foramen?
X = vagus
Phonation
Swallowing
Innervates viscera
Uvula deviates away from site of lesion
Loss of gag reflex (efferent)
Jugular foramen
What is CNXI, its function, symptoms of palsy and foramen?
XI – accessory
Head and shoulder movement
Weakness turning head to contralateral side
Jugular foramen
What is CNXII, its function, symptoms of palsy and foramen?
XII – hypoglossal
Tongue movement
Tongue deviates towards side of lesion
Hypoglossal canal
Afferent and efferent limb of corneal reflex
Ophthalmic nerve (V1) Facial nerve
Afferent and efferent limb of jaw jerk
Mandibular nerve
Mandibular nerve
Afferent and efferent limb of gag reflex
glossopharyngeal nerve
Vagal nerve
Afferent and efferent limb of carotid sinus reflex
Glossopharyngeal nerve
Vagal nerve
Afferent and efferent limb of pupillary light reflex
Optic nerve
Oculomotor nerve
Afferent and efferent limb of lacrimation reflex
Ophthalmic nerve (v1) Facial nerve
What is dementia
a syndrome characterised by deterioration in cognition resulting in impairment in the activities of daily living. Cognitive decline often affects multiple domains.
Memory screening tools
o 10 point cognitive screener o 6 item cognitive impairment test o Abbreviated mental test score o GP assessment of cognition o Mini mental state examination (MMSE score <24 = dementia)
Bloods for impaired memory
o FBC o U&E o LFT o Calcium o Glucose o ESR/CRP o TFTs o Vitamin B12 o Folate
causes of dementia
- Alzheimer’s disease
- CVS – multi infarct dementia
- Lewy bpdy dementia
- Huntington’s
- CJD
- Pick’s disease – atrophy of frontal and temporal lobes
- HIV
Symptoms of Alzheimer’s disease
Progressive persistent global cognitive impairment. Short term memory impairment.
Irritable, behaviour/mood change. Apathy.
causes of Alzheimer’s disease
Unknown
Risk factors for Alzheimer’s disease
amyloid precursor protein gene mutations and old age
Ix for Alzheimer’s disease
MMSE
CT head
Pathology of Alzheimer’s disease
Accumulation of B-amyloid peptide that results in progressive neuronal damage, neurofibrillary tangles, amyloid plaques and loss of ACh
Tx for Alzheimer’s disease
Acetylcholinesterase inhibitors e.g. donepezil, rivastigmine, galantamine.
NMDA antagonist = memantine
Symptoms of vascular dementia
Sudden onset and stepwise deterioration
Cognitive impairment, motor disorders and changes in behaviour.
Cause of vascular dementia
Cumulative effect of many small strokes.
RFs for vascular dementia
HTN, DM, hyperlipidaemia, old age, TIA, AF, smoking, obesity, CAD
Ix for vascular dementia
MMSE
US of carotids
Cranial MRI – infarcts and extensive white matter changes
Mx for vascular dementia
There’s damage to grey and white matter from vascular causes
Tx for vascular dementia
Treat risk factors.
Antiplatelet therapy e.g. aspirin to prevent strokes/TIA
There is often co-morbid Alzheimer’s so then give a cholinesterase inhibitor
What are the 3 main subtypes of vascular dementia?
3 main subtypes:
- Stroke related VD
- Subcortical VD (small vessel disease)
- Mixed dementia – VD + alzheimer’s
Symptoms of frontotemporal dementia
Onset in middle age, before 65 yo.
Slow onset
Inappropriate social behaviour and motor deficits/akinetic Parkinsonism in later stages.
Relatively preserved memory.
types of frontotemporal dementia
- Pick’s disease
- Chronic progressive aphasia (CPA) – non fluent speech
- Semantic dementia – fluent progressive aphasia
cause of frontotemporal dementia
Genetic component
ix for frontotemporal dementia
MMSE
CT/MRI
pathology of frontotemporal dementia
Atrophy of frontal and temporal lobes. Pick bodies (cytoplasmic inclusions of aggregated tau proteins – silver staining). Associated w Pick’s disease
tx for frontotemporal dementia
Cholinesterase inhibitors and memantine are usually not effective & can worsen symptoms.
Give SSRIs for depression
Give olanzapine for agitation, hallucinations, insomnia
symptoms of lewy body dementia
Dementia with extrapyramidal / Parkinson’s motor symptoms, visual hallucinations, falls, rapid eye movement sleep behaviour disorder
Cognition may be fluctuating – in contrast to other forms of dementia
ix for lewy body dementia
SPECT (called a DaTscan)– decreased occipital perfusion / metabolism
Clinical diagnosis
pathology of lewy body dementia
Cerebral atrophy.
Lewy bodies = alpha-synuclein-positive cytoplasmic inclusions in neurones which cause neuronal degeneration
mx for lewy body dementia
Can treat Parkinsonian symptoms with Parkinson’s drugs
Acetylcholinesterase inhibitors (donepezil) and memantine can be used
Avoid antipsychotics – can develop irreversible parkinson’s
important differentials for dementia that are possibly treatable
- Hypothyroidism
- Addison’s
- B12/folate/thiamine deficiency
- Syphilis
- Brain tumour
- Normal pressure hydrocephalus
- Subdural haematoma
- Depression
- Chronic drug use e.g., alcohol, barbiturates
how do cholinesterase inhibitors work and what are they used for?
- Reversible cholinesterase inhibition leads to increased Ach concentration = improves dementia symptoms
- 1st line = Alzheimer’s dementia (mild-moderate) & vascular dementia
- Can be used in some cases of Lewy body dementia, frontotemporal dementia and Parkinson’s disease
example cholinesterase inhibitors
donepezil, rivastigmine, galantamine
side effects of cholinesterase inhibitors
nausea, dizziness, insomnia, cholinergic crisis
when is donepezil CI
relatively CI in patients with bradycardia
What is memantine and when is it used?
- Used in moderate to advanced Alzheimer’s disease & vascular dementia
- Can be used in combination with cholinesterase inhibitors
- An NMDA antagonist = results in decreased glutamate-induced calcium-mediated excitotoxicity