Neurology Flashcards
1
Q
features of 3rd nerve palsy
A
Parasympathetic fibres on outside of nerve
Over apex of petrous part of temporal bone
Fixed dilated pupil
2
Q
5 key landmarks on the base of the skull/ posterior fossa
A
Petrous apex/cavernous sinus/ orbital apex
Internal acoustic meatus
Jugular foramen
3
Q
foramina involved in obstructive hydrocephalus
A
Foramina of Magendie and Lushka
4
Q
5 brainstem-associated neural structures
A
Cranial nerves III-XII
Descending motor tracts (pyramidal tracts)
Ascending sensory tracts (Lemnisci)
Reticular activation
Cerebellar peduncles
5
Q
3 structures involved in the ascending sensory system
A
Thalamus
Posterior columns
Lateral spinothalamic tract
6
Q
3 structures involved in the descending motor system
A
Internal capsule
Pyramidal decussation
Corticospinal tract
7
Q
3 nerve fibre types in motor nerves
A
Somatic
Branchial (motor only)
Autonomic
8
Q
3 nerve fibre types in sensory nerves
A
Somatic
Autonomic
Special (sensory only)
9
Q
Autonomic nerve features
A
Arise in the most evolutionary primitive parts of the brain
No conscious control
Smooth and cardiac muscle
Glands
10
Q
What is a dermatome
A
area of skin supplied by a single spinal nerve
11
Q
what is a myotome
A
a volume of muscle supplied by a single spinal nerve
12
Q
Course and features of corticospinal tract
A
Starts in the cortex
Ends in the spinal cord
A well-defined bundle of white matter
Motor
From the precentral gyrus
Through internal capsule
Crura cerebri
85% decussates medulla – lateral tract
15% same side – anterior tract
13
Q
Why use epidural anaethetic
A
The spinal cord finishes at L1
The corda equina continues through the lumbar vertebra
The cell bodies for the sensory neurones are in the dorsal root ganglia
Cell bodies have a higher surface area and take up anaesthetic better than axons
Epidural anaesthetic gives a greater sensory block than motor block
14
Q
Branches off the aortic arch
A
Brachiocephalic trunk – divides into right common carotid and right subclavian arteries
Left common carotid artery
Left subclavian artery
Left vertebral artery
15
Q
features of Common carotid arteries
A
Right CCA arises from the brachiocephalic artery
Left CCA arises from the aortic arch
They have no branches
The CCAs bifurcate at approx. C3-C4
16
Q
A
17
Q
.
A
No narrowings/ dilatations/ branches
Anterior and medial to internal jugular vein
Lies posterior and lateral to ECA at origin
Ascends behind and then medial to ECA
Rare carotid-basilar anastomoses
18
Q
course of the petrous ICA
A
Penetrates temporal bone and runs horizontally (anteromedially) in the carotid canal
Small branch to middle/ inner ear (caroticotympanic artery)
Small potential connection with ECA – vidian artery
19
Q
A
20
Q
course of the supraclinoid ICA
A
Ophthalmic artery is usually intradural and passes into optic canal
Superior hypophyseal arteries/ trunk supply pituitary gland, stalk, hypothalamus and optic chiasm
Posterior communicating artery runs backwards above CN3 to connect with the PCA
Anterior choroidal artery supplies choroid plexus, optic tract, cerebral peduncle, internal capsule and medial temporal lobe
21
Q
4 types of inter-cranial haemorrhage
A
Extradural haemorrhage
Subdural haemorrhage
Subarachnoid haemorrhage
Intracerebral haemorrhage
22
Q
3 layers of the meninges
A
Dura, usually firmly adherent to the inside of the skull
Arachnoid, more adherent to the brain
Pia, on the surface of the brain and cannot be separated from the brain
23
Q
blood vessels of the meninges
A
Meningeal vessels are in the extradural space
Bridging veins cross the subdural space
The circle of willis lies in the subarachnoid space
There are no vessels deep to the pia, the pia forms part of the blood brain barrier
24
Q
features of extradural haemorrhage
A
Traumatic
Fractured skull
Bleeding from middle meningeal artery
Lucid period
Rapid rise in inter-cranial pressure (ICP)
Coning and death if not treated
25
features of subdural haemorrhage
Bleeding from bridging veins
Commonest where the patient has a small brain (alcoholics, dementia)
Occurs in shaken babies
Bridging veins bleed, low pressure so soon stops
Days/ weeks later the haematoma starts to autolyse
Massive increase in oncotic and osmotic pressure sucks water into the haematoma
Gradual rise in ICP over many weeks
26
features of subarachnoid haemorrhage
Rupture of the arteries forming the circle of Willis
Often because of berry aneurysms
Sudden onset severe headache photophobia and reduced consciousness
Thunderclap headache
Rapidly fatal, the commonest source of organs for transplant since seat belts were made compulsory
27
features of embolic stroke
Death of cell bodies in the cortex
Small well-defined territory of loss of motor and sensory function
No recovery
28
features of haemorrhagic stroke
Compression of the internal capsule with no death of cells
Large territory of loss of motor and sensory function
Possibility of complete recovery
29
cerebrovascular disease
Cerebrovascular diseases are conditions caused by problems that affect the blood supply to the brain.
30
4 most common types of cerebrovascular disease
Stroke
Transient ischaemic attack
Subarachnoid haemorrhage
Vascular dementia
31
5 causes of stroke
Small vessel occlusion/cerebral microangiopathy or thrombosis in situ
Cardiac emboli
Atherothromboembolism
CNS bleeds e.g. trauma, aneurysm rupture
Subarachnoid haemorrhage, venous sinus thrombosis, thrombophilia
32
5 modifiable risk factors for stroke
High blood pressure
Smoking
Diabetes mellitus, heart disease, peripheral vascular disease
33
5 conditions which can cause stroke
hypertension, cardiac source of emboli, carotid artery stenosis, vasculitis, hyper viscosity.
34
pathology of ischaemic stroke
sustained occlusion of a cerebral artery leads to ischaemic necrosis of the territory of the brain supplied by the affected artery.
35
pathology of haemorrhagic stroke
Most cases related to hypertension are due to ruptured Charcot-Bouchard microaneurysms
A haematoma forms which destroys the brain structure and causes a sudden rise in intracranial pressure
36
when are stroke symptoms worst
Worst at onset.
37
3 pointers to haemorrhagic stroke
meningism, severe headache, coma
38
4 pointers to ischaemic stroke
carotid bruit, AF, past TIA, IHD
39
clinical manifestations for cerebral infarcts
Depending on site there may be contralateral sensory loss or hemiplegia – initially flaccid (floppy limb, falls like a dead weight when lifted)
Becoming spastic (UMN)
Dysphasia
Contralateral homonymous hemianopia, visuo-spatial deficit
40
clinical manifestations for brainstem infarcts
Varied: include quadriplegia, disturbances of gaze and vision, locked-in syndrome (aware, but unable to respond)
41
clinical manifestations of lacunar infarcts
Five syndromes: ataxic hemiparesis, pure motor, pure sensory, sensorimotor, and dysarthria/clumsy hand.
42
locations of lacunar infarcts
Basal ganglia, internal capsule, thalamus, and pons.
43
differential diagnosis for stroke
Head injury
Hypo/hyperglycaemia
Subdural haemorrhage
Intracranial tumours, hemiplegic migraine, CNS lymphoma, Wernicke’s encephalopathy
44
investigations for stroke
FAST: facial asymmetry, arm/leg weakness, speech difficulty, time to call 999
Imaging: CT/ MRI to check for haematoma
ECG: to check for atrial fibrillation
CXR: left ventricular hypertrophy
Carotid doppler ultrasound: to look for stenosis of the carotid
45
management of ischaemic stroke
Thrombolysis- IV altepase
Aspirin for 2 wks then clopidogrel
rehabilitation- physio,OT
stop smoking/alcohol, exercise
46
Management of haemorrhagic stroke
Control BP- beta blocker/ ARB
Beriplex if warfarin related
Surgery- Clot evation
Rehabilitation- physio, OT
Stop smoking/alcohol, exercise
47
Acute management of stroke
Protect the airway: this avoids hypoxia/aspiration
Maintain homeostasis: blood glucose, blood pressure
Screen swallow: ‘nil by mouth’ until this is done
CT/MRI within 1 hour: essential if thrombolysis considered, high risk of haemorrhage
Antiplatelet agents: once haemorrhagic stroke excluded, give aspirin 300mg
Thrombolysis (IV alteplase): consider as soon as haemorrhage has been excluded
Thrombectomy
48
primary prevention of stroke
Control risk factors:
Hypertension
Diabetes mellitus, raised lipids
Cardiac disease
Help to quit smoking
Use lifelong anticoagulant in AF and prosthetic heart valves
49
secondary prevention for stroke
Control risk factors: there is considerable advantage from lowering blood pressure and cholesterol
Antiplatelet agents after stroke
Anticoagulation after stroke from AF
50
Transient ischaemic attack
An ischaemic (usually embolic) neurological event with symptoms lasting <24h (often much shorter).
51
causes of TIA
Atherothromboembolism from the carotid is the chief cause for bruits.
Cardioembolism: mural thrombus post-MI or in AF, valve disease, prosthetic valve
Hyperviscosity: e.g. polycythaemia, sickle-cell anaemia, myeloma
Vasculitis: a rare, non-embolic cause of TIA symptoms
52
Which score is used to assess TIA risk
ABCD2 score
53
points to the ABCD2 score
A – age: 60 years of age or more (1 point)
B – BP 140/90mmHg or greater (1 point)
C – clinical features – unilateral weakness 2 points, speech disturbance without weakness 1 point
D- duration (60 minutes + (2 points), 10-59 minutes (1 point))
D- diabetes (1 point)
54
What classifies as High risk for TIA
ABCD2 score of 4 or more
Atrial fibrillation
More than one TIA in one week
TIA whilst on an anticoagulant
55
What is amaurosis fugax
occurs when the retinal artery is occluded, causing unilateral progressive vision loss ‘like a curtain descending’.
56
clinical manifestations of TIA
Specific to the arterial territory involved.
Global events e.g. syncope, dizziness, are not typical of TIAs
Attacks may be single or many;
Multiple highly stereotyped attacks suggest a critical intracranial stenosis
57
5 differential diagnoses for TIA
Hypoglycaemia
Migraine aura
Focal epilepsy
Hyperventilation
Retinal bleeds
58
1st line investigations for TIA
Bloods: FBC (look for polycythaemia), glucose, ESR (raised in vasculitis), U&Es, cholesterol, INR (if on warfarin), ECG, lipid profile, prothrombin time
59
Gold standard investigations for TIA
Symptoms 10-15mins, <24 hours + no infarction
60
Controlling CV risk factors for TIA
Optimise BP (aim for <140/85mmHg)
Hyperlipidaemia
Diabetes mellitus
Help to stop smokin
61
Management for TIA
Control CV risk factors
Antiplatelet drugs
Anticoagulation indications: cardiac source of emboli
Carotid endarterectomy: surgery to remove a build-up of plaque in the carotid artery
62
Antiplatelet drugs for TIA
As with stroke, give aspirin 300mg OD for 2 weeks, then switch to Clopidogrel 75mg.
63
Subarachnoid haemorrhage
A spontaneous, non-traumatic bleed into the subarachnoid space.
64
Aetiology of subarachnoid haemorrhage
Most commonly due to rupture of a berry aneurysm
It has been hypothesised that a congenital defect in the tunica media of the cerebral vessels leads to aneurysm formation later in life due to atherosclerosis and hypertension.
Arterio-venous malformations
Encephalitis, vasculitis, tumour invading blood vessels, idiopathic.
65
Pathology of Subarachnoid haemorrhage
Most berry aneurysms arise at the site of arterial bifurcation at the base of the brain
Rupture of the aneurysm usually results in extensive bleeding through the subarachnoid space. The haemorrhage may extend into the brain tissue, as well as the ventricular system.
66
5 risk factors for Sub arachnoid haemorrhage
Previous aneurysmal SAH
Smoking/ alcohol misuse
Raised BP
Bleeding disorders
Polycystic kidneys, aortic coarctation and Ehlers-Danlos syndrome are all associated with berry aneurysms.
67
5 symptoms of Subarachnoid haemorrhage
Sudden-onset excruciating headache – like a thunderclap
Vomiting
Collapse
Seizures
Coma/drowsiness – may last for days
68
Signs of Subarchnoid haemorrhage
Neck stiffness
Kernig’s sign (severe stiffness of the hamstrings – can’t straighten leg when hip is flexed)
Retinal, sub-hyaloid and vitreous bleeds
69
complications of subarachnoid haemorrhage
re-bleeding from the aneurysm, CSF malabsorption problems, and arterial vasospasm
70
differential diagnoses for Subarachnoid haemorrhage
Meningitis
Migraine
Intracerebral bleed
Cortical vein thrombosis
Benign thunderclap headache (triggered by Valsalva manoeuvre e.g. cough, coitus)
71
investigations for subarachnoid haemorrhage
Macroscopy: blood is present within the subarachnoid space, often with abundant clots around the circle of Willis at the base of the brain.
Urgent CT: detects 95% of subarachnoid haemorrhages
72
Management of subarachnoid haemorrhage
Re-examine CNS often: chart BP, pupils and GCS. Repeat CT if deteriorating
Maintain cerebral perfusion by keeping well hydrated
Nimodipine is a calcium antagonist that reduces vasospasm and consequent morbidity from cerebral ischaemia
Mannitol – decreases ICP
Surgery: endovascular coiling vs surgical clipping (requiring craniotomy) – decision depends on accessibility and size of aneurysm
73
complications of subarachnoid haemorrhage
Re-bleeding – commonest cause of death
Cerebral ischaemia due to vasospasm may cause a permanent CNS deficit
Hydrocephalus due to blockage of arachnoid granulations (requires a lumbar drain)
Hyponatraemia
74
summary of subarachnoid haemorrhages
Rupture of the arteries forming the circle of Willis
Often because of berry aneurysms
Sudden onset severe headache, photophobia and reduced consciousness
Thunderclap headache
Rapidly fatal, the commonest source of organs for transplant since seat belts were made compulsory
75
complications of base of skull fractures
may cause lower cranial nerves palsies or CSF discharge from the nose or ear
76
What are cerebral contusions
Bruises on the surface of the brain
Occur when the brain suddenly moves within the cranial cavity and is crushed against the skull
Typically, there is injury at the site of impact and at the site diagonally opposite this point
Oozing of blood into the brain parenchyma and associated cerebral oedema are important contributors to raised intracranial pressure
77
Subdural haemorrhage
Bleeding from bridging veins between cortex and venous sinuses, resulting in accumulating haematoma. Common where the patient has a small brain (alcoholics, dementia).
78
pathology of subdural haemorrhage
Due to haemorrhage between the dura and the arachnoid.
Results from tearing of delicate bridging veins that traverse the subdural space to drain into the cerebral venous sinuses
Blood from these veins spread freely through the subdural space, enveloping the entire cerebral hemisphere on the side of the injury
79
Causes of subdural haemorrhage
Minor trauma up to 9 months previously
Without trauma e.g. Dural metastases, lowered intracranial pressure
80
symptoms of subdural haemorrhage
Fluctuating level of consciousness
Insidious physical or intellectual slowing
Sleepiness, headache, personality change, unsteadiness
81
signs of subdural haemorrage
Raised Intracranial pressure (massive increase in oncotic and osmotic pressure sucks water into the haematoma, gradual rise in ICP)
Seizures
Localising neurological symptoms e.g. unequal pupils
82
Differential diagnoses for subdural haemorrhage
Stroke
Dementia
CNS masses e.g. tumours, abscesses
83
investigations for subdural haemorrhage
Imaging: CT/ MRI shows clot, with/without midline shift
Look for crescent-shaped collection of blood over 1 hemisphere.
The sickle-shape differentiates subdural blood from extradural haemorrhage.
84
management of subdural haemorrhage
Reverse clotting abnormalities urgently
IV mannitol to decrease ICP
Surgical management depends on the size of the clot, its chronicity, and the clinical picture;
Generally, those >10mm or with midline shift >5mm need evacuating
Address the cause of the trauma
85
extradural haemorrhage
Bleeding from middle meningeal artery (between bone and dura) with a characteristic lucid period.
86
pathology of extradural haemorrage
Due to haemorrhage between the dura and the skull
The bleeding vessel is often the middle meningeal artery which is torn following fracture of the squamous temporal bone
Accumulation of extradural blood is slow, as the firmly adherent dura is slowly peeled away from the inner surface of the skull.
87
causes of extradural haemorrhage
Suspect after any traumatic skull fracture.
Often due to a fractured temporal or parietal bone causing laceration of the middle meningeal artery and vein, typically after trauma to a temple just lateral to the eye.
Any tear in a dural venous sinus will also result in an extradural bleed. Blood accumulates between bone and dura.
88
clinical presentations of extradural haemorrhage
Patients may appear well for several hours following a head injury but then quickly deteriorate as the haematoma enlarges and compresses the brain.
The lucid interval may last a few hours to a few days before a bleed declares itself by low GCS (Glasgow coma scale) from rising ICP.
Increasingly severe headache, vomiting, confusion and seizures follow
If bleeding continues, the ipsilateral pupil dilates, coma deepens, bilateral limb weakness develops and breathing becomes deep and irregular
Death follows a period of coma and is due to respiratory arrest (tentorial herniation)
89
differential diagnosis for extradural haemorrhage
Epilepsy
Carotid dissection
Carbon monoxide poisoning
90
investigations for extradural haemorrhage
CT shows a haematoma – biconvex (lemon shaped), hyperdense haematoma
Skull X-ray may be normal or show fracture lines crossing the course of the middle meningeal vessels
91
Management of extradural haemorrhage
Stabilise and transfer urgently to a neurosurgical unit for clot evacuation
IV mannitol
Care of the airway in an unconscious patient and measures to lower ICP often require intubation and ventilation
92
epilepsy
A recurrent tendency to spontaneous episodes of abnormal electrical activity within the brain which manifest as seizures.
93
3 Classifications of epileptic seizures
Partial seizures
Generalised seizures
Focal seizures
94
What are partial seizures
Features attributable to a localised part of one hemisphere
95
difference between simple and complex partial seizures
In simple partial seizures, consciousness is unimpaired (e.g. a focal motor seizure)
In complex partial seizures, consciousness is impaired (e.g. motionless staring)
96
what are generalized seizures
originating at some point within, and rapidly engaging bilaterally distributed networks leading to simultaneous onset of widespread electrical discharge with no localising features referable to a single hemisphere.
97
What are absence seizures
type of generalized seizure
Absence seizures cause brief (<10s) pauses, e.g. stopping talking in mid-sentence and then carrying on where left off
98
what are tonic-clonic seizures
type of generalized seizures
cause sudden loss of consciousness with stiffening (tonic) of limbs and then jerking (clonic)
99
What are myoclonic jerks
sudden violent movement of the limbs
100
What are focal seizures
originating within networks linked to one hemisphere and often seen with underlying structural disease.
101
3 subclasses of focal seizures
Without impairment of consciousness
With impairment of consciousness
bilateral, convulsive seizure
102
focal seizures without impairment of consciousness
awareness is unimpaired, autonomic, or psychic symptoms. No post-ictal symptoms.
103
focal seizures With impairment of consciousness
awareness is impaired, either at seizure onset or following a simple partial aura. Most commonly arise from temporal lobe; post-ictal confusion.
104
bilateral convulsive focal seizures
the electrical disturbance, which starts focally, spreads widely, causing a generalised seizure, which is typically convulsive.
105
cause of epilepsy
Very often idiopathic with no clear cause found
May be associated with underlying structural lesions (trauma, neoplasms, malformations), metabolic conditions (alcohol, electrolyte disorders), infections, and rare genetic diseases (e.g. ion channel mutations)
106
prodomes in epilepsy
Some patients may experience a preceding prodrome (an early sign or symptom) lasting hours or days in which there may be a change in mood or behaviour.
107
Aura in epilepsy
prodrome that implies a focal seizure, often from the temporal lobe. May be a strange feeling in the gut or flashing lights.
108
post-ictal presentation of epilepsy
altered state of consciousness after an epileptic seizure
Headache
Confusion
Myalgia (pain in a muscle or group of muscles).
109
clinical presentation for temporal lobe seizure
emotional disturbance, dysphasia, hallucinations, bizarre associations
110
clinical presentation of frontal lobe seizures
motor features such as peddling movements of the legs. Motor arrest, dysphasia or speech arrest.
Post-ictal Todd’s Palsy
111
what is post ictal Todd's palsy
Paralysis of the limbs involved in a seizure for several hours
112
clinical presentation of parietal lobe seizure
sensory disturbances – tingling, numbness, pain. Motor symptoms
113
clinical presentation of occipital lobe seizure
visual phenomena such as spots, lines, flashes
114
differential diagnosis for seizure
Migraine
TIA
Cardiogenic syncope
Parasomnia
115
how to diagnose epilepsy
Take a thorough history: include a detailed description from a witness
Ask specifically about tongue biting and a slow recovery
Are there any triggers e.g. alcohol, stress, flickering lights
Establish the type of seizure – focal or generalised
Rule out provoking causes
116
provoking causes for seizure
Trauma
Stroke
Haemorrhage
Alcohol or benzodiazepine withdrawal
Metabolic disturbance
117
1st line investigation for focal epilepsy
Electroencephalogram (supportive not diagnostic, can determine type of epileptic syndrome)
MRI/CT (examine hippocampus, rule out other causes, e.g., tumour, bleeding)
Bloods (rule out other causes - FBC, Ca2+, electrolytes, U&Es, LFTs, glucose)
Genetic testing
118
gold standard investigations for focal epilepsy
Clinical diagnosis (at least 2 seizures more than 24hours apart) and EEG (focal spikes or sharp waves in affected area)
119
management for focal epilepsy
Usually only started after 2nd epileptic episode.
1st line – lamotrigine/carbamazepine. 2nd line – sodium valproate/levetiracetam
120
1st line investigations for generalised epilepsy
Electroencephalogram (supportive not diagnostic, can determine type of epileptic syndrome, e.g., 3Hz spike in absence seizure)
MRI/CT (examine hippocampus, rule out other causes, e.g., tumour, bleeding)
Bloods (rule out other causes - FBC, Ca2+, electrolytes, U&Es, LFTs, glucose)
Genetic testing (e.g., for juvenile myoclonic epilepsy)
121
gold standard investigations for generalised epilepsy
Clinical diagnosis (at least 2 seizures more than 24hours apart) and EEG (determine type of seizure)
122
management of generalised epilepsy
Usually only started after 2nd epileptic episode.
1st line – sodium valproate for all generalised seizures in males and women not childbearing age.
123
generalised epilepsy treatment for women of childbearing age
Women of childbearing age: give lamotrigine for all generalised seizures except myoclonic (levetiracetam/topiramate) and absence (ethosuximide). Sodium valproate highly teratogenic
124
atonic seizures
sudden loss of muscle tone causing a fall, no LOC
125
non drug epilepsy therapies
Psychological therapies
Relaxation
CBT
Do not improve seizure frequency
Surgical intervention
Neurosurgical resection
Vagus nerve stimulation is a palliative treatment option for refractory epilepsy
126
what is Dementia
A neurodegenerative syndrome with progressive decline in several cognitive domains.
127
4 types of dementia
Alzheimer’s, Lewy body, Parkinson’s, vascular
128
features of vascular dementia
Cumulative effect of many small strokes.
Sudden onset and stepwise deterioration is characteristic.
129
features of lewy body dementia
Fluctuating cognitive impairment, detailed visual hallucinations, parkinsonism
Histology is characterised by Lewy bodies in brainstem and neocortex
130
features of fronto-temporal dementia
Frontal and temporal atrophy with loss of >70% of spindle neurons.
Patients may display executive impairment – behavioural/ personality change, disinhibition, hyperorality, emotional unconcern.
131
10 causes of dementia
Lewy body, Parkinson’s, vascular,Familial autosomal dominant Alzheimer’s
Alcohol/ drug abuse
Repeated head trauma
Pellagra – lack of nicotinic acid
Whipple’s disease – GI malabsorption
Huntington’s
132
history taking for dementia
ask about timeline of decline and the domains affected. Non-cognitive symptoms such as agitation, aggression, or apathy indicate late disease
133
cognitive testing for dementia
use a validated dementia screen such as the AMTs or similar, plus short tests of executive function and language.
Carry out a mental state examination to identify anxiety, depression or hallucinations
134
examination for dementia
identify a physical cause, risk factors (e.g. for vascular dementia) or parkinsonism.
135
why conduct a medication review for dementia diagnosis
important to exclude drug-induced cognitive impairment
136
what is the 6CIT Dementia test
Six item cognitive impairment test
What year is it?
What month is it?
Give an address with 5 parts (John, Smith, 42, High, St, Bedford)
Count 20-1
Say months of year in reverse
Repeat address
137
investigations for dementia
Look for reversible/ organic causes: raised TSH/low B12/folate
Check MSU, FBC, ESR, U&E, LFT and glucose.
MRI can identify other reversible pathologies e.g. subdural haematoma, as well as underlying vascular damage or structural pathology
Functional imaging may help delineate subtypes where diagnosis is not clear
138
Medication management of dementia
avoid drugs that impair cognition (e.g. sedatives, tricyclics)
139
Non- pharmacological interventions for dementia
non-cognitive symptoms may respond to measures such as aromatherapy, multisensory stimulation, massage, music, and animal-assisted therapy
140
what is vascular dementia
A disease characterised clinically by dementia and histopathologically by injury to the brain parenchyma, associated with a wide range of cerebrovascular lesions.
141
presentation of vascular dementia
Impairment of executive function and slowing of mental processing may be prominent, particularly with diffuse subcortical involvement.
May be difficult to capture on standard cognitive testing (Mini-mental state examination, MMSE)
May present with stepwise progression (multi-infarct dementia) and focal neurology (depending on infarct location)
142
presentation of dementia with lewy bodies
Progressively worsening dementia very similar to Alzheimer’s disease
Useful distinguishing features from Alzheimer’s disease include fluctuating levels of cognition, recurrent visual hallucinations, features of parkinsonism, and hypersensitivity to neuroleptics
Autonomic nervous system problems and sleep disorders are also described
143
Alzheimer's disease
A neurodegenerative disease characterised clinically by dementia and histopathologically by neuronal loss in the cerebral cortex, in associated with numerous amyloid plaques and neuro-fibrally tangles.
144
Aetiology of alzheimers
Environmental and genetic factors play a role
Accumulation of β-amyloid peptide, a degradation product of amyloid precursor protein, results in progressive neuronal damage, neurofibrillary tangles, raised number of amyloid plaques and loss of acetylcholine.
Neuronal loss is selective – the hippocampus, amygdala, temporal neocortex, and subcortical nuclei are most vulnerable.
145
pathology of alzheimers
extracellular deposition of beta-amyloid plaques, tau-containing intracellular neurofibrillary tangles, damaged synapses, atrophy, cortical scarring, decreased Ach neurotransmitter.
146
temporal lobe functions
Hearing (superior temporal lobe)
Language comprehension (superior temporal lobe)
Semantic knowledge (anterior temporal lobe)
Memory (hippocampus)
Emotional/ effective behaviour (limbic system)
147
early presentation of alzheimers
Begins with memory loss, particularly day-to-day memory and new learning, which correlates with the early involvement of the medial temporal lobe and the hippocampus.
Episodic memory: frequent intrusions and repetition errors, and high numbers of false positive errors in recall
148
later stage presentation of alzheimers
Over time, there is increasing disability in managing daily activities such as finances and shopping
Agnosia – not being able to recognise self in the mirror
Psychotic symptoms: delusions (delusions of theft) or hallucinations
Loss of motor skills then causes difficulty dressing, cooking and cleaning
Late in the disease, there is agitation, restlessness, wandering and disinhibition.
This may cause considerable upset to the family and carers.
149
terminal stage presentations of dementia
reduced speech, immobility, and incontinence.
150
differential diagnosis of alzheimers
Vascular/mixed dementia
Dementia with Lewy bodies
Depressive pseudo dementia
151
1st line investigation for alzheimers
MMSE (mini mental state examination): score /30. >25 = normal. 18-25 = impaired. <18 = severely impaired. Tests communication, memory, activities of daily life.
memory clinic assessment, Bloods – FBC, U&Es, B12 (rule out other causes), brain MRI
152
gold standard investigation for alzheimers
Brain MRI (temporal lobe and cortical atrophy)
153
prevention of alzheimers
Socially active
Cognitively active
Control vascular risk factors
Treat mood and anxiety
154
medication for alzheimers
Acetyl choline esterase inhibitors e.g. Rivastigmine
Memantine (anti-glutamate)
Antipsychotics – consider only if severe e.g. extreme agitation/ psychosis
155
Parkinsons
A neurodegenerative hypokinetic movement disorder characterised clinically by parkinsonism and histologically by neuronal loss and Lewy bodies concentrated in the substantia nigra.
156
pathology of parkinsons
Neurones from the substantia nigra connect to the putamen and globus pallidus where they release dopamine and control movement
Lack of dopamine release results in movement disorder (loss of dopaminergic neurons in substantia nigra)
It is recognised that other parts of the nervous system are involved, resulting in additional symptoms
Most cases are sporadic, though multiple genetic loci have been identified in familial cases
157
classical triad of parkinsons manifestations
Tremor. Worse at rest; often ‘pill-rolling’ of thumb over fingers
Rigidity. Hypertonia: rigidity and tremor give cogwheel rigidity felt during rapid pronation/supination
Bradykinesia (parkinsonism): slow to initiate movement. Shuffling, pitched forward gait
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clinical manifestations of parkinsons
Onset is typically unilateral
Tremor.
Rigidity
Bradykinesia ]Autonomic dysfunction, cognitive neurobehavioral disturbances, and sleep dysfunction are also common
Rapid eye movement (REM) sleep behaviour disorder may precede parkinsonism
Dysphagia may be seen with disease progression
Patients may develop dementia and depression - debilitating
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differential diagnosis for parkinsons
Cerebellar disease
Fronto-temporal dementia
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1st line investigations for parkinsons
dopaminergic agent trial
161
3 step diagnosis of parkinsons
1. Diagnosis of parkinsonian syndrome: bradykinesia + one of rigidity, resting tremor, or postural instability
2. Exclusion criteria (none to be met): Hx stroke, repeated head injury, neuroleptic treatment, unilateral features after 3 years, cerebellar signs, Babinski’s sign, early severe dementia, negative response to large L-dopa dose.
3. Supportive criteria (3+ required): unilateral onset, rest tremor present, progressive, excellent response to L-dopa, visual hallucinations.
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pharmacological management of parkinsons
Treatment with dopaminergic drugs eases symptoms of parkinsonism but does not slow the progression of the disease.
Co-careldopa – levodopa and carbidopa
Pramiprexole/ ropinirole – dopamine receptor agonists
Tremor management – anticholinergic such as amantadine.
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problem with levodopa use
Patients on long term treatment with levodopa develop severe dyskinesias (involuntary jerking movements) as a side effect
164
management of selected parkinsons patients with severe tremor
Deep brain stimulation of the subthalamic nucleus works by rebalancing aspects of the basal ganglia circuit and is helpful in a small number
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huntingtons chorea
An inherited neurodegenerative disorder caused by mutation of the HTT gene
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genetics of huntingtons
HTT contains a sequence of CAG trinucleotide repeats (chromosome 4) which usually number <36
Mutant HTT has >36 trinucleotide repeats. The higher the number of trinucleotide repeats, the fuller the penetrance and the younger the age of onset
Instability of the repeat sequences tends to result in their expansion in each successive generation, a phenomenon known as anticipation
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pathology of huntingtons
Huntingtin, the protein coded by HTT, interacts with many other proteins and has many biological functions. It is expressed in all cells but is present in highest concentration in the brain and testis
Mutated huntingtin is thought to be cytotoxic to certain cell types, most notably neurones in the caudate nucleus and putamen
Atrophy and neuronal loss of striatum and cortex
Loss of neurotransmitters, including GABA, acetylcholine and glutamate.
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clinical manifestation of huntingtons
Decrease of GABA and unbalanced dopamine activity result in chorea - Uncontrolled, random, jerky movements
Over time, there is motor, neuropsychiatric, and cognitive decline, ultimately terminating in dementia
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differential diagnoses for huntingtons
SLE
Multiple sclerosis
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investigations of huntingtons
Clinical diagnosis.
MRI/CT brain – loss of striatal volume. Genetic testing (>35 CAG repeats on chromosome 4)
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clinical diagnosis of huntingtons
Abnormal eye movements
Problems with initiating saccades
Broken pursuit
Chorea
Random, unpredictable movements
Often additional touch of parkinsonism
Rigidity
Slowness of fine finger movements
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management of huntingtons
Chorea – antipsychotics: risperidone (dopamine receptor antagonists)
Depression – selective serotonin reuptake inhibitors: sertraline
Psychosis – neuroleptics: haloperidol
Aggression – antipsychotics: risperidone
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3 types of primary headaches
Migraine, cluster, tension type
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6 types of secondary headaches
Meningitis, subarachnoid haemorrhage, GCA, idiopathic intracranial hypertension, medication overuse headache
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Headache history markers needing further investigation
>50
Hx of HIV or cancer or trauma or risk factors cerebral vein sinus thrombosis
Changing personality or cognitive dysfunction
Vomiting without other obvious cause
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headache features which indicate need for further investigation
Jaw claudication (pain associated with chewing) or visual disturbance
Severe eye pain – closed angle glaucoma
Changing in frequency, characteristics or associated symptoms
Postural
Sudden onset headache/ thunderclap
Exercise or Valsalva (e.g. coughing, laughing, straining)
Focal neurological symptoms (e.g. limb weakness, unusual area aura <5 min or >1hr)
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features of a headache exam indicating need for further investigation
Fever
Altered consciousness
Neck stiffness
Other abnormal neurological examination
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5 headache features indicating immediate referral
Thunderclap headache
Seizure and new headache
Suspected encephalitis
Red eye – acute glaucoma
Headache + new focal neurology – including papilledema
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4 cancer red flags for headache
new onset + history of cancer, papilledema, cluster headache
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questions needed in a headache history
Types/number – history for each one
Time – onset/duration/how long/why now/ frequency and pattern
Pain – severity/quality/site and spread
Associated – N/V/P/P/cranial autonomic features
Triggers +/- - triggers/ aggravating/ relieving/ FHx
Response – during attack/ function/ medication useful
Between attacks – normal/persisting symptoms
Any change in attacks
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Migraine
A recurrent throbbing headache that typically affects one side of the head and is often accompanied by nausea and disturbed vision.
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risk factors for migraine
Smoking
Age >35 yrs
High blood pressure
Obesity/ diabetes mellitus
Oral contraceptive pill
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potential triggers for migraines
CHOCOLATE
Chocolate
Hangovers
Orgasms
Cheese/ caffeine
Oral contraceptives
Lie-ins
Alcohol
Travel
Exercise
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clinical presentation of migraine
Visual or other aura lasting 15-30min followed within 1h by unilateral, throbbing headache
Isolated aura with no headache
Episodic severe headache without aura, often premenstrual, usually unilateral, with nausea, vomiting
Allodynia – all stimuli produce pain (brushing hair/wear earrings/glasses)
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differential diagnoses for migraine
Cluster or tension headache
Cervical spondylosis
Intracranial pathology
TIAs
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investigations for migraine
1st line+ GS= clinical diagnosis
187
diagnosis criteria for migraine
if no aura:
>5 headaches lasting 4-72hours + nausea/vomiting + any 2 of;
Unilateral
Pulsating
Impairs routine activity
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management of migraines
Avoid identified triggers and ensure analgesic rebound headache is not complicating matters
Prophylactic treatment: reduced attack frequency – propranolol
Treatment during an attack: oral triptan (Severe) combined with either an NSAID (mild) or paracetamol
Non-pharmacological therapies: warm or cold packs to the head or rebreathing into paper bag may help abort attacks.
Transcutaneous nerve stimulation may help
189
What are tension headaches
Primary headache. Most common chronic and recurrent daily headache. Bilateral generalised pain, can spread to neck. Can be episodic <15 days/per month, or chronic >15 days/month (for at least 3 months)
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9 triggers for tension headaches
stress, sleep deprivation, bad posture, hunger, eyestrain, anxiety, noise, overexertion, tension in muscles of face/jaw/neck
191
clinical presentations for tension headaches
At least one of: bilateral, pressing/tight and non-pulsatile (like an elastic band around head), mild/moderate intensity, +/- scalp tenderness.
No aura, vomiting or head sensitivity to movement.
Can be some ‘pressure’ behind eyes, but pain isn’t localised around eye
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investigations for tension headaches
1st line+ GS= clinical diagnosis
If suspected pathology: CT sinus, MRI brain, lumbar puncture
193
differential diagnoses for tension headaches
Migraine, cluster headache, giant cell arteritis, sphenoid sinusitis
194
management of tension headaches
Avoid triggers and stress relief. Symptomatic relief: aspirin, paracetamol, ibuprofen, AVOID OPIOIDS
Chronic: antidepressants (amitriptyline)
Limit analgesics to no more than 6 days per month to reduce the risk of medication-overuse headaches
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cluster headache clinical manifestations
Rapid-onset of excruciating pain around one eye that may become watery and bloodshot with lid swelling, lacrimation, facial flushing, rhinorrhoea, miosis.
Pain is strictly unilateral and almost always affects the same side.
It lasts 15-180min, occurs once or twice a day, and is often nocturnal.
Clusters last 4-12 weeks and are followed by pain-free periods of months or even 1-2 years before the next cluster
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treatment of cluster headaches
Acute attack: give 100% O2 for 15 min via non-rebreathable mask. Sumatriptan sc 6mg at onset
197
preventative measures for cluster headaches
Avoid triggers: e.g. alcohol
Medication: consider corticosteroids short term e.g. prednisolone
Verapamil (CCB)
198
two classes of drug overuse for headaches
A: Headache present on >15 days/month
B: Regular use for >3 months of one or more symptomatic treatment drugs
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management of drug overuse for headaches
Withdraw analgesics – aspirin or naproxen may mollify the rebound headache.
201
Giant cell arteritis
A vasculitis of medium and large vessels which preferentially affects head and neck arteries. Most patients are adults aged >50y.
202
clinical manifestations of giant cell arteritis
Presents over weeks or months with;
Fever
Anorexia
Weight loss
Involvement of the temporal artery causes headache, scalp tenderness, and jaw claudication
Involvement of ocular vessels can cause blindness
Aortic involvement may lead to thoracic or abdominal aortic aneurysm formation
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1st line investigation for giant cell arteritis
Raised CRP, Raised ESR >50mm/hr. FBC (anaemia), LFT/RFT may be abnormal
Halo sign (wall thickening) on vascular ultrasonography of temporal and axillary artery
204
gold standard investigation for giant cell arteritis
Temporal artery biopsy (shows giant cells, granulomatous inflammation – patchy lesions therefore take big sample)
205
management of giant cell arteritis
Management;
Start prednisolone PO immediately or IV methylprednisolone if evolving visual loss
Main cause of death in giant cell arteritis is long-term steroid treatment
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trigeminal neuralgia (face pain)
Neuralgia involving one or more of the branches of the trigeminal nerves, and often causing severe pain.
207
triggers for trigeminal neuralgia
Washing affected area
Shaving
Eating
Talking
Dental prostheses
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secondary causes of trigeminal neuralgia
Compression of the trigeminal root by anomalous or aneurysmal intracranial vessels or a tumour
Hypertension
Chronic meningeal inflammation
MS
Skull base malformation e.g. Chiari
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clinical manifestations of trigeminal neuralgia
Paroxysms of intense, stabbing pain, lasting seconds, in the trigeminal nerve distribution.
Unilateral, typically affecting mandibular or maxillary divisions.
The face screws up with pain
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differential diagnosis for trigeminal neuralgia
Migraine
Glossopharyngeal neuralgia
Sinusitis
Giant cell arteritis
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gold standard investigations for trigeminal neuralgia
Clinical, 3 or more attacks with same presentation (paroxysmal sharp stabbing facial pain up to 2 mins)
212
management of trigeminal neuralgia
Carbamazepine
If drugs fail, surgery may be necessary – directed at the peripheral nerve, the trigeminal ganglion or the nerve root
Microvascular decompression: anomalous vessels are separated from the trigeminal root.
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causes for spinal cord compression
Secondary malignancy (breast, lung, prostate, thyroid, kidney)
Rare:
Infection
Cervical disc prolapse
Haematoma/ myeloma
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symptoms of cord compression
Bilateral leg weakness
Preceding back pain
Bladder (and anal) sphincter involvement is late and manifests as hesitancy, frequency and painless retention
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signs for cord compression
Look for a motor, reflex, and sensory level, with normal findings above the level of the lesion
LMN signs at the level
UMN signs below the level
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differential diagnosis for cord compression
Transverse myelitis
MS
Carcinomatous meningitis
Cord vasculitis
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1st line investigations for cord compression
X-ray whole spine, MRI spine, RFTs, haemoglobin – monitor blood loss
218
gold standard investigation for cord compression
MRI spine (visualise cord compression)
219
management for cord compression
Give urgent dexamethasone in malignancy while considering more specific therapy e.g. radiotherapy or chemotherapy
If reduced mobility consider thromboprophylaxis – compression stockings, LMWH
Epidural abscesses must be surgically decompressed, and antibiotics given
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cauda equina syndrome
Spinal cord compression at the site of the cauda equina.
221
causes of cauda equina syndrome
Secondary malignancy (breast, lung, prostate, thyroid, kidney)
Rare:
Infection
Haematoma/ myeloma
congenital lumbar disc disease and lumbosacral nerve lesions
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signs of cauda equina syndrome
Back pain and radicular pain down the legs;
Asymmetrical, atrophic, areflexic paralysis of the legs
Sensory loss in a root distribution
Decreased anal sphincter tone on PR, bladder/bowel incontinence
223
multiple sclerosis
A relapsing and remitting demyelinating disease of the CNS, in which episodes of neurological disturbance affect different parts of the CNS at different times.
224
pathology of MS
Episodes of demyelination lead to attacks of acute neurological deficit, which develop over a period of a few days and remain for a few weeks before symptom recovery
In the early stages of the disease, complete or almost complete recovery from an episode of demyelination is typical
As the diseases progresses, recovery is slower and residual deficit remains as a critical threshold of axonal death.
Eventually, extensive axonal death results in permanent neurological disability, characteristic of progressive disease
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clinical presentations of MS
Symptoms may be highly variable, depending on the lesion site in the CNS
Blurred vision/ loss of colour vision due to optic nerve demyelination
Vertigo and incoordination due to cerebellar demyelination
Eye movement disorders due to brainstem demyelination
Unilateral optic neuritis (pain on eye movement and reduced rapid central vision)
Patchy numbness and tingling in a limb, with progression to paraplegia, incontinence, and sexual dysfunction due to spinal cord demyelination
Symptoms worsen with heat – Uhthoff’s phenomenon
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relapsing/remitting patient features for MS
Random attacks over a number of years
More frequent in the first 3 – 4 years
Recovery varies markedly among patients and from one attack to the next
Disabilities often accumulate with each successive attack
227
primary/secondary chronic progressive MS features
Slow, inexorable decline in neurological functions
From disease onset
Following an initial relapsing/ remitting course
228
benign chronic progressive MS features
Few relapses
Little disability
229
differential diagnoses for MS
Infectious disease - Lyme disease
Autoimmune disorders – SLE, primary Sjogren’s syndrome
230
first line investigations for MS
Bloods should be normal: FBC, U&Es, LFTs, TFTs, B12, HIV serology, calcium, glucose.
Lumbar puncture (oligoclonal IgG bands in CSF), MRI, evoked potentials (measures brain electrical activity in response to stimulation of sight, sound or touch).
231
Gold standard investigations for MS
McDonald criteria: symptoms disseminated in time (>1 month apart) and space (damage to different parts of CNS seen on MRI). GS tool = MRI brain and spinal cord
232
General management of MS
MDT care, supportive therapy, legal obligation to inform DVLA.
233
Management of acute relapses of MS
steroids (IV methylprednisolone).
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management of relapsing remitting MS
interferon beta (CI in pregnancy), DMARDs, biologics (IV natalizumab), oral fingolimod (immunomodulator)
235
Management of secondary progressive MS
Siponimod or methylprednisolone.
236
management of primary progressive MS
ocrelizumab (DMARD)
237
symptom control for MS
Spasticity – baclofen
Tremor – botulinum toxin type A injections improve arm tremor and functioning
Urgency/ frequency – teach intermittent self-catheterisation
Fatigue – amantadine, CBT, exercise.
238
Myasthenia gravis- NMJ disorder
An autoimmune disease caused by production of autoantibodies directed against various antigens of the neuromuscular junction - typically the nicotinic acetylcholine receptor
239
aetiology of myasthenia gravis
Precisely what leads to the production of the autoantibodies is unclear
Up to 75% of patients with nAChR autoantibodies have an abnormality of the thymus, either a neoplasm (thymoma) or hyperplasia.
240
Pathology of myasthenia gravis
The nAChR is the receptor at the motor endplate, through which the neurotransmitter acetylcholine acts to stimulate muscular contraction.
Autoantibodies binding to the nAChR limit depolarisation at the endplate and thus impair muscular contraction
MuSK is involved with clustering of nAChR, which is important for its normal function
241
clinical manifestations of myasthenia gravis
The key feature is muscular fatigability
Symptoms can be very subtle, and the diagnosis is easily missed or mistaken for other conditions.
242
muscle groups affected by myasthenia gravis
in order, are extraocular, bulbar face, neck, limb girdle, and trunk
243
What is lambert- eaton syndrome
typically a paraneoplastic syndrome and patients develop autoantibodies against voltage-gated calcium channel on the presynaptic nerve terminal.
244
symptoms of lambert-eaton syndrome
Gait difficulty before eye signs
Autonomic involvement (dry mouth, constipation, impotence
Hyporeflexia and weakness, which improve after exercise
245
differential diagnosis for myasthenia gravis
Polymyositis/ other myopathies
SLE
Takayasu’s arteritis
246
investigations for myasthenia gravis
Antibodies: increased anti-AChR antibodies, -ve look for MuSK antibodies
EMG: decremental muscle response to repetitive nerve stimulation
Imaging: CT to exclude thymoma
247
management of Myasthenia gravis
Combination of acetylcholinesterase inhibitors (such as pyridostigmine) and immunomodulatory therapies.
Immunosuppression: treat relapses with prednisolone
248
myasthenic crisis
Life-threatening weakness of respiratory muscles during a relapse.
Can be difficult to differentiate from cholinergic crisis.
Monitor forced vital capacity
Ventilatory support may be needed. Treat with plasmapheresis or IVIg and identify and treat the trigger for the relapse (e.g. infection, medications)
249
motor neuron disease
A group of neurodegenerative diseases characterised by selective loss of motor neurones.
250
4 clinical patterns for MND
ALS/ amyotrophic lateral sclerosis. Loss of motor neurons in motor cortex and the anterior horn of the cord, so combined UMN + LMN signs.
Progressive bulbar palsy. Only affects cranial nerves IX-XII
Progressive muscular atrophy. Anterior horn cell lesion, so LMN signs only. Affects distal muscle groups before proximal.
Primary lateral sclerosis. Rare. Loss of Betz cells in motor cortex: mainly UMN signs, marked spastic leg weakness and pseudobulbar palsy. No cognitive decline.
251
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Clinical manifestations of MND
Asymmetric weakness, wasting, fasciculation, and spasticity of limb muscles
Difficulty swallowing, chewing, speaking, coughing, and breathing
Cognitive changes may also occur (overlap with frontotemporal dementia)
253
Clinical features of lower motor neurone lesions
Muscle tone normal or reduced (flaccid)
Muscle wasting
Fasciculation – visible spontaneous contraction of motor units
Reflexes depressed or absent
Everything goes down!!!
254
clinical features of upper motor neurone pathology
Muscle tone is increased (spasticity)
Tendon reflexes/ jaw jerk are brisk
Extensor Plantar response (+Babinski sign)
Characteristic pattern of limb muscle weakness (pyramidal pattern)
Emotional lability may be present
Everything goes up!!!
255
What is the Characteristic pattern of limb muscle weakness (pyramidal pattern) for upper motor neurone pathology
Upper limbs extensor muscles weaker than flexors
Lower limbs flexors weaker than extensors
Finer more skilful movements most severely impaired
256
differential diagnosis for MND
Multifocal motor neuropathy with conduction block
Bulbospinal muscular atrophy (Kennedy syndrome)
Motor neuropathies
257
investigations for MND
There is no diagnostic test.
Brain/ cord MRI helps exclude structural causes, LP helps exclude inflammatory ones
Neurophysiology can detect subclinical denervation and help exclude mimicking motor neuropathies.
258
Management of MND
The disease is usually progressive and fatal within a few years
Adopt a multidisciplinary approach: neurologist, palliative nurse, hospice, physio, speech therapist, dietician, social services
Riluzole (an inhibitor of glutamate release and NMDA receptor antagonist) is the only medication shown to improve survival.
Dysphagia: blend food. Gastrostomy is an option
Spasticity: exercise, orthotics
Communication difficulty: provide augmentative and alternative communication equipment
End of life care: involve palliative care team from diagnosis
259
Guillain-Barre syndrome
Classical Guillain-Barre syndrome (GBS) is an acute demyelinating polyneuropathy which usually follows 1-2 weeks after an upper respiratory tract or GI infection.
260
Aetiology of GBS
Common triggers are Clostridium jejuni, Mycoplasma, CMV, HIV, VZV, and EBV
Other associations include vaccination, surgery, and malignancy
In many cases, no clear cause can be identified
261
pathology of GBS
Theories suggest that the immune response mounted to an antigen on a pathogen cross-reacts with components of the peripheral nerve, particularly myelin
Demyelination leads to an acute polyneuropathy
262
clinical manifestitions of GBS
A few weeks after an infection a symmetrical ascending muscle weakness starts
Sudden onset of tingling and numbness of fingers and toes
Over a period of weeks, the weakness spreads proximally
Classical form is acute inflammatory demyelinating polyneuropathy (AIDP). Antibodies to gangliosides, basal lamina components, and several myelin proteins
263
investigations for GBS
Lumbar puncture typically shows increased CSF protein with a normal cell count – progressive ventilatory failure is the main danger and ventilatory support may be required
264
management of GBS
IV immunoglobulin
265
division of chronic neuropathies
small fibre and larger fibre
266
division of larger fibre neuropathies
axonal or demyelinating
267
4 common mononeuropathies
Carpal tunnel syndrome (median nerve)
Ulnar neuropathy (entrapment at the cubital tunnel)
Peroneal neuropathy (entrapment at the fibular head)
Cranial mononeuropathies (III or VII cranial nerve palsy)
268
3 causes of mononeuropathies
Idiopathic
Immune mediated
Ischaemic
269
Ataxia
Poor balance
Sensory (loss of proprioception) or cerebellar
When sensory, ataxia gets worse with eyes closed or when dark
270
motor symptoms of peripheral neuropathies
Muscle cramps
Weakness
Fasciculations – muscle twitches
Atrophy
High arced feet (pes cavus)
271
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273
274
275
1st line investigations for PN
Bloods – FBC, glucose, U&Es, LFTs, TFTs, B12, ESR.
Nerve conduction studies. Electromyography (measures muscle electrical activity). Nerve biopsy.
276
GS investigation for PN
Nerve conduction studies
277
olfactory nerve lesion presentation
impaired/lost sense of smell
278
optic nerve lesion presentation
blindness, visual field defects
279
oculomotor lesion presentation
ptosis, down + out eye, fixed dilated pupil
280
trochlear lesion presentation
diplopia looking down, always due to trauma
281
trigeminal lesion presentation
jaw deviates to affected side, loss of corneal reflex, causes: trigeminal neuralgia: sensory pain/motor jaw pain in V1/2/3
282
abducens lesion presentation
adducted eye, inability to look laterally, sign of raised ICP
283
facial lesion presentation
facial droop with forehead sparing, causes: bell’s palsy, parotid inflammation
284
vestibulocochlear lesion presentation
hearing loss, loss of balance, causes: skull changes, (e.g., Paget’s), compression, middle ear disease
285
glossopharyngeal lesion presentation
impaired gag reflex
286
vagus lesion presentation
impaired gag reflex, swallowing, respiration, vocal issues, causes: jugular foramen lesion
287
accessory lesion presentation
can’t shrug shoulders or turn head against resistance
288
hypoglossal lesion presentation
tongue deviation towards affected side
289
investigations for cranial nerve lesions
Neurological examination, MRI
290
types of primary brain tumour
gliomas – astrocytoma (most common), oligodendroglioma. Others – ependymoma, meningioma, schwannoma, craniopharyngiomas
291
types of secondary brain tumours
non-small cell lung cancers (most common), small cell lung cancer, breast, melanoma, renal cell carcinoma, GI
292
pathophysiology of gliomas
tumours of glial cells of brain and spinal cord
293
key presentations of brain tumours
Raised ICP, Cushing triad (bradycardia, raised pulse pressure, irregular breathing), focal neurology, epileptic seizures, lethargy, weight loss, papilloedema (swelling of optic disc), CN6 palsy.
294
gold standard investigations for brain tumours
MRI head to locate tumour then biopsy to determine grade
No LP due to raised ICP- big Contraindication
295
management of brain tumours
1st line – surgery to remove tumour and decrease ICP. + chemo before/after/during surgery
Dexamethasone + mannitol to decrease ICP
296
meningitis
Infection of the subarachnoid space. Inflammation of the meninges.
297
microbiology of meningitis
Viruses - usually echoviruses, EBV, herpes simplex, mumps
Most cases of bacterial meningitis are caused by Neisseria meningitidis or streptococcus pneumoniae. Escherichia coli and group B streptococci are important causes in neonates.
298
4 infective causes of meningitis
Bacterial
Viral
Fungal
Parasitic
299
3 non-infective causes of meningitis
Paraneoplastic
Drug side effects
Autoimmune (e.g. vasculitis/ SLE)
300
3 routes of infection to the meniges
Extracranial infection
Neurosurgical complications
Via blood stream
301
pathology of meningitis
Bacteria usually reach the meninges via the bloodstream from the nasal cavity, often following a viral upper respiratory tract infection
Both Meningococcus and Pneumococcus have capsules which render them resistant to phagocytosis and complement.
The bacteria enter the subarachnoid space where the blood-brain barrier is weak, e.g. the choroid plexus
Once in the CSF, the bacteria multiply rapidly and stimulate an acute inflammatory response within the meninges
302
pathophysiology of menigitis
Blood – CSF – brain barrier
Bacteria enter CSF, and can be isolated from the immune cells due to BBB
Replication – number of bacteria increases
Blood vessels become leaky
WBCs can enter the CSF, meninges and brain
Meningeal inflammation. Brain swelling
303
6 clinical menifestations of meningitis
Headache
Fever
Neck stiffness
Photophobia
The symptoms are usually more severe in bacterial meningitis
Non-blanching purpuric rash
304
differential diagnosis for meningitis
“worst headache ever”
Subarachnoid haemorrhage, trauma, thunderclap onset
Flu and other viral illnesses
Sinusitis
305
1st line investigations of meningitis
If suspected do not delay treatment – IV antibiotics before lumbar puncture. Lumbar puncture within 1 hour of arrival.
Blood cultures (positive).
FBC (leucocytosis, anaemia, thrombocytopenia),
U&E (acidosis, hypokalaemia, hypocalcaemia, hypomagnesemia),
Glucose, lactate dehydrogenase, LFTs. ABG (acidosis), clotting screen (DIC).
Pneumococcal and meningococcal PCR. Viral PCR. Fungal cultures (3 sets)
306
gold standard tests for meningitis
Lumbar puncture (L3/L4) and CSF analysis. Contraindicated with raised ICP, shock
307
results of normal LP
Opening pressure 90-180
Appearance Clear
WCC <8
Protein 15-45
Glucose (vs serum level) 50-80
308
results of bacterial meningitis LP
Opening pressure Elevated
Appearance Turbid
WCC >1000-2000 neutrophils
Protein >200
Glucose (vs serum level) <40
309
LP results for viral meningitis
Opening pressure Normal
Appearance Clear
WCC <300 lymphocytes
Protein <200
Glucose (vs serum level) Normal
310
LP results for fungal meningitis
Opening pressure Normal-elevated
Appearance Clear
WCC <500
Protein >200
Glucose (vs serum level) Normal-low
311
312
management for meningitis
Viral meningitis usually runs a mild course with complete recovery
Bacterial meningitis is a much more serious, potentially life-threatening infection if not treated early with appropriate antibiotics.
313
immediate management steps for meningitis
1.Assess GCS (Glasgow coma score)
2. Blood cultures – takes hours – days for organism to grow and be distinguished
3. Broad spectrum antibiotics
a. First line antibiotics - either ceftriaxone or cefotaxime
4. Special considerations
a. Penicillin allergies
b. Immunocompromised – risk of listeria
c. Recent travel – risk of penicillin resistance
5. Steroids
a. IV dexamethasone
b. Steroids reduce neurological sequelae and therefore reduce morbidity
6. Lumbar puncture
a. Definitive investigation to diagnose meningitis
b. Microscopy, gram stain, culture, protein, glucose, viral PCR
314
encephalitis
Infection of the brain parenchyma. Inflammation of the brain – confusion due to direct inflammation/infection of brain.
315
viral causes of encephalitis
Viruses are the most common cause, usually HSV
Herpes simplex
Varicella zoster
Other viral culprits: measles, mumps, rubella, EBV, HIV, CMV
316
non-viral causes of encephalitis
Any bacterial meningitis
TB
Malaria
Lyme disease
317
other causes of encephalitis
Japanese encephalitis virus
Tick-borne encephalitis
Rabies
West Nile virus
Non-infective – autoimmune, paraneoplastic
318
pathology of HSV encephalitis
HSV encephalitis occurs following reactivation of the virus in the trigeminal ganglion, from which the virus can pass into the temporal lobe.
319
clinical manifestations of encephalitis
Precedes with ‘flu-like’ illness
Confusion
Behavioural changes
Altered consciousness: low GCS or coma
Seizures in severe cases
320
differential diagnosis for encephalitis
Meningitis
TB
Brain abscess
321
1st line investigations for encephalitis
Bloods – FBC (raised WCC), U&Es (hyponatraemia), LFTs, TFTs, B12, lactate
Lumbar puncture and CSF analysis – viral PCR to detect virus (lymphocytosis with normal CSF:plasma glucose ratio)
Blood cultures. EEG (background slowing). HIV testing
322
Gold standard investigations for encephalitis
MRI brain (swelling of brain)
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management of encephalitis
Urgent antiviral treatment
IV if HSV or VZV
Mostly supportive
Symptomatic treatment e.g. phenytoin for seizures
324
Herpes zoster (shingles) pathology
Varicella-zoster virus (VZV) is highly contagious and most individuals are infected in childhood, leading to chickenpox.
Transmitted by respiratory droplets
Infection is lifelong due to viral latency within sensory ganglia.
Reactivation of the virus in adulthood leads to herpes zoster (shingles).
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clinical manifestations of chicken pox
Fever
Malaise
Headache
Abdominal pain
Rash: pruritic, erythematous macules -> vesicles, crust
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clinical manifestations of shingles
Presents as a band-like vesicular eruption along the distribution of a sensory nerve. (Macular -> vesicular rash in dermatomal distribution)
Painful, hyperaesthetic area
Infectious until scabs appear
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investigations for shingles
Clinical diagnosis (based on rash within a dermatome) unless immunosuppressed:
Viral PCR, culture, immunofluorescence
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treatment of shingles
Oral acyclovir/ valaciclovir for uncomplicated chicken pox/shingles in adults. Aim to give within 48 hours of rash
IV acyclovir if pregnant, immunosuppressed, severe/disseminated disease
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prevention of herpes zoster
not routine in children in UK, given at aged 70 to prevent shingles reactivation
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