Neurology: Clinical - CNS infection, muscle/nerve diseases, spinal cord disease, CSF Flashcards
1
Q
What is meningitis?
A
Inflammation/infection of the meninges
2
Q
What is encephalitis?
A
Inflammation/infection of the brain substance
3
Q
What is myelitis?
A
Inflammation/infection of the spinal cord
4
Q
What is the classical triad of meningitis symptoms?
A
Fever
Neck stiffness
Altered mental status
5
Q
What is meningism?
A
Neck stiffness, photophobia, nausea and vomiting
6
Q
What are the clinical features of meningitis?
A
Classical triad - fever, neck stiffness, altered mental state
Progressive headache
Meningism
Cerebral dysfunction - confusion, delirium, declining conscious level (GCS <14)
Sometimes: cranial nerve palsy, seizures, focal neurological deficits
Petechial skin rash (Tumbler test)
7
Q
What is the hallmark of meningococcal meningitis?
A
Petechial skin rash
8
Q
What are some differential diagnoses for meningitis?
A
Infective - bacterial, fungal, viral
Inflammatory - sarcoidosis
Drug induced
Malignant - metastatic, haematological e.g. leukaemia, lymphoma
9
Q
Which bacteria can cause meningitis?
A
Neisseria meningitidis (meningococcus) Streptococcus pneumonias (pneumococcus)
10
Q
What is an example of a viral cause of meningitis?
A
Enteroviruses
11
Q
Which has the slower onset: viral encephalitis or bacterial meningitis?
A
Viral encephalitis
12
Q
For which is cerebral dysfunction a more prominent feature: viral encephalitis or bacterial meningitis?
A
Viral encephalitis
13
Q
What are the clinical features of encephalitis?
A
Flu-like prodrome (4-10 days)
Progressive headache associated with fever
+/- meningism
Progression cerebral dysfunction: confusion, abnormal behaviour, memory disturbance, depressed conscious level
Seizures
Focal symptoms/signs
14
Q
What are differential diagnoses of encephalitis?
A
Infection: viral (HSV) Inflammatory: limbic encephalitis Metabolic: hepatic, uraemia, hyperglycaemic Malignant: metastatic, paraneoplastic Migraine Post-ictal
15
Q
What are the investigations for meningitis?
A
Blood cultures Lumbar puncture (CSF culture/microscopy)
16
Q
What are the investigations encephalitis?
A
Blood cultures
Imaging: CT and MRI
Lumbar puncture
EEG
17
Q
When would you do a CT scan before a LP?
A
Focal neurological deficit New-onset seizures Papilloedema Abnormal level of consciousness (GCS <10) Severe immunocompromised state
18
Q
What are the CSF findings in bacterial meningitis?
A
Opening pressure = increased
Cell count = high (mainly neutrophils)
Glucose = reduced
Protein = high
19
Q
What are the CSF findings in viral meningitis or encephalitis?
A
Opening pressure = normal/increased
Cell count = high (mainly lymphocytes)
Glucose = normal (60% of blood glucose)
Protein = slightly increased
20
Q
In what condition would the CSF cell count be high and mainly neutrophils?
A
Bacterial meningitis
21
Q
In what condition would CSF cell count be high and mainly lymphocytes?
A
Viral meningitis (or encephalitis)
22
Q
In what condition would CSF glucose be reduced?
A
Bacterial meningitis?
23
Q
In what condition would CSF protein be elevated?
A
Both bacterial meningitis and viral meningitis
Bacterial meningitis higher
24
Q
What is the commonest cause of encephalitis?
A
Herpes simplex (HSV) encephalitis
25
Which type of HSV is more likely to cause coldsores?
Type 1
26
Where does HSV remain latent after primary infection?
Trigeminal or sacral ganglion
27
How are enteroviruses spread?
Faecal-oral route
28
What do enteroviruses include?
Polioviruses, coxsackieviruses and echoviruses
29
What are examples of arbovirus encephalitis?
West Nile virus
Japanese B encephalitis
Tick Borne encephalitis
30
How are arboviruses spread?
Arthropod vectors
31
What is a brain abscess?
Localised area of pus in brain
32
What is a subdural empyema?
Thin layer of pus between dura and arachnoid membranes over surface of the brain
33
What are the clinical features of a brain abscess or subdural empyema?
Fever, headache, focal symptoms/signs (seizures, dysphagia, hemiparesis), signs of raised ICP (papilloedema, false localising signs, depressed conscious level), meningism may be present (empyema esp.), features of underlying source (e.g. dental, sinus, ear infection)
34
What are some causes of brain abscess or empyema?
Penetrating head injury
Spread from adjacent infection (dental, sinus, ear)
Blood borne infection (bacterial endocarditis)
Neurosurgical procedure
35
What are the investigations for brain abscess/empyema?
```
CT
MRI
Investigate source
Blood cultures
Biopsy (drainage of pus)
```
36
What are the organisms usually causing brain abscess?
Streptococci - anginosus, intermedius, constellatus
| Anaerobes
37
What is the management of brain abscesses?
Surgical drainage is possible
Penicillin or ceftriaxone to cover streps
Metronidazole for anaerobes
Culture and sensitivity tests on aspirate
38
What are HIV indicator illnesses of the brain?
```
Cerebral toxoplasmosis
Aseptic meningitis/encephalitis
Primary cerebral lymphoma
Cerebral abscess
Cryptococcal meningitis
SOP of unknown cause
Dementia
Leucoencephalopathy
```
39
What are likely brain infections in HIV patients with low CD4 counts?
HIV-encephalopathy (HIV-associated dementia)
Cryptococcus neoformans
Toxoplasma gondii
Progressive multifocal leukoencephalopathy (PML)
Cytomegalovirus (CMV)
40
What is the main likely brain infection in HIV patients with low CD4 counts?
HIV-encephalopathy
41
What species causes cryptococcal meningitis?
Cryptococcal neoformans and cryptococcal gatti
42
Who is at an increased risk of getting a cryptococcal infection?
Immunocompromised e.g. AIDS
43
How does exposure and infection of cryptococcal infection occur?
Inhalation of airborne organisms into the lungs
44
How do most clinical cases of cryptococcal infection present?
Meningoencephalitis
45
What are examples of diseases of spirochetes in the CNS?
```
Lyme disease (Borrelia burgoferi)
Syphilis (Trepomena pallidum)
Leptospirosis (Leptospira interrogens)
```
46
What is the organism causing Lyme disease?
Borrelia (burgoferi)
47
What is the organism causing syphilis?
Trepomena pallidum
48
What is the organism causing leptospirosis?
Leptospira
49
How many stages of Lyme disease are there?
3
50
What happens during the stage 1 of Lyme disease?
Early localised infection (1-30d)
Characteristic expanding rash at site of tick bite = erythema migrans
50% flu-like symptoms e.g. fatigue, myalgia, arthralgia, headache, fever, chills, neck stiffness
51
What happens during the stage 2 of Lyme disease?
Early disseminated infection (wks-mnths)
1+ organ systems involved (haematology/lymphatic spread)
Musculoskeletal and neurological most common
PNS>CNS e.g. mononeuropathy, mononeuritis multiplex, painful radiculoneuropathy, cranial neuropathy, myelitis, meningo-encephalitis
52
What happens during the stage 3 of Lyme disease?
Chronic infection (mnths-yrs)
Musculoskeletal and neurological involvement most common
As stage 2 but subacute encephalopathy, encephalomyelitis
53
What are the investigations for Lyme disease?
```
Serological tests
CSF lymphocytosis
PCR of CSF
MRI brain/spine
Nerve conduction studies/EMG
```
54
What is the treatment for Lyme disease?
Prolonged antibiotic treatment:
IV ceftriaxone
Oral doxycycline
55
What is poliomyelitis caused by?
Poliovirus types 1, 2 or 3 (enteroviruses)
56
What are the symptoms of most polio infections?
Asymptomatic
57
What are the features of polio if there are symptoms?
Muscle weakness, flaccid paralysis
58
What is rabies?
Acute infectious disease of the CNS
59
How is rabies transmitted?
Bite or salivary contamination of open lesion
60
What is the causative agent of tetanus?
Claustridium tetani
61
What is claustridium tetani?
Anaerobic gram positive bacillus
62
What is botulism caused by?
Clostridium botulinum
63
What is clostridium botulinum?
Anaerobic gram positive bacillus
64
What are the three modes of infection of botulism?
Infantile - intestinal colonization
Food-borne - outbreaks
Wound - almost exclusively injecting
65
What is an example of a post infective inflammatory syndrome of the CNS?
Acute disseminated encephalomyelitis (ADEM)
66
What is an example of post infective inflammatory syndrome of the PNS?
Guillain Barre Syndrome (GBS)
67
What are general symptoms of muscle disease?
```
Weakness of skeletal muscles
Short of breath (respiratory muscles)
Poor swallow (aspiration)
Cardiomyopathy
Cramp, pain, stiffness, myoglobinuria
```
68
What are the general signs of muscle disease?
Wasting/hypertrophy
Normal or reduced tone and reflexes
Motor weakness (NOT SENSORY)
69
What investigations would you do for muscle disease?
```
History and examination
Creatine kinase (CK)
EMG
Muscle biopsy
Genetic testing
```
70
What are the different classifications of muscle disease?
Congenital/genetic: structural, contractile, coupling, energy
Acquired: metabolic, endocrine, inflammatory muscle disease, iatrogenic
71
What are the symptoms of myasthenia gravis?
Fatiguable weakness in: limbs, eyelids (ptosis), muscles of mastication (chewing/swallowing), talking, SOB, diplopia
72
What are the investigations for myasthenia gravis?
Serology:
AChR antibodies
Anti-MuSK antibodies
Neurophysiology: repetitive stimulation, jitter
CT chest (to check for widening of mediastinum due to tumour = thymoma, found in many MG patients)
73
What are the treatment options for myasthenia gravis?
Symptomatic:
Acetylcholinesterase inhibitor (pyridostigmine)
Immunosuppresion: prednisolone, steroid saving agent (azathioprine)
Immunoglobulin/plasma exchange
Thymectomy
74
What would a disorder of the spinal cord be called?
Myelopathy
75
What would a disorder of the spinal root be called?
Radiculopathy
76
What would be the expected signs if there was a cord pathology?
```
UMN motor signs:
No wasting
Increased tone
Increased reflexes, extensor plantar
Pyramidal pattern of weakness
```
77
What is Brown-Sequard syndrome?
Damage to one half of the spinal cord resulting in weakness, decreased vibration sense and decreased joint position sense on the ipsilateral side and decreased pain and temperature sense on the contralateral side
78
What is syringomyelia?
Cyst or cavity develops in spinal cord and destroys spinal cord
79
What would be the signs of a C5 cord lesion?
Wasting of C5 innervated muscles
Increased tone in legs > arms
Increased all lower reflexes
Power decreased in C5 innervated muscles, pyramidal pattern below
80
What can cause ischaemic myelopathy?
Spinal stroke/infarction
81
What are some causes of spinal cord ischaemia?
Atheromatous disease (aortic aneurysm)
Thromboembolic disease (endocarditis, AF)
Arterial dissection
Systemic hypotension
82
What is the clinical presentation of a spinal cord stroke?
Onset may be sudden or over several hours
Pain: back pain/radicular, visceral referred pain
Weakness: usually paraparesis
Numbness and paraethesia
Urinary symptoms: retention and then incontinence
83
Where is spinal cord stroke usually located?
Anterior spinal artery (mid-thoracic)
84
What is the treatment for a spinal cord stroke?
Reduce risk of reoccurrence - BP, reverse hypovolaemia/arrhythmia, anti platelet therapy
OT and physio
Manage vascular risk factors
85
What is autoimmune condition which prevents B12 absorption?
Pernicious anaemia
86
How is B12 absorption prevented in pernicious anaemia?
Antibodies to intrinsic factor prevent B12 absorption
87
How would B12 deficient myelopathy present?
```
Paraesthesia hands and feet, areflexia
First UMN sign extensor plantars
Paraplegia
Secondary ataxia
Painless retention of urine
```
88
What is the treatment for B12 deficient myelopathy?
IM B12
89
What is hydrocephalus?
Excess CSF within intracranial space and intraventricular spaces within the brain
90
What does hydrocephalus do to the ventricles?
Causes dilation of the ventricles
91
Where is CSF produced?
Choroid plexus
92
Where is choroid plexus mainly located?
In the lateral ventricles, posterior 3rd ventricle roof, caudal 4th ventricle roof
93
How much CSF is there at any given moment in the average adult?
150cc's
94
How much CSF does the average adult brain produce per day?
450-600cc's
95
What is the route of CSF?
From lateral ventricle -> Foramen of Munro -> 3rd ventricle -> cerebral aqueduct -> 4th ventricle -> Formaina of Luschka/Foramen of Magendie -> through subarachnoid space to surround the brain and spine -> arachnoid granulations along dural venous sinuses and into venous system
96
What are the two types of hydrocephalus?
```
Communicating hydrocephalus (CoH) (non-obstructive)
Non-communicating hydrocephalus (NCH) (obstructive)
```
97
Which type of hydrocephalus is it if CSF can flow freely from choroid plexus to arachnoid granulations?
Communicating hydrocephalus
98
Which type of hydrocephalus is it if CSF can't travel freely from start to finish?
Non-communicating hydrocephalus
99
What is usually the cause of communicating hydrocephalus?
CSF production > resorption
100
What happens when CSF production > resorption?
Ventricular system dilates uniformly and ICP rises
101
What are the signs/symptoms of communicating hydrocephalus?
If cranial sutures not fused, can see disproportional increase in head circumference, 'sunset' eyes
If cranial sutures fused, symptoms of increased ICP = headaches, nausea/vomiting, papilloedema, gait disturbance, CNVI palsy, upgaze difficulty
102
Why is there CNVI palsy in someone with communicating hydrocephalus?
Abducens nerve has longest course through brain, can get damaged
103
What are some of the causes of communicating hydrocephalus?
Infection
SAH
Post-operative
Head trauma
104
How can SAH cause communicating hydrocephalus?
Blood and blood breakdown products cause scarring of arachnoid granulations
105
When does non-communicating hydrocephalus occur?
When there is ANY physical obstruction to normal flow of CSF before it leaves the ventricles
106
What are some causes of non-communicating hydrocephalus?
```
Aqueductal stenosis
Tumours/cancers/masses
Cysts
Infection
Haemorrhage/hematoma
Congenital malformations/conditions
```
107
What is the earliest radiographic finding indicative of development of hydrocephalus?
Dilation of the temporal horns of the lateral ventricles
108
What are findings on imaging of hydrocephalus?
3rd ventricle becomes ballooned
Lateral ventricle size increase
Peripheral sulk effaced
Look at Evans ratio
109
What does the Evans ratio have to be for a diagnosis of hydrocephalus?
An Evans ratio of at least 0.3 may be consistent with a diagnosis of hydrocephalus
110
What is the treatment for communicating hydrocephalus?
External ventricular drain (EVD)
| Permanent shunt
111
What are the treatment options for non-communicating hydrocephalus?
Removal of obstructing lesion
Shunt placement
EVD
Third ventriculostomy
112
What is third ventriculostomy?
Hole surgically opened in floor of 3rd ventricle so CSF flows out into the interpeduncular cistern and pre-ponitine space (bypasses cerebral aqueduct)
113
What is normal pressure hydrocephalus often misdiagnosed as?
Dementia
114
What is the classic triad of normal pressure hydrocephalus?
Wet, wobbly and wacky
115
What is a contraindication for LP?
Unstable patient with cardiovascular or respiratory instability
Localised skin/soft tissue infection over puncture site
Evidence of unstable bleeding disorder
Increased ICP (focal neurological findings)
Chiari malformations
116
What is the spinal needle gauge used for LP usually?
22 gauge
117
What is the position called for LP?
Lateral decubitus position
118
Where are the sites for LP?
L3-4 or L4-5
119
What records opening pressure of CSF during an LP?
Manometer
120
What 3 lab tests does the CSF go to?
Culture and gram stain
Glucose, protein
Cell count and differential
121
When do you use the paramedic (lateral) approach for LPs?
In patients who have calcifications from repeated LPs or anatomic abnormalities
122
What are some of the complications of LP?
```
Headache
Apnea
Back pain
Bleeding or fluid leak around spinal cord
Infection, pain, hematoma
Subarachnoid epidermal cyst
Ocular muscle palsy
Nerve trauma
Brainstem herniation
```
123
What is the most common complication of LP?
Spinal headache
124
What are the risk factors for a spinal headache post-LP?
Female, age 18-30, low BMI, Hx of headache, prior spinal HA
125
What are the treatments for a spinal headache post-LP?
Hydration, caffeine either PO or IV, epidural blood patch
126
How does herniation post-LP present?
Altered mental status, cranial nerve abnormalities, Cushing triad
127
What treatment would you use for brain herniation?
Mannitol
128
What would you do if LP fails?
Someone else: anesthesia/neurology
Bedside ultrasound for difficult LPs
Radiographic guided procedure
Cisterna magna tap
129
What are the normal CSF ranges?
```
Appears clear and colourless
Opening pressure 6-16mm/H20
Protein level - 35mg%
Glucose level - 60mg%
(60% of serum glucose)
WCC <5 (Ratio WCC:RCC = 1/750)
```
