Neurological disease- Part 2 Flashcards
(154 cards)
1
Q
What 3 components in the brain keep the intracranial pressure stable?
A
Brain tissue, blood, CSF
2
Q
Localised lesions that cause a raised intracranial pressure
A
Haemorrhage, abscess, tumour (HAT)
3
Q
Generalised pathology that causes a raised intracranial pressure?
A
Oedema post trauma
4
Q
Another name for localised lesions that raise intracranial pressure?
A
Space Occupying Lesions
5
Q
What is an effect of intracranial space occupying lesions?
A
Causes an internal shift between intracranial spaces.
6
Q
What is uncal herniation
A
Cerebellum moves inferiorly over edge of tentorium
7
Q
What is coning
A
Cerebellum moves inferiorly into foramen magnum
8
Q
Name the 6 different types of brain herniation
A
Cingulate, central, uncal, cerebellotonsilar(coning), upward (cerebellum up into cerebrum space), transcalvarial (out via skull fracture)
9
Q
What is subfalcine herniation?
A
Midline shift
10
Q
What can be a consequence of cingulate herniation
A
Crushed lateral ventricle
11
Q
What can be a consequence of uncal herniation (tentorial herniation)
A
Aqueduct is narrowed
12
Q
What are the symptoms and signs of pressure on brain?
A
Morning headaches and nausea (due to squeeze on cortex and brainstem) and papilloedema (squeeze on optic nerve)
13
Q
Consequences as intracranial pressure contonues to increase?
A
pupillary dilation, falling GCS, brain stem death
14
Q
Name the different types of primary brain tumours and their cell of origin
A
Glial cells- gliomas (glioblastoma, oligodendroglioma, ependymoma)
Embryonic neural cells- medulloblastoma
Arachnoidal cell- meningioma
Nerve sheath cell- schwannoma, neurofibroma
Pituitary gland- adenoma
Lymphoid cell- lymphoma
Capillary vessels- haemangioblastoma
15
Q
Common metastastic malignancy sites to brain
A
Breast, lung, kidney, colon, melanoma
16
Q
What is the difference in location of brain tumours in adults and children
A
Adults more likely to find the tumour above tentorium, in a child more likely below tentorium
17
Q
Do glioma’s metastasie outside of the CNS?
A
no
18
Q
What are 3 common types of Glioma
A
Astrocytoma ,glioblastoma (astrocytes)
Oligodendroglioma (oligodendrocytes)
Ependymoma (ependymal cells)
19
Q
Describe an astrocytoma
A
On microsopy they look like normal astrocytes, it grows very slowly
20
Q
Describe a glioblastoma
A
Under microsope- necrosis is seen and cells are large with multiple/ irregular nuclei, they grow quickly
21
Q
Describe a medulloblastoma
A
Tumour of primitive neuroectoderm
22
Q
Where would you find, who is most likely to be affect and what does a medulloblastoma look like under a microscope?
A
Posterior fossa, especially brainstem
Children
Sheets of small undifferentiated cells
23
Q
Describe a meningioma
A
From arachnocytes, “benign”- don’t metastasis but can be locally aggressive and invade the skull, they are slow growing and often resectable
24
Q
What does a mengioma look like under a microscope?
A
Bland cells forming small groups which resemble an arachnoid granulation, sometimes there is calcification called psammoma body formation
25
Describe where you find a 8th vestibulocochlear nerve schwannoma
at angle between pons and cerebellum
26
What is another name for a 8th vestibulocochlear nerve schwannoma
Acoustic neuroma
27
Symptom of an acoustic neuroma
Unilateral deafness, is a benign lesion but removal is difficult technically
28
Describe a pituitary adenoma
Benign tumour of pituitary in pituitary fossa, it often secretes a pituitary hormone, it grows superiorly and impinges on optic chiasma creating visual signs.
29
Describe a CNS lymphoma
Is a high grade neoplasm and is usually diffuse large B-cell lymphoma, it is often deep and acentral site in the brain making it difficult to biopsy
30
How would you treat a CNS lymphoma
Difficultly as you can't biopsy as so deep and drugs can't cross the blood brain barrier
31
Does a CNS lymphoma spread outside CNS
generally no
32
Describe a haemangioblastoma
Tumour of the blood vessels, is space occupying that may bleed and is most often found in the cerebellum
33
Define functional neurological disorders
Change in function rather than structure of a system, symptoms are not explained by a neurological disease
34
What is the diagnostic criteria for functional neurological symptom disorder?
A->/1 symptoms of altered voluntary motor or sensory function
B- Clinical findings show incompatibility between symptom anf recognised neurological or medical conditions
C-Symptom/ deficit is not better explained by another medical or mental disorder
D-Causes clinically significant distress or impairment in social, occupational or other important areas of functioning or warrant medical evaluation
35
Functional symptoms and signs of functional neurological dysorder
Hoover's sign- Ask to push down with right heel- shows hip extension is weak but hen when asked to push heel down and flex the opposite hip hip extension is normal
Functional sensory- hemisensory disturbance
36
Investigations for functional neurological syndrome
MRI brain scan, negative video EEG, functional MRI
37
Management of functional neurological disorder
Explain what they do and don't have, you believe them, explain that it is common and self-help is key to recovery, antidepressants, referral to psychiatry, physical rehabilitation, cognitive behavioural therapy
38
What is the average normal cerebral blood flow?
55-60mL/100g brain tissue per minute
39
What is the average cerebral blood flow to thegrey matter and white matter?
Grey matter- 75mL/100g/minute
White matter-
45ML/100g/minute
40
At what cerebral blood flow is it classed as ischaemia and at what level is there permanent damage causes?
Ischaemia at 20mL/100g/minute
Permanent damage at 10mL/100g/minute
41
What factor determines cerebral blood flow and how can you calculate this?
Cerebreal perfusion pressure, calculated
CPP=MAP-ICP
42
What factors regulate cerebral blood flow under physiological conditions?
CPP, concentration of arterial CO2, arterial PO2
43
Define cerebral autoregulation
The ability to maintain constant blood flow to the brain over a wide range of CPP (50-150mmHg)
44
What happens to the blood vessels if cerebral perfusion pressure is low or high?
CPP is low the cerebral arterioles dilate to allow adequate flow at the decreased pressure
CPP is high, the cerebral arterioles constrict
45
Under what pathological conditions can cerebral blood flow not be autoregulated?
If CPP exceeds 150mmHg (hypertensive crisis), exudation of the fluid from the vascular system with resultant vasogenic oedema, toxins such as CO2, first 4-5 days of head trauma
46
Define cerebral oedema
Is a state of increased brain volume as a result of an increase in water content, a prominent cause of subacute to chronic intracranial hypertension
47
Go over different types of oedema
On spreadsheet
48
What does the Monro-Kelly Doctrine state?
When a new intracranial mass is introduced a compensatory change in volume must occur through a reciprocal decrease in venous blood or CSF to keep total incracranial volume constant
49
Define compliance
Change in volume observed for a given change in pressure
dV/dP
50
Define elastance
Change in pressure observed for a given change in volume
dP/dV
Represents the accomodation to outward expansion of an intracranial mass
51
What is the homeostatic mechanism 8-15 mmHg?
When the venous system collapse and squeezes venous blood out throuhg jugular, emissary and scalp veins
CSF is displaced from ventricular system through the foramina of Luschka and Magendie into spinal subarachoid space
This is done in response to increased volume
52
Describe Lundberg A waves
Abrupt elevation in ICP for 5-20 minutes followed by a rapid fall in the pressure to resting levels, amplitude may reach as high as 50-100mmHg
53
Describe Lundberg B waves
Frequency of 0.5-2 waves per minute, are related to rhythmic variations in breathing
54
Describe Lundberg C waves
Rhymthic variations related to waves of systemic blood pressure have small amplitude
55
What is Cushing's reflex and what is it characterised by?
Is a vasopressor response in response to increased ICP (>MAP), characterised by hypertension, irregular breathing and bradycardia
56
How would you manage increased ICP?
head and elevation, mannitol/ hypertonic saline, hyperventilation- decreased CBF, barbiturate coma (decrease cerebral metabolism, CBF), surgical decompression
57
What levels does the spinal cord extend?
C1-L2
58
Is weakness a sign of UMN or LMN lesion
Both
59
Is atrophy a sign of UMN or LMN lesion
LMN
60
Are decreased reflexes a sign of UMN or LMN lesion
LMN
61
Are increased reflexes a sign of UMN or LMN lesions?
UMN
62
Is increased tone a sign of UMN or LMN lesion
UMN
63
Is decreased tone a sign of UMN or LMN lesion
LMN
64
Is fasiculations a sign of UMN or LMN lesion
LMN
65
Is babinski a sign of UMN or LMN lesion
UMN
66
Spinal level myotome actions
On sheet
67
Dermatomes
On sheet
68
Define disc prolapse
An acute herniation of intervertebra disc causing compression of spina roots or spinal cord, can occur centrally causing- cervical/thoracic myelopathy/cauda equine syndrome or occur laterally causing radiculopathy
69
Sympoms/signs/investigations for disc prolapse?
acute pain down arm/leg, numbness and weakness in distribution of nerve root involves, investigate with MRi
70
Disc prolapse management?
rehabilitation, nerve root inject, lumbar/ cervical discetomy
71
Whar are some of the causes of degenerative spinal diseases?
disc prolapse, ligamentum hypertrophy, osteophyte formation
72
Define cervical spondylosis
Umberella term for degenerative change in cervical spine leading to spine and nerve root compression, patient presents with either myelopathy or radiculopathy
73
cervical spondylosis management
surgery for progressive moderate to severe myelopathy otherwise conservation
74
the 3 sub categories of spinal tumours
Extradural, intradural and intramedullary
75
Examples of extradural tumours
Metastases, primary bone tumours
76
Examples of intradural tumours
meningioma, neurofibroma, lipoma
77
Examples of intramedullary
astrocytes, ependymoma, teratoma, haemangioblastoma
78
Investigation for malignant cord compression and treatment
malignant cord compression considered if patient presenst with pain, weakness, sphincter disturbance
need MRI
Management involves surgical decompression and radiotherapy
79
Name 3 types of spina linfections
osteomyelitis- infection within vertebral body
Discitis- infection of intervertebral disc
Epidural abscess- infection in the epidural space
80
A patient presents with back pain, pyrexia and focal neurology, what is the dianosis and what investigation would you use?
urgent MRI and epidural abscess
81
What are the risk factors for epidural abscess?
IV drug abuse, diabetes, chronic renal failure, alcoholism
82
What organisms cause an epidural abscess?
staph aureus, streptococcus, e.coli
83
How is an epidural abscess managed?
with urgent surgical decompression and long-term IV antibiotics
84
What are the risk factors for osteomyelitis?
IV drug abuse, diabetes, chronic renal failure, alcoholism, AIDS
85
How do you treat oteomyelitis?
with antibiotics
86
What is the purpose of a cognitive assessment?
To raise the possibilty of cognitive impairments which may need further assessment/ onwards referral and may impact treatment/ consent
87
What are you assessing in a cognitive assessment?
memory, language, processing speed, attention/ concentration, executive functioning, personality, insight, visual spatial,
88
Names of methods used to assess?
Hodges, Addenbrooke's Cognitive Examination-III, MOCA
89
How do you treat congnitive problems
quantifying and monitoring change, pre and post surgery assessments, impact of medication on cognition, rehab potential, behavioural management, cognitive rehabilitation, support and education, advice on return to work/ education, advice on care requirements
90
Hydrocephalus types
On spreadsheet
91
Describe the process of production of CSF
CSf is produced by the choroid plexus within the brain through a metabolically active process whereby Na is pumped into the subarachnoid space and water follows from the blood vessels.
92
How much CSF does the average adult brain produce in a day?
450-600cc's of CSF every day
93
At any given moment how much CSF is present in an average adult?
150cc's of CSF, only 25cc's is whith the brain ventricles
94
Whch formen does the CSF travel through to get from the lateral ventricle to the 3rd ventricle?
Foramen monro
95
Which foramen does the CSF travel through to pass from the 3rd ventricle to the 4th ventricle?
Cerebral aqueduct of Sylvius
96
Which foramen does the CSF exit the 4th ventricle via?
Exits through either of two Foramina of Luschka (L=lateral) or the single foramen of Magendie (M=midline)
97
After the CSF has left the 4th ventricle what path does it take
CSF flows through the subarachnoid space around brain and spinal cord, is eventually reabsorbed into the venous system through numerous arachnoid granulations along the dural venous sinuse`s
98
When do arachnoid villi open?
Arachnoid granulations contain arachnoid villi open when the ICP is 3-5cm H2O greater than dural venous sinus pressure
99
How is CSF reabsorbed
CSF is reabsorbed by the pressure gradient between the intracranial space (ICP) and the venous system
100
Indications for performing a lumbar puncture
to obtain CSF for the diagnosis of:
meningitis, meningoencephalitis, subarachnoid haemorrhage, malignancy, idiopathic intracranial hypertension, other neurologic syndromes, infusions of drugs or contrast
101
Contraindications for performing a lumbar puncture
unstable patient with cardio or resp instability, localised skin/ soft tissue infection over puncture site, evidence of unstable bleeding disorder, increased intracranial pressure, chiari malformations
102
Size of spinal needle normally used in a lumbar puncture
22 gauge
1. 5 <1yr
2. 5 for 1yr to middle childhood
3. 5 for older children and adolescents
use atraumatic needles, less spinal headaches
103
What position should a patient lie in before getting a lumbar puncture?
Lateral Decubitus position:
maximally flex spine without compressing airway, keep alignment of feet, knees and hips, position head to left if right handed or vice versa
104
Describe the steps of a lumbar puncture?
Apply topical anesthetic 30-45 mins prior to procedure at site L3-L4
Put patient in lateral decubitus position
Cleanse skin with povidone iodine (puncture site and radially out to 10cm, allow to dry)
Drape patient
Anesthetize with lidocaine if topical wasn't used (by intradermally raising a wheal at needle insertion site)
Insert spinal needle with stylet with bevel up, aim towards umbilicus directing needle slightly cephalad
A pop of sudden decrease in resitance indicated that the ligamentum flavum and dura are punctured
Remove stylet and check for flow of spinal fluid
When CSF flows, attach a manometer to obtain opening pressure, attach the manometer with a 3 way stopcock, record column with highest level is achieved and respiratory variation is noted.
Collect 3 vials each 1ml of CSF
Check closing pressure with manometer
Reinsert stylet and remove needle in one quiick motion
Cleanse back and cover puncture site
105
When conducting a lumbar puncture and you have got to the step of checking for spinal fluid flow, if there is no fluid what should you do?
Rotate needle 90degrees, and then reinsert the stylet and advance needle slowly checking frequently for CSF
If in a low flow situations, compression of the jugular vein can increase CSF pressure
106
What are the 3 vials collected in a lumbar puncture of CSF used to check?
Tube 1- culture and gram stain
tube 2- glucose and protein
tube 3- cell count and differential and extra CSF
107
How would you hold a child during this procedure?
Hold infant's hands between flexed legs with one hand and flex head with other hand
108
What is the paramedian (lateral) approach for lumbar puncture?
needle passes through eerector spinae muscles and ligamentum flavum
This is used for patients who have calcifications from repeated LPs or anatomical abnormalities
109
Complications from a lumbar puncture
headache, apnea, back pain (can cause disc herniation), bleeding or fluid leak, infection, pain, haematoma, subarachnoid epidermal cyst, ocluar muscle palsy, nerve trauma, brainstem herniation
110
How to improve a spinal headache caused from a lumbar puncture
make patient supine for at least 2hours, hydration, caffeiene, epidural blood patch
111
How to prevent spinal headache from lumbar puncture
passing needle bevel parallel to longitudinal fibres of dura, replacing stylet before removing needle, using small diameter needles, using atraumatic needles
112
if a patient feels an electric shock or dysesthesias when doing a lumbar puncture what do you do?
wihtdram needle immediately, if the pain or motor weakness continues start corticoseroids and schedule electromyogram/ nerve conduction velocity studies
113
What do you do if a herniation occurs during a lumbar puncture?
it manifests as altered mental status followed by cranial nerve abnormalities and Cushing triad, is rapidly fatal.
immediately remove needel and raise head of bed 30-45o and use mannitol or 3% slaine, intubate and hyperventilate, emergency neurosurgical consult
114
How does an epidermal inclusion cyst occur when completing a lumbar puncture
Due to use of stylet and occurs when a core of skin is driven into spinal or paraspinal space with hollow needle, you should not remove stylet until through the skin
115
What should normal CSF results be?
appears clear and colourless, opening pressure is 6-16mm/H2O
Protein level-35mg%
glucose level-60mg%
WCC<5
116
Define a coma
A state of unrousable psychological unresponsiveness in which the subject lies with eyes closed and show no psychologically undertandable response to external stimulus or inner need
117
What are the 2 things consciousness depends on?
intact ascending reticular activatinf system (arousal) and a functional cerberal cortex (content of consciousness, awareness)
118
Common causes of GCS
Toxic/ metabolic states (hypoxia/ hypercapnia/ sepsis /hypotension, drug intoxication, renal or liver failure, hypoglycaemia, ketoacidosis), seizures, damage to reticular activating system, causes of raised intracranial pressure (tumour, stroke, EDH, SDH, SAH, hydrocephalus)
119
Define a persistent vegetative state
A state in which the brain stem recovers to a considerable extent but there is no evidence of recovery of cortical function
120
What is "locked-in" syndrome
Patient has total paralysis below 3rd cranial nerve nuclei, so no horizontal eye movements
121
If a patient is unconscious and has a depressed respiration what are common causes?
drug overdose, metabolic disturbance
122
If a patient is unconscious and has a increased respiration what are common causes?
hypoxia, hypercapnia, acidosis
123
If a patient is unconscious and has a fluctuating respiration what are common causes?
brainstem lesion
124
Using the GCS what is considered a coma?
GCS = to 8
eye opening <2/=2
verbal response <2/=2
Motor response 4 or less
125
Causes of a coma without focal or lateralising signs and without meningism?
anoxic/ ischaemic conditions, metabolic disturbances, intoxications, systemic infections, hyperthermia/ hypothermia, epilepsy
126
Investigations for causes of a coma without focal or lateralising signs and without meningism?
toxicology, blood sugar and electrolytes, hepatic and renal function, blood gases, BP, CO poisoning
127
Causes of a coma without focal or lateralising signs but signs of meningism?
subarrachnoid haemorrhage, meningitis, encephalitis
128
Investigations for causes of a coma without focal or lateralising signs but signs of meningism?
CT head scan, LP (appearance, cell count, glucose level, capsular antigen tests)
129
Causes of a coma with focal or lateralising signs and without meningism?
cerebral tumour, cerebral haemorrhage, cerberal infarction, cerebral abscess
130
What does a subdural haematoma look like on CT
convex
131
What does a extradural haematoma look like on a CT scan?
concave
132
Parasympathetic function of the facial nerve?
lacrimation, salivation of submandibular and sublingual glands
133
Parasympathetic function of the glossopharyngeal nerve?
parotid gland
134
What is the location on the III and IV cn nuclei?
midbrain
135
What is the location on the V, VI and VII cn nuclei?
pons
136
What is the location on the VIII cn nuclei?
pontomedullary junction
137
What is the location on the IX, X, XI cn nuclei?
medulla
138
If someone presents with unusual combinations of cranial nerve sings what should be suspected?
chronic or malignant meningitis
139
If someone present with pure motor signs what condition is expected?
myasthenia gravis
140
Optic neuritis
on spreadsheet
141
Causes of dilated pupils?
youth, dim lighting, anxiety, excitement, "mydriatic" eye drops, amphetamine, cocaine overdose, 3rd nerve palsy, brain death
142
Causes of small pupils
old age, bright light, "miotic" eye drops, opiate overdose, horner's syndrome
143
Causes for painless, pupil spared isolated 3rd nerve palsy?
microvascular- diabetes, hypertension
144
Causes for painful, pupil affected isolated 3rd nerve palsy
posterior communicating artery aneurysm, raised ICP
145
Isolated 6th nerve palsy causes?
idiopathic, diabetes, meningitis, raised intracranial pressure
146
Causes for nystagmus?
congenital, serious visual impairment, peripheral vestibular problem, central vestibular/ brainste disease, cerebellar disease, toxins (medication and alcohol)
147
What is trigeminal neuralgia?
paroxysmal attacks of lanciating pain caused by a vascular loop- compression of 5th nerve in the posterior fossa
148
How is trigeminal neuralgia treated?
with carbamazepine
149
What is Bell's palsy
unilateral facial weakness, lmn palsy, often have pain behind ear, eye closure is often affected, treated with steroids
150
How can you tell the difference between UMN or LMN facial paralysis
In UMn both sides of the face will get wrinkles which asked to scruch their face- UMN would be a stroke or tumour
151
What is vestibular neuronitis?
Has a sudden onset and has symptoms of disabling vertigo, vomiting
152
Pseudobulbar palsy and bulbar palsy
on spreadsheet
153
Is pseudobulbar palsy a UMN or LMN lesion
UMN
154
Is bulbar palsy a UMN or LMN lesion
LMN
