Clinical Examination Flashcards
Concepts to approach threatening topics
Normalizing questions
Symptom expectation and reduction of guilt
Symptom exaggeration
Familiar language when asking about behaviours
Purpose of normalizing questions?
Decrease patients embarrassment about feeling or behaviour
Purpose of symptom expectation?
Defuse admission of embarrassing behaviour
Purpose of symptom exaggeration?
Determine actual frequency of sensitive or shameful behaviour
Techniques to change topics?
Smooth transitions
Referred transitions
Introduced transitions
When to use smooth transitions?
To hint at something the patient just said
When to use referred transitions?
Hint at something mentioned earlier
When to use introduced transitions?
To pull a new topic from thin air
What are directive techniques?
Focused on seeking a particular answer or driven by motives of doctor.
Give e.g. of limit setting
I am going to interrupt you as there are a few things to cover.
Name some directive techniques
Limit setting Closed questions Question rephrasing Redirection Transition
Describe confrontation
Point out to a patient something which the doctor thinks the patient is missing or denying
Give e.g. of suggestive question
These voices are not from your head. Am I right?
What is functional analysis?
Attempts to explain and predict functions of a phenomenon by examining any relationships to the outcome.
What medical intervention can confirm a panic disorder?
Lactate provocation
Hyperventilation
CO2 inhalation
What inhibits panic attacks triggered by sodium lactate?
Benzos
TCAs
In which psychiatric diagnosis is infusion of amobarital (narcoanalysis) helpful?
Catatonia Stupor Muteness Repression Dissociation
What happens to organic conditions when infused of amobarbital?
They worsen
Why do non-organic conditions get better with infusion of amo-barbital?
Due to disinhibition, decreased anxiety or increased relaxation
What can be substituted for amo-barbital?
Benzos
Investigations for suspected encephalitis syndrome
NMDA receptor and voltage-gated K+ channel receptor auto-antibodies (IgG0
Investigations for porphyria
Spot urine sample for porphobilinogen during acute attack and 24 hour urine for porphyrins, porphobilinogen and delta-aminolevulinic acid
Investigations for Wilsons Disease
Serum ceruloplasmin
24 hour copper excretion test
Investigations for lysosomal storage disease
Skin biopsy
Genetic tests
Detection of serum alpha-galactosidase enzyme
Investigations for Homocystinuria?
Homocysteine in urine and blood
Molecular genetic testing
Investigations for metachromatic leukodystrophy
Arylsulfate A enzyme activity in WCCs or in cultured skin fibroblasts
Investigations in malnourishment
Serum homocystine and folate Vitamin B12 Niacin Trytophan Nicotinamide adenine Dinucleotide (NAD) and NADP
Difference between AIP and porphyria?
AIP does not present with rash
Onset of porphyria
18-40 years of age
What triggers AIP?
Oestrogens
Barbituates
Benzos
Diclofenac
Treatment for AIP
Haemin - reduces haem synthesis
important receptors involved in autoimmune encephalitis
Voltage gated K+ channel complex - LGI1, CASPR2, contactin-2 NMDA AMPA receptor GABA-B Glycine receptor
How do anti-NMDA receptor antibodies work?
Titre-dependent destruction of synaptic NMDAR through crosslinking and internalisation
Gender variability in anti NMDAR encephalitis?
80% are female
50% of women with it have underlying ovarian teratoma
How does psychosis with anti NMDAR first present usually?
Fever, headache, malaise
EEG in anti-NMDAR encephalitis?
Disorganized delta/theta activity
What to look for in MRI in anti-NMDAR encephalitis?
Medial temporal hyperintensity in hippocampi, frontobasal and insular regions in basal ganglia
How to confirm anti-NMDAR encephalitis?
CSF: lymphocytic pleocytosis, elevated protein and oligloclonal bands in 60%, anti-NMDAR antibodies.
Treatment of anti-NMDAR encephalitis
3 days of methylprednisolone PO/IV followed by PO prednisolone in association with 5 days of plasma exchange
Why must you not give antipsychotics in anti-NMDAR encephalitis?
Dystonic reactions and NMS-like syndrome can occur
What type of thyroid problem can cause cognitive impairment?
Low T4
When would EEG be required to diagnose dementia?
Rapid onset; may suggest CJD.
Need EEG and MRI
TFTs in patients with anorexia
Low T3
Low normal range T4
Normal TSH
(low T3 syndrome)
GI effects of anorexia
Delayed gastric emptying
Decreased colonic motility - secondary to chronic laxative misuse
Acute gastric dilatation - rare, secondary to binge eating
Haematological signs of anorexia
Moderate normocytic anaemia
Mild leucopenia with relative lymphocytosis
Thrombocytopenia
Electrolyte result of laxative misuse
Metabolic acidosis
Hyponatraemia
Hypokalaemia
Brain abnormalities resulting in anorexia
Enlarged cerebral ventricles and external CSF spaces (pseudo atrophy)
BMI for obesity
30 or greater
Most specific and sensitive test for detecting heavy alcohol use over 10 days
Carbohydrate deficiency test
What is Marchiafava syndrome?
Corpus callosum damage often due to alcohol misuse
Normal QTc for men
440ms
Normal QTc for women
470ms
Which recreational drugs increase risk of QTc prolongation?
Stimulants
Method of testing drug use aside from urine
Specific gravity in urine
How long is alcohol present in urine?
Up to 12 hours
How long is amphetamine present in urine?
Up to 48 hours
How long is benzo present in urine?
3 days depending on half life
How long does cannabis last in urine if occasional use?
Up to 3 days
How long does cannabis last in urine if high daily use?
Up to 4 weeks
How long does cocaine last in urine?
6-8 hours
How long does cocaine metabolite last in urine?
2-4 days
How long does codeine stay in urine?
48 hours
How long does heroin last in urine?
1-3 days
How long does methadone stay in urine?
3 days or more
How long does morphine last in urine?
2-3 days
How long does PCP stay in urine?
8 days
Which recreational drugs are associated with renal disease?
Cocaine
Heroin
Common renal dysfunction in black patients with drug misuse
Segmental glomerulosclerosis
Common renal dysfunction in white patients
Membranoproliferative glomerulonephritis
Plasma and urine osmolality in diabetes insipidues
Plasma: High (>295)
Urine: low
Plasma and urine osmolalities in psychogenic polydipsia?
Plasma: Low (<280)
Urine: Low
Plasma and urine osmolalities in SIADH
Plasma: low
Urine: high
At what Na level do symptoms of hyponatraemia occur?
Na <125
At what Na level can seizures and irreversible brain damage occur?
Below 110-115
Most common cause of Argyll-Robertson pupil
Diabetes
What is checker-board abdomen?
Multiple surgical scars in factitious disease
In which drug misuse is piloerection seen?
Opiate withdrawl
How can one rate Minor Physical anomalies?
Lane Scale
In what type of patients are Minor Physical Anomalies noted?
Developmental disorders
Which tuning fork is used to test auditory function?
512Hz
Which tuning fork is used to test peripheral neuropathy?
128 Hc
What type of diseases result in a positive Romberg test?
Polyneuropathies
Disease of dorsal column
Normal caloric testing result
On cold water testing, nystagmus noted to opposite side.
On warm water, nystagmus to same side
What are hard neurological signs?
Imapirments of basic motor and sensory functions that are localisable to pyramidal, extrapyramidal or cranial nerve systems.
what are neurological soft signs?
Non-localisable neurological findings thought to reflect neurodevelopmental aberrations when seen in psychiatric disorders.
Three groups of soft signs
Abnormalities of motor coordination, sensory integration and signs of cortical disinhibition
Signs of midline cerebellar dysfunction
Ataxic gait
Difficulty in maintaining upright posture
Truncal ataxia
What is the neocerebeullum?
Lateral cerebellar hemispheres
What does neocerebeullum control?
Movement of ipsilateral limb
What is the midline vermis involved in?
Control of truncal tone, speech and eye movements
What is the archicerebeullum?
Flocculonodular lobe
What does flocculonodular lobe do?
Vestibular functions
What part of the cerebellum controls vestibular functions?
Archicerebellum/flocculonodular lobe
How to test for ataxia
Tandem gait
Which type of tremor accelerates in pace on approaching the target
Intention tremor
What is dyssynergia?
Incoordination
What is dysmetria?
Past pointing
What is dysrhythmia?
Inability to tap and keep to a rhythm
What is dysarthria a sign of?
Diffuse involvement of cerebellum
What is the Brudzinski sign?
Flexion of hips and knees when you try to flex the neck
What is Kernigs sign?
Flexing one hip and knee and then extending knee with hip still flexed. If opposite knee flexes, this test is positive
What is another name of the straight-leg raising test?
Lasegue
Describe the straight leg raising sign
Passively flexing hip with knees straight while patient is in supine position.
Limitation of flexion due to hamstring spasm or pain indicates local irritation of lower lumbar nerve roots
Describe reverse straight leg raise sign
Passively hyperextending hip with knees straight while prone; limitation of extension due to spasm or pain in anterior thigh muscle indicates local irritation of upper lumbar nerve roots
Functions of cortical sensory system
Kinaesthetic sensation Stereognosis Graphesthesia Tactile localization Tactile 2 point discrimination on both sides of body
Which type of fibrillations are visible?
TOngue
Describe myoclonus
Brief <0.25 second muscle jerk, generalized.
What is myoclonus associated with
Generalized epilepsy
CJD
Severe Alzheimers
What is athetosis
Slow writhing spasms along long axis of limbs or body itself.
What is chorea
Quasi-purposeful movements affecting multiple joints with distal preponderance.
What lesion is chorea associated with?
Caudate
What is hemiballismus?
Violent flinging of half of body
What area of the brain is hemiballismus associated with?
Lesion of subthalamic nucleus
Give examples of primary reflexes
Glabellar tap Rooting Snout Sucking Palmomental
What are primary reflexes?
Absent in adults
What does primary reflex in adult suggest?
Possible frontal lobe damage
What are superficial reflexes?
Responses that indicate integrity of cutaneous innervation and corresponding motor outflow
What are the superficial reflexes?
Corneal and conjunctival
Abdominal
Cremasteric
Plantar
What controls corneal and conjunctival reflexes?
Afferent: 5th nerve
Efferent: 7th nerve
What is the abdominal reflex/
Drawing line away from umbilicus in diagonals of 4 abdominal quadrants. Normal reflex draws umbilicus towards direction of line.
Describe cremasteric reflex
Scratching medial surface of thigh to elicit scrotal contraction or lift.
Normal: elevation of ipsilateral testis.
What does lack of both positive and negative Babinski sign suggest?
Absence of cutaneous innervation in S1 or loss of motor innervation in L5
What is required for a deep tendon reflex?
Intact cutaneous innervation
Motor supply
Cortical input to corresponding spinal segment
Spinal roots of biceps reflex
C5, C6
Spinal roots of brachoradialis reflex
C6
Spinal roots of triceps reflex
C7
Spinal roots of patellar reflex
L2-L4
Spinal roots of Achilles reflex
S4
What type of lesion is a pseudobulbar palsy?
UMN lesion
What type of lesion is exaggerated jaw jerk?
UMN lesion
What type of lesion is bulbar palsy?
LMN
Which disease is frontal baldness associated with?
Myotonic dystrophy
Neurocutaneous signs of Tuberous Sclerosis
Dermatomal eruptions
Ash leaf macules
Ungual fibromas
Café au lait spots
Neurocutaneous signs of Neurofibroma
café au lait spots
Axillary freckling
Describe spastic dysarthria
Strained, hoarse voice
Hypernasality
Slow, imprecise articulation
Cause of spastic dysarthria
Bilateral UMN lesions
Cause of flaccid dysarthria
LMN
XII nerve involved if tongue is small due to loss of tone
Cause of ataxic dysarthria
Cerebellar
What is ataxic dysarthria?
Excess loudness, tremor and irregular articulatory breakdowns (scanning speech)
What is hypokinetic dysarthria
Breathy monotone voice with reduced loudness and articulation leads it to be accelerated and imprecise
Damage leading to hypokinetic dysarthria?
Motor control circuit
Which type of speech is associated with basal ganglia damage?
Hyperkinetic dysarthria
Describe hyperkinetic dysarthria
Strained hoarseness and voice arrests
Describe mixed dysarthria
Similar to spastic, accompanied by wet sounding voice with rapid tremor, poor laryngeal and tongue movements and poor control of lips
What results in mixed dysarthria?
Damage to more than one motor control system
What happens in hysterical aphonia?
Sudden loss of voice but preserved vocal cord activity
Normal examination
What type of dysarthria results from bilateral UMN lesions
Spastic
What type of dysarthria results from LMN lesion?
Flaccid
What type of dysarthria results from motor control circuit?
Hypokinetic
What type of dysarthria results from multiple motor system damage?
Mixed
What disorder leads to hemiparetic gait?
Stroke affecting pyramidal system
How does hemiparetic gait present?
Clenched hand with extended knee and plantarflexed ankle.
Makes paralyzed leg appear longed than other. Results in circumduction of affected leg when walking.
What results in patient veering to one side with ataxic gait?
Unilateral cerebellar lesion - patient veers to side of lesion
What causes steppage gait
Chronic peripheral neuropathies e.g. drop foot and dorsal column disorders
What compensation occurs in proximal myopathy resulting in waddling gait
Forward curvature of lumbar spine adds to body swing.
What diseases result in waddling gait?
Proximal myopathy
Congenital hip dislocation
Near term pregnant women
What disease causes scissoring gait?
Spastic paraplegia
How does scissoring gait present?
Marked rigidity and excessive adduction of swinging leg together with plantar flexion of ankle and flexion at knee due to contractures of all spastic muscles leads to forced tip-toe walking with knees rubbing together and crossing like scissors.
What condition caused gait apraxia/magnetic gait?
Hydrocephalus
Conditions causing high stepping gait due to foot drop?
Neuropathic
Polio
Peripheral lesions in MS
What type of gait occurs in Huntingtons?
Lurching, chaotic gait
What conditions lead to pigeon gait?
Torsional abnormalities seen in hip dysplasia
What gait occurs with Carbon monoxide poisoning?
Propulsive
What conditions cause stiff, scissoring gait?
UMN lesions
Cerebral lesions
Cortical lesions in MS
Stroke
What conditions cause stomping gait?
Friedreich’s ataxia
Pernicious anaemia
Tabes Dorsalis (Syphilis)
What causes Trendelenburg gait?
Weakness of abductor muscles of lower limb, mainly gluteus medius
Conditions causing absent ankle jerks and upgoing plantars?
Subacute combined degernation cord
Syphilitic taboparesis
Friedrich’s ataxia
MND
Underlying pathology causing absent ankle jerks and upgoing plantars
Absence of absence jerk as spinal reflex pathway is affected (afferent) while UMN type damage still produces Babinski
What is anisocoria?
Pupil asymmetry
Which type of nervous system deficit leads to tonic pupil?
Parasympathetic dysfunction
What is Argyll-Robertson pupil?
Irregular and small
Doesn’t react to light but does accommate
Damage leading to anosognosia
Right frontoparietal lesions resulting in left hemiplegia that patient denies
What is Beevor sign?
Upward deviation of umbilicus when patient tries to raise head and sit up from supine position
When is Beevor sign seen?
Bilateral lower abominal paralysis
Signs of lateral corticospinal damage
Ipsilateral spastic paralysis below level of lesionn
Babinski sign ipsilateral to lesion
UMN type hyper-reflexia
Signs of posterior column damage
Ipsilateral loss of tactile discrimination, vibratory and position sensation below level of lesion
Signs of lateral spinothalamic damage
Contralateral loss of pain and temperature sensation, usually 2-3 segments below level of lesion
Describe Chvoestek sign
Tapping cheek at angle of jaw precipitates tetanic facial contractions
What does Chvoestek sign occur?
Hypocalcaemia
Describe Doll’s eye maneuver?
Turning head passively with patient awake and fixated or patient in coma.
Result of Doll’s eye maneuver in awake patient?
Eyes remain fixated at original focus when all gaze pathways normal
Result of Doll’s eye maneuver in coma?
Eyes deviate in opposite direction with brainstem intact
What type of disease is Friedreich’s ataxia?
Trinucleotide repeat
Signs in Friedreich’s ataxia?
Pes cavus Kyphoscoliosis Cerebellar signs Impaired joint position/vibration Cardiomyopathy Optic atrophy
What is seen in Holmes Adie syndrome?
Benign tonic pupil
Absent patellar and achilles reflexes
Signs in Horner’s syndrome
Ptosis Anhidrosis Miosis Enophtholmos Loss of cilospinal reflex
Describe Marcus Gunn pupil
Abnormal pupil dilates as light swings back from normal side.
Pathology underlying Marcus Gunn pupil
Afferent (optic nerve) pupillary defect
Describe mononeuritis multiplex
Painful asymmetric asynchronous sensory and motor peripheral neuropathy with isolated damage to at least 2 separate nerve areas
Causes of mononeuritis multiplex
Diabetes Vasculitis Amyloidosis Direct tumour involvement Autoimmune disorders Paraneoplastic
What is milkmaid’s grip
Inability to maintain sustained grip
What pathology does Milkmaids grip occur in
Chorea
What is Myerson sign?
Continuing to blink with repeated glabellar taps
In which diseases does Myerson sign occur
Parkinsons, particularly those with bilateral frontal lobe dysfunction
Triad of optic neuritis
Loss of vision Eye pain Dyschromatopsia (70% unilateral) Spontaneous recovery
Describe Uhthoff symptom
Exercise/heat-induced vision loss - MS
Cause of subacute combined degeneratio
Vitamin B12 deficiency
Signs of subacute combined degeneration
Peripheral neuropathy
Posterior column signs with pyramidal signs below wait
Which types of patients show trombone tongue?
Patients with chorea
What is trombone tongue?
Unsteadiness of tongue when patient tries to protrude it outside mouth
Signs of UMN lesion
Rigidity
Hypertonia
Exaggerated reflexes
Mild atrophy
Signs of LMN lesion
Atonia/hypotonia
Loss of deep tendon reflexes
Atrophic, wasted
Fasciculations
Cause of bulbar palsy
LMN weakness of CN 9-12
Cause of pseudobulbar palsy
Bilateral supranuclear (UM) lesions of lower CN
Signs of Bulbar palsy
Wasted, fasciculating tongue
Nasal speech
Loss of jaw jerk and gag reflex
Diseases in Bulbar palsy
MND Polio Botutilism Myasthenia Gravis Muscular dystrophies
Signs of pseudobulbar palsy
Stiff tongue - wasting only in later stages
Donald-duck speech
Exaggerated jaw jerk, preserved gag reflex
Emotional lability
Diseases in pseudobulbar palsy
MND
MS
Multiinfarch dementa
Severe HI
In which type of lesion is there Donald Duck speech?
UMN
In which type of lesion is there loss of jaw jerk and gag reflex?
LMN
Who created the MMSE?
Folstein, 1976
How many points in MMSE
30
Cut off for dementia in MMSE
23/24
21/22 if less than 9 years formal education
What is MMSE insensitive to
Early decline
What does MMSE not pick up
Frontal executive defects
Items in MMSE
Orientation (10) Registration (3) and recall (3) Attention (5) Multistep command (3) Naming (2) Repetition language (1) Reading comprehension (1) Writing (1) Visual construction (1)
What does clock drawing test require
Verbal understanding
Short-term memory
Spatially coded knowledge
Constructive skills and planning - executive function
Which subjects perform poorly in clock drawing test?
Low education
Advanced age
Depression
What can normal clock drawing ability reasonably exclude?
Cognitive impairment
Who created the Clock drawing test?
Watson
What is the clock drawing test scored out of?
7
Normal score for clock drawing test
0-3
How many digits is deemed to be correct in clock drawing test
Placing of any three digits in a quadrant
What does Addenbrookes test
Orientation Attention Memory Verbal fluency Language Visuospatial ability
What test helps to differentiate subtypes of dementia?
Addenbrookes
Cut off for dementia in Addenbrookes
82
Major area of scoring in Addenbrookes
Language
What determines CT image contrast?
Degree to which tissues absorb x-rays
Which structures are likely to be obscured in CT?
Those close to bone e.g. brainstem
Plane of rotation of CT?
One - axial
How can one visualise tumours and inflammation in CT?
Infusion of iodine-containing contrast agents; once in vascular compartments, iodinated compounds absorb more irradiation than brain tissue
What area of the brain does CT have poor visualization capacity for
Posterior fossa
What are MRI magnets rated in
Tesla units of magnetic field strength
What happens when atoms are placed in a magnetic field
Axes of all odd-numbered nuclei (i.e. H1) align with magnetic field
This axis deviates away from magnetic field when exposed to pulse of radiofrequency electromagnetic radiation oriented at 90 or 180 degrees to magnetic field.
When pulse terminates, axis of spinning nucleus realigns itself with magnetic field and emits its own radiofrequency signal.
This is collected by MRI scanners
Planes of MRI
Axial
Coronal
Sagittal
What affects the realignment of H1 axis?
Immediate environment and degree of water content
Difference between hydrogen in fat and wat
Fat: realign rapidly
Water: realign slowly
Describe pulses in T1 images
Brief
What is emphasised in T1 images?
Hydrophobic environments - i.e. fat is bright, CSF is dark
In which type of MRI is CSF dark?
T1
Which type of MRi scan closely resembles CT?
T1
Which MRI scan allows contrast enhancement with contrast agent gadolinium-DTPA?
T1 - these appear white
Pulses in T2
Four times as long as T1
What images are emphasised in T2?
Signal from hydrophilic areas - brain tissue is dark, CSF is whtie
What is revealed in T2 images?
Brain tissue with abnormally high water content - tumours, inflammation, strokes
What is protein density sequence in MRI helpful for?
Periventricular structures
What is fluid attenuated inversion recovery (FLAIR) in MRI?
When T1 image is inverted and added to T2 image to double contrast between gray and white matter
What is FLAIR in MRI images helpful for?
Detecting sclerosis of huppocampus caused by temporal lobe epilepsy
Localizing areas of abnormal metabolism in degenerative neurological disorders
When are MRI scans contra-indicated?
PPM
Implants of ferromagnetic metals
Radiation in MRI?
None
Which scan has good sensitivity to early ischaemia?
MRI
How does infarct appear in T2 image?
Bright
How does infarct appear in T1 image?
Dark
How does infarct appear in CT?
Infarct
How does haemorrhage apear in T2?
Bright
How does haemorrhage appear in T1?
Bright
How do tumours appear in T2?
Bright
How do tumours appear in T1?
Dark
How do tumours appear in CT?
Dark
How does bone appear in T2?
Dark
How does bone appear in T1?
Bright
How does air appear in T2?
Dark
How does air appear in T1?
Dark
How does fat appear in T2?
Bright
How does fat appear in T1?
Bright
How does fat appear in CT?
Dark
How does white matter appear in T1?
White
What can MR spectroscopy detect?
Several biologically important nuclei with odd number of protons and neutrons
What is H1 proton spectroscopy useful for?
To quantify N-acetyl aspartate, creatinine and choline-containing molecules
What cannot be detected with MRS
Dopamine
What can phosphorus-31 MRS determine
pH of brain regions and concentrations of phosphorus-containing compounds i.e. metabolic activity of brain
Other indications of MRS
Measure concentration of psychotherapeutic drugs such as lithium, fluoxetine and trifluoperazine which contain fluorine-19
What is blood oxygen level dependent technique?
Neuronal activity = local increase in o2 consumption, so local conc of deoxyhaemoglobin increases relative to oxyhaemoglobin.
Oxyhaemoglobin is diamagnetic (weak magnetic contrast)
Deoxyhaemoglobin is paramegnetic, producing MR signal detected in T2.
What is fMRI based on?
Blood oxygen level dependent technique
What is fMRI a measure of?
Proxy measure of tissue activity that depends on relative changes in perfusion
Advantage of fMRI over PET and SPECT
No radioactive isotopes used
Structures studied in resting fMRI
Brain regions with high levels of activity during rest: precuneus, lateral parietal regions and medial prefrontal cortex
What are brain networks that show higher baseline activity at rest in fMRI called?
Default mode network
What does SPECT stand for?
Single Photon Emission Computed Tomography
How does SPECT work?
Uses radioactive compounds to study regional differences in cerebral blood flow in brain.
This records patterns of photon emission from bloodstream which varies according to level of perfusion
What does SPECT use?
Compounds labeled with single photon-emitting isotopes
Name the three isotopes used in SPECT
Iodine-123
Technetium-99m
Xenon-133
What type of SPECT is referred to as the cerebral blood flow technique?
Xenon-SPECT
How does Xenon-133 work in SPECT?
Enters blood quickly and is distributed to areas of the brain as a function of regional blood flow
Limitation of Xenon-SPECT
Can only measure blood flow on surface of brain
What do you need to use to assess blood flow in the whole brain?
Injectable tracers such as HMPAO
How does HMPAO work in SPECT?
Attaches to highly lipophilic molecules that cross Blood brain barrier to enter brain cells. Once inside, ligands are enzymatically converted to charged ions, which remain trapped in cell.
Over time, tracers concentrate in areas of high blood flow.
Which compound is used to study receptors in SPECT?
Iodine-123-labeled ligands
What can Iodine-123 ligands be used to study in SPECT?
Muscarinic
Dopaminergic
Serotonergic
(occupancy and distribution)
What compound is used to study D1/D2 receptors in SPECT?
Iodobenzamide
What compound is used to study GABA-A receptors in SPECT?
Iomazenil
What compound is used to study dopamine and serotonin transporters in SPECT?
Nor-beta-CIT
What compound is used to study D2/D3 receptors?
Epidepride
What can PET study?
Blood flow
Receptor distribution
Metabolic activity
Difference between SPECT and PET
SPECT; single particle is emitted
PET: two particles are emitted, thus more precise location for event and better resolution of image
What happens to isotopes used in PET?
Decay by emitting positrons with resolution closer to its theoretical minimum of 3mm
Limitation of PET
Require on-site cyclotron
Most commonly used isotopes in PET
Fluorine-18
Nitrogen-13
Oxygen-15
Which isotope used in PET is not linked to another molecule?
Oxygen-15
Advantage of fluorine-18 used in PET?
Gives direct information about neuronal metabolism
PET ligand used in blood flow
C15/H215O
PET ligand used for glucose metabolism
F18 deoxyglucose
PET ligand used for D2 receptors
11C raclopride
PET ligand used for ropamine neuron density
18F dopa
18F metatyrosine
PET ligand used for GABA-A receptors
11C Flumazenil
PET ligand used for 5HT2 receptors
18F altanserin
Setoperone
PET ligand used in striatal D2 and cortical 5HT2
11C methylspiperone
What PET ligand is used for seretonin synthesis rate
11C methyltryptophan
PET ligand used for muscarinic receptors
11C scopolamine
What does DTI stand for
Diffusion tensor imaging
How does DT1 work
Combines principle of nuclear magnetic resonance and molecular diffusion
What is diffusion in DT1?
Random translational motion of molecules - Brownian notion - that results from energy carried by these molecules
How does DT1 work
During random Brownian motion, molecules probe tissue structure at a microscopic scale beyond usual image resolution; direction of movement determines integrity and trace of white matter tracts
Gradients allowed via DT1
16
In which scan can Fractional Anisotrophy be calculated?
DT1
What is Fractional Anisotrophy?
Index of integrity of white matter
What is tractography?
Using principal direction of diffusion tensor to infer white-matter connectivity of brain
Neuro-imaging findings in depression re metabolism
Decreased metabolism in prefrontal cortex, anterior cingulate and amygdala
Brain volumes seen in depression
Decreased frontal and basal ganglia volumes
Hyperintensities seen in neuroimagingin depression
Periventricular and deep white matter
Subcortical - thalamic and striatal
Neuroimaging findings in treatment response for depression
Higher prefrontal metabolism (anterior cingulate) predict better treatment response
Neuroimaging findings in patients with depression with higher dysfunctional negative thoughts
Higher 5HT2A receptor density
Neuroimaging findings in women with depression
Increased MAO-A activity
Neuroimaging findings in psychomotor retardation in depression
Elevated D2 binding in untreated depression
Neuro-imaging findings in patients on therapeutic dose of SSRIs
80% of 5HT transporters occupied
Neuro-imaging findings in schizophrenia
Ventricular enlargement
Loss of grey matter - insular cortex, anterior cingulate (medical prefrontal cortex) and medial temporal lobe
Neuro-imaging findings in first few years of diagnosis?
Progressive loss of brain volume
Neuro-imaging findingin schizophrenia linked with executive tasks
fMRI revealrs poor DLPFC activation
MRS findings in schizophrenia
Decreased n-acetyl aspartate in PFC (neuronal loss)
Findings in DT1 in schizophrenia
Widespread reduction
Fractional anisotrophy: frontal and corpus callosum - more in chronic treated patients
Neuro-imaging findings in Alzheimers
Ventricular enlargement
Loss of temporal lobe volume - hippocampus
Decreased parieto-temporal fMRI activation and SPECT blood flow
Neuro-imaging findings in OCD
Reduced and increases volumes of caudate nuclei noted (both)
Higher caudate blood flow - increased metabolism
What neuro-imaging findings decrease with effective treatment of OCD?
Higher caudate blood flow reduces with treatment
Neuro-imaging findings in childhood-onset schizophrenia
Ventricular enlargement at baseline and slower growth rates (right hemispheric) white matter also noted
A non-invasive perfusion MRI methodology used to quantify cerebral blood flow is?
Arterial spin labelling
What is used in MRS to measure cellular metabolism?
R-31
What is used in MRS to quantify N-acetylaspartate, choline, glutamatate, lactate and creatinine?
H-1
What is used in MRS to study labelled drugs and deoxyglucose?
F-19
What is Gedankenlautwerden?
Thought echo
What is moria?
Tendency to be inappropriately euphoric
Who came up with the idea of autochthonous delusions?
Wernicke