Deck 1 Flashcards
Patchell’s study findings
patients with MESCC, wide decompression and reconstruction if appropriate can keep patients ambulating and extend life expectancy when paraplegia < 48 hrs, life expectancy > 3 months, and no multiple non-continguous stenotic regions
Suprascapular nerve does…
Supraspinatous - shoulder abduction
Infraspinatous - external rotation
Brachial plexopathy, EMG findings will show sensory nerve action potential will be…
SNAP will be abnormal because injuries distal to DRG
What is the most common major motor nerve affected by diabetic amyotrophy
Femoral nerve
What is Lambert-Eaton syndrome
- caused by antibodies to presynaptic calcium channels, associated with paraneoplastic disorders (SCLC)
- presents with weakness early in the morning and improves with time
- weakness overcome with exercise
What is a high riding vertebral artery
VA passes close to the C2 pedicle, making C2 pedicle screws dangerous
Most cases do not need a contrast scan
What is the decerebrate response, and what spinal cord tract mediates this response
Extension posturing, a lesion between the superior and inferior colliculi releases the inhibition on vestibular nucleus
Vestibulospinal tract begins in the Dieter’s nucleus (vestibular nucleus) and descends to rexed lamina 7, 8, and 9. Mediates extensor tone and usually under tonic inhibition by higher brain centers.
What is the most common mycotic infection in the CNS
Candidiasis
What is the most common bug for diskitis/osteomyelitis related to IVDU
S aureus
What are the contents of the carpal tunnel?
Carpal tunnel is made of bones of the wrist and transverse carpal ligament
It contains median nerve, tendons of the FDS (flexor digitorum superficialis), FDP, and FPL (flexor pollicis longus).
What is the fencer’s posture?
Classic for posterior frontal (motor strip) seizure onset
Head turned to the right, right arm extends, left arm flexes and abducts
Follow-up plan for < 1.5 cm acoustic neuroma with intact hearing
Serial scans every 6 months
If > 2cm, treatment is recommended
What is the most common isolate from brain abscesses in adults?
Strep. milleri
How long will it take IV vitamin K to normalize INR in a patient on warfarin?
24-72 hrs
Because vit K dependent coagulation factors have long half lives
What is the major complication of impenem?
generalized seizures in 3%
Neurenteric cysts: characteristics, pathophysiology
Also embryologic inclusion cyst
Remnants of persistent endodermal cell rests that remained attached to ectoderm
Can rupture and cause meningitis
Ventral location
SRS dose for acoustic neuromas
12-13 Gy, good tumor control with decreased complications to CN 7 and 8
What is the ideal entry for syringosubarachnoid shunt?
Dorsal root entry zone DREZ
May be the thinnest part of the cord
How to differentiate pre and post ganglionic brachial plexus injuries
Preganglionic injuries - from nerve root avulsion; no neurolysis or repair will fix this injury
- often demonstrate winged scapula (long thoracic loss)
- pseudomeningocele
- Horner’s syndrome (lower trunk injuries)
- intact SNAP
Postganglionic injuries have disrupted SNAP
Idiopathic brachial plexitis, “Parsonage-Turner Syndrome”
Severe shoulder pain without weakness, followed by weakness in one or more muscle groups
89% recovery at 3 years
EMG H reflex
S1 nerve; spinal cord reflex arc
if H reflex absent, but F wave is intact, then injury is at the DRG
EMG F wave
a way to determine the integrity of the motor roots
supramaximal stimulation of peripheral motor nerves
wave propagates proximally through nerve root into spinal canal, and fires other nerve roots as well
When is ossification of the axis complete
by 11 years of age
4 different ossification centers
What pathway mediates mydriasis
Hypothalamus –> intermediolateral cell column –> superior cervical ganglion –> long ciliary nerves (dilates pupil)
What is Paget’s disease
“Picture frame vertebral bodies”
Can also have hearing loss, and higher risk of bony tumors
According to landmark controlled trial on MTE, what % of patients complete seizure free at 1 year?
60%
Lateral recess stenosis is a common cause of radicular leg pain, what is compressing on the nerve?
SAP of the vertebrae below
Post op management of DNET
Observation
No XRT or chemo after GTR
WHO grade 1, medically intractable epilepsy
Pineal tumor with + BHCG, - AFP, - PLAP
Choriocarcinoma
Dysembryoplastic gangliocytoma of cerebellum
Also Lhermitte-Duclos syndrome
PTEN mutation
Cowden’s syndrome
also associated with multiple trichilemmomas, breast, and endometrial carcinoma
Wyburg-Mason syndrome
presents with facial nevi, orbital/optic pathway AVMs
presents with SAH, seizures
underlying cause unknown
Marchiafava-Bignami disease
classic “Italian man” disorder, those who consume ++ wine
demyelination, necrosis of CC
onset leads to initially nonspecific symptoms including depression, memory loss, and confusion
Hnad-Schuller-Christian triad
exopthalmos from intraorbital tumor
lytic bone lesions in the cranium
diabetes insipidus from mass
because of Langerhans cell histiocytosis
Difference between a Sunderland grade III and IV lesion
Immobile Tinel’s Sign
In grade III injury, the tinel sign over the injury slowly progresses distally with nerve regeneration
Neuroma in continuity develops in grade IV lesions - Immobile Tinel’s Sign
What is F wave most helpful in determining what underlying disorder?
Multilevel radiculopathy - suggests multilevel involvement
Cause of PCNSL in HIV patient?
EBV, B cell type
5% of HIV patients
median survival 3 months
Joubert syndrome
molar tooth malformation on MRI
cerebellar peduncle hypoplasia
small midbrain
batwing shaped 4th ventricle
Internal arcuate fibers
Decussating connections in the medulla where myelinated neurons from nucleus gracilis and cuneatus form the medial lemniscus
Kawase’s triangle, or posteromedial triangle
V3 mandibular nerve
GSPN inferiorly
superior petrosal sinus
allows by anterior petrosectomy, connecting middle and posterior cranial fossa; contains petrous corner of ICA, and lateral aspect contains the cochlea
SEGA: histology
gemistocytic type cells with large eosinophilic cytoplasm, large eccentric nucleus
Verocay bodies
sequential nuclear palisading
present in schwannomas
Charcot-Marie-Tooth disease
peripheral neuropathies, lower extremity deformities
onion bulb formation in peripheral nerve system
Suprachiasmatic nucleus of hypothalamus
Circadian rhythm
Duration of rocuronium
30-90 minutes
Friedrich’s ataxia
autosomal recessive
mutation in frataxin gene, iron transport into mitochondria
trunk and limb ataxia, nystagmus, sensory loss, spasticity with hyporeflexia
often die by 40 years of age
What is the maximum safe dose of radiation to the optic apparatus?
10 Gy
Percentage of patients with recurrent lumbar disk herniation after discectomy
4% at 10 years, 1/3 of those in the first year
Ligament of Struthers
connects a supracondylar process(5 cm proximal to medial epicondyle) to medial epicondyle
present in 3% of patients, median nerve and brachial artery passes there
compresses median nerve
What structures pass through the ambient cistern?
CN 4, basal veins of Rosenthal, SCA
What supplies the vein of Galen?
Paired internal cerebral veins
Paired basal veins of Rosenthal
Precentral cerebellar vein
(thalamostriate veins drain into the internal cerebral veins near foramen of Monro)
What are the deep cerebellar nuclei?
Lateral to medial
Dentate, Emboliform, Globose, Fastigial
Which hypothalamus nucleus controls satiety?
Ventromedial nucleus
Pineoblastoma: hsitology
Poorly differentiated cancer of embryonal origin
Sheets of blue cells forming classic Flexner Wintersteiner rosettes
Rosettes formed around cellular extensions rather than blood vessel
Risks (OR) of having a spontaneous ICH with sBP > 160 as opposed with good BP control
5 times
Fibrous dysplasia of the skull
At risk of malignant degeneration into osteosarcoma, so RADIATION is CONTRAINDICATED
What % of patients with myelomeningocele ambulate in adolescence?
50% with aids
What is the most common causative organism in pediatric shunt infections?
Coagulase-negative Staph (Staph epidermidis) - 50-72%
What pineal region tumor has + AFP, - PLAP, - BHCG
Embryonal carcinoma, yolk sac carcinoma, immature teratoma
Most commonly elevated hormone from pituitary adenoma
GH
Patients with acromegaly have increased risk of what cancer?
2x risk of colon cancer
What age can a child be eligible for cranial radiation?
3 years
demonstrated decrease in IQ if done before 7 years of age
DBS STN targeting, where is in relation the 3rd nerve?
Efferent fibers of 3rd nerve are medial to STN, causing ipsilateral eye deviation
Organization of cerebral peduncles
Sacral fibers - most lateral aspect
Head and arms - most medial
Pathway of cochlear nerve
Hair cells in organ of Corti (Cochlea) –> Spiral ganglion –> cochlear nerve –> cochlear nucleus in the brainstem
Pathway of vestibular nerve
Receptors in labyrinth of saccule, utricle, semicircular canals –> Scarpa’s ganglion –> vestibular nerve –> vestibular nuclei
Some fibers from Scarpa’s ganglion –> mossy fibers –> flocculonodular lobe (mediating balance)
Medication for frequent urination in SCI
Oxybutynin - anticholinergic, M1-3 receptors on bladder wall, inhibit ACh activity
Leads to bladder relaxation for bladder spasticity and frequent urination
Serotonergic neurons are primarily located where?
Raphe nucleus of brainstem reticular formation
Neurofibroma: histology
Spindle cells in wavy pattern with large amounts of collagen and myxoid background
What is a hippus?
Normal physiologic response where pupils dilate and contract seemingly randomly
Can also be seen during recovery of CN 3
Mechanism of plavix
inhibits platelet function by inhibiting P2Y12 receptor and ADP-mediated GPIIb/IIIa complex formation
Irreversible
Precedex is thought to act where?
On locus coeruleus - mediating arousal, sleep-wave cycles
This nucleus is primarily noradrenergic
What percentage of patients > 65 will have spondylosis on imaging
95%
What hormone to check after resection of pituitary adenoma in a patient with acromegaly
GH
IGH-1 lasts much longer
What percentage of GBM resection is associated with improved overall survival
> 97%
Ulnar neuropathy, differences in relation to compression at Guyon’s canal or more proximal
Dorsal cutaneous branch of ulnar nerve takes off 5-8 cm proximal to Guyon’s canal
Recurrent branch of laryngeal nerve
Branch of vagus
Recurrent route runs alone tracheoesophageal groove
Innervates all intrinsic muscles of larynx with exception of cricothyroid muscle
Uncovertebral joints
Laterally on each cervical vertebral body
Formed by uncinate process, help provide stability to the cervical spine by limiting lateral movement
What cortical layer projects to the thalamus?
Layer 6
What cortical layer receives input from thalamus
Layer 4, heavily myelinated in the occipital cortex (aka Stria of Gennari, striate cortex)
What cortical layer contains the large pyramidal Betz cells that project to the spinal cord?
Layer 5
What chromosomes are affected in familial cavernomas
Chromosome 3 and 7
During brachial plexus exploration, what runs on the anterior scalene muscle
Phrenic nerve
Semiology of right temporal lobe epilepsy (MTS)
olfactory hallucinations, followed by behavioral arrest, lip smacking, left upper extremity shaking
Extent of resection of amydalohippampectomy, left and right
Left: 4-5 cm (language near angular gyrus)
Right: 6-7 cm
Posterior-superior aspect of amygdalohippocampectomy
Meyer’s loop - contralateral superior quandranopsia
Internal capsule in relation to STN
Anterolateral
Wolf’s law
bone will form along lines of stress
variable angle screws are used in ACDF to allow the bone to settle and put stress on the graft, leading to higher rates of fusion
stress shielded
when there is no stress on the graft
WHO grade III meningiomas
Papillary, rhabdoid, anaplastic
Histology of chordoma
groups of cells with vacuolated cytoplasm, known as physaliphorous cells
glycogen deposits can also be seen
locally aggressive, from remnants of notochord
Origin of medulloblastoma
Arise from roof of 4th ventricle, specifically granular layer of cerebellum
Fetal surgery for myelomeningocele is undertaken what time?
24-26 weeks GA
Poiseuille’s law, flow is related to resistance to the power of ?
4
Rate of control with AEDs in patients with epilepsy
AED naive patient, 1st AED control seizures in roughly 50%
2nd AED, a further 15%
3rd AED, another 4%
medically refractory epilepsy is declared after failure of 2 adequate AED trials
What is the paramedian pontine reticular formation (PPRF)
abducens nucleus, lateral gaze centre
ipsilateral PPRF stimulates ipsilateral abducens nerve to abduct the eye and sends fibres to MLF to contralateral CN3 nucleus
What does the thoracodorsal nerve innervate
latissimus dorsi
comes from posterior cord of brachial plexus; straddled by upper and lower subscapular nerve
Volume of CSF; rate of production
approximately 150cc at any time
450-500cc produced each day
CSF turns over 3 times per day
What is the most common type of paraganglioma?
Pheochromocytoma
also common is carotid body tumor
less common: glomus jugulare, glomus intravagle, glomus tympanicum
Starting dose of carbamazepine for TN
100mg BID
What is the most common cranial neuropathy after CEA?
Cranial nerves overall 8-10%
Hypoglossal -1%; most common of all cranial nerves; tongue deviation towards side of injury
Other: vagus or recurrent laryngeal nerve 1%
Mandibular branch of facial nerve - loss of ipsilateral lip depressor
What is brachium pontis, brachium conjunctivis, restiform body
Middle cerebellar peduncle
Superior cerebellar peduncle
Inferior cerebellar peduncle
What is the functional spinocerebellum?
Vermis, projects to fastigial nucleus; receives afferent from spinocerebellar tract
Efferent from fastigial nucleus goes to reticular formation and lateral vestibular nuclei AND contralateral motor cortex via VL thalamus
Path of CN3
Begins at CN3 nucleus at superior colliculus
Travels between PCA and SCA
Enters SOF, within annulus of Zinn
superior and inferior division
superior division = levator palpebrae and superior rectus
inferior division = medial/inferior rectus, inferior oblique
CN4 innervates? and which way does patient compensate
superior oblique muscle
tilt head to contralateral side
CN4 only nerve to deccusate outside CNS, and exit dorsally from the brainstem
Function of nervus intermedius
Parasympathetic fibers to lacrimal gland (GSPN, pterygopalatine ganglion); submandibular gland (submandibular ganglion), taste afferents (chorda tympani)
What is in the tarsal tunnel
Tibial nerve Posterior tibial artery Posterior tibial vein Flexor hallicus longus tendon Flexor digitorum longus tendon Tibialis posterior tendon
What does the deep peroneal nerve innervate?
EHL; foot extensors
What does the superficial peroneal nerve innervate
Sensory to majority of top of foot
Muscles of foot eversion - peroneus longus/brevis
Differentiating Cushing’s disease vs ectopic ACTH secretion
Cushing’s disease: random ACTH > 5ng/L; 50% or more reduction in cortisol after high dose DMZ; positive IPS (maybe); positive metyrapone test
What is Nissl substance?
granular body of the cell containing rough endoplasmic reticulum, ribosomes
not present in axons
Cauda equina compression leads to what type of bladder dysfunction as opposed to spinal cord compression
Atonic bladder (both efferent and afferent are damaged) - no urgency vs Hyper-reflexic bladder
What nucleus in the brainstem mediates the jaw jerk reflex
Mesencephalic nucleus - proprioception of the jaw
Glossopharyngeal nerve innervates the parotid gland via which branch?
lesser superficial petrosal nerve
LSPN contains preganglionic parasympathetic nerves from inferior salivatory nucleus of brain stem, synpase in otic ganglion
from the otic ganglion, the auriculotemporal nerve travels with V3
Atlas ossification centres, when do the posterior persist, when do the anterior persist
up to 3 years
up to 7 years
Which tract carries information from superior colliculus to all levels of hte cervical cord and mediates postural reflexes and movement of the upper body in response to visual and auditory stimuli?
Tectospinal tract
Peroneal nerve comes from which nerve?
Sciatic nerve
Peroneal nerve comes from which nerve?
Sciatic nerve
What muscle group is weak with L3?
Quadricep
BMP is contraindicated for what condition?
Soft-tissue sarcoma
Recruit mesenchymal cells to differentiate into chondroblasts and osteolbastas
What % of patients with urinary retention in CES recover?
50%
in full saddle anesthesia - very few
What diameter diagnosis spinal epidural lipomatosis
7mm
What forms the Broca’s area
Pars triangularis and opercularis
both inferior frontal gyrus
C7 myotome
tricep - elbow extension
wrist flexion
What innervates the latissimus dorsi, and from what cord of the brachial plexus?
Thoracodorsal nerve
Posterior cord
What are the 5 branches of the posterior cord?
Upper subscapular nerve, thoracodorsal nerve, lower subscapular nerve, axillary nerve, radial nerve
Post op treatment for ependymoma, and dose
45-48 Gy XRT
15-20 Gy for recurrence
radiosensitive
prophylactic radiation to spine if drop mets
Rate of stabilization after syringoarachnoid shunt for syrinx at 10 years
50%
Factor to consider when repairing nerve injury
In most cases, surgical repair utilizing end to end direct repair or grafting occurs sometime between 3 and 6 months after injury. Timing is based on several factors, but most importantly, the distance of nerve regeneration between the area of injury and the target muscle should be considered. Longer distances for regeneration should be operated earlier in an attempt to beat the “24-month rule” where irrecoverable atrophy of the muscle has occurred. Some surgeons consider 18 months the point at which irrecoverable atrophy has occurred.
Describe a diabetic third nerve palsy?
Painful, temporary Pupil sparing (center of the nerve is involved rather than parasympathetic fibers that travel in the peripheral aspect of the never)
What is corticobasal degeneration?
Involves only one limb, “alien-limb”
Parkinson-like symptoms of the limb
Increased deep tendon reflexes
Not usually have dementia
Describe the auditory dampening reflex
Superior olivary nucleus
Contraction of stapedius (CN 7) and tensor tympani (CN 5)
Anterior spinal artery syndrome
Paraplegia
Loss of pain/temperature
Preserved pinprick sensation (dorsal column) supplied by posterior spinal arteries)
NF-1 optic glioma
Cure if complete excision of the optic nerve and eye before tumor invade the optic chiasm
How much of dominant temporal lobe can be resected?
3 to 4.5 cm
Opsoclonus-myoclonus reaction is seen in what kind of tumors?
Rapid, involuntary conjugate eye movements in multiple directions associated with myoclonic jerks
Neuroblastoma
Mediated by autoimmune phenomenon
Optic strut separates what structures
Optic canal from superior orbital fissure
Joins lesser wing of the sphenoid to the body of the sphenoid bone
inferior and lateral wall of optic canal
Endonasal approach - inferior to optic protuberence, superiomedial to carotid protuberence, medial to lateral opticocarotid recess
Marker for transverse sigmoid sinus
Asterion - where squamous and parietomastoid suture join
What muscles do musculocutaneous nerve innervates
BBC
Biceps, brachialis, coracobrachialis
What nerve innervates brachioradialis
C6, radial nerve
What muscle does axiallary nerve innervate?
From the posterior cord
Deltoid muscle, Teres minor
What muscle does axiallary nerve innervate?
From the posterior cord
Deltoid muscle, Teres minor
Hemangiopericytoma vs meningioma
Staghorn vessels
both are positive for vimentin
HPCs are EMA negative while meningioma is EMA positive
Cyst with dot sign on MRI
neurocysticercosis
Paget’s bone disease
Hearing loss, higher risk of developing bony tumors
Serum ALP is elevated; calcium and PO4 are normal
Uncinate fasciculus
Connects anterior temporal lobe to orbitofrontal cortex
Pathway of propagation for seizure
Based on large studies, % of shunt revision within 1 year
30%
younger < 2 years have higher risk
DBS target for dystonia
GPi
If targeting GPi, and patient gets contralateral muscle contractions, where do you move?
Lateral
Histology of pilocytic astrocytomas
parallel arrangement of bipolar astrocytes with Rosenthal fibers and eosinophilic granular bodies
Results of STICH II
Small benefit in survival, no change in morbidity when early surgery < 48 hrs, for superficial ICH (< 1cm), 10-100cc, and no IVH; GCS 5-6 and eye opening score > 2
Where are the motor neurons damaged in CES that cause urinary incontinence
Onuf’s nucleus, in the conus medullaris, projects to pudendal nerve
SM grading and chance of good outcome
grade 1 = 100% grade 2 = 95% grade 3 = 84% grade 4 = 73% grade 5 = 69%
Risk of DVT after L3-5 D and F
10-40%
Blue rubber bleb nevus syndrome, also Bean Syndrome
Has persistent connection btw extracranial veins and SSS = sinus pericranii
Palinopsia
burnt in images when eyes are closed
What is albuminocytologic dissociation in GBS
high protein and low cellularity
What is normal ADI - atlantodental interval
< 3 mm
What is the only neurotransmitter made in synaptic vesicles?
norepinephrine
made from dopamine, by dopamine hydroxylase
Mucormycosis
commonly in bad diabetics
from anterior skull base
highly fatal
Reversal of enoxaparin
Protamine can be given, 1mg per 1mg
Reverse 60% of active circulating
What bladder problem does ASIA B have?
Detrusor hyperreflexia
Because intact bladder reflex arc but no inhibition from pontine micturition center
reflexive emptying of bladder and urge incontinence
Post op radiation in GTR of LGG?
No benefit (54 Gy XRT), no increase in PFS, defer until progression occurs
post op treatment of subtotal resection of oligodendroglioma
PCV chemotherapy
XRT is controversial - saved for malignant transformation or recurrent growth
5 year survival of biopsy proven primary CNS lymphoma
3-4 %
Post op treatment of primary CNS lymphoma
XRT, methotrexate
Cognard classification
I - anterograde drainage through a sinus
IIa - retrograde sinus drainage only
IIb - anterograde sinus drainage with retrograde cortical venous influx
IIa+b - retrograde sinus and retrograde cortical venous reflux
III - direct cortical venous drainage without ectasia
IV - direct cortical venous drainage with ectasia
V - direct drainage into spinal perimedullary vein
1 unit of platelet raises by how much?
5-10k
What is the most common mass lesion in patients with known AIDS
toxoplasmosis
What % of retinal hemorrhages are from accidental trauma
5%
Arnold-Chiari III malformations
very rare severe developmental abnormalities neurosurgery has minor role high cervical spina bifida - herniated hindbrain contents ensure there is skin covering the defect no spinal cord tethering is present
Surgical approach to myxopapillary ependymoma
ID and cut the filum terminale above and below the lesion
Do not violate capsule and spill the contents
if adherent to the conus, do not perform subpial resection of the conus, as will result in permanent bowel/bladder incontinence
What is an eosinophilic granuloma
Punched out lesion of the skull
Does not have sclerotic margins like skull epidermoid
Name radioresistant tumors
Thyroid, melanoma, renal cell carcinoma
How long after onset of radiculopathy does reliable acute EMG findings present?
3 weeks
Central vs peripheral vertigo
Central: acute onset, little nausea, skew deviation and spontaneous direction changing nystagmusf\
What mediates decorticate (flexor) posturing
rubrospinal tract (red nucleus) mediate flexor tone
flexion means that rubrospinal tract or red nucleus is intact
Ulnar nerve compression at Guyon vs cubital tunnel
Dorsal ulnar cutaneous nerve - dorsum of hand, exits 6 cm before Guyon’s canal
What is Collin’s law about pilocytic astrocytoma
Pediatric patients are considered cured if no recurrence after patient’sage at time of diagnosis + 9 months has passed
Controversial rule
Origin of neuroblastoma?
aggressive tumors that arise from sympathetic ganglion
e.g. adrenal gland (40%)
can cause Horner’s
Dose of SRS to tumors 21-30mm in diameter
18Gy used with acceptable risks
Anesthesia dolorosa
Injury to V1, recurrent corneal abrasions
Posterior interosseous nerve
Pure motor branch of radial nerve
Innervates abductor pollicis longus, extensor pollicis longus/brevis, extensor indices, extensor carpi ulnaris, extensor digitorum and extensor digit minimi
What markers are associated with ependymomas
Loss of chromosome 22
GFAP, PTAH, and EMA positivity
Sheehan’s syndrome
pituitary infarct caused by large volume blood loss during delivery
necrosis and hemorrhage
can decompensate from lack of cortisol; give hydrocortisone immediately and then consider pituitary decompression to save vision
Who should receive washed blood products?
Patients with history of allergic transfusions reactions with anaphylaxis
Who should receive leukoreduced / irradiated PRBCs
Multiple febrile reactions
Succinylcholine and SCI
can cause dangerous hyperkalemia
What % of patients with TN treated medically eventually need surgery
75%
Muscles innervates by deep peroneal nerve and superficial peroneal nerve
Deep peroneal nerve = anterior tibialis
Superficial peroneal nerve = peroneus longus, peroneus brevis
Blood T1 and T2 signals
Hyperacute (< 24hrs); Acute (1-3 days); Early subacute (3-7 days); Late subacute (7-14 days); Chronic (> 14 days)
T1: Iso - dark - bright - bright - dark
T2: bright - dark - dark - bright - dark
