Random Neuro facts Flashcards
Treatment for absence seizures
Ethosuximide and if that fails valproic acid
What type of seizures is phenytoin indicated for?
Partial and generalized tonic clonic seizures
Gerstmann’s syndrome
- usually involves the left parietal lobe damage
- tetrad of acalculia, agraphia wihtout alexia, right left confusion, finger agnosia
- left angular gyrus
What type of lesions is alexia without agraphia seen?
Splenium of the corpus callosum
What is the treatment for trigeminal neuralgia?
carbamazepine and oxcarbazepine
- other treatments: gabapentin, TCAs, tiagabine, opioids, NSAIDS, lidocaine patches, benzos, stereotatic gamma knife
Giant cell arteritis
Medium sized vessels, women affected more than men
- new onset or change in headache with fever, fatigue, myalgia, night sweat, weight loss, jaw claudication. 25% of pts have polymyalgia rheumatica. The temporal artery can demonstrate tenderness with induration and diminished or absent pulse. Can have irreversible and sudden vision loss as a result of central retinal artery occlusion.
Test of choice is ESR, then gold standard temporal artery biopsy.
Treatment is prednisone.
cluster headaches
attaches generally nocturnal
alcohol consumption is a common trigger
Abortive therapies: oxygen, sumatriptan subcutaneous injection, ergotamine
Prophylactic therapies: prednisone, verapamil, depakote, methysergide and lithium
What are causes of acquired peripheral neuropathy?
Vincristine and isoniazid, excess B6 therapy, inhalant abuse (toluene, NFO), heavy metal poisoning, hydrocarbon exposure, vitamin B12 deficiency, niacin deficiency, complications of mono, lupus
dermatomyositis
autoimmune disease that affects skin and muscle, purplish rash on face and eyelids(can also appear on neck, elbows, and knees which are often red and indurated), and muscle weakness
- CPK levels often elevated
- EMG shows myopathy and muscle irritability
- Biopsy shows perifascicular atrophy and “ghost fibers”
- Strong relationship between dermatomyositis and occult neoplasm in up to 50% usually carcinoma
What is the most significant genetic risk factor for Familial Alzheimer’s dementia?
homozygosity for the inheritance of E4 allele of apolipoprotein E (apo E). Apo E4 has been associated with chromosome 19.
What is Saturday night palsy?
Radial nerve entrapment- prolonged armpit compression when the arm is draped over the edge of a chair or on crutches
- weakness in the extensor muscles of the wrist, fingers, tricept weakness, and supinator weakness.
usually resolves after 1-2 months
Ulnar nerve entrapment
- occurs at elbow or wrist (elbow trauma w/ entrapment in cubital tunnel or with compression during surgery)
- weakness in the flexor carpi ulnaris, intrinsic hand muscles, and fourth and fifth deep flexor weakness
Musculocutaneous nerve injury
Injury to brachial plexus such as shoulder dislocation, shoulder compression
- weakness of biceps and brachialis
Median nerve entrapment
Carpal tunnel
tenosynovitis of the transverse carpal ligament places pressure on the median nerve in the tunnel
- causes nocturnal hand paresthesias of thumb and index and middle fingers
- may be sensory loss, thenar atrophy and positive tinels test
- diagnostic test is needle EMG and nerve conduction studies which show delayed sensory latency across the wrist
Suprascapular nerve entrapment
can occur after repetitive forward traction of the shoulder. diffuse aching of posterior shoulder. EMG shows denervation of the infraspinatus and supraspinatus muscles
The most common cause of intracerebral hemorrhage is hypertension, how does this happen?
Chronic hypertension probably causes lipohyalinosis of the small intraparenchymal arteries and charcot bouchard microaneurysms that rupture owing to increased vascular pressure
Where is the most common area of predilection for ICH
putamen followed by the thalamus
Screening test for sarcoidosis
serum ace level
Cryptococcal meningitis
yeast, AIDS w/ CD4 count generally less than 200. opening pressure usually elevated, csf colorless and clear, leukocytosis of 50 to 1000 cells with lymphocytic predominance, elevated protein.
Indian ink - capsule and budding yeast (can also do cryptococcal antigen assay-more sensitive)
Treatment: amphotericin B (but this does have high rate of renal toxicity)
What protein makes up amyloid plaques found in alzheimers disease?
APP, found on chromosome 21
Creutzfeldt-Jakob disease
Prodromal period of vegetative symptoms such as weakness, sleep and appetite disturbances
Then, rapidly progressive dementia with deficits in memory and concentration, depression, self neglect and personality changes.
Then, global dementia and death typically 2-7 months after onset of symptoms
Diagnostic tests: lumbar puncture CSF assay of 14-3-3 and tau proteins
Internuclear ophthalmoplegia
Seen in MS
lesion localizes to the medial longitudinal fasiculus of the brain stem
- abnormal horizontal ocular movements with absence or delayed adduction of the eye ipsilateral to MLF lesion and course horizontal nystagmus in the abducting eye. Convergence is preserved
Lesion is ipsilateral to the eye that does not adduct
anosognosia
inability to recognize a neurological deficit that is occurring to oneself
MS
the most common inflammatory demyelinating disease
Onset: 15-50 years old
2/3 have relapsing-remitting at onset
- only 20% of patients have primary progressive disease at onset
- heat sensitivity-increases in core body temp can bring on or worsen already existing symptoms (uhthoff’s phenomenon)- conduction block as body temperature rises
optic neuritis
optic neuritis is a common sign of MS- eye pain that increases with movement, central visual loss (scotoma), afferent pupillary defect
Internuclear ophthalmoplegia
common sign of MS
lesion in MLF of brainstem
eye ipsilateral to the lesion cannot adduct past the midline, contralateral eye fully abducts and displays a coarse end gaze nystagmus
What is Lhermitte’s sign
Transient neurological sign-sensation of an electric shock that descends down the spine or the extremities on neck flexion
- suggestive of MS but can be seen in other conditions
Do MS lesions enhance with gadolinium early during an attack and can persist to 8 weeks?
yes
Treatment for MS attack
IV corticosteriods
Aphasias (fluency, comprehension, repetition)
Brocas, Wernickes, conduction, transcortical motor, transcortical sensory, transcortical mixed, global
Brocas (left posterior inferior frontal gyrus): No fluency, Yes comprehension, No repetition
Wernickes(superior temporal gyrus): Yes fluency, No comprehension, No repetition
Conduction(arcuate fasiculus): Yes fluency, Yes comprehension, No repetition
-right homonysmous hemianopsia- with absence of motor and sensory signs
Transcortical motor: No fluency, yes comprehension, yes repetition
Transcortical sensory: Yes fluency, No comprehension, Yes repetition
Transcortical mixed: No fluency, No comprehension, yes repetition (watershet)
Global: No fluency, No comprehension, No repetition
What happens with rapid sodium replacement in hyponatremia?
Central pontine myelinolysis which can result in clinical transection of the pons and locked in syndrome.
- can move eyes up and down and blink
- Most common cause of locked in syndrome is ventral pontine infarct as a consequence of basilar artery thrombosis (other causes: are acute inflammatory demylinating poly neuropathy, myasthenia gravis, and neuromuscular blocking agents)
pseudotumor cerebri (intracranial hypertension)
Classically seen in young obese AA women
Risk factors: Hypervitaminosis A, high does corticosteriods, tetracycline, oral contraceptives, and head trauma
Symptoms: Waxing and waning headache w/ visual obscurations
Exam: papilledema and enlargement of blind spot
Test:: lumbar puncture (opening pressure over 20 cm H20)
Treatment: acetazolamide or prednisone, lumbar puncture, ventriculoperitoneal shunting, lunboperitoneal shunting optic nerve sheath fenestration
Migraine without aura criteria
- at least 5 headache attacks lasting 4-72 hours
which have at least 2 of the four characteristics: - unilateral
- pulsating
- moderate to severe intensity
- aggravated by walking stairs or similar routine physical activity
at least of of the two - photophobia/phonophobia
- nausea/vomiting
inclusion/exclusion criteria for TPA
Inclusion:
- acute ischemic stroke with a clear time of onset less than or equal to 3 hours prior
- neurological deficit measurable on NIH stroke scale
- CT head demonstrating no intracranial hemorrhage
Exclusion:
- rapidly improving symptoms
- seizure at onset of stroke
- prior intracranial hemorrhage
- pretreatment blood pressure greater than 185/110
- major surgery within previous 14 ays
- prior stroke or head injury within the past 3 months
- intestingal or urinary bleeding within 3 weeks prior to stroke
- subarachnoid hemorrhage
- really low or really high sugars
- recent MI
- current use of anticoagulants (PT>15 INR>1.7)
- heparin within past 48 hours
- platelet count of <100,000
- arterial puncture at noncompressible site within past 7 days
Left lateral medullary syndrome (wallenberg’s syndrome)
Caused by: occlusion of one of the vertebral arteries or less commonly posterior inferior cerebellar arteries
- ipsilateral horners
- ipsilateral loss of pain and temperature sensation in the face
- cerebellar ataxia
- weakness of the vocal cord/pharynx, and palate
- contralateral loss of pain and temperature sensation to the hemibody
- no visual system changes
What is the most common offending infectious agent in AIDS-related retinopathy?
Cytomegalovirus
What does JV virus cause?
progressive multifocal leukoencephalopathy in AIDS patients
Is intramuscular phenytoin a good choice for status epilepticus? What are useful treatments
No because its erratic rate of absorption
- useful: rectal or IV diazepam, IV lorazepam, IV phenytoin or fosphenytoin, IV valproic acid, oxygen by nasal cannula and airway protection, IV phenobarbitol (but not great narrow therapeutic window)
Which anticonvulsant has the broadest spectrum of coverage?
Depakote
- blockade voltage gated sodium channels and GABA enhancement
Foot flexion involves which nerve root and which muscles?
- tibialis anterior muscle
- L5 (also controls extension of extensor hallucis longus)
- Lesion at L5 often causes foot drop
S1 nerve root
- foot extension (pushing down on the gas petal)
Leg extension involves which muscles and which nerve roots?
quads
L3/L4 nerve roots
Hip flexion uses which muscles and which nerve roots?
iliopsoas muscle
L1, L2, L3
Achilles motor reflex is a function of which motor nerve root?
S1
Brown Sequard syndrome
hemisection of the spinal cord
- ipsilateral and below lesion: loss of motor control and posterior column function (proprioception and vibration)
- contralateral one or two dermatomal levels below the level of the lesion: loss of pain and temperature sensation
Pure motor hemiparesis is expected from an infarct in what area?
internal capsule, the basis pontis, or the corona radiata
What is a lacunar stroke?
ischemic strokes resulting from small vellel lipohyalinosis that is caused by htn and diabetes
microembolism may also be a mechanism for lacunar stroke
Pure sensory lacunar syndrome result from a lesion where?
ventroposterolateral nucleus of the THALAMUS
Lesion to what causes left-arm hemiballismus?
right subthalamic nucleus
Reserpine interferes with the magnesium and ATP-dependent uptake of amines which results in the depletion of dopamine, NE, and serotonin and can relieve symptoms of what but also cause what?
- can relieve symptoms of dystonia but can also cause depression, sedation, parkinson’s like symptoms
arachnoid granulations are the major site for what?
drainage of CSF into the blood
what is responsible for the majority of CSF production
chorioid plexus
What drugs can temporarily reduce production of CSF and ease increased intracranial pressure?
Mannitor and acetazolamide
States of hypothermia, hypocarbia, hypoxia and hyperosmolality
What is virchow-robin spaces
act as a duct for substances in the subarachnoid space to enter the brain
What is the most common place of intracranial hemorrhage?
putamen then lobar
How do you reverse anticoagnulation?
protamine sulfate for heparine
parental vitamin K or fresh frozen plasma for warfarin
What releases melatonin?
pineal gland (secreted at night)
- feedback look between pineal gland and suprachiasmatic nucleus in the hypothalamus
What is botulinum toxin used for?
cervical dystonia, blepharospasm, hemifacial spasm, stabismus, axillary hyperhydrosis, cosmetically for hyperactive glabellar lines of the procerus muscles of the forehead
not fda approved but used for MS spasticity , mingraines
- blockade of presynaptic acetylcholine release
Bailar migraine
Occiptial headache and neurologic symptoms attributable to the brainstem. Aura can involve visual and sensory phenomena, accompanied by vertigo, dysarthria, tinnitus, speech deficits. May have LOC. Resemble stroke-like symptoms in the vetebrosbasilar territory
Paroxysmal hemicrania
indomethacin-responsive headache syndromes
- women more than men
- unitlateral brief in the periorbital or temporal areas
5 or more daily lasting 20 minutes
- accompanied by autonomic features such as conjunctival injection, lacrimation, ptosis, rhinorrhea
- treatment indomethacin
What is the generator of migraines thought to be?
Trigeminal nucleus cuadalis (TNC) in the pons, ergot and triptan medications effectively block neuronal firing int he TNC and can abort an attack
How does carbidopa work?
it inhibits DOPA decarboxylase and prevents the peripheral metabolism of levodopa to dopamine before it can cross the blood brain barrier
How do the dopamine agnoists ropinerole, pramipexole, pergolide and bromocriptine work?
direct postsynaptic dopamine receptor agonist
What do COMT (catecholo-o-methyltransferase) inhibitors do?
tolcapone and entacapone prevent peripheral and central degradation of levodopa and dopamine thereby increasing central levodopa and dopamine levels
What anticholinergic agents such as trihexyphenidyl and benztropine do in parkinson’s disease?
reduce tremor by blockade of postsynaptic muscarinic receptor
apoptosis
programmed neuronal cell death
Pain syndrome or reflex sympathetic dystrophy
regional pain and sensory changes following trauma or noxious event
Stage 1(acute): pain is out of proportion to the initial injury
Stage 2 (dystrophic): tissue edema and skin that is cool cyanotic, hyperhidrotic, with livedo reticularis
Stage 3 (atrophic): paroxysmal pain and irreversible tissue damage
Treatment: Physical therapy, steriods, phenoxybenzamine , regional block
Sheehan’s syndrome
postpartum pituitary infarction or apoplexy
- treatment generally supportive but may need corticosteriod replacement or surgical decompression
cushing’s disease
Endogenous overproduction of andrenocorticotropic hormone from the anterior pituitary gland
- result of exposure to excessive endogenous or exogenous corticosteriods
Hypertension, truncal obesity, impaired glucose tolerance/DM, menstrual irregularities, hirsutism, acne, purple striae, osteoporosis, thin skin, excessive bruising, proximal myopathy
Test: dexamethasone supression test
What is the treatment for NPH?
ventriculoperitoneal shunting
Diffuse Lewy-body dementia
second most prevalent dementia is after alzheimers
- triad of dementia, parkinsonism, and VH
- extreme sensitivity to dopamine blockade- severe parkinsonism
What does Wernicke’s show on MRI and autopsy?
MRI: abnormalities in the periqueductal regions, bilateral mamillary bodies, and medial thalami
Autopsy: Multiple small hemorrhages in teh periventricular gray matter mainly around the aqueduct and third and fourth ventricles
Sydenham’s chorea
result of rheumatic fever
-more frequent in girls 5-15
- chorea, irritability, obsessive compulsive traits, restlessness
MRI shows enlargement of the basil ganglia
- self limited symptoms 6 months
- anti-basal ganglia antibodies can be detected by western blot testing
- valproic acid is useful for the chorea
What is cerebellum perfused by?
vertebrobasilar arterial system
What are symptoms that suggest carotid territory ischemic attack?
- ipsilateral monocular blindness (amaurosis fugax)
- contralateral body weakness or sensory loss
- aphasia with dominant hemisphere
- contralateral homonymous visual field deficits
What are symptoms of vertebrobasilar territory stroke?
bilateral, shifting, or crosssed weakness or sensory loss (ispilateral face with contralateral body)
- bilateral or contralateral homonymous visual field defects or binocular vision loss and two or more of vertigo, diplopia, dysphagia, dysarthria, ataxia
Essential tremor
postural and kinetic tremor of the forearms and hands that gradually increases in amplitude over time
- 2/3 pt w/ fam hx
Treatment: beta blocker (main*), primidone, benzos, botulinum toxin, stereotactic thalamotomy, thalamic brain stimulation
Desipramine and TCA-not helpful! can worsen
Migraine is most likely a hereditary disorder that maps to which chromosome?
19
Familial hemiplegic migraine associated with 19
Miller fisher syndrom
varient of guillain-barre
- ataxia, areflexia, opthalmoplegia
GBS CSF
cytoalbuminergic dissociation: elevated protein with an acellular fluid
Is depression less common in cortical dementia (such as Alzheimers) than subcortical disease (prkinsons)
Yes
Which surgical intervensions can be used for the treatment of idiopathic parkinsons disease?
- thalamotomy
- subthalamic nucleus deep brain stimulation
- pallidotomy
- pallidal deep brain stimulaion
What does right-left disorientation result of?
lesion to the dominant angular gyrus
- one of the symptoms of grestmanns syndrome
Diabetic third nerve palsy
spares pupillary function
third nerve palsy from aneurysm
dilated pupil, eyelid ptosis
transient global amnesia
reversible anterograde and retrograde memory loss
- inability to learn newly acquired information and total amnesia of events during the attacks
- retain personal information and identity
- the person may ask the same question repeatedly
-men more than women usually 50s or older
- onset often occurs after physical exertion or exposure to extreme temps
-MOA unknown
B. burgdorferi, lyme disease
early infection:
- meningitis, a unilateral or bilateral bell’s palsy
- painful radiculoneuritis
- optic nueritis
- mononeuritis multiplex
- guillain barre
then:
- lyme rash
Diagnosis: ELISA confirmed by western blot or CSF lyme antibody pcr
Treatment: ceftriaxone or penicillin IV 2-4 weeks
CSF aseptic or viral meningitis
mild to moderate lymphocytic pleocytosis, normal glucose, normal to mildly elevated protein
gram stain and cultures negative
CSF bacterial meningitis
- marked lymphocytosis, polymophonuclear neutriphils
- markedly increased protein
- decreased glucose
Fungal CSF
- moderate lymphocytic pleocytosis
- mildly decreased glucose
- mildly increased protein
Herpetic meningitis CSF
similar to aseptic meningitis but also maybe red blood cells
Guillain barre CSF
- high protein and absence of pleocytosis
Lower motor neuron signs
hypotonia, muscle atrophy, fasiculations, hyporeflexia, flaccidity, muscle cramps, and marked motor weakness
distal to anterior horn cells
upper motor neuron
hyperreflexia, spactificy, bab, clonus, pseudobulbar palsy, loss of dexterity, mild motor weakness
brandt-daroff exercises
exercises in benign paroxysmal positional vertigo
nystagmus and bppv
fast phase of nystagmus is in direction of the lower ear (the ear with the vestibular problem) when the patient looks toward the affected side
persistent vegetative state
period of 1 month must elapse
-perserved sleep wake cycles
-spontaneous movements may be noted and eye opening, eye tracking and swallowing can be preserved.
- no response to noxious stimulation
West’s syndrome
triad of:
infantile spasms
hypsarrhythmia (posterior diffuse slow and sharp wave spikes)
psychomotor development arrest
Treatment: adrencorticoptropic hormone, presnisone, prednisolone
- poor prognosis
Papez circuit
hippocampus with thalamus, hypothalamus, and cortex
What causes benign familial neonatal convulsion?
AD
defect in voltage gated potassium channels
- generalized tonic clonic seizures disappear spontaneously in a few weeks to months
what do malignant hyerthermia, hypokalemic periodic paralysis and familial hemiplegic migraine all have in common?
all genetic disorders involving gene mutations that result in abnormal voltage-gated calcium channels
arnold chiari type 1 malformation
- descent of the cerebellar tonsils below the level of the foramen magnum with or without displacement of the medulla.
- low intracranial pressure
- often accompanied by syringomyelia, syringobulbia, hydrocephalus
Headache, cranial neuropathies, visual distrubances
-shawl distribution of sensory deficit over the shoulders
Chiari type 2 malformation
caudal displacement of medula and 4th ventricle ( hydrocephalus )and addition of lumbar myelomeningocele (paralysis/sensory loss at and below the level of the lesion).
lissencephaly