nelson essentials 2 neuro Flashcards
How is ataxia telangiectasia inherited?
autosomal recessive most common degenerative ataxia present with ataxia around age 2 mid-childhood, get telangiectasia can also have abnormalities in immune function and increased risk of tumours -lead to death
When does Freidrich ataxia present?
late elementary years - ataxia, dysmetria, dysarthria, diminished proprioception and vibration, absent DTRs, and nystagmus
many get hypertrophic cardiomyopathy and skeletal abnormalities (high arched feet, hammer toes, kyphoscoliosis)
acute dystonic reaction
caused by antipsychotic and anti emetics
usually involve the face and neck with torticollis, retrocollis, tongue protrusions, oculogyric crisis
Tardive dyskinesia
after chronic antipsychotic drug use - face involvement - tongue thrusting and chewing
how long do tics need to last for Tourette syndrome diagnosis?
> 12 months of motor tics with vocal tics
Treatment of tics: habit reversal, alpha adrenergic receptor agonists
What is Cheyne Stokes respiration?
hyperventilation with crescendo-decresendo pattern, alternates with shorter period of apnea
can also see with metabolic condition, heart failure, or primary resp disease
Important parts of neuro exam on a comatose patient
need to see if the brainstem works
- doll’s eye maneuver
- cold caloric stimulation - oculovestibular response - cold water into ear canal, conscious person will have nystagmus and vertigo, in comatose, will have tonic eye deviation towards ear that is irrigated (if patient not brain dead and brainstem functioning), if complete loss of oculomotor function, then eyes stay straight ahead-indicates brainstem failure
GCS
E - 4: 1- nothing 2- with stimulation 3 - with verbal 4- spontaneous
V - 5 1- nothing 2- incoherent moans 3- few words 4- confused speech 5- oriented speech
M - 6 1- nothing 2- decerebrate 3- decorticate 4- move away from pain 5- localize pain 6- spontaneous purposeful movement
3 major categories that cause coma
- metabolic/toxic
- infectious
- structural
Types of herniation
- transtentorial (unilateral - uncial or bilateral): downward displacement of supratentorial brain tissue into infratentorial compartment, compresses the cerebral peduncles, midbrain, third cranial nerve and posterior circulation
- clinicaL: headache, altered LOC, dilated ipsilateral pupil, CN III palsy, hemiparesis, decerebrate posturing, Cushing triad, respiratory arrest - Subfalcin herniation - brain tissue under the flax cerebra, comprises the anterior cerebral artery
clinical: weakness, bladder incontinence, coma - foramen magnum herniation: cerebellar mass or edema - downward displacement of cerebellar tonsils, compresses the medulla oblongata and upper spinal cord - bradycardia, bradypnea, hypertension, death
Why do you get a blown pupil with uncial herniation?
temporal lobe displaces over the tenteorial edge - unilateral third nerve palsy and hemiparesis (either ipsilateral or contralateral depending on which peduncle is compassed)
Increased ICP causes:
- structural - bleed, space occupying lesions, inflammatory
- metabolic derangements: hepatic encephalopathy, Reye syndrome, hyponatremia, lead encephalopathy, DKA, HIE (**can cause increased ICP without CT abnormalities which are obvious)
Blood in CSF, main causes
- subarachnoid hemorrhage
2. HSV
What is a confusional migraine?
basilar artery or confusional migraine - accompanied by agitation, ataxia, cortical blindness, vertigo or CN palsies, can have headache before or after the neuro signs
used to think these signs were from basilar artery problem, now thought to be more of a brainstem problem (big Nelson)
these can last hours
types of skull fractures
- linear - no treatment
- diastatic - spreading the suture - no treatment, but may have underlying hematoma
- depressed - inferior displacement of edge
- compound - bone breaks the skin
Which skull fractures need surgical management
small depressed fractures with depression >0.5-1cm, need surgical elevation of bone and repair dural tears
compound fractures: emergency surgery and TETANUS - high risk of brain injury
Types of post traumatic seizures
- impact seizures: within seconds of the injury, presumed to reflect a direct mechanical stimulation to the cortex. prognosis is excellent, likelihood of later epilepsy is negligible
- Early post traumatic seizures: within the first week of the head injury - likely from localized area of cerebral contusion or edema - pretty good long term prognosis
- Late post traumatic seizures - more than a week after the trauma, most likely indicate an area of cortical gliosis or scaring that can lead to long term epilepsy
Types of hydrocephalus
- obstructive/noncommunicating hydrocephalus - when the CSF can’t drain (blocking)
Causes of why this happens: abnormality of aqueduct or lesion in the 4th ventricle
- aqueductal stenosis is the most common cause (can be AR inherited, with neurofibromatosis, with other neural tube problems)-
- can also be secondary to infection - i.e. neonatal meningitis, SAH, or intrauterine viral infection (look at eyes for todo), mumps infection also
- vein of Galen malformation
- posterior fossa: tumors, Chiari malformation, Dandy-Walker syndrome - Nonobstructive/communicating - most commonly from SAH, usually from iVH in a perm - blood in the subarachnoid villi will obliterate the cisterns, can also get similar mechanism from penumococcal and TB meningitis, leukaemia infiltrates
- too much CSF - from choroid plexus papilloma
Metabolic disorders that cause megalencephaly
1 lysosomal diseases - Tay-Saches, gangliosidosis, mucopolysacchridoses
- aminoacidurias (ie maple syrup)
- leukodystrophy
- cerebral gigantism
- neurofibromatosis
- familial megalencephaly - AD trait, delayed motor milestones and hypotonia but normal intelligence