Neuro E2- Disorders of Consciousness

LOC due to cerebral hypoperfusion is ____

syncope

What are brief sx that may precede onset of some seizures?

aura

What is an episode of altered consciousness due to excessive or over-synchronized discharges of cerebral neurons?

seizure

What is a disturbance of brain function marked by recurrent episodes of seizure activity?

epilepsy

What occurs when the function of both cerebral hemispheres or the brainstem reticular activating system is compromised?

loss of consciousness (LOC)

What are the 2 major causes of LOC?

syncope & seizures

What is the most frequent type of syncope (“the common faint”)?

vasodepressor

What condition?

• LOC caused by excessive vagal tone or impaired reflex control of peripheral circulation

• initiated by stress, pain, claustrophobia, prolonged standing, heat exposure, exertion, straining/obstipation

• N, diaphoresis, tachycardia, pallor

• seizure like motor movements but NO postictal period

• rapid recovery, fully lucent

vasodepressor / vasovagal syncope

Who is vasodepressor syncope MC in?

young females

What does enhanced vagal tone result in?

peripheral vasodilation → hypotension; sinus bradycardia & sinus arrest

(occurs sitting or standing)

How do you abort vasodepressor syncope episodes?

lying supine to restore blood flow to brain or remove inciting stimulus

What is orthostatic syncope also known as?

postural hypotension

What condition?

• impaired vasoconstrictive response to assuming upright position (>20 mmHg decline in BP immediately from supine to standing)

• common cause of vasodepressor syncope

orthostatic syncope

Who is orthostatic syncope common in?

elderly, hypovolemia (dehydration), DM, pts on vasodilators, diuretics or adrenergic blockers

What condition?

• no prodrome

• syncope episodes are exertional/postexertional

• mechanical causes: AS, PS, HOCM

• arrhythmic causes: automaticity (SSS), conduction (AV block), tachyarrhythmias (V-tach/SVT)

cardiogenic syncope

What is the workup for cardiogenic syncope?

EKG, ambulatory monitoring, autonomic testing (carotid massage, head up tilt table test), EPS

What is the treatment for syncope?

avoid predisposing situations, BBs for vasovagal, tx arrhythmias if present, pacemaker if severe pause/bradycardia, volume expanders (fludrocortisone), vasoconstrictors (midodrine), SSRIs

When might a seizure occur in normal brain tissue?

acid base imbalances, electrolyte imbalances

When is the peak incidence of seizure disorders?

childhood and late adulthood (after age 60)

What are primary CNS causes of seizures?

benign febrile convulsion of childhood, epilepsy, head trauma, stroke/TIA, mass lesions

What are systemic causes for seizures?

hyperosmolar state, hypocalcemia, uremia, hypoglycemia, hyponatremia

What is the usual cause of of seizures before the age of 2?

developmental defects, birth injuries, metabolic disorders

What condition?

• genetic- often fhx of epilepsy

• appears during childhood/adolescence (2-14) but may not dx until adulthood

• no nervous system abnormalities other than seizure- brain is structurally normal

idiopathic generalized epilepsy

What condition?

• caused be widespread brain damage (MCC injury during birth)

• seizures + other neuro problems (mental retardation, cerebral palsy)

symptomatic generalized epilepsy

What is prolonged muscular contraction?

tonic activity

What is relaxed w/o normal tone?

atonic activity

What movements are seen with seizures?

convulsions, violent spasms or jerking of face/extremities/trunk

what is rapid succession of contraction then relaxation / repetitive rhythmical jerking of all or part of body?

clinical activity

What is as series of shock like contractions of muscle groups?

myoclonic activity

What is a motor seizure that initially involves one part of the body then progressively spreads to other parts on the same side?

Jacksonian March

What is ictal?

relating to stroke or seizure

What is postictal?

following a seizure

Is a single seizure enough to diagnose epilepsy?

no

What type of seizure?

• one area of brain; preservation of consciousness

partial

What type of seizure?

• affects entire brain; loss of consciousness

generalized

What is the most common type of seizures?

partial

What must be done before treatment of seizures?

classify type

What type of seizure?

• no LOC; can be difficult to control

• isolated tonic or clonic activity of limb, transient altered sensory perception, Jacksonian march

• special sensory or autonomic sx indicate affected region of brain

• other: deja vu, j’aimais vu, illusions, hallucinations

simple partial seizures

What type of seizure?

• aura - transient abnormality of sensation, perception, emotion, or memory

• impaired LOC = amnesia

• N/V, focal sensory perception & tonic or clonic activity

• automatisms

• lasts 30s-2min

complex partial seizure

What type of seizure?

• brief impairment, < 20 sec, pt usually unaware

• pt in conversation - misses words

• mild clonic, tonic, or atonic components

• impaired consciousness - blank stare or day dreaming

• starts in childhood & stops by age 20

• can progress to other types

absence (petit mal) generalized seizure

What type of seizure?

• single or multiple myoclonic jerks

• inc in muscle tone

myoclonic generalized seizure

What type of seizure?

• drop attacks - brief lapse in muscle tone

• dec in muscle tone

• lasts < 5 sec

atonic generalized seizure

What type of seizure?

• tonic phase: < 1 min

  • sudden LOC, rigid, fall to ground, respiration arrested

• clonic phase: jerking of muscles 1-2 min

  • tongue biting, sphincter relax, incontinence

  • deep sleep, breathing deeply, wake up gradually & may complain of HA

  • sluggish postictal mins-hrs

Tonic-Clonic generalized seizure (Grand mal)

The following effects are seen with tonic clonic seizures lasting how long?

• tachycardia, elevated BP, hyperglycemia, elevated temp, leukocytosis

< 15 min

The following effects are seen with tonic clonic seizures lasting how long?

• hypotension w/ dec cerebral blood flow, disruption of BBB leading to cerebral edema

> 1 hr

What condition?

• medical emergency ; prolonged seizure activity > 5 mins

• can cause brain damage or death due to hyperthermia, circulatory collapse, or excitotoxic neuronal damage

status epilepticus

What is the treatment for status epilepticus?

lorazepam (Ativan) or diazepam (valium) to break seizure

give phenytoin (dilantin)

What is the workup for seizures?

EEG (gold standard), head CT/MRI, LP if indicated, CBC;

dx based on H&P

What are emergent indications for a non-contrast CT in a patient with a first time seizure?

new focal deficits, persistent AMS, fever, trauma, persistent HA, hx cancer or anticoagulation, suspicion of AIDs, pt > 40 y/o

What are emergent non-contrast CT indications for epilepsy w/ recurrent seizures?

new seizure pattern or type, prolonged postictal confusion, plus same indications as first time seizure patients

How do general absence seizures appear on EEG?

generalized spikes w. associated slow waves

How do simple partial seizures appear on EEG?

focal rhythmic discharge at start of seizure; might not have ictal activity

How do complex partial seizures appear on EEG?

interictal spikes or spikes assoc w/ slow waves in temporal or fronto-temporal areas

What is the treatment options for generalized tonic-clonic or partial focal seizures?

Phenytoin, Carbamazepine, VPA, Gabapentin, Lamotrigine, Topiramate, Oxcarbazepine, Levetiracetam, etc

What are treatment options for absence seizures?

Ethosuximide, VPA, Clonazepam

What are treatment options for myoclonic seizures?

VPA, Clonazepam

What is the MC trigger in epileptic patients on medications to control seizures?

not take med as instructed / missing dose

What are limitations for epileptic patients?

pt shouldn’t work around moving machinery or at heights, should not swim alone, ~6 month seizure free period before driving

What SE can all anticonvulsants lead to?

hematologic or hepatic toxicity

(check CBC/LFTs at 2 wks, 1 mo, 3 mos, 6 mos, then every 6 mos)

What condition?

• irresistible sleep attacks & episodic muscular atonia

• sleepiness accompanied by attacks of weakness when awake

• CNS disorder w/ abnormal REM brainwaves when awake

Narcolepsy

What confirms a narcolepsy diagnosis?

sleep studies & neuro consult

What is the treatment for narcolepsy?

napping/sleep hygiene therapy, psychosocial support, avoid sedative drugs

CNS stimulants- modafinil (1st line), armodafinil, methylphenidate, amphetamines

What is a coma?

transitional state that rarely lasts for more than several weeks; can recover or progress to vegetative state or brain death

What is brain death?

irreversible loss of function of the brain, including brain stem

What can cause brain death?

primary neurological disease (head injury, aneurysmal SAH), hypoxic ischemic brain insults, fulminant hepatic failure

What is the criteria for diagnosing brain death?

evidence of acute CNS event that is demonstrably irreversible

no drug intoxication or poisoning

core temp > 32C/90F

exclusion of complicating medical conditions that may confound assessment (elyte, acid-base, endocrine disturbances)

What medical record documentation should be included for brain death?

etiology & irreversibility of condition, absence of brainstem reflexes & motor response to pain, absence of respiration w/ PCO2 > 60, confirmatory testing (angiography, EEG, evoked potentials), repeat neuro exams (2 positive apnea tests 6 hrs apart)