Neurology #4 Flashcards
What is the difference between a simple and a complex focal (partial) seizure?
Simple: with retained awareness
Complex: with impaired awareness
Automatisms are _____ and what type of seizure can they accompany?
Repetitive behaviors (lip smacking, facial grimacing, chewing, etc.) -Complex partial seizures
What is seen on an electroencephalogram with a absence (petit mal) seizure
Bilateral symmetric 3 Hertz spike and wave activity (2.5-5 Hz)
Explain the symptoms of an absence seizure
- MC in childhood
- Sudden, marked impairment of consciousness without loss of body tone
- Staring episodes with pauses (behavioral arrest)
- Last between 5-10 seconds
First line treatment for absence seizures
-Ethosuximide
What two medications can exacerbate absence seizures?
Carbamezapine and Gabapentin
Explain what a tonic-clonic (Grand Mal) seizure is
- Sudden loss of consciousness with tonic activity (contraction and rigidity) that may be associated with respiratory arrest
- Followed by 1-2 minutes of clonic activity (repetitive, symmetric jerking)
- Followed by post-ictal confusion phase. Cyanosis and urinary incontinence can occur
What labs occur immediately after seizures can rule out pseudo-seizures?
Increased prolactin and lactic acid
What seizure medications are safest in pregnancy?
-Levetiracetam & Lamotrigine
What is status epilepticus?
- A single, continuous epileptic seizure lasting 5 minutes or more, or more than 1 seizure within a 5 minute period without recovery in between episodes
- Considered a neurologic emergency
What are the preferred initial agents in management of status epilepticus?
Benzodiazepines (Lorazepam)
However, if no response to Benzodiazepines, what can be given?
Phenytoin or Fosphenytoin
How does Phenytoin work?
Stabilizes neuronal membranes by blocking voltage-gated sodium channels
Name some side effects of Phenytoin
-P: P450 inducer and induces Lupus-like syndrome
-H: Hyperplasia of gums and Hirsuitism
-E: Erythema Multiforme
-T: Teratogenic
O: Osteopenia
I: Inhibits folic acid absorption
N: Nystagmus
Ethosuximide, the drug of choice for ______, has side effects such as _____
Absence (Petit Mal) seizures
-Rash (SJS), GI upset, drowsiness
MOA for Ethosuximide
Blocks calcium channels
What is a lacunar infarct?
Small vessel disease of the penetrating branches of the cerebral arteries in hte pons and basal ganglia
Risk factors for a lacunar infarct
Hypertension (MC)
DM
5 Classic Presentations of a lacunar infarct
- Pure motor (MC): hemiparesis or hemiplegia
- Ataxic hemiparesis: ipsilateral weakness and clumsiness in the leg > arm
- Pure sensory deficits: numbness and paresthesias on one side of body
- Sensorimotor
- Dysarthria (Clumsy hand)
Diagnostic for lacunar infarct
-CT scan: small punched out hypodense areas usually in central and non cortical areas
Management of lacunar infarct
- Aspirin
- Control risk factors: Hypertension and DM
What is a transient ischemic attack?
Transient episode of neurologic deficits without acute infarction
Symptoms of a TIA
- Neurologic deficits lasting < 24 hours, depending on artery involved
- Most last for a few minutes
- Amaurosis Fugax: transient monocular vision loss (temporary shade down on one eye)
What may be heard on physical examination of a patient with a TIA
Carotid bruits
Diagnostics done for a TIA (3 steps)
Neuroimaging + Neurovascular imaging + rule out cardioembolic source
1) CT scan performed but MRI more sensitive
2) CT or MR angiography, carotid Doppler. Angiography is definitive
3) Ancillary testing: ECG, telemetry, echocardiogram
How to manage a patient with a TIA
- Place patient in supine position
- Avoid lowering BP unless > 220/120
- DO NOT GIVE THROMBOLYTICS
If the TIA is noncardiogenic in nature, what is the treatment?
- Antiplatelet therapy: aspirin, Clopidogrel, Aspirin + Dipyridamole
- Carotid endarterectomy if stenosis 50-99%
If the TIA is cardiogenic in nature, as if it is from A-fib, what is the treatment?
Oral anticoagulation
The risk of a stroke after a TIA is significantly increased. The ABCD2 score is used to determine the risk of stroke 3-90 days after a TIA. Explain.
A: Age > 60
B: BP > 140/90
C: Clinical symptoms (slurred speech = 1 points, unilateral weakness = 2 pts)
D: Duration ( > 10 minutes = 1 point, > 60 minutes = 2 pts)
D: Diabetes
0-3 pts: 3.1%
4-5 pts: 9.8%
6-7 pts: 17.8%
MC type of ischemic stroke?
Thrombotic
Risk factors for ischemic strokes
- Hypertension
- Dyslipidemia
- DM
- A-fib
- Cigarette Smoking
- Males, age, ethnicity, family history
Which artery is most commonly involved in an ischemic stroke?
Middle cerebral artery
Symptoms of an MCA ischemic stroke
- Contralateral sensory and motor deficits greater in face and arm > leg > foot
- Only involves lower half of face (still can raise forehead)
- Gaze preference toward side of the lesion
With an MCA ischemic stroke, if the lesion is on the dominant side, what are the symptoms?
Aphasia, math deficits
With an anterior cerebral artery stroke, what are the symptoms?
- Contralateral sensory and motor deficits greater in the leg, foot > arm
- Face is usually spared
- Urinary incontinence
- Gażę toward side of lesion
- Personality/cognitive deficits (impaired judgment)
With a posterior cerebral artery stroke, what are the symptoms?
-Vertigo (with nystagmus), vomiting, visual changes (diplopia)
Diagnostics for an ischemic stroke
- CT head without contrast: best initial test (MRI most accurate though)
- Ancillary testing: ECG, carotid Doppler US, echo
- Conventional angiography rarely needed
Immediate management of an ischemic stroke
- Within 3 hours of symptom onset: Alteplase if no contraindications (BP > 185/110, recent bleeding, bleeding disorder, recent trauma)
- Mechanical thrombolectomy within 24 hours of symptom onset
- Aspirin and long-term management within 3-4.5 hours
What should be started in a patient for long-term management?
Statin therapy, regardless of LDL level
True or False: Aspirin therapy should not be initiated until 24 hours after the time of thrombolytic therapy
True. If the patient was already on Aspirin prior to stroke, add Dipyridamole or switch to Clopidogrel.
An epidural hematoma is bleeding in
the space between the skull and the dura
MC etiology of an epidural hematoma
-Rupture of the middle meningeal artery, often associated with a temporal bone fracture
3 classic phases of an epidural hematoma
-Brief loss of consciousness followed by a lucid interval followed by neurologic deterioration
With an epidural hematoma, an uncal herniation is present. What does this mean?
Cranial nerve III palsy–fixed dilated blown pupil on the ipsilateral side of the injury
What is the initial test of choice for an epidural hematoma and what is seen?
Head CT without contrast
-Biconvex (lens-shaped) hyperdensity in the temporal area that does NOT cross suture lines
Treatment for an epidural hematoma
- Hematoma evacuation or craniotomy
- May be observed closely if the patient is in good condition, with serial imaging
If the patient has an epidural hematoma and increased intracranial pressure, what should you do?
head elevation short-term hyperventilation hyperosmolar therapy (IV Mannitol)
A subdural hematoma is
bleeding between the dura and arachnoid membranes
MC etiology of a subdural hematoma
Rupture of cortical bridging veins after blunt trauma
Who is most at risk for a subdural hematoma
Elderly and alcoholics
Anticoagulant use
Shaken baby syndrome, child abuse
Symptoms of a subdural hematoma
-Gradual increase in generalized neurologic symptoms
What is seen on a head CT without contrast in a subdural hematoma?
Concave (crescent-shaped) bleed that can cross the suture lines
Management for a subdural hematoma (both nonoperative and operative)
Nonoperative: if clinically stable, or small ( < 5 mm), observe
Operative: surgical evacuation if > 5 mm or greater midline shift (burr hole trephination, craniotomy, decompressive craniectomy)
