Neurology Flashcards
(143 cards)
Diabetic CN III Neuropathy
- Ischemic deficit (not compression) affecting somatic fibers only.
- CN III has both somatic and parasympathetic fibers which have different blood supplies.
Somatic fibers: innervates superior, inferior, and medial rectus, inferior oblique, and levator palpebrae
Parasympathetic fibers: innervates the sphincter of the iris and ciliary muscle —–> fixed, dilated pupil and loss of accomodation
Symptoms: “down and out” gaze, ptosis (unopposed action of the lateral rectus and superior oblique)
- Intact pupillary response and accommodation.
- Compression neuropathy affects all functions.
Todd’s palsy
preceded by a focal motor seizure
Carotid artery thrombosis
- Most commonly affects the middle cerebral a. —> contralateral hemiparesis and hemianesthesia
Lacunar stroke - pure motor hemiparesis
- Lacunar infarction in the posterior limb of the internal capsule
Presentation: unilateral motor deficit (face, arm, and to a lesser extent leg), mild dysarthria
- No loss of sensory, visual, or higher cortical function
Lacunar stroke - pure sensory stroke
- Stroke in the ventroposterolateral nucleus of the thalamus.
Presentation: unilateral numbness, parasthesias and hemisensory deficit involving the face, arm, trunk, and leg
Lacunar stroke - ataxic hemiparesis
Lacunar infarction of the anterior limb of the internal capsule
Presentation: weakness that is more prominent in the lower extremity, along with ipsilateral arm and leg incoordination
Lacunar stroke - dysarthria-clumsy hand syndrome
Lacunar stroke at the basis of the pons
Presentation: hand weakness, mild motor aphasia
- NO sensory abnormalities
Migraine treatment and prophylaxis
Antiemetics: prochlorperazine, chlorpromazine, and metaclopramide
- NSAIDS or triptans if started early into the headache.
Prophylaxis: amitriptyline, propranolol
Basal ganglia hemorrhage
Symptoms: contralateral hemiparesis and hemisensory loss, homonomyous hemianopsia, gaze palsy
Cerebellar hemorrhage
- Usually NO hemiparesis
- Facial weakness, ataxia, nystagmus, occipital headache, and neck stiffness
Thalamic hemorrhage
Symptoms: contralateral hemiparesis and hemisensory loss, non-reactive miotic pupils, upgaze palsy, eyes deviate towards hemiparesis
Cerebral lobe hemorrhage
Symptoms: Contralateral hemiparesis (frontal lobe), contralateral hemisensory loss (parietal lobe), homonymous hemianopsia (occipital lobe), eyes deviate away from hemiparesis, high incidence of seizures
Pons hemorrhage
Symptoms: deep coma and total paralysis within minutes, pinpoint reactive pupils
Essential tremor
- Bilateral action tremor of the hands, usually without leg involvment
- Possible isolated head tremor without dystonia(involuntary repetitive movement)
- Relieved with alcohol
- no other neurologic defecits.
Treatment: propranolol; second-line: primidone and topiramate
Parkinson’s disease tremor
- resting tremor (4-6Hz) that decreases with voluntary movement
- Usually involves legs and hands
- facial involvement less common
- May progress to involve other areas of the body
Tetrad: resting tremor, rigidity, postural instability, and bradykinesia
- Tremor worsens when performing mental tasks and disappears with movement
- Due to progressive loss of dopaminergic neurons in the basal ganglia.
Cerebellar tremor
- Usually associated with ataxia, dysmetria (lack of accuracy during voluntary movement), or gait disorder
- Tremor increases steadily as hand reaches its target
-Can see postural, action, or intention tremors
Physiologic
- Low amplitude (10-12Hz), not visible under normal conditions
- acute onset with sympathetic activity (drugs, hyperthyroidism, caffeine)
- Usually worse with movement and can involve the face and extremities
Brain death
- Absent cortical and brainstem function
- Spinal cord may still be functioning, so DTR can still be present.
- HR becomes invariant due to loss of vagal control.
Status epilepticus
- single seizure lasting longer than 30 mins
- Brains that have seized for >5 minutes are at risk of permanent injury due to excitatory cytotoxicity —-> cortical laminar necrosis
Neurofibromatosis type 2
- mutation in tumor suppressor gene on chromosome 22
- Subcutaneous neurofibromas, cafe-au-lait spots, deafness due to acoustic neuromas
severe variant - Wishart - framshift or nonsense mutations
milder variant - Gardner - missense or splice-site mutation
Primary sclerosing cholangitis
Clinical features: fatigue, pruritis
- 90% of pts have underlying IBS, mainly ulcerative colitis
Labs: Aminotransferases
Ascited Fluid Characteristics
Neutrophils: 250 peritonitis (secondary or spontaneous)
Total protein: >or= 2.5 (high-protein ascites) - CHF, constrictive pericarditis, peritoneal carcinomatosis, TB, Budd-Chiari syndrome, fungal
or=1.1 (indicates portal hypertension) - cardiac ascites, cirrhosis, Budd-Chiari syndrome
Blood supply of the brain
Common carotids —> internal carotids —> opthalmic artery and then anterior and middle cerebral arteries
Subclavian arteries —> vertebral a. —> posterior inferior cerebellar a., then anterior spinal a., then basilar a. —> anterior inferior cerebellar a., then pontine a. —> superior cerebellar a., then posterior cerebral a. which connect to circle of willis vis posterior communicating a.
Middle cerebral artery supply
lateral surface of the frontal, parietal, and upper temporal lobes, genu and posterior limb of internal capsule, majority of the basal ganglia, proximal parts of the visual radiations as they emerge from the lateral geniculate nucleus of the thalamus and course in Meyer’s loop