Neurology Flashcards
Generalized Tonic-Clonic Seizures
Drugs: Valporic Acid, Phenytoin, Carbamazepine
Alt. drugs: Phenobarbital, Lamotrigine, Topiramate
Partial Seizures
Drugs: Carbamazepine, Lamotrigine, Phenytoin
Alt. drugs: Felbamate, Phenobarbital, Topiramate, Valporic Acid
Absence Seizures
Drugs: Ethosuximide, Valporic Acid
Alt Drugs: Lamotrigine, Levetiracetam, Zonisamide, Clonazepam
Myoclonic and Atypical Absence Syndromes
Drugs: Valporic Acid
Alt Drugs: Clonazepam, Levetiracetam, Topiramate, Zonisamide, Felbamate
Status Epilepticus
Lorazepam, Diazepam, Phenytoin, Phenobarbital
Ethanol
Most frequently abused drug, causes Wernicke-Korsakoff syndrome in overdose and delirium tremens in withdrawal
Thiamine
Used for prevention of Wernicke-Korsakoff syndrome
Diazepam
Used for treatment of alcohol withdrawal
Methanol
Wood alcohol, causes visual dysfunction due to formaldehyde accumulation
Ethylene glycol
Found in antifreeze, causes nephrotoxicity due to oxalic acid accumulation
Formepizole
Alcohol dehydrogenase inhibitor
Disulfiram
Alcohol dehydrogenase inhibitor
Midazolam
Used in acute anxiety attacks, anesthesia induction, preoperative sedation
Diazepam
Used in seizure disorders (status epilepticus), alcohol withdrawal, tranquilizer
Flunitrazepam
Date-rape drug
Flumazenil
Antidote to benzodiazepine overdose
Thiopental
Used in anesthesia induction, Lethal injection, Truth serum
Phenobarbital
Used in seizure disorders in children, can precipitate porphyria, potent inducer of CYP450
Parkinson’s Disease (PD)
Most common form of Parkinsonism
Mutations of the LKKR2 gene
Most common cause of Familial PD
Dopamine blocking agents
Most common cause of secondary Parkinsonism
Protein misfolding & accumulation and mitochondrial dysfunction
Most significant pathogenic mechanism in Parkinsonism
Levodopa-carbidopa
Mainstay therapy for PD
Tremors
Major clinical effect of central-acting anticholinergic drugs
Amantadine
Most widely used antidyskinesia agent in patients with advanced PD and the only oral agent that has been demonstrated in controlled studies to reduce dyskinesia
Dementia
Most common cause of nursing home placement in PD patients
Essential tremor
Most common movement disorder
Dystonic tremor of PD
Major differentials for tremors
B-blockers or primidone
Standard drug therapies for essential tremors
Focal dystonias
Most common form of dystonia
Drug-induced dystonia
Most commonly seen with neuroleptic drugs or after chronic levodopa treatment in PD patients
SLE
Most common systemic disorder that causes chorea
Dystonia
Most common acute hyperkinetic drug reaction
Akathisia
Most common subacute drug reaction
Liver Biopsy
Gold standard for diagnosis of Wilson’s disease
Tremor affecting the upper limbs
Most common psychogenic movement disorder
Diabetes mellitus
Most common cause of peripheral neuropathy in developed countries
Median neuropathy at the wrist and ulnar neuropathy at the elbow
Most common diabetic mononeuropathies
Seventh nerve palsy, followed by third nerve, sixth nerve, and, less frequently, fourth nerve palsies
Most common cranial mononeuropathies in DM
Trigeminal nerve
Most common mononeuropathies in scleroderma
Seventh nerve
Most common cranial nerve involved in sarcoidosis
Carpal tunnel syndrome
Most common mononeuropathies in uremia
Distal symmetric polyneuropathy
Most common form of peripheral neuropathy associated with HIV infection & usually seen in patients with AIDS
Lung cancer
Most common associated malignancy with neuropathies
GBS and myasthenia gravis
Most common causes of acute generalized weakness leading to admission in ICU
Guillain Barre Syndrome (GBS)
Manifests as rapidly evolving areflexic motor paralysis with or without sensory disturbance, associated with Campylobacter jejuni found in undercooked chicken
Myasthenia Gravis (MG)
Neuromuscular disorder characterized by weakness and fatigability of skeletal muscles, caused by a decrease in the number of available acetylcholine receptors (AChRs) at neuromuscular junctions due to an antibody-mediated autoimmune attack, associated with diplopia
Trainsient Ischemic Response (TIA)
Requires that all neurologic signs and symptoms resolve within 24 hrs (most last <1hr) regardless of whether there is an imaging evidence of new permanent brain injury
Stroke
Occurred in the neurologic signs last for more than 24 hours
Ischemic Penumbra
Tissue surrounding the core region of infarction is ischemic but reversibly dysfuncitonal
Lacunar Infarction
Refers to infarction following atherothrombotic of lipohyalinotic occlusion of a small artery (30-300 um)
4-10 minutes
Decrease in cerebral blood flow to zero causes death of brain tissue within
Nonrheumatic atrial fibrilation
Most common cause of cerebral embolism overall
Carotid bifurcation atherosclerosis
Most common source of artery to artery embolism
Common carotid bifurcation and proximal internal carotid artery
Atherosclerosis within the carotid artery occurs most frequently in
Transient symptoms (small vessel TIA)
Herald a small-vessel infarct
Hypertension
Most significant risk factor of stroke and TIA
Aspirin
Only antiplatelet agent that has proven effective for the acute treatment of ischemic stroke
Headache
Principal side effect of dipyridamole
Within 2 weeks of symptom onset (benefit is more pronounced in men>75 y.o.)
Endarterectomy for carotid atherosclerosis is most beneficial when performed
Hallmark of top of the basilar artery occlusion
Sudden onset of bilateral signs, including ptosis, papillary asymmetry or lack of reaction to light and somnolence
Plain cranial CT
Imaging modality of choice in patients with acute stroke to rule out bleed
Conventional x-ray cerebral angiography
Gold standard for identifying and quantifying atherosclerotic stenoses of arteries
Trauma
Bleeding into subdural and epidural spaces is principally produced by
Basal ganglia (especially putamen), thalamus, cerebellum, pons
Most common sites of hypertensive intraparenchymal hemorrhage
Putamen (Sentinel) sign: contralateral hemiparesis
Most common site of hypertensive hemorrhage
Cerebral amyloid angiopathy
Most common cause of lobar hemorrhage in the elderly
Choriocarcinoma Malignant melanoma Renal cell carcinoma Bronchogenic carcinoma
Most common metastatic tumors associated with intracerebral hemorrhage
> 3cm in diameter
Most cerebellar hematomas of this diameter will require surgical evacuation
Seizure
Paroxysomal event due to abnormal excessive or synchronous neuronal activity in the brain
Epilepsy
Condition where a person has recurrent seizures due to underlying causes not associated with structural brain damage
Triad of Lennox-Gastaus Syndrome
- Multiple seizure typers (usually generalized tonig-clonic, atonig, and atypical absence seizures)
Early childhood and late adulthood
Highest incident of seizures
Daydreamind and a decline in school performance recognized by the teacher
First clue of typical absence seizures
Electrophysiologic hallmark of typical absence seizures
Generalized, symmetric, 3-Hz spike-and-wave discharge that begins and ends abruptly, superimposed on a normal EEG background
Generalize tonic-clonic seizures
Main seizure type in 10% of all persons with epilepsy
Generalize tonic-clonic seizures
Most common seizure type resulting from metabolic derangements
Metabolic disorders
Degenerative CNS diseases
Anoxic brain injury
Pathologic myoclonus is the most commonly seen in association with
Mesial Temporal Lobe Epilepsy Syndrome
Most common syndrome associated with focal seizures with dyscognitive features
Febrile seizures
Most common seizures arising in late infancy and early childhood
First goal in the approach to seizure
Determine if event was truly a seizure
Valporic acid Lamotrigine
Best initial choice for the treatment of primary generalized tonig-clonic seizures
Valpotic acid
Drug choice in patients with generalized epilepsy syndromes having mixed seizure types
Key determinants in initiation and the monitoring of therapy
Clinical measures of seizure frequency and presence of side effects, not the laboratory values
First 3 months after discontinuing therapy
Most recurrences of seizure occur in the
Most common surgical procedure for patients with temporal lobe epilepsy
Resection of the anteromedial temporam lobe (temporal lobectomy) or a more limited removal of the underlying hippocampus and amygdala (amygdalohippocampectomy)
First task in the approach to CNS infection
Identify whether an infection predominantly involves the subarachnoid space (meningitis) or whether there is evidence of either generalized or focal involvement of brain tissue in the cerebral hemispheres, cerebellum, or brainstem
Bain tissue is directly injured by a viral infection
Encephalitis
Fever, headache, and nuchal rigidity
Classical clinical triad of meningitis
Headache, fever, focal neurologic deficit (present in <50%)
Classic clinical triad of brain abscess
Cerebritis
Non-encapsulated brain abscess
Nuchal rigidity (“stiff neck”)
Pathognomonic sign of meningeal irritation and is present when neck resists passive flexion
Bacterial meningitis
Most common form of suppurative CNS infection
S. pneumoniae
Most common cause of meningitis in adults>20 years
Petechial or purpuric skin lesions
Important clue to diagnosis of meningococcal infection
Cerebral herniation
Most disastrous complication of increased ICP
S. pneumoniae and N. meningitides
Most common etiologic organisms of community-acquired bacterial meningitis
Enteroviruses, HSV type 2, HIV, Arboviruses
Most important agents in acute viral meningitis
Headache
Most common symptom of brain abscess
Combination of high dose parenteral antibiotics and neurosurgical drainage
Optimal therapy for brain abscess
Cranial MRI
Preferred diagnostic test for any patient suspected of having a brain tumor, and should be performed with gadolinium contrast administration
Neuroimaging
The only test necessary to diagnose a brain tumor
Dexamethasone
Glucocorticoid of choice for brain tumors because of its relatively low mineralocorticaoid activity
The only established risk factors for primary brain tumors
Exposure to ionizing radiation: meningiomas, gliomas, schwannomas Immunosuppression: primary CNS lymphoma
Most common primary brain tumor of childhood
Grade I astocytomas: pilocytic astrocytomas (WHO grade I)
Meningiomas
Most common primary brain tumor overall
Epstein-Barr Virus (EBV)
Frequently plays an important role in the pathogenesis of HIV-related primary CNS lymphoma
Medulloblastomas
Most common malignant brain tumor of chilhood
Grade IV astrocytoma (Glioblastoma)
Most common malignant brain tumor overall
Cerebral convexities
Where meningiomas are most commonly located
Dural metastasis
Main differential diagnosis for meningioma
Most common schwannomas
Vestibular schwannomas or acoustic neurons
Gray matter-white matter junction
Most common site of brain metastases
Supratentorial
85% of all brain metastases are
Lung and breast cancer
Most common sources of brain metastases
Melanoma
Malignancy with greatest propensity for brain metastasis, found in 80% of patients at autopsy
Prostate and breast cancer
Malignancies with propensity to metastasize to the dura and can mimic meningioma
MRI
Brain metastases are best visualized on ___ where they appear as well-circumscribed lesions
Melanoma, thyroid, kidney cancer
Cancers with greatest propensity to bleed
Lung cancer
Most common cause of hemorrhagic metastasis
Acute leukemia
Most common among hematologic malignancies to matastasize to the subarachnoid space
Breast and lung carcinomas and melanoma
Solid tumors that most frequently cause leptomeningeal metastases
Demonstration of tumor cells in CSF
Definitive method and often considered the gold standard to diagnose leptomeningeal metastases
Hematologic malignancies
CSF cytologic examination is most useful in
Thoracic spine, followed by the lumbar and then cervical spine
Part of the spine affected most commonly in epidural metastasis
Back pain
Presenting symptom of epidural metastasis in virtually all patients
MRI of the complete spine
Best test for epidural metastasis
Complete removal of the mass, typically anterior to the spinal canal
Surgical procedure of choice for epidural metastasis
Whole-Brain Radiotherapy (WBRT)
Standard treatment for beain metastases
Late delayed toxicity
Most serious toxicity from radiotherapy as they are often irreversible
Leukoencephalopathy
Complication seen most commonly after WBRT
Neurotoxicity
Second only to myelosupression as dose-limiting toxicity of chemotherapeutic agents
Vomiting that precedes headaches
Highly characteristic of posterior fossa brain tumors
Headache
Dominant symptom in temporal (giant cell) arteritis
Migraine, tension-type headache, and cluter headache
Most common primary headache syndromes
Trigeminovascular input from the meningeal vessels
Key pathway for pain in migraine
Migraine
Most disabling headache
Judicious use of one or more drugs that are effective in migraine
Mainstays of pharmacologic therapy in migraine
Severity of the attack
Most important factor in selection of the optimal regimen for a migraine patient
Most effective drug classes in the treatment of migraine
Anti-inflammatory agents, 5-HT, 1B/1D receptor agonists (triptans), and dopamine receptor antagonists
Most efficacious of the triptans
Rizatriptan and eletriptan
Periodicity
Core feature of cluster headache
Most satisfactory treatment in cluster headache
Administration of drugs to prevent cluster attacks until the bout is over
Subarachnoid hemorrhage
Most serious cause of secondary headache
Most evident in the morning and improves during the day
Classic headache associated with a brain tumor
Sympathetic Effects
Myrdiasis, sweating, increased heart rate, bronchodilation, GU and GI contraction, uterine relaxation and contraction, vasodilation of the skeletal muscles, vasoconstriction of the skin and GI tract, ejaculation
Adrenergic receptors
Alpha-1 (for smooth muscle contraction in sphincters, radial muscle of the iris, vasoconstriction)
CN III (Oculomotor nerve)
Cranial nerve for opening of eyelids, contraction of most EOMs, accommodation and pupillary constriction
CN VII (Facial nerve)
Cranial nerve for specail sensation (taste) of the anterior 2/3 of the tongue
CN V (Trigeminal nerve)
Cranial nerve for general sensation (e.g. pain) of the anterior 2/3 of tongue
CN VII (Facial nerve)
Cranial nerve for facial muscles
CN V (Trigeminal nerve)
Cranial nerve for facial sensation and muscles of mastication
Acetylcholine (Ach)
Found in various sites (e.g. ANS and NMJ), decreased in HUntington’s dementia and Alzheimer’s dementia
Norephinephrine (NE)
Found in the locus ceruleus of the pons, for arousal/wakefulness
Dopamine
Found in the substantia nigra, decreased in Parkinson’s disease, increased in schizophrenia, for fine-tuning of movements
Serotonin
Found in the median raphe of the brainstem, derived from tryptophan, converted to melatonin, involved in mood and sleep
Glycine
Found in spiral interneurons, main inhibitory neurotransmitter
GABA
Found in the brain, main inhibitory neurotransmitter, from glutamate
Glutamate
Excitatory neurotransmitter in the CNS
Hippocampus
Output pathway from reward and punishment centers, lesions here will produce anterograde amnesia
Thalamus
Helps seach memory storehouses, lesions here will produce retrograde amnesia
Beta waves, Alpha waves, Delta waves
Waves in the EEG of alert, sleeping, and relaxed individuals, respectively
