Neurology Flashcards
What is the massive transfusion protocol?
administration of PRBC, FFP, and Platelets in 1:1:1 ratio in order to avoid coagulation in patient with hemorrhagic shock after a massive trauma
What is adverse long term effect of metformin in some patients?
vit b12 deficiency due to alteration in calcium homeostasis leading to impaired absorption of vit b12 in the terminal ileum
How to diagnose Guillain barre syndrome?
1) Lumbar puncture for CSF analysis. High protein (Albuminocytologic dissociation) with normal WBCs and glucose
Or
2) Nerve conduction study and Electromyography
What is Miller Fisher syndrome?
It is a variant of Guillain barre syndrome. It has ophthalmoplegia, ataxia and areflexia.
What is subacute combined degeneration syndrome?
Seen in Vit b12 deficiency. Dorsal column and lateral corticospinal tracts are affected. Sxs are diminished vibration, proprioception, light touch and spastic paresis, enhanced reflexes
How to diagnose for myasthenia gravis?
Bedside ice pack test (improvement in sxs) for screening. Confirmation with acetylcholine receptor antibody. Also thymoma on chest CT.
What is the treatment for MG?
Pyridostigmine which is a Acetylcholine esterase inhibitor. Increases the availability of Ach at NMJ. Corticosterioids are also helpful. Thymectomy is also helpful.
What is the pathogenesis of Lambert Eaton myasthenic syndrome?
Autoantibodies against voltage gated calcium channels which subsequently results in decreased release of Ach from the presynaptic end in the NMJ.
What is the pathogenesis of Tetanus?
C tetini toxin blocks the release of inhibitory neurotransmitters like glycine and GABA across the presynaptic cleft, leading to fever, painful muscular spasms, and trismus (Lock Jaw)
What is the pathogenesis of vasovagal syncope?
increased parasympathetic and decreased sympathetic signalling resulting in arterial and venous vasodilation and decreased heart rate and contractility
How to diagnose ALS?
Electromyography; MRI of head and spinal cord (to exclude other causes)
What is the pathogenesis of Benign paroxysmal positional vertigo (BPPV)?
Crystalline debris (canalith) in the semicircular canals that disrupt the normal flow of fluid in the vestibular system. Diagnosed with provocative head positioning maneuver to illicit vertigo and nystagmus.
What are CYP450 inducers?
Barbiturates, Antiepileptics and smoking and EtOH
Pathogenesis of acute intermittent porphyria?
Reduced activity of Porphobilinogen (PBG) deaminase resulting in accumulation of neurotoxic heme pathway intermediates such as ALA and PBG
What are symptoms of Acute intermittent porphyria?
Abdominal pain, peripheral neuropathy, autonomic dysfunction, neuropsychiatric sxs.
Red tinged urine due to PBG
Diagnosis of Acute intermittent porphyria?
Elevated levels Porphobilinogen and porphyrins in Urine and serum
What does Pronator drift indicate?
pronator drift is sensitive and specific for upper motor neuron or pyramidal/corticospinal tract disease
What are risk factor of multiple sclerosis?
young caucasian women, vitamin D deficiency, HLA-DRB1, smoking
Why is estrogen containing contraceptions are contraindicated in patients with migraine?
Due to increased risk of ischemic stroke
What are the abortive therapies for Migraine?
Triptans, NSAIDs, Ergotamine, acetaminophen and antiemetics (prochlorperazine, metoclopramide)
What are the preventative (prophylactic) medication for Migraine?
Topiramate, Divalproex sodium, Beta blockers, TCA
Name cholinesterase inhibitors?
Donepezil, Galantamine and rivastigmine
What is the treatment for mild to moderate Alzheimer’s disease?
Cholinesterase inhibitors such as rivastigmine, galantamine, donepezil.
What is dementia + parkinson + hallucination?
Dementia with lewy bodies;
Biopsy will show eosinophilic intracytoplasmic inclusions
What is Huntington disease?
CAG trinucleotide expansion disease. Atrophy of neostriatum (caudate nucleus and putamen); loss of GABA-ergic neurons; SXS are choreoathetosis (writhing movements), psychiatric sxs like depression, irritability, psychosis and cognitive executive dysfunction
What is the standard treatment for NPH?
Ventriculoperitoneal shunting
What is glasgow coma scale?
Eyes: Spontaneously (4) to voice (3) to pain (2) none (1)
Verbal: ans appropriately (5) confused, disoriented (4) inappropriate word (3) incomprehensible sound (2) No sound (1)
Motor: obeys command (6) localizes to pain (5) withdraws from pain (4) flexion (3) extension (2) no response (1)
In what condition is topiramate contraindicated?
kidney stones or those taking high dose vitamin C
What is the initial treatment of BPPV?
Epley maneuver
What percent of risk each child has of inheriting Huntington disease?
50% risk of inheritance
What is Wernicke’s encephalopathy?
alcoholism, severe nutrition deficiency esp thiamine, confusion, ataxia, nystagmus
Korsakoff syndrome has all of the above plus recent memory loss
What is natalizumab is associated with?
It is associated with Progressive multifocal leukoencephalopathy (PML).
What is PML?
PML is caused by JC virus. It affects the frontal lobe resulting in behavioural changes, motor disorders, and visual defects.
What is the next best diagnostic test when BPPV is suspected and dix hallpike maneuver induces vertigo but no nystagmus visualized?
Frenzel lenses or infrared nystagmography may be employed to improve the senstivity of dix hallpike test
What is the treatment for essential tremor?
propanolol and primidone
What is the treatment of choice for tonic clonic seizure?
valproic acid. it increases the level of GABA by altering the properties of voltage gated sodium channels
What is internuclear ophthalmoplegia?
disorder of horizontal eye movements due to lesion in the medial longitudinal fasciculus (MLF) in the mid pons, between 3rd and 6th cranial nerves.
What is shy-drager syndrome (multiple system atrophy)?
patient with parkinsonism experiences autonomic dysfunction such as orthostatic hypotension, impotence, incontinence, or other autonomic symptoms. Treatment is aimed at increasing intravascular volume expansion with fludrocortisone, salt, alpha adrenergic agonist.
CT scan finding of Epidural vs subdural hematoma?
Epidural (blood between skull and dura mater) seen as Biconvex (lens shaped);
Subdural (blood between dura mater and arachnoid membrane) seen as crescent shape.
What is phenytoin toxicity?
phenytoin is a long acting anti-epileptic medication that inhibits voltage gated sodium channels;
Signs of toxicity is due to cerebellar dysfunction such as horizontal nystagmus, ataxia, slurred speech, N/V and significant toxicity can result in altered mental status, coma and death.
What is the treatment for restless leg syndrome?
dopamine agonist such as pramipexole and alpha-2-delta calcium channel ligand such as gabapentin
What is transverse myelitis? How is it diagnosed?
It is immune mediated myelopathy. Sxs involve motor weakness (UMN and LMN lesions), sensory weakness, autonomic dysfunction. Perform MRI to rule out cord compression. Treatment includes high dose IV glucocorticoids or plasmapharesis
What is the treatment of acute dystonia?
Anticholinergic (IV Benztropine or trihexphenidyl) and Antihistamine (diphenhydramine)
What is the treatment for akathesia?
Beta blockers (propranolol); Benzodiazepine (lorazepam); anticholinergic (benztropine, trihexphenidyl)
What is the treatment of Parkinsonism?
Benztropine; Amantadine
What is the treatment of Tardive dyskinesia?
VMT2 inhibitors eg; Valbenazine or Deutetrabenazine
What is the first line therapy for trigeminal neuralgia?
Antiepileptic meds such as Carbamazepine or Oxcarbazepine (better tolerated)
What is the treatment for tourette syndrome?
Behavioral therapy (habit reversal training);
Antidopaminergic:
- Antipsychotics (block the post synaptic dopamine receptors)
- VMAT2 inhibitors like tetrabenazine
Alpha receptor agonists like clonidine and guanafacine
What is the common risk factor for retinal detachment?
posterior detachment of the vitreous
What is the most common cause monocular visual impairment in children and young adults?
Amblyopia treated with eye patch and corrective lens
What is the composition of lactate’s ringer and when to avoid it?
it contains sodium, calcium, potassium and water. It is similar in composition to plasma. It is avoided in Liver disease, Kidney failure, lactic acidosis or when pH is more than 7.5
