Neurology Flashcards
In which patients do you perform a head CT scan before lumbar punction when suspect meningitis?
- Papilledema
- Immunocompromised state
- New-onset seizure (within one week of presentation)
- History of CNS disease (mass lesion, stroke, focal infection)
- Abnormal level of consciousness
- Focal neurologic deficit
Most effective method to diagnose dural sinus thrombosis and findings on it
Cerebral venogram→bilateral infarcts along the posterior and anterior frontal lobes and parietal lobes, extending into the white matter (Sagital sinus infarcts)
*Example: Sagital sinus infarcts tend to cross arterial vascular territories and extend into the white matter
Other tests rather than the best initial one that can provide information about myasthenia gravis
- Iced pack test (bedside)➡Application of an ice pack over the eyelids may improve symptoms
- Tensilon test➡Edrophonium (anticholinesterase inhibitor)▶rapidly reverses symptoms
- Abnormal single-fiber EMG and/or a decremental response to repetitive nerve stimulation
Important features to recognize dementia with Lewy bodies
- Visual hallucinations
- Spontaneous parkinsonism
- Fluctuating cognition
- REM sleep behavior disorder
What is Ramsay-Hunt syndrome?
Herpes zoster oticus➡reactivation of VZV in geniculate ganglion➡disrupting VII CN motor fibers, subsequent spread to VIII CN▶painful, erythematous, vesicular rash in auditory canal or auricle; ipsilateral facial paralysis; vestibular (vertigo, nausea/vomiting), hearing, taste disturbances.
What is multiple system atrophy (Shy-Drager syndrome)?
- Parkinsonism
- Autonomic dysfunction (orthostatic hypotension, erectile dysfunction, incontinence, disturbance bowel control, abnormal salivation, lacrimation and sweating, gastroparesis, etc.)
- Widespread neurological signs (cerebellar, pyramidal, lower motor neuron)➡bulbar dysfunction and laryngeal stridor may be fatal
Where is the stroke localization in a patient having right hemiparesis (with hyperreflexia) and left upper and lower facial weakness?
Left pons
*Left CN VI or VII palsy (LMN pattern facial weakness)
Best initial test and their results when suspect idiopathic intracranial hypertension
- MRI→Normal or empty sella (70%)
- MRV→Normal
- Lumbar puncture→Opening pressure >250 mmH2O
Typical MRI/CT finding of high-grade (ex, IV grade) astrocytoma (glioblastoma)
Butterfly appearance with central necrosis, heterogenous serpiginous contrast enhancement
Neuropsychiatric manifestations of Wilson disease
- Psychiatric→Depression, personality changes, psychosis, mania, anxiety
- Neurologic→parkinsonism, dysarthria, choreoathetosis, ataxia
Risk factors of Multiple Sclerosis
- Female, caucasian, HLA-DRB1
- Location: USA, Europe, cold climate
- Low Vitamin D levels
- Smoking
- EBV
Diagnostic and therapeutic (short-term) maneuver for cervical radiculopathy
Shoulder abduction test➡improve radicular symptoms when hand is placed on the top of the head
Ptosis, “down-and-out” gaze, diplopia and normal pupillary response in a patient with poorly controlled diabetes mellitus
Ischemic oculomotor (CN III) palsy [Diabetic ophthalmoplegia]
*Damage to the inner somatic nerve fibers while sparing the more peripheral parasympathetic fibers
Medications that may precipitate myasthenic crisis
- Antibiotics: aminioglycosides, fluoroquinolones
- Beta-blockers
- Calcium channel blockers
- Magnesium
Ulnar nerve neuropathy differences between wrist and elbow level injury
- Wrist➡numbness, paresthesia at medial side of the hand + intrinsic hand weakness (“clumsiness”) [hypothenar, medial lumbrical, adductor pollicis]
- Elbow➡⬇grip strength [flexor carpi ulnaris, medial portion of flexor digitorum profundus]
How you may differentiate guillain-barré syndrome vs tick paralysis?
- GBS➡Autonomic dysfunction in 70% of patients (tachycardia, urinary tract retention, arrhythmias). CSF with albuminocytologic dissociation (⬆proteins, ⬇cells). Ascending symmetrical paralysis over days to weeks.
- Tick-borne paralysis➡Ascending paralysis over hours to days, may be localized or more pronunced on 1 extremity. Look for and find the tick (next best step)
Etiology of tick-borne paralysis
Neurotoxin release: tick needs 4-7 days for neurotoxin release
*Remove the tick➡improvement in an hour, complete recovery in several days (Dermacentor app, Ixodes holocyclus)
Most common adolescent- and adult-onset muscular dystrophy and mode of genetic transmission
- Classic myotonic dystrophy
- Autosomal dominant➡CTG repeat expansion on the DMPK gene
Main clinical presentation of classic myotonic dystrophy
- Progressive skeletal muscle weakness➡face and distal extremities (forearms, hands, ankle flexors)▶muscle wasting➡ptosis, temporal wasting, limb muscle atrophy
- Grip myotonia (hand)
- Dysphagia
- Conduction anomalies
- Testicular atrophy/infertility
Which clinical manifestations might raise suspicion of cervical myelopathy?
- Lower motor neuron (LMN) signs (Ex, weakness and atrophy) at the level of the lesion (arms)
- Upper motor neuron (UMN) signs (Ex, hyperreflexia) below the level of the lesion (legs)
Most common cause of cervical myelopathy in older adults
Spondylosis➡canal narrowing➡spinal cord compression
Most important side effects of phenytoin
- Phenytoin➡❌folic acid absorption in jejunum▶folic acid deficiency over weeks or months
- Megaloblastic anemia
- Gingival overgrowth/hyperplasia
- Phenytoin➡❌bone and mineral metabolism (⬇bone density): calcium and vitamin D supplementation
Symptoms of papilledema due to increased intracranial pressure
- Momentary vision loss that varies according to changes in head position
- Large blind spot in visual fields
Treatment alternative for Parkinson disease when tremor is the dominant symptom and bradykinesia/rigidity are not significant
Anticholinergic therapy (Trihexyphenidyl)
*Limited to younger patients (≤65)→risk of adverse effects in older patients
Ocular manifestations of Neurofibromatosis type 1
- Optic pathway glioma (15% of patients, age<6)➡asymptomatic or grow large to compress optic nerve▶⬇visual acuity, ❌color vision, optic nerve atrophy, proptosis, esotropia, optic disc pallor
- Lisch nodules➡pigmented iris hamartomas