UKOM Sp.N (Neurology) flashcards

41 cards. Read the term and the definition here. The deck at the top of this page is optional.

Corticospinal decussation

Pyramidal fibers cross in the medulla; therefore a lesion above the decussation causes contralateral weakness, while a spinal cord lesion causes ipsilateral weakness below the level.

Internal capsule blood supply

Lenticulostriate branches of the middle cerebral artery supply the posterior limb; lacunar infarction here produces a pure motor hemiparesis without cortical signs.

Broca versus Wernicke aphasia

Broca aphasia is non-fluent with preserved comprehension; Wernicke aphasia is fluent with impaired comprehension. Both show impaired repetition, distinguishing them from conduction aphasia.

Resting membrane potential

Approximately −70 mV, determined largely by potassium permeability and the concentration gradient. The Nernst equation predicts the equilibrium potential for each ion.

Cerebral blood flow thresholds

Normal flow is about 50 mL/100 g/min. Flow below 20 mL causes EEG slowing and electrical failure; below 10 mL causes membrane failure and irreversible infarction.

CSF production and volume

The choroid plexus produces roughly 500 mL daily; total CSF volume is about 150 mL, so the compartment turns over three to four times per day.

Upper versus lower motor neuron signs

Upper motor neuron lesions cause spasticity, hyperreflexia, and Babinski sign. Lower motor neuron lesions cause flaccidity, atrophy, fasciculations, and areflexia.

Sensory level localization

A sensory level on the trunk localizes a spinal cord lesion to approximately one or two segments above the level of sensory loss.

Red flags in headache

New onset after age 50, thunderclap onset, fever, papilledema, focal deficit, cancer, immunosuppression, or positional change warrant urgent imaging and evaluation.

Thrombolysis time window

Intravenous alteplase or tenecteplase is indicated within 4.5 hours of last known well for disabling ischemic stroke after hemorrhage is excluded by imaging.

Thrombectomy selection

Mechanical thrombectomy is indicated for large-vessel occlusion within 6 hours, or 6 to 24 hours when perfusion imaging shows salvageable penumbra with a small core.

Aneurysmal SAH management

Secure the aneurysm by clipping or coiling, give nimodipine 60 mg every 4 hours for 21 days to reduce delayed ischemia, and monitor for hydrocephalus and hyponatremia.

Status epilepticus treatment

Give a benzodiazepine first, then a second-line agent such as levetiracetam, valproate, or phenytoin. Refractory cases require anesthetic infusion and EEG monitoring.

Valproate pregnancy risk

Valproate causes neural tube defects and neurodevelopmental harm and is contraindicated in pregnancy. It should be avoided in women of childbearing potential unless no alternative exists.

Narcolepsy MSLT criteria

The multiple sleep latency test shows a mean sleep latency under 8 minutes with at least two sleep-onset REM periods, alongside cataplexy or other characteristic features.

Myasthenia gravis antibodies

Anti-acetylcholine receptor antibodies are found in most generalized cases; anti-MuSK antibodies occur in a subset. Weakness is fatigable and often involves ptosis and diplopia.

Guillain-Barré syndrome

Ascending symmetric weakness with areflexia and albuminocytologic dissociation in CSF. Treat with IVIG or plasma exchange and monitor vital capacity for respiratory failure.

Amyotrophic lateral sclerosis

Combined upper and lower motor neuron signs with fasciculations and no sensory loss. Riluzole and edaravone offer modest benefit; noninvasive ventilation supports respiratory failure.

Demyelinating versus axonal neuropathy

Demyelinating neuropathy shows slowed conduction velocity, prolonged distal latency, and conduction block. Axonal neuropathy shows reduced compound muscle action potential amplitudes with preserved velocities.

Neuropathic pain first-line drugs

Gabapentin, pregabalin, duloxetine, and amitriptyline are first-line for neuropathic pain. Opioids are not recommended because of limited benefit and dependence risk.

McDonald criteria

Multiple sclerosis diagnosis requires dissemination in space and time demonstrated clinically or by MRI, with alternative diagnoses excluded. CSF oligoclonal bands can substitute for time dissemination.

Neuromyelitis optica spectrum disorder

Anti-aquaporin-4 antibodies cause longitudinally extensive transverse myelitis and optic neuritis. Attacks are treated with steroids and plasma exchange; maintenance uses rituximab or complement inhibitors.

Anti-NMDAR encephalitis

Presents with psychiatric symptoms, dyskinesias, seizures, and autonomic instability, often with an ovarian teratoma. EEG may show extreme delta brush; treat with immunotherapy and tumor removal.

Bacterial meningitis CSF

Neutrophilic pleocytosis with low glucose and high protein. Empiric ceftriaxone plus vancomycin, adding ampicillin when Listeria is possible in older or immunocompromised patients.

HSV encephalitis treatment

Temporal lobe hemorrhagic necrosis suggests herpes simplex encephalitis. Start intravenous aciclovir 10 mg/kg every 8 hours empirically for 14 to 21 days without waiting for PCR.

Parkinson disease treatment

Levodopa with carbidopa is the most effective symptomatic therapy. Motor fluctuations and dyskinesias emerge after several years and may require COMT or MAO-B inhibitors.

Progressive supranuclear palsy

Atypical parkinsonism with early falls, vertical supranuclear gaze palsy, and axial rigidity. It responds poorly to levodopa and progresses more rapidly than Parkinson disease.

Cluster headache treatment

High-flow oxygen and subcutaneous sumatriptan abort attacks. Verapamil is first-line prophylaxis; transitional steroids may be used while prophylaxis takes effect.

Trigeminal neuralgia

Lancinating unilateral facial pain in the second or third trigeminal division, often triggered by touch or chewing. Carbamazepine is first-line; microvascular decompression is definitive.

Diffusion-weighted imaging

DWI detects restricted diffusion within minutes of acute infarction and is the most sensitive MRI sequence. Restricted diffusion also occurs in abscess, prion disease, and highly cellular tumors.

CT head in acute stroke

Non-contrast CT excludes hemorrhage immediately and may show early ischemic change. It is the first-line imaging test before thrombolysis in acute stroke.

Absence seizure EEG

Generalized 3 Hz spike-and-wave discharges provoked by hyperventilation, with abrupt onset and offset of impaired awareness and no postictal confusion.

EMG denervation signs

Fibrillation potentials and positive sharp waves appear after denervation. Large, long-duration motor unit potentials indicate chronic reinnervation from collateral sprouting.

Febrile seizure features

Occurs between 6 months and 5 years with fever, lasting under 15 minutes without focal features. Routine EEG and imaging are not indicated for simple febrile seizures.

West syndrome

Infantile spasms with hypsarrhythmia on EEG and developmental arrest. Treatment includes adrenocorticotropic hormone or vigabatrin, especially when associated with tuberous sclerosis.

Delirium assessment

Acute fluctuating inattention and altered awareness, screened with the Confusion Assessment Method. Identify and treat the underlying cause; antipsychotics are reserved for severe agitation.

Psychosis in Parkinson disease

Reduce dopaminergic medication first. If symptoms persist, use quetiapine or clozapine; typical antipsychotics worsen motor symptoms and should be avoided.

Enzyme-inducing antiepileptics

Carbamazepine, phenytoin, and phenobarbital induce hepatic enzymes, reducing levels of oral contraceptives, warfarin, and other antiepileptic drugs.

Lamotrigine titration

Start low and titrate slowly to reduce the risk of Stevens-Johnson syndrome. Valproate inhibits lamotrigine metabolism, so the starting dose must be halved.

Informed consent elements

Valid consent requires capacity, adequate information about risks, benefits, and alternatives, and voluntary decision-making. Document the discussion in the medical record.

Duty of candour

When harm occurs, promptly disclose it to the patient, apologize, explain what happened, and offer support. This is a statutory professional obligation in the UK.