Neurology: UWorld Flashcards
What part of the brain is predominantly affected by Progressive multifocal leukoencephalopathy (PML)?
Cortical white matter
The brainstem and cerebellum can be involved too.
The following findings are consistent with what diagnosis?
- Spontaneous speech: Fluent & voluminous but lacks meaning
- Comprehension: Greatly diminished
- Repetition: Impaired
- Associated features: Right superior visual field defect
Wernicke’s (Receptive) aphasia
Patient’s with Wernickes’s aphasia have difficulty comprehending and following commands but are able to speak fluently. However, their speech tends to be rambling without concrete meaning. Receptive aphasia results from a dominant temporal lobe lesion.
A person’s ability to comprehend emotional gestures can be affected by a brain lesion located where?
Nondominant temporal lobe
These patients can also develop a contralateral homonymous quadrantanopsia due to the inferior optic radiations involvement.
Any patient admitted for Guillain-Barre syndrome should be evaluated frequently with serial measurements of what?
Vital capacity
Vital capacity is the best way to monitor respiratory function and assess for respiratory failure.
The following findings are consistent with what diagnosis?
- Spontaneous speech: Fluent with phonemic errors
- Comprehension: Relatively preserved
- Repetition: Very poor
- Associated features: None
Conduction aphasia
Conductive aphasia results from a dominant temporal lobe lesion (like receptive aphasia). It occurs when the lesion involves the arcuate fasciculus.
Herpes mainly affects which lobe of the brain?
Temporal lobe
Herpes encephalitis accounts for 10-20% of all viral encephalitis, and is the most common cause of fatal sporadic encephalitis in the United States. HSV-1 is the etiological agent in almost all cases beyond the neonatal period. Intravenous acyclovir is the treatment of choice.
What is the management for both cauda equina syndrome and conus medularis syndrome?
- Emergency magnetic resonance imaging
- Intravenous glucocorticoids
- Neursurgical evaluation
Diffuse atrophy of the cerebral cortex is a feature of what disease?
Alzheimer’s disease
What test/study is useful in differentiating conditions like infectious meningitis and multiple sclerosis?
Lumbar puncture
Oligoclonal bands are characteristic of Multiple Sclerosis.
The following characteristics are indicative of which subtype of stroke?
- Risk factors: Uncontrolled hypertension, diabetes
- Fluctuating symptoms - stuttering progression with periods of improvement
Thrombotic (ischemic) stroke
Local in-situ obstruction of an artery occurs.
The following signs/symptoms are characteristic of which diagnosis?
- Severe lower back pain with bilateral radiculopathy
- Saddle anesthesia
- Hyporeflexia
- Profound asymmetric motor weakness
- Bowel and bladder dysfunction.
Cauda equina syndrome
This is contrasted to conus medullaris syndrome which presents with
- Severe back pain with lesser degree of radiculopathy
- Perianal anesthesia
- Hyperreflexia
- Mild bilateral motor weakness
- Bowel and bladder disturbances
What is the study of choice in diagnosing multiple sclerosis?
Magnetic resonance imaging (MRI)
Cerebral and spinal plaques composed of clusters of demyelinated axons appear as hypo/hyperintense lesions on MRI. The lesions involve the white matter of the central nervous system, particularly the periventricular and subpial white matter of the cerebrum (corpus callosum), optic nerves, brain stem, and spinal cord. Lumbar puncture is also recommended to document oligoclonal IgG bands (found in >95% of clinically definite multiple sclerosis patients) in the cerebrospinal fluid to establish the diagnosis.
Tabes dorsalis is a manifestation of what condition?
Neurosyphilis
It is characterized by destruction of the posterior columns leading to loss of proprioception. The patient walks with his/her legs wide apart. The feet are lifted higher than usual, and make a slapping sound when they come in contact with the floor. Romberg’s sign may be positive.
Unilateral eye pain, vision loss, and an associated afferent pupillary defect are characteristic features of what condition?
Optic neuritis
This is commonly associated with multiple sclerosis, but can be seen with other disorders as well.
The following findings are consistent with a lesion to what region?
- Contralateral ataxia
- Hemiparesis of the face, trunk, and limbs (ataxic hemiparesis)
- Variable loss of contralateral tactile and position sense
Medial mid-pontine infarction
Cognitive dysfunction with motor and sensory neurological dysfuntion is characteristic of what condition?
Multi-infarct dementia
This accounts for 15-20% of dementia cases. The associated risk factors are: older age, male sex, black race, cigarette smoking, hypertension, diabetes, and vasculitis. The treatment is generally directed towards the risk factors.
The following findings are consistent with what diagnosis?
- Deep coma and paraplegia that develops within minutes
- Pupils pinpoint and reactive to light
- Decerebrate rigidity
Pontine hemorrhage
This accounts for 5-12% of cases of hypertensive intraparenchymal hemorrhages.
Hemi-sensory loss with severe dysesthesia (unpleasant abnormal sense of touch) of the affected area is typical for what?
A thalamic stroke (Dejerine-Roussy syndrome)
This condition is caused by a stroke involving ventral postero-lateral (VPL) nucleus of the thalamus, which transmits sensory information from the contralateral side of the body.
Corticospinal tract lesions cause what?
Spastic paresis
Unilateral corticospinal lesions may cause hemiplegic gait, where the spastic leg is held extended and internally rotated and walking is accomplished by abducting and advancing the spastic leg.
Fatigable muscle weakness that primarily involves the extraocular and bulbar musculature is most consistent with what condition?
Myasthenia gravis
Myasthenia gravis affects only motor nerves, with preservation of the sensory nerves. The creatine phosphokinase (CPK) is generally normal, which helps to distinguish it from a primary muscle problem. Approximately 15% of patients with myasthenia gravis have a coexisting thymoma, thus screening computed tomography of the chest is generally recommended.
What condition presents as recurrent, acute-onset vertigo that is precipitated by head movement, and has associated symptoms of nystagmus, nausea, and vomiting?
Benign paroxysmal positional vertigo
This occurs when calcium crystals within the inner ear shift position.
What two medications can be given to treat essential tremor in a patient who cannot tolerate propranolol?
- Primidone
- Topiramate
What is the most effective symptomatic therapy for parkinsonism?
Levodopa/Carbidopa
The most common early side effects are hallucinations, dizziness, headache, and agitation. After several years of therapy, involuntary movements are more likely to occur.
Acute exacerbations of multiple sclerosis (MS) are treated with what?
Corticosteroids
Plasmapheresis may enhance the beneficial effect of immunosuppression. Although they have no proven role in the treatment of acut MS exacerbations, beta-interferon or glatiramer acetate can be used used to decrease the frequency of exacerbations in patients with relapsing-remitting or secondary progressive form of MS.
If there is evidence of ischemic stroke (suggested by computed tomography without contrast of the head), what two tests should be pursued next?
Carotid doppler and transesophageal echocardiogram
These are performed to locate a possible source of embolism.
What diagnosis should be suspected in elderly patients with dementia in the setting of severe depression?
Pseudodementia
Antidepressants are the treatment of choice.
Lacunar stroke at the basis pontis will have what presentation?
Dysarthria-clumsy hand syndrome
It presents as hand weakness and mild motor aphasia, but no sensory abnormalities.
Lower extremity weakness that may ascend over hours to days to involve the arms, and cranial nerves is the typical presentation of what condition?
Guillain-Barre syndrome (GBS)
GBS is an acute idiopathic inflammatory demyelinating polyneruopathy.
What condition is characterized by gross dysfunction of the autonomic nervous system with severe orthostatic hypotension?
Familial dysautonomia (Riley-Day syndrome)
This is an autosomal-recessive disease seen predominately in children of Ashkenazi jewish ancestry.
What should you suspect in an HIV-infected patient with focal neurological signs and multiple non-enhancing lesions with no mass effect on the CT scan?
Progressive multifocal leukoencephalopathy (PML)
PML is an opportunistic infection caused by the JC virus (Human polyomavirus) and is seen in immunocompromised patients.
Diffuse cortical and subcortical atrophy which is disproportionately greater in the temporal and parietal lobes is characteristic of what condition?
Alzheimer’s disease
The following findings are consistent with a brain lesion occurring where?
- Alternate syndromes with contralateral hemiplegia & ipsilateral cranial nerve involvement
- Possible ataxia
Vertebrobasilar system (supplying the brain stem)
What condition is characterized by the presence of both upper (spasticity, bulbar symptoms, hyperreflexia) and lower (fasciculations) motor neuron lesions?
Amyotrophic lateral sclerosis (ALS)
In all patients with symptoms of stroke, what should be obtained as soon as possible?
Computed tomography (CT) without contrast
This is done to rule out hemorrhage, as hemorrhagic and ischemic strokes are treated differently. Once hemorrhage is ruled out, fibrinolytic therapy should be considered. Intravenous alteplase has been shown to improve outcomes in victims of ischemic stroke when given within 3-4.5 hours of symptom onset.
What often presents with signs and symptoms of elevated intracranial pressure like headache, vision changes, nausea, vomiting, and papilledema, and shows a lesion, edema, or a midline shift on non-contrast CT of the brain?
Brain tumor
Unilateral motor weakness of the face, arm, and leg without any higher cortical dysfunction or visual field abnormalities is characteristic of a lesion occuring where?
Posterior limb of the internal capsule
Lesions in the vertebrobasilar system that supply the brainstem are characterized by “alternate” syndromes, with contralateral hemiplegia and ipsilateral cranial nerve involvement.
Sensory ataxia is associated with which gait abnormality?
Wide-based, high stepping gait
This is the result of the loss of proprioception, and is seen with lesions involving the peripheral nerves, dorsal roots or posterior columns. Romberg’s sign may be positive (I.E. the patient sways on standing with his feet together and eyes closed).
What condition is characterized by fluctuating cognitive impairment, bizarre visual hallucinations, and parkinsonism?
Dementia with Lewy Bodies
The following signs/symptoms are characteristic of what diagnosis?
- Dizziness
- Hearing loss
- Tinnitus
Meniere’s disease
A wide-based, erratic, staggering gait is caused by a lesion in what location?
Cerebellum
Patients with cerebellar lesions classically walk as if they are drunk.
Strokes involving the internal capsule are typically accompanied by what category of symptoms?
Motor symptoms
It occurs in 7% of patients with hypothyroidism.
Ptosis and a “down and out” gaze in conjunction with normal light and accommodation reflexes indicate what diagnosis?
Diabetic cranial nerve III neuropathy
Nerve damage is ischemic, and only somatic nerve fibers are affected. Parasympathetic fibers of CN III retain function.
What condition typically presents with optic neuritis (painful loss of vision), diplopia, sensory deficits, motor weakness, bowel and bladder dysfunction, and neuropsychiatric disturbances?
Multiple Sclerosis
Other features include Uhthoff phenomenon (worsening of symptoms with heat) and Lhermitte’s sign (electric shock-like sensation down the spine or limbs on flexion of the neck.
What condition is characterized by ataxia, ophthalmoplegia, confusion, and amnesia with confabulation?
Thiamine deficiency (Wernicke-Korsakoff syndrome)
It is particularly common in alcoholics.
What is the treatment of choice for pseudodementia?
Antidepressants
Suspect pseudodementia in elderly patients with dementia in the setting of severe depression.
Where does syringomyelia most frequently occur?
Lower cervical or upper thoracic spine
When the syringes occur in the upper cervical cord and extend proximally to involve the medulla oblongata, the condition is called syringobulbia.
What is characterized by progressive muscle weakness and areflexia, and is usually associated with spontaneous remission?
Guillain-Barre syndrome (GBS)
Sensory symptoms are less pronounced than motor ones, but distal paresthesias can occur. Autonomic disturbances and respiratory failure can also occur and may be life-threatening.
Blindness is a symptoms characteristic of a lesion occurring where?
Optic nerve
Internuclear ophthalmoplegia is a characteristic finding of multiple sclerosis, and is due to demyelination of what?
Medial longitudinal fasciculus
This is located in the dorsal pontine tegument. It is characterized by the following: On attempted left gaze, the left eye abducts and exhibits horizontal jerk nystagmus, but the right eye remains stationary. On attempted right gaze, the right eye abducts and exhibits horizontal jerk nystagmus, but the left eye remains stationary. The patient will be able to converge both eyes together, without any associated nystagmus.
Which electrolyte abnormality is an important complication of subarachnoid hemorrhage?
Hyponatremia
“Cerebral salt-wasting syndrome” may occur in patients with subarachnoid hemorrhage. The pathology involves an inappropriate secretion of vasopressin (causing water retention), and an increased secretion of atrial/brain natriuretic peptide (causing cerebral salt-wasting).
Atrophy of the frontal and/or temporal lobes is a feature of what disease?
Pick’s disease
This presents with dementia and personality changes.
Occlusion of which vessel causes contralateral somatosensory and motor weakness (face, arm, leg), conjugate eye deviation toward the side of the infarct, Broca’s expressive aphasia (when dominant side affected), homonymous hemianopia, and hemineglect (when nondominant side affected)?
Middle cerebral artery occlusion
Which anticonvulsant used to treat benign essential tremors can precipitate acute intermittent prophyria?
Primidone
Most patients who are only mildly affected by essential tremor do not require treatment. Patients who require medication are given either beta-blockers or primidone. Primidone is an anticonvulsant that converts into phenylethylmalonamide and phenobarbital. The administration of primidone may precipitate acute intermittent porphyria, which manifests as abdominal pain, neurologic, and psychiatric abnormalities. Acute intermittent porphyria can be diagnosed by checking for urine porphobilinogen.
Broca’s aphasia is caused by a brain lesion located where?
Dominant frontal lobe
Broca’s aphasia is an expressive aphasia.
What condition is characterized as a labyrinthe dysfunction caused by increased pressure of the endolymph, and resulting in recurrent vertigo, tinnitus, and hearing problems?
Meniere disease
Imaging studies revealing cortical and subcortical atrophy as well as secondary ventricular enlargement are suggestive of what?
AIDS dementia complex
What medication used to treat moderate to severe Alzheimer’s disease works by blocking glutamate’s actions on the NMDA receptor?
Memantine
Destruction of the posterior columns leading to loss of proprioception is characteristic of what?
Tabes dorsalis
This is a manifestation of neurosyphilis.
What diagnosis should be suspected in a patient with a sudden onset of eye pain, photophobia, and a mid-dilated pupil?
Acute glaucoma
Drugs that dilate the pupil can precipitate glaucoma. The best diagnostic test is tonometry.
What diagnosis should be suspected in an old patient (age 50-70 years old) with rapidly progressive dementia, myoclonus, and periodic synchronous bi or triphasic sharp wave complexes on Electroencephalogram (EEG)?
Creutzfeldt-Jakob disease
This is a fatal neurodegenerative disease caused by prions. EEG pattern of periodic synchronous bi or triphasic sharp wave complexes is very typical. Brain biopsy shows cortical spongiform changes. The cerebrospinal fluid is usually normal. Most cases are sporadic (80-85%), others are familial or iatrogenic. Death usually occurs within 12 months. There is no specific treatment.
What occurs when calcium crystals within the inner ear shift position?
Benign positional vertigo
Patients present with recurrent, acute-onset vertigo that is precipitated by head movement. Nystagmus, nausea and vomiting are common associated findings.
A stepwise cognitive deterioration is characteristic of what diagnosis?
Multi-infarct dementia
Psychiatric disturbances such as depression and agitation are common.
What is the most frequent pathogen responsible for causing Guillain-Barre syndrome (GBS)?
Campylobacter jejuni
More than two-thirds of patients with GBS have an antecedent respiratory or gastrointestinal infection, of which campylobacter jejuni is the most frequent precipitant. Other precipitants include human herpes viruses, mycoplasma, and hemophilus influenzae. GBS also occurs more frequently in patients with lymphoma, sarcoidosis, and systemic lupus erythematosus. Recent HIV infection and recent immunization have also been associated with GBS.
What is the initial treatment of choice for myasthenia gravis?
Oral anticholinesterase (I.E. pyridostigmine)
There are 3 treatment options available for myasthenia gravis. These include acetylcholinesterase inhibitors, immunosuppressive agents, and thymectomy. Anticholinesterases provide symptomatic benefit, but do not induce remission. Immunosuppressive agents and thymectomy may induce remission. Oral anticholinesterase is usually the initial treatment for myasthenia gravis. It produces its useful effect by increasing the availability of acetylcholine at the neuromuscular junction, where the number of acetylcholine receptors is reduced due to acetylcholine receptor antibodies. Pyridostigmine or neostigmine is used for treatment purposes. Edrophonium is a short-acting anti-cholinesterase, and is used for diagnostic purposes only.
What causes paraplegia, bladder and bowel incontinence, and absent sensation from the nipple downwards?
A lesion in the upper thoracic spinal cord
A lesion in the lower thoracic spinal cord causes absent sensation from the unbilicus downwards.
In what condition does a T2-weighted magnetic resonance imaging show multifocal ovoid subcortical white matter lesions located in periventricular, juxtacortical, infratentorial, or spinal cord areas?
Multiple sclerosis
Cerebrospinal fluid analysis shows normal pressure and the presence of olioclonal IgG bands in >95% of patients.
What condition is characterized by ignoring the left side of a space, and involves the right (non-dominant) parietal lobe?
Hemi-neglect syndrome
What is the treatment for heat stroke?
Induction of evaporative cooling to reverse hyperthermia
What is the drug of choice for trigeminal neuralgia?
Carbamazepine
It is the most effective treatment for trigeminal neuralgia, being effective in approximately 80% of such individuals. Aplastic anemia can occur with prolonged use; therefore, routine CBC is included in the follow-up management of such patients. When medication fails to control the pain, surgical gangliolysis or suboccipital craniectomy for decompression of the trigeminal nerve are options.
Atrophy of the caudate nucleus is a characteristic feature of what condition?
Huntington’s chorea
This usually presents at 40-50 years old.
What test/study is useful in excluding multi-infarcts or normal pressure hydrocephalus from a differential diagnosis?
MRI
A CT scan that shows scarring and atrophy in the setting of an antecedant measles infection many years previous is suggestive of what diagnosis?
Subacute sclerosing panencephalitis
Approximately 2/3 of Guillain-Barre patients give a history of what?
An antecedent respiratory tract or gastrointestinal (especially Campylobacter) infection
Parkinson Disease is a neurodegenerative disorder caused by the accumulation of what within the neurons of the substantia nigra pars compacta?
Alpha-synuclein
What test/study is typically used to assess for peripheral neuropathy?
Peripheral nerve conduction study
Intracranial hypertension is defined as intracranial pressure of what?
_>_20 mmHg
Dizziness, ataxia, weakness, and a tendency to sway to one side is characteristic of what?
Lateral cerebellar infarction
The tendency is to sway towards the side of the lesion.
What is due to microatheroma and liphyalinosis in small penetrating arteries of the brain?
Lacunar stroke
They often affect the internal capsule and result in pure motor dysfuntion. Lacunes comprise 25% of ischemic strokes. Hypertension and diabetes are two major risk factors.
What disease is similar to Alzheimer’s disease, except that it presents at an earlier age?
Pick’s disease
It is seen more frequently in females, and frequently causes personality changes due to involvement of the frontal lobes.
Wernicke’s aphasia is caused by a brain lesion located where?
Dominant temporal lobe
Wernicke’s aphasia is a receptive aphasia.
What condition is characterized by a tremor that is suppressed at rest and exacerbated toward the end of a goal-directed movement?
Essential tremor
Affected patients typically have difficulty holding a newspaper, writing legibly, drinking a cup of coffee, or feeding themselves.
What is the only antiplatelet agent that is effective in reducing the risk of early recurrence of ischemic stroke?
Aspirin
It should be given within 24 hours to all patients presenting with ischemic stroke. Aspirin plus dipyridamole or clopidogrel is recommended for patients who have recurrent stroke on aspirin therapy.
Hemi-neglect syndrome is cause by what?
A lesion of the right (non-dominant) parietal lobe
The non-dominant parietal lobe is responsible for spatial organization.
What is the test of choice in diagnosing cavernous sinus thrombosis?
Magnetic resonance imaging with magnetic resonance venography
Treatment includes broad-spectrum intravenous antibiotics and prevention or reversal of cerebral herniation.
What medication is indicated when urgen reversal of the action of heparin is needed?
Protamine sulfate
Tarsal tunnel syndrome results from entrapment of what nerve?
Posterior tibial nerve
This occurs as it passes underneath the flexor retinaculum on the medial aspect of the ankle. Symptoms include dysesthesia and numbness in the plantar foot.
What 3 medications are recommended for prophylaxis of cluster headaches?
- Verapamil
- Lithium
- Ergotamine
The treatment for an acute attack is inhalation of 100% oxygen and subcutaneous sumatriptan.
Cavitary expansion of the spinal cord is the pathophysiological mechanism of what condition?
Syringomyelia
The most characteristic feature is the presence of a cord cavity, which usually communicates with the central canal of the spinal cord. The most frequent site of involvement is the lower cervical or upper thoracic region. When the syringes occur in the upper cervical cord and extend proximally to involve the medulla oblongata, the condition is called syringobulbia.
What is the most common site of ulnar nerve entrapment?
The elbow
This is where the ulnar nerve lies at the medial epicondylar groove.
The following signs/symptoms are characteristic of which diagnosis?
- Severe back pain with lesser degree of radiculopathy
- Perianal anesthesia
- Hyperreflexia
- Mild bilateral motor weakness
- Bowel and bladder disturbances
Conus medullaris syndrome
This is contrasted to cauda equina syndrome which presents with
- Severe lower back pain with bilateral radiculopathy
- Saddle anesthesia
- Hyporeflexia
- Profound asymmetric motor weakness
- Bowel and bladder dysfunction.
The following findings are consistent with what diagnosis?
- Severe headache
- Bilateral periorbital edema
- Cranial nerve III, IV, V, and VI deficits
Cavernous sinus thrombosis
Cranial nerves III, IV, V, and VI pass through the cavernous sinus, which has anastomoses crossing midline. As a result, unilateral symptoms (I.E. headache, binocular palsies, periorbital edema, hypoesthesia, or hyperesthesthia in V1/V2 distribution) can rapidly become bilateral. Magnetic resonance imaging with magnetic resonance venography is the imaging modality of choice for diagnosis of cavernous sinus thrombosis.
The following symptoms are suggestive of what?
- Diffuse headaches that tend to be worse in the morning
- Nausea and vomiting early in the day
- Vision changes
- Papilledema
- Cranial nerve deficits
- Somnolence
- Confusion
- Unsteadiness
- Cushing’s reflex (Hypertension and bradycardia)
Intracranial hypertension
The following findings are consistent with a lesion to which vessel in the brain?
- Contralateral somatosensory & motor weakness (predominantly in lower extremity)
- Abulia (lack of will or initiation)
- Dyspraxia (inability to perform coordinated movements)
- Emotional disturbances
- Urinary incontinence
Anterior cerebral artery