Neurology Flashcards
(44 cards)
What does a negative Romberg test means?
A Romberg test is negative if the patient is able to stay stable during the test and have minimal swaying.
This means that the vestibular or proprioceptive symptoms may not be related to balancing issues.
Thus, is a patient is ataxic with a negative Romberg test, it suggests that the ataxia is cerebellar in nature, not sensory.
How to differentiate cortical strokes (caused by MCA, ARA and PCA)?
Cortical strokes cause focal motor deficits.
Middle cerebral artery (FACE)
- most common cerebral occlusion site
- contralateral hemiplegia
- contralateral hemianasthesia
- dysarthria due to facial weakness
- can cause homonymous hemianopia, but less common than PCA
Anterior cerebral artery (LEG)
- relatively rare
- motor deficits of the contralateral lower limb
- lesser degree paresis of the contralateral arm
- urinary incontinence and altered phychiatric status can also occur
Posterior cerebral artery (VISION)
- homonymous hemianopia (not a complete loss of vision)
Internal carotid artery stroke is the only one that causes complete loss of vision.
How to diagnose subarachnoid haemorrhage?
- CT scan without contrast
- Lumbar puncture (if the CT is negative but the history is suggestive, a LP should be undertaken)
- MRI (can be more sensitive than CT, but only after several days have passed
After the bleeding is confirmed, its origin needs to be determined. The choice then is between cerebral angiography and CT angiography to identify aneurisms.
Subarachnoid heamorrhages can be associated to which conditions?
Hypertension, polycystic kidney disease, Ehler Danlos syndrome, hyponatremia (due to syndrome of inappropriate antidiuretic hormone)
SAH - SIADH
Under which circumstances can epileptic patients drive?
Drivers of cars or motorbikes who suffer from epileptic seizures while awake and lose consciousness can continue to drive provided they have been
- seizure-free for the last year, or
- seizure-free for more than 6 months of anti-epileptic drugs were changed
What is syringomyelia? What are its features? How does it differ from syringobulbia?
Syringomyelia is a rare condition in which there is a fluid-filled tubular cyst (syrinx) within the central (usually cervical), spinal cord.
- upper limb pain exacerbated by exertion or coughing
- sensory loss of pain and temperature senses of upper limbs (may present with burns as the patient doesn’t feel)
- paraparesis (partial paralysis of lower limbs)
- muscle wasting and weakness in hands, forearms and shoulders
- cape-like bilateral loss of pain and temperature sensation along the upper chest and arms
- loss of tendon reflexes
Syringobulbia occurs when the syrinx extends into the brainstem, affecting cranial nerves, which can result in facial palsies and eventually affect the function of the lower brain stem, producing respiratory failure and death
What should be suspected in a patient presenting with dizziness, difficulty walking and slurred speech? Which imaging method should be ordered as initial, and as choice for diagnosing this condition?
Cerebellar infarction, which requires imagem that is capable of accurately visualising the posterior fossa.
Initial - CT head
Choice - MRI head
Which structures are impaired in chronic alcoholic patients, leading to memory loss?
The critical structures that could lead to memory impairment in patients who suffer from Wernicke-Korsakoff syndrome are the mammillary bodies and the thalamic regions. Atrophy of the mammillary bodies can be seen
Which diagnosis to suspect in a patient with difficulty in swallowing and walking?
Motor neuron disease
Which diagnosis to suspect in a patient with rapid onset confusion and hallucinations?
Hyponatraemia
What differentiates Wernicke’s encephalopathy from Korsakoff’s syndrome?
WE
- triad of confusion + ataxia + ophthalmoplegia
- caused by B1 deficiency
- also seen in pregnancy with severe persistent hyperemesis gravidarum
KS = WE + amnesia + confabulation
What are the features of parkinson’s disease?
- above 65 yo
- bradykinesia
- rigidity
- resting tremor
- postural instability
What are the characteristics of CSF in bacterial meningitis, viral meningitis, and tuberculous meningitis?
Bacterial: low glucose, high protein, neutrophils
Viral: normal glucose, normal-high protein, lymphocytes
Tuberculous: low glucose, high protein, neutrophils in early disease and lymphocytes later
What is the most likely gram positive organism to cause meningitis?
Streptococcus pneumoniae, since Neisseria meningitidis is gram negative
What should be suspected in a patient with gait disturbance, urinary incontinence, and cognitive dysfunction in an elderly patient?
Normal pressure hydrocephalus.
It’s different from parkinsons, since NPH presents with less rigidity and tremors, and doesn’t responde to levodopa. And it’s different from Alzheimer’s, since NPH has a much slower progressive memory loss
What should be suspected in a patient with acute onset of double vision, vertigo, paraesthesia of upper limbs, and unsteady gait? How does it differ from cerebellar infarcts?
Brain stem should be an important differential in a patient with acute vertigo with neurological symptoms.
The hallmark of brain stem strokes are symptoms of vertigo, ataxia and diplopia.
Brainstem strokes cause gross, global motor weakness. A lesion that affects both the ipsilateral and contralateral side of the body, as well as the entire side of the body, think of brainstem strokes.
They differ from cerebellar infarcts (that also present with acute vertigo) because those never have limb paresthesia or diplopia. Those can also present with nystagmus and dysarthria
Both of those differ from cortical lesions, which affect the contralateral side alone, and affect either the upper limb or lower limb.
What are the definitions for Horner’s syndrome and Pancoast tumor? What is the most likely underlying mechanism for the syndrome?
Pancoast tumours are located in the apex of the lung, causing compression of the ipsilateral sympathetic chain, which result in symptoms of Horner’s syndrome (unilateral ptosis, anhidrosis and miosis)
Which medications can be used for migraine prophylaxis?
Topiramate, propranolol and amitriptyline
What should be suspected in a patient who had flu-like symptoms that follow with rapid deterioration like fever, neck stiffness, and confusion?
Encephalitis
What should be suspected in a patient with confusion and hyponatraemia followed by infusion of 5% dextrose in NaCl 0.45% IV?
Cerebral oedema.
Causes of hyponatraemia: high blood sugar and iatrogenic administration of hypotonic solution
Hyponatraemia = diluted blood = water shifts into the brain
On the other side, osmotic shrinkage and even cerebral demyelination would occur after iatrogenic rapid correction of low blood sodium levels.
“From low to high, pons will die. From high to low, your brain will blow”
What should be suspected in a patient with proximal weakness at the pelvic or shoulder girdle, which improves with exercise, as well as reflexes that improve with exercises, in addition to dysphagia, dysarthria, ptosis or diplopia? Which disease is it associated to? And how to differentiate it from miastenia gravis?
Suspect of Lambert-Eaton syndrome is an autoimmune/ paraneoplastic disorder associated with small cell lung cancer.
It differs from myastenia gravis because the patient has increased strength on repetition of power.
Which are of CNS would cause symptoms of diabetes insipidus when damaged?
Diencephalon, which consists of the thalamus, the hypothalamus (including the posterior pituitary), the epithalamus and subthalamus.
Diencephalon for DI
What is the suspected diagnosis and treatment for a patient with sharp shooting unilateral pain?
Trigeminal neuralgia, which is typically confined to the area supplied by the second and third divisions of the trigeminal nerve.
Anticonvulsants like carbamazepine has been shown to dramatically relief the pain.
What should be suspected in a patient with intermittent diplopia and droopy eyelid after working in the computer for several hours?
Myasthenia Gravis, which is a neuromuscular junction disorder that can lead to fatiguability of the limbs, ocular, speech and swallowing muscles.
It often presents with diplopia and ptosis.
Mnemonic to remember clinica features:
- diplopia
- drooping eyelids
- dysphagia
- dysarthria
- dysphonia
