MTB Neuro Flashcards
The risk factors for stroke are
the same as those for myocardial infarction: hypertension, diabetes, hyperlipidemia, and tobacco smoking.
Middle cerebral artery (MCA) stroke (more than 90% ofcases):
- Weakness or sensory loss on the opposite (contralateral) side of the lesions causing stroke.
- Homonymous hemianopsia: loss of visual field on the opposite side of the stroke. A left-sided MCA stroke results in loss of the right visual fields. The eyes can’t see the right side, so the eyes deviate to the left. Hence the eyes “look towards the side of the lesion.”
- Aphasia if the stroke occurs on the same side as the speech center. This is the left side in 90% of patients.
Anterior cerebral artery (ACA) stroke:
- Personality/cognitive defects such as confusion
- Urinary incontinence
- Leg more than arm weakness
Posterior cerebral artery (PCA) stroke:
- Ipsilateral sensory loss of the face, ninth and lOth cranial nerves
- Contralateral sensory loss of the limbs
- Limb ataxia
Pseudotumor cerebri: associated with
obesity, venous sinus thrombosis, oral contraceptives, and vitamin A toxicity. Mimics a brain tumor with nausea, vomiting, and visual disturbance.
Pseudotumor cerebri: physical findings
papilledema with diplopia from sixth cranial nerve (abducens) palsy
Pseudotumor cerebri: diagnosisi
The diagnosis cannot be made without a CT or MRI to exclude an intracranial mass lesion and a lumbar puncture (LP) showing increased pressure. Only the pressure is abnormal. The CSF itselfis normal.
Pseudotumor cerebri: Treatment
weight loss; acetazolamide to decrease production
of cerebrospinal fluid. Steroids help. Repeated lumbar puncture rapidly lowers intracranial pressure. Place a ventriculoperitoneal shunt or fenestrate (cut into) the optic nerve if medical therapy does not control it.
Therapy for Migraine and Cluster Headache
Both of these can be rapidly interrupted by either ergotamine or one of the triptans (e.g., sumaptriptan, eletriptan, almotriptan, zolmitriptan). The main difference is that 100% oxygen, prednisone, and lithium are effective at inter- rupting cluster headaches, but not migraines.
Provide cluster prophylaxis with verapamil!
Prophylactic (Preventive) Therapy for Migraine
The best preventive therapy is propranolol.
Other preventive medications are: • Calciumchannelblockers • Tricyclicantidepressants(amitriptyline) • SSRis, topiramate • Botulinum toxin injections
Trigeminal neuralgia is
an idiopathic disorder of the fifth cranial nerve result- ing in severe, overwhelming pain in the face. Attacks of pain can be precipi- tated by chewing, touching the face, or pronouncing certain words in which the tongue strikes the back of the front teeth. Patients describe the pain as feeling as if a knife is being stuck into the face. There is no specific diagnostic test. Treat with oxcarbazepine or carbamazepine. Baclofen and lamotrigine have also been effective. Ifmedications do not control the pain, gamma knife surgery or surgical decompression can be curative.
Postherpetic Neuralgia
Treatment with antiherpetic medications such as acyclovir,
The pain is treated with tricyclic antidepressants, gabapentin, pregabalin, car- bamazepine, or phenytoin until an effective therapy is found. Topical capsaicin is helpful.
These terms represent variations on a spectrum of abnormalities of altered consciousness or unresponsiveness to stimuli.
Delirium, Stupor, and Coma
Treatment of Status Epilepticus
ABC
benzodiazepine such as lorazepam or diazepam intravenously. If the seizure persists, then give phenytoin
- Benzodiazepine
- Fosphenytoin
- Phenobarbital
- General anesthesia
Partial seizure:
Like the name implies, this is a seizure that is focal to one part of the body. For instance, a patient may have a seizure that is limited just to an arm or leg. Partial seizures can either be simple (intact consciousness) or complex (loss or alteration of consciousness).
Tonic-clonic seizure:
This is a generalized seizure with varying phases ofmus- cular rigidity (tonic) followed by jerking of the muscles of the body for several minutes (clonic).
Absence (petit-mal) seizure:
Consciousness is impaired only briefly. The patient often remains upright and gives a normal appearance or seems to be staring into space. Absence seizures occur more often in children.
The best therapy for absence seizures.
Ethosuximide
Contrast on CT or MRI improves detection of
mass lesions such as cancer or abscess.
Don’t use contrast when looking for blood.
SAH treatment
- Nimodipine (calcium channel blocker) prevents subsequent ischemic stroke.
- Embolization (coiling) uses a catheter to “clog up” the site of bleeding to prevent a repeated hemorrhage. An interventional neuroradiologist places platinum wire into the site of hemorrhage. Embolization is superior to surgical clipping in terms of survival and complications.
- Ventriculoperitoneal shunt: SAH is associated with hydrocephalus. Place a shunt only if hydrocephalus develops.
- Seizure prophylaxis: Phenytoin is generally given to prevent seizures. If the question asks “Which of the following is indicated?” antiepileptic therapy is the answer, although somewhat controversial.
Anterior spinal artery infarction presents with:
• Loss of all function except for the posterior column (position and vibratory sensation intact)
• Flaccid paralysis below the level of the infarction
• Loss of deep tendon reflexes (DTRs) at the level of the infarction
• Evolves into spastic paraplegia several weeks later
• Loss of pain and temperature
• Extensor plantar response
There is no specific therapy.
Subacute Combined Degeneration of the Cord
- From Bl2 deficiency or neurosyphilis.
* Position and vibratory sensation are lost.
Brown-Sequard Syndrome
lose pain and temperature on the contralateral side from the injury, and lose motor function as well as position and vibratory sense on the ipsilateral side ofthe injury. For a mass, surgically decompress.
Syringiomyelia
Look for the loss of pain and temperature bilaterally across the upper back and both arms
Look for the phrase capelike distribution of deficits.
Presentation is somewhat nonspecific and there is no way to distinguish a brain abscess from cancer without
a biopsy. Cancer and infection are indistinguishable based on an imaging study alone.
headache, nausea, vomiting, fever, seizures, and focal neurological findings.
Empiric therapy with penicillin plus metronidazole plus ceftriaxone (or cefepime) is acceptable
Parkinson treatment
Anticholinergic medications (benztropine and trihexyphenidyl) relieve tremor and rigidity.
Amantadine may work by increasing the release of dopamine from the substantia nigra.
Dopamine agonists: pramipexole and ropinirole
Levodopa/carbidopa:
COMT inhibitors (tolcapone,entacapone)
MAO inhibitors(rasagiline, selegiline
Lewy body dementia =
parkinsonism with dementia
Huntington disease HD is the answer when you see:
- Choreaformmovementdisorder(dyskinesia)
- Dementia
- Behavior changes (irritability, moodiness, antisocial behavior)
- Onset between the ages of30 and 50 with a family history ofHD
Internuclear ophthalmoplegia (INO) is
the inability to adduct one eye with nystagmus in the other eye. INO is characteristic of MS.
Motor neuron disease and Amyotrophic lacteral sclerosis
Look for weakness of unclear etiology starting in the 20s to 40s with a unique combination ofupper and lower motor neuron loss. The most serious presenta- tion is difficulty in chewing and swallowing and a decrease in gag reflex. This leads to pooling of saliva in the pharynx and frequent episodes of aspiration. A weak cough and loss of swallowing offer poor prognosis.
In ALS, there is no
sensory loss and the sphincters are spared.
In ALS, the most common cause of death is
respiratory failure.
Most cases of facial palsy are idiopathic. Some identified causes are
Lyme dis- ease, sarcoidosis, herpes zoster, and tumors.
Paralysis of the entire side of the face is classic. Stroke will paralyze only the lower half of the face because the upper half of the face receives innervation from both cerebral hemispheres.
Guillain-Barre Syndrome (GBS) is an
autoimmune damage of multiple peripheral nerves. By definition, there is no CNS involvement. A circulating antibody attacks the myelin sheaths of the peripheral nerves, removing their insulation. GBS is associated with Campylobacter jejuni infection.
Look for weakness in the legs that ascends from the feet and moves toward the chest, associated with a loss of DTRs.
Myasthenia gravis
Look for a question describing “double vision and difficulty chewing,” “dys- phonia,” or “weakness oflimb muscles worse at the end of the day.”
Edrophonium:
Neostigmine or pyridostigmine.
