Neurología Flashcards
A history of camping in an endemic region (regardless of whether patients can recall tick bites) in conjunction with multiple erythema migrans (EM) lesions and migratory arthralgia suggests early disseminated (stage Il) Lyme disease. What do you have highest risk to develop in this disease?
Cranial nerve palsy (most commonly peripheral facial nerve palsy is a common complication of stage I Lyme disease that is caused by early neuroborreliosis.
Also meningitis and poly neuropathy
A 1-year-old boy is brought to the physician for a well-child examination. He has no history of serious illness. His older sister had an eye disease that required removal of one eye at the age of 3 years. Examination shows inward deviation of the right eye. Penlight examination shows a white reflex in the right eye and a red reflex in the left eye. The patient is at increased risk for which condition?
Osteosarcoma
Patients with inherited retinoblastoma gene mutations (Rb gene mutations) have a significantly increased risk of developing osteosarcomas.
A 60-year-old woman is brought to the emergency department because of sudden, painless loss of vision in her right eye that occurred 30 minutes ago while watching TV. She has coronary artery disease, hypertension, and type 2 diabetes mellitus, and has had trouble adhering to her medication regimen. Her blood pressure is 160/85 mm Hg. Examination shows 20/50 vision in the left eye and no perception of light in the right eye. Direct pupillary reflex is present in the left eye but absent in the right eye. Accommodation is intact bilaterally. Intraocular pressure is 16 mm Hg in the left eye and 18 mm Hg in the right eye. Fundoscopic examination of the right eye shows a pale, white retina with a bright red area within the macula. The optic disc appears normal. Which of the following is the most likely diagnosis?
Central retinal artery occlusion
A 56-year-old man is brought to the emergency department by his neighbor 2 hours after ingesting an unknown substance in a suicide attempt. He is confused and unable to provide further history. His temperature is 39.1°C (102.4°F), pulse is 124/min, respirations are 12/min, and blood pressure is 150/92 mm Hg. His skin is dry. Pupils are 12 mm and minimally reactive to light. An ECG shows no abnormalities. Which of the following is the most appropriate pharmacotherapy?
Physostigmine
Physostigmine is the first-line treatment for anticholinergic syndrome because it crosses the blood-brain barrier and rapidly enhances parasympathetic signaling.
Patient with history of diabetes presents upper eyelid droop due to..
Diabetes mononeuropathy: Oculomotor nerve palsy
A 69-year-old man comes to the physician with a 2-year history of progressive hearing loss. His hearing is worse in crowded rooms, and he has noticed that he has more difficulty understanding women than men. He has no history of serious illness and does not take any medications. A Rinne test shows air conduction is greater than bone conduction bilaterally (normal). This condition is most likely associated with damage closest to which of the following structures?
Basal turn of the cochlea
Sound waves cause vibrations that resonate with the basilar membrane of the cochlea, which converts this input into nerve signals that encode the auditory information.
The sound wave’s point of optimal resonance within the cochlea depends on the frequency of the sound wave (tonotopy). The base of the cochlea, including the basal turn, responds to higher frequencies. Progressive degeneration of the organ of Corti near this region causes presbycusis.
A 39-year-old man comes to the physician for evaluation of hearing loss. He reports difficulty hearing sounds like the beeping of the microwave or birds chirping, but can easily hear the pipe organ at church. He works as an aircraft marshaller. A Rinne test shows air conduction greater than bone conduction bilaterally. A Weber test does not lateralize. Which of the following is the most likely underlying cause of this patient’s condition?
Noise-induced hearing loss is caused by the destruction of cochlear hair cells, also known as the organ of Corti.
In this unvaccinated child, the most likely cause of acute flaccid paralysis (weakness with decreased deep tendon reflexes) is anterior horn cell destruction caused by…
Poliomyelitis, which is caused by the poliovirus, manifests as acute lower motor neuron weakness that begins asymmetrically in the lower extremities and ascends over hours to days. Patients can have prodromal flu-like symptoms before the onset of weakness. Cerebrospinal fluid analysis in poliomyelitis is typically consistent with viral infection (lymphocytic pleocytosis, normal or slightly increased protein levels, and normal glucose levels). Diaphragmatic involvement ultimately results in respiratory failure and death.
This patient has a history and physical exam findings consistent with malignant otitis externa given his severe ear pain, vital sign abnormalities (i.e., high fever, tachycardia), facial droop (indicating progression to osteomyelitis of the temporal bone with associated CN VII palsy), and the presence of granulation tissue in the ear canal. It could be associated with..
Glucose intolerance
There is a strong association between diabetes mellitus and the development of malignant otitis externa, which is most commonly caused by an infection with Pseudomonas aeruginosa.
A 26-year-old man comes to the physician for a follow-up examination. Two weeks ago, he was treated in the emergency department for head trauma after being hit by a bicycle while crossing the street. Neurological examination shows decreased taste on the right anterior tongue. This patient’s condition is most likely caused by damage to a cranial nerve that is also responsible for which of the following?
Closing the eyelids is accomplished through the contraction of the orbicularis oculi muscle, which is, like all facial muscles, innervated by the facial nerve (CN VII).
An otherwise healthy 62-year-old woman comes to the physician because of a 3-year history of hearing loss. To test her hearing, the physician performs two tests. First, a vibrating tuning fork is held against the mastoid bone of the patient and then near her ear, to which the patient responds she hears the sound better on both sides when the tuning fork is held near her ear. Next, the physician holds the tuning fork against the bridge of her forehead, to which the patient responds she hears the sound better on the right side than the left. The patient’s examination findings are most consistent with which of the following conditions?
Acoustic neuroma on the left
A 69-year-old man undergoes modified radical neck dissection for an oropharyngeal tumor. During the procedure, he requires multiple blood transfusions. Four hours after the surgery, examination shows that the right and left pupils do not constrict when a light is shone into the left eye. When light is shone into the right eye, both pupils constrict. Fundoscopic examination shows no abnormalities. Which of the following is the most likely location of the lesion?
Optic nerve
A 75-year-old man comes to the physician because of a 2-week history of sharp, stabbing pain in the lower back that radiates to the back of his left leg. He also has had a loss of sensitivity around his buttocks and inner thighs as well as increased trouble urinating the last week. Two years ago, he was diagnosed with prostate cancer and was treated with radiation therapy. Neurologic examination shows reduced strength and reflexes in the left lower extremity; the right side is normal. The resting anal sphincter tone is normal but the squeeze tone is reduced. Which of the following is the most likely diagnosis?
Cauda equina syndrome
Two key factors that differentiate this diagnosis are the strong unilateral radicular pain and asymmetrical weakness.
A 51-year-old woman comes to the physician because of progressively worsening lower back pain. The pain radiates down the right leg to the lateral side of the foot. She has had no trauma, urinary incontinence, or fever. An MRI of the lumbar spine shows disk degeneration and herniation compressing the S1 nerve root. Which of the following is the most likely finding on physical examination?
Weak achilles tendon reflex
S1 radiculopathy causes motor deficits in the gastrocnemius muscle.
A 29-year-old man comes to the physician for a follow-up examination. He has had numbness and tingling of his legs for the past 10 days. Three months ago, he was diagnosed with pulmonary tuberculosis and started on antituberculosis therapy. Examination shows dry scaly lips and cracks at the corner of the mouth. Sensation to pinprick and light touch is decreased over the lower extremities. His hemoglobin concentration is 10.4 g/dL and mean corpuscular volume is 76 μm3. Administration of which of the following is most likely to have prevented this patient’s current symptoms?
This patient’s sensory neuropathy and microcytic anemia are the result of isoniazid toxicity.
Since pyridoxine (vitamin B6) is an essential cofactor in the synthesis of neurotransmitters and heme, patients with a chronic pyridoxine deficiency typically present with sensory peripheral neuropathy and hypochromic, microcytic anemia (sideroblastic anemia), as seen here.
