Neuro exam Flashcards
What nerve root does the biceps reflex correspond to?
C5, C6
What nerve root does the triceps reflex correspond to?
C7
What nerve root does the brachioradialis reflex correspond to?
C6
What nerve root does the patellar reflex correspond to?
L4
What nerve root does the Achilles tendon reflex correspond to?
S1
What is Kernig sign?
It is positive when the thigh is flexed at the hip and knee at 90 degree angles, and subsequent extension in the knee is painful (leading to resistance). This may indicate subarachnoid hemorrhage or meningitis.
What is Brudzinski sign?
It is a clinical sign in which forced flexion of the neck elicits a reflex flexion of the hips. It is found in patients with meningitis, subarachnoid hemorrhage and possibly encephalitis. It is not very commonly seen.
What conditions predispose to berry aneurysms?
Marfan syndrome, aortic coarctation, autosomal dominant polycystic kidney disease, Ehlers-Danlos syndrome, sickle cell anemia, smoking tobacco, atherosclerosis, family history, hypertension, hyperlipidemia
What is dysdiadochokinesis?
Difficulty with rapid alternating movements
What exam task is best for eliciting ataxia?
Tandem gait
What is decreased arm swing usually a sign of?
Extrapyramidal disorders
What is gait apraxia?
It is found in patients with bilateral frontal lobe disorders. It is characterized by an inability to initiate the process of walking, despite the power and coordination of the legs being normal when tested in the seated or lying position.
What does the oculocephalic reflex test?
Performed by turning the head is briskly from side to side with the head held briefly at the end of each turn.
A positive response occurs when the eyes rotate to the opposite side to the direction of head rotation, thus indicating that the brainstem (CN3,4,6,8) is intact.
What reflexes should be tested in an unresponsive patient?
Pupillary, corneal, oculocephalic, and gag reflexes, along with peripheral reflexes
How is caloric testing done?
50 mL of ice water is injected into the ear and conjugate eye deviation should be toward the ear injected (tests CN 3,4,6,8)
What are the criteria for declaration of brain death?
Patient must be comatose, have absent brainstem reflexes, and have no spontaneous respirations even when the PCO2 has been allowed to rise (the apnea test). Confirmatory tests include an EEG that shows electrocerebral silence (“flat line”) or cerebral angiography which shows absence of blood flow to the brain.
Compare peripheral (vestibular) with central nystagmus?
Peripheral - unidirectional, fast phase away from lesion, combines horizontal and torsional movements and is inhibited by visual fixation.
Central - normally bidirectional, often purely horizontal, vertical or torsional, not inhibited by fixation
What is dysdiadochokinesia?
Abnormality of the rate and rhythm of a movement demonstrated by asking the patient to perform a rapid alternating movement
What is a slapping gait indicative of?
B12 deficiency or Tabes dorsalis (due to loss of proprioceptive input)
What does a waddling gait suggest?
Proximal muscle (hip-girdle) weakness
What direction is the nystagmus when caloric stimulation of the ear is done?
COWS (cold opposite, warm same). When cold water is applied, their are impulses sent to the brain indicating that the head is turning away from the stimulation causing the eyes to deviate towards the stimulation, leading to the fast phase of nystagmus correcting towards the opposite direction. Opposite when warm water is applied.
