Flashcards in Neurology Deck (83)
What is the visual acuity of term infants and when does it approach adult levels (20/20)?
Visual acuity in term infants approximates 20/150 and reaches the adult level of 20/20 by about 6 mo of age
Characterized by ipsilateral ptosis (droopy eyelid), miosis (constricted pupil), and anhidrosis (lack of sweating) of the face
Characterized by an initial resistance to passive movement, followed by a sudden release, referred to as the clasp-knife phenomenon
- Abnormalities of tone include spasticity, rigidity, and hypotonia
- results from upper motor neuron dysfunction
- tends to occur in conjunction with disuse atrophy
Seen with lesions of the basal ganglia, characterized by resistance to passive movement that is equal in the flexors and extensors regardless of the velocity of movement (lead pipe)
abnormally diminished tone and is the most common abnormality of tone in neurologically compromised neonates
At what age is clonus not a pathologic sign in a pediatric patient?
in patients <3 mos old, 5-10 beats of clonus may be observed, symmetrically
- sustained clonus is always pathologic
Primitive reflex elicited by supporting the infant in a semierect position and then allowing his or her head to fall backwards onto the examiner's hand
- normal response consists of symmetric extension and abduction of the fingers and upper extremities, followed by flexion of the upper extremities and an audible cry.
- onset: 28-32 wks
- fully developed: 37 wks
- duration: 5-6 mos
- Absence: suggests significant dysfunction of the CNS
- asymmetry: fractured clavicle, brachial plexus injury or hemiparesis
Primitive response elicited by placing a finger in the open palm of each hand; by 37 wk of gestation, the reflex is strong enough that the examiner can lift the infant from the bed with gentle traction
onset: 28 wks
fully developed: 32 wks
duration: 2-3 mos
A primitive reflex produced by manually rotating the infant's head to one side and observing for the characteristic fencing posture (extension of the arm on the side to which the face is rotated and flexion of the contralateral arm)
tonic neck reflex
- abnormal when infant gets stuck in this posture, implies CNS disorder
- onset: 35 wks
- fully developed: 1 mo
- duration: 6-7 mos
Primitive reflex that occurs in slightly older infants, can be evoked by holding the infant's trunk and then suddenly lowering the infant as if he or she were falling. The arms will spontaneously extend to break the infant's fall, making this reflex a prerequisite to walking.
- onset: 7-8 mos
- fully developed: 10-11 mos
- duration: remains throughout life
When does the rooting reflex develop?
onset: 32 wks
fully developed: 36 wks
duration: less prominent after 1 mo
What are the contraindications to performing a lumbar puncture?
suspected mass lesion of the brain/spinal cord
symptoms and signs of impending cerebral herniation in a child with probable meningitis; critical illness (on rare occasions); skin infection at the site of the lumbar puncture; and thrombocytopenia with a platelet count <20 ? 109/L.
The most common form of migraine in both children and adults
migraine without aura
- recurrent (at least 5 attacks)
- lasts 4-72 hrs
- 2 of the ff: unilateral, pulsating, mod-sev pain, aggravated by or cause avoidance of physical activity
- during headache: nausea/vomiting or photophobia/phonophobia
- in children, headaches may be shorter and bilateral
How can one differentiate migraine headache from secondary headache related to increased ICP?
headaches related to increase in ICP tend to be increasing in intensity, usu in early morning upon awakening, occuring almost daily, remits with upright posture
migraine headaches are episodic, not worsening, but when it presents upon awakening, getting up and doing upright activities will make headache and vomiting worse.
What are the indications for neuroimaging in a child with headaches?
Abnormal neuro exam
Focal neurologic signs
Seizures or very brief auras (<6 yr old or any child that cannot adequately describe their headache
Brief cough headache in a child or adolescent
Headache worst on first awakening or that awakens the child from sleep
Migrainous headache in the child with no family history of migraine or its equivalent
What is the imaging of choice for a child with headache, if indicated?
an MRI is the imaging of choice as it provides the highest sensitivity of detecting posterior fossa lesions and does not expose the child to radiation
Two groups of medications for acute migraine attacks
NSAIDs and triptans
- goal of the primary acute medication should be headache relief within 1 hr with return to function in 10 out of 10 headaches
- use NSAIDs first, for only 2-3x/wk then add triptans (almotriptan) for mod-sev attacks
Which antiemetic drugs are very helpful adjuncts in relieving acute migraine headaches because of their mechanism of action (dopamine antagonist) and can be added to the regimen if unresponsive to NSAIDs and triptans?
metoclopramide and prochlorperazine
Preventive therapy for migraine may be done if headaches frequent and disabling. What is the most commonly used preventive therapy for headache and migraine?
- antiepileptic drugs have also been used: topiramate, valproic acid, levetiracetam
seizures that occur between the age of 6 and 60 mo with a temperature of 38C or higher, that are not the result of CNS infection or any metabolic imbalance, and that occur in the absence of a history of prior afebrile seizures
- patients with febrile seizures do not have any increase in incidence of abnormalities of behavior, scholastic performance, neurocognitive function, or attention
Differentiate a simple febrile seizure from complex febrile seizure
simple febrile seizure: generalized, usually tonic-clonic, attack associated with fever, lasting for a maximum of 15 min, and NOT recurrent within a 24-hour period
complex febrile seizure: more prolonged (>15 min), is focal, and/or recurs within 24 hr
What are the major risk factors in recurrence of febrile seizures?
Age < 1 yr
Duration of fever < 24 hr
Minor risk factors:
Family history of febrile seizures
Family history of epilepsy
Complex febrile seizure
Lower serum sodium
Having no risk factors carries a recurrence risk of about 12%; 1 risk factor, 25-50%; 2 risk factors, 50-59%; 3 or more, 73-100%
When is lumbar puncture indicated in a patient with febrile seizure?
Recommended in children below 18 mos because the clinical signs of meningitis may be subtle in this age group
- EEG would not predict the future recurrence of febrile seizures or epilepsy even if the result is abnormal - not routinely done
- blood studies not routinely recommended
- CT or MRI not recommended after first simple febrile seizure
When are apneic episodes in neonates associated with seizures?
When the apnea is accompanied by tachycardia (not bradycardia)
Prolonged expiratory apnea is responsible for the cyanotic episodes, which result from intrapulmonary shunting. An episode starts with a cry and marked pallor, progresses to apnea and cyanosis. Spells usually begin between 6 and 18 mo of age. Syncope, tonic posturing, and even reflex anoxic seizures may follow significant episodes
pallid breath-holding spell
- Often pallid breath-holding spells are made worse by iron deficiency anemia
One of the most common mimickers of generalized tonic clonic seizures and is usually triggered by dehydration, heat, standing for a long time without movement, hot showers, the sight of blood, pain, or sudden stress
Vasovagal (neurocardiogenic) syncope
How can seizures be differentiated from jitteriness?
Jitteriness can be defined as rapid motor activities, such as a tremor or shake, that can be ended by flexion or holding the limb
Seizures do not end with tactile or motor suppression
Starts between the ages of 2 and 12 mo and consists of a triad of infantile spasms that usually occur in clusters (particularly in drowsiness or upon arousal), developmental regression, and a typical EEG picture called hypsarrhythmia
- Many patients start with Ohtahara syndrome, develop West syndrome, and then progress to Lennox-Gastaut syndrome.
usually last 1-2 min and are often preceded by an aura, such as a rising abdominal feeling, d?j? vu or d?j? v?cu, a sense of fear, complex visual hallucinations, micropsia or macropsia (temporal lobe), generalized difficult-to-characterize sensations (frontal lobe), focal sensations (parietal lobe), or simple visual experiences (occipital lobe)
Complex partial seizures
- Subsequent manifestations consist of decreased responsiveness, staring, looking around seemingly purposelessly, and automatisms.