Neurology Flashcards
1
Q
Seizures in the neonatal period may be associated with what type of hypotonia
A
Central hypotonia
2
Q
Acquired causes of central hypotonia
A
- Electrolyte abnormalities
- Hypoxic-ischemic injury
- Infection: sepsis, meningitis
- Intracranial hemorrhage
- Trauma: cerebral, cervical
3
Q
Congenital causes of central hypotonia
A
- Cerebral malformation
- Chromosomal disorder: Down syndrome, Prader-Willi syndrome
- Metabolic disorder: urea cycle defect
4
Q
Causes of peripheral hypotonia
A
- Spinal cord: spinal muscular atrophy
- Peripheral nerves: familial dysautonomia
- Neuromuscular junction: botulism, neonatal myasthenia, magnesium toxicity
- Muscle: congenital muscular dystrophy, congenital myotonic dystrophy, metabolic myopathy (Pompe’s disease, phosphofructokinase deficiency), structural myopathy (central core disease, nemaline rod myopathy)
5
Q
Spinal muscular atrophy
A
Anterior horn cell degeneration that presents with hypotonia, weakness and tongue fasciculations
6
Q
Classifications of spinal muscular atrophy
A
- Type I: infantile form with onset less than 6 months, aka Werdnig-Hoffman disease
- Type II: intermediate form with onset 6-12 months
- Type III: juvenile form with onset after 3 years
7
Q
Etiology of spinal muscular atrophy
A
- Autosomal recessive
- Mutation of survival motor neuron gene (SMN1) on chromosome 5
- Pathology of the spin cord shows degeneration and loss of anterior horn motor neurons and infiltration of microglia and astrocytes
8
Q
Clinical features of spinal muscular atrophy
A
- Weak cry, tongue fasciculations, and difficulty sucking and swallowing
- Bell shaped chest
- Frog leg posture when in supine position, generalized hypotonia, weakness and areflexia
- Normal extraocular movements and normal sensory exam
9
Q
Infantile botulism
A
Bulbar weakness (impairment in CN IX-XII) and paralysis that develops infants during the first year of life secondary to ingestion of Clostridium botulinum spores and absorption of the toxin
10
Q
Etiology of infantile botulism
A
Toxin prevents the presynaptic release of acetylcholine
11
Q
Clinical features of infantile botulism
A
- Onset of symptoms occurs 12-48 hours after ingestion of spores
- Constipation is the classic first symptom of botulism
- Neurologic symptoms follow, including weak cry and suck, loss of previously obtained motor milestones, ophthalmoplegia and hyporeflexia
- Paralysis is symmetric and descending
12
Q
Management of infantile botulism
A
- Botulism immune globulin improves the clinical course
- Antibiotics are contraindicated and may worsen the clinical course
13
Q
Congenital myotonic dystrophy
A
- Autosomal dominant
- Muscle disorder that presents in the newborn period with weakness and hypotonia
- Myotonia is the inability to relax contracted muscles
14
Q
Etiology of congenital myotonic dystrophy
A
- Trinucleotide repead disorder with autosomal dominant inheritance and variable penetrance
- Chromosome 19
- Transmission to affected infant is throughout the affected mother in more than 90% of cases
- the earlier the onset of the disease in the mother, the more likely she will have affected offspring
15
Q
Clinical features of congenital myotonic dystrophy
A
- Polyhydramnios
- Decreased fetal movement
- Feeding and respiratory problems
- Physical examination is notable for facial diplegia (bilateral weakness), hypotonia, areflexia and arthrogryposis (multiple joint contractors)
- Myotonia is not always present in the newborn but develops later, almost always be 5 years
- In adulthood, typical myotonic features include myotonic facies (atrophy of masseter and temporal is muscles), ptosis, a stiff straight smile and inability to release the grip after hand shaking (myotonia)
16
Q
Congenital causes of hydrocephalus
A
- Chiari type II malformation
- Dandy-Walker malformation
- Congenital aqueductal stenosis
17
Q
Chiari type II malformation
A
- Downward displacement of the cerebellum and medulla through the foramen magnum, blocking CSF flow
- Often associated with lumbosacral myelomeningocele
18
Q
Dandy-Walker malformation
A
Combination of an absent or hypo plastic cerebellar vermis and cystic enlargement of the fourth ventricle, which blocks the flow of CSF
19
Q
Congenital aqueductal stenosis
A
Some cases of aqueductal stenosis are inherited as an X linked trait and these patients may have thumb abnormalities and other CNS anomalies such as spina bifida
20
Q
Sunset sign
A
A tonic downward deviation of both eyes caused by pressure from the enlarged third ventricles on the upward gaze center in the midbrain
21
Q
Highest and lowest incidence of spina bifida occur where
A
Highest incidence occurs in Ireland and lowest in Japan
22
Q
Associated anomalies and complications of spina bifida
A
- Hydrocephalus
- Cervical hydrosyringomyelia (accumulation of fluid within the central spinal cord canal and with the cord itself)
- Defect in neuronal migration
- Orthopaedic problems
- Genitourinary defects
23
Q
Most common causes of coma in children younger than 5
A
Nonaccidental trauma and near-drowning
24
Q
Most common causes of coma in older children
A
Drug overdose and accidental head injury
25
Flaccidity or no movement suggests
Severe spinal or brainstem injury
26
Decerebrate posturing (extension of arms and legs) suggests
Subcortical injury
27
Decorticate posturing (flexion of arms and extension of legs) suggests
Bilateral cortical injury
28
Asymmetric responses suggests
Hemispheric injury
29
Hypoventilation suggests
Opiate or sedative overdose
30
Hyperventilation suggests
- Metabolic acidosis (Kussmaul respirations or rapid, deep breathing, may occur)
- Neurogenic pulmonary edema
- Midbrain injury
31
Cheyne-Stokes breathing (alternating apnea and hyper apneas) suggests
Bilateral cortical injury
32
Apneustic breathing (pausing at full inspiration) suggests
Pontine damage
33
Ataxic or atonal breathing (irregular respirations with no particular pattern) suggests
Medullary injury and impending brain death
34
Unilateral dilated nonreactive pupil suggests
Uncal herniation
35
Bilateral dilated nonreactive pupils suggest
- Topical application of dilating agent
- Postictal state
- Irreversible brainstem injury
36
Bilateral constricted reactive pupils suggest
- Opiate ingestion
| - Pontine injury
37
Oculocephalic maneuver (doll's eyes)
- When turning the head of the unconscious patient, the eyes normally look straight ahead and the slowly drift back to midline position because the intact vestibular apparatus senses a change in position
- INJURED BRAINSTEM: movement of the head does not evoke any eye movement; termed negative oculocephalic maneuver
38
Caloric irrigation
- When the oculocephalic response is negative or cannot be performed because of possible cervical cord injury, this test should be performed
- Involves angling the head at 30 degrees and irrigating each auditory canal with 10-30 mL of ice water
- An intact (normal) cold caloric response is reflected by eye deviation to the irrigated side
- Abnormal response suggests PONTINE INJURY
39
Abnormal corneal and gag reflexes suggest
Significant brainstem injury
40
Causes of acute seizures during childhood
- Head trauma: cerebral contusion, subdural hematoma
- Brain tumor: astrocytoma, meningioma
- Toxins: amphetamines, cocaine
- Infections: meningitis, encephalitis, brain abscess, neurocysticercosis
- Vascular: cerebral infarction, intracranial hemorrhage
- Metabolic disturbances: hypocalcemia, hypoglycemia, hypomagnesemia, hyponatremia, hypernatremia, pyridoxine deficiency
- Systemic diseases: hypertension, hypoxic-ischemic injury, inherited metabolic disorder, liver disease, renal failure, neurocutaneous disorders (tuberous sclerosis)
41
Types of generalized seizures
- Tonic-clonic (most common) (has postictal state)
- Tonic
- Clonic
- Myoclonic
- Absence (no postictal state)
- Atonic
42
Alternative treatments for seizures
- Vagal nerve stimulator: pacemaker sized device that sends an electrical impulse to the vagus nerve; common side effect is hoarseness
- Ketogenic diet
43
Simple febrile seizures last
Less than 15 minutes and is generalized
44
Complex febrile seizures last
More than 15 minutes, has focal features or recurs within 24 hours
45
Epidemiology of infantile spasms/ West syndrome
Age of onset is typically 3-8 months. Infantile spasms are rare in children older than 2 years.
46
Etiology of infantile spasms/ West syndrome
- Tuberous sclerosis is the most commonly identified cause
- Other inherited and acquired causes include phenyketonuria, hypoxic-ischemic injury, intraventricular hemorrhage, meningitis and encephalitis
47
Clinical features of infantile spasms/ West syndrome
- Brief myoclonic jerks, lasting 1-2 seconds each, occurring in clusters of 5-10 seizures spread over 3-5 minutes
- The jerks consist of sudden arm extension or head and trunk flexion (also known as jackknife seizures or salaam seizures)
48
Diagnosis of infantile spasms/ West syndrome
EEG shows hypsarrhythmia pattern, a highly disorganized pattern of high amplitude spike and waves occurring in both cerebral hemispheres
49
Management of infantile spasms/ West syndrome
- ACTH intramuscular injections for a 4-6 week period are effective in more than 70% of affected patients
- Valproate is 2nd line
- Vigabatrin is the most effective drug for patients with infantile spasms associated with tuberous sclerosis
50
Etiology of absence epilepsy of childhood
Autosomal dominant with age-dependent penetrance
51
Clinical features of absence epilepsy of childhood
- Absence seizures last 5-10 seconds
- Occur frequently
- Often accompanied by automatisms, such as eye blinking and incomprehensible utterances
- Loss of posture, urinary incontinence and postictal state do not occur
52
Benign rolandic epilepsy/ benign centrotemporal epilepsy
Involves partial seizures with secondary generalization
53
Epidemiology of benign rolandic epilepsy/ benign centrotemporal epilepsy
- Most common partial epilepsy during childhood
- Commonly presents at 3-13 years
- Peak incidence is at 6-7 years
- Boys more likely to be affected
54
Etiology of benign rolandic epilepsy/ benign centrotemporal epilepsy
Autosomal dominant with variable penetrance
55
Clinical features of benign rolandic epilepsy/ benign centrotemporal epilepsy
- Seizures occur in the early morning hours when patients are asleep with oral-buccal manifestations (moaning, grunting, pooling of saliva)
- Seizures spread to face and arm then generalize into tonic-clonic seizures
56
Diagnosis of benign rolandic epilepsy/ benign centrotemporal epilepsy
EEG shows biphasic spikes and sharp wave disturbance in the mid-temporal and central regions
57
Management of benign rolandic epilepsy/ benign centrotemporal epilepsy
Valproate (1st line) or carbamazepine
58
Primary intracranial causes of headaches
- Primary dysfunction of neurons or muscles
- Migraine
- Cluster
- Tension
59
Secondary intracranial causes of headaches
- Increased intracranial pressure or meningeal irritation
- Irritative: meningitis, subarachnoid hemorrhage
- Increased ICP: brain tumor, hydrocephalus, subdural hematoma
60
Local causes of headaches
- Sinusitis, perioral abscess, toothache, chronic titis media, or refractive errors
- Ears (otitis media)
- Eyes (refractive error, glaucoma)
- Nose (sinusitis)
- Mouth (toothache, abscess)
- Temporomandibular joint dysfunction
61
Systemic causes of headaches
- Anemia
- Depression
- Hypoglycemia
- Hypertension
- Psychogenic
- Carbon monoxide poisoning
62
Migraine headaches
- Prolonged, often more than an hour
- Unilateral
- Associated with nausea, vomiting, visual changes
- Caused by changes in cerebral blood flow
63
Epidemiology of migraine headaches
- Most common cause of headaches in children and adolescents
- Age of onset is younger than 5 years in 20%
- Before puberty, incidence is higher in males
64
Etiology of migraine headaches
- Autosomal dominant
- Changes in cerebral blood flow are secondary to release of 5-HT, substance P, and vasoactive intestinal peptide from changes in neuronal activity
65
Most common form of migraine in children
Migraine without aura
66
Migraine with aura
Onset of headaches is preceded by transient visual changes or unilateral paresthesias or weakness
67
Migraine equivalent
In young children, the headaches itself may be absent, but there is a prolonged, but transient, alteration of behavior that manifests as cyclic vomiting, abdominal pain or paroxysmal vertigo
68
Ophthalmoplegic migraine
Unilateral ptosis or cranial nerve III palsy accompanies this headache
69
Basilar artery migraine
Vertigo, tinnitus, ataxia or dysarthria may precede the onset of this headache
70
Clinical features of migraines
- Prolonged, throbbing unilateral headache starts in the supraorbital area and radiates to the occiput
- Nausea and vomiting
- Visual disturbances include blurred vision, scotomata, and jagged streaks of light that take on the outline of old forts
- Photophobia or phonophobia
- OTC analgesics often ineffective
- Improved with sleep
- Neuro exam is normal
71
Management of migraines
- Abortive: sumatriptan, selective 5-HT agonist available in injectable, intranasal and oral forms
- Prophylactic: propranolol
72
Tension headaches
Bifrontal or diffuse, dull, aching headaches that are often associated with muscle contraction
73
Epidemiology of tension headaches
Unusual during childhood and extremely rare in children younger than 7
74
Clinical features of tension headaches
- Dull, aching and rarely throbbing
- Increases in intensity during the day
- Usually bifrontal pain but may be diffuse
- Isometric contraction of the temporalis, masseter, or trapezius often companies this headache
- NO vomiting, visual changes or paresthesias occur
75
Cluster headaches
- Extremely rare in childhood
- Unilateral frontal or facial pain, accompanied by conjunctival erythema, lacrimation and nasal congestion
- Last less than 30 min but may recur several times in a day and then not again for weeks or months
- Abortive: oxygen or sumatriptan
- Prophylactic: calcium channel bluchers or valproate
76
Acute cerebellar ataxia of childhood
Unsteady gait secondary to presumed autoimmune or postinfectious cause
77
Epidemiology of acute cerebellar ataxia of childhood
- Most common cause of ataxia in children
- Age of onset between 18 months and 7 years
- Rarely occurs in older than 10 years
78
Etiology of acute cerebellar ataxia of childhood
- Common preceding infections: varicella, influenza, EBV, mycoplsama
- Follows viral illness by 2-3 weeks
- Postulated cause is immune complex deposition in the cerebellum
79
Clinical features of acute cerebellar ataxia of childhood
- Truncal ataxia with deterioration of gait
- Slurred speech and nystagmus
- Fever is absent
80
Guillain-Barre syndrome/ acute inflammatory demyelinating polyneuropathy
Demyelinating polyneuritis characterized by ascending weakness, areflexia and normal sensation
81
Pathophysiology of Guillain-Barre syndrome/ acute inflammatory demyelinating polyneuropathy
- Principal sites of demyelination are the ventral spinal roots and peripheral myelinated nerves
- Injury is triggered by a cell mediated immune response to an infectious agent that cross reacts to antigens on the Schwann cell membrane
82
Clinical features of Guillain-Barre syndrome/ acute inflammatory demyelinating polyneuropathy
- Ascending, symmetric paralysis
- No sensory loss
- Cranial nerve involvement
- MILLER-FISHER SYNDROME: variant of Guillan-Barre syndrome characterized by ophthalmoplegia, ataxia and areflexia
83
Albuminocytologic dissociation
- Finding in Guillan-Barre syndrome
| - Increase in CSF protein in absence of increased cell count
84
Management of Guillain-Barre syndrome/ acute inflammatory demyelinating polyneuropathy
- IVIG
| - Plasmapheresis - removes patients plasma along with anti-myelin antibodies
85
Syndenham chorea
Self limited autoimmune disorder associated with rheumatic fever that presents with chorea and emotional lability
86
Epidemiology of syndenham chorea
- Occurs in 25% of patients with rheumatic fever
| - Most commonly between 5-13 years
87
Pathophysiology of syndenham chorea
Secondary to antibodies that cross react with membrane antigens on both group A beta hemolytic streptococcus and basal ganglia cells
88
Clinical features of syndenham chorea
- Immunologic response usually follows the streptococcal pharyngitis by 2-7 months
- Children appear restless
- Speech affected
- Unable to sustain protrusion of tongue (chameleon tongue)
- Wrist is held flexed and hyperextended at the metacarpal joints (choleric hand)
- On gripping examiners fingers, patients are unable to maintain the grip (milkmaid's grip)
- Emotional lability
- Gait and cognition are not affected
89
Neuroimaging of syndenham chorea
- MRI may show increased signal intensity in the caudate and putamen on T2 sequence
- Single photon emission computed tomography (SPECT) may demonstrate increased perfusion to thalamus and striatum
90
Management of syndenham chorea
- Haloperidol
- Valproate
- Phenobarbital
91
Tourette syndrome
- Chronic lifelong movement disorder that presents with motor and phonic tics before 18 years
- Tics are brief, stereotypical behaviors that are initiated by an unconscious urge that can be temporarily suppressed
92
Clinical features of Tourette syndrome
- Motor tics can be simple (e.g. eye blinking, head or shoulder shaking) or complex (e.g. bouncing, jumping, kicking)
- Phonic tics can be simple (e.g. coughing, groaning, barking) or complex (e.g. echolalia)
- Tics must be present greater than 1 year
- Absence of any signs of a neurodegenerative disorder
- Associated findings include learning disabilities, ADHD, and OCD
93
Management of Tourette syndrome
- Pimozide is the drug of choice because it is effective with minimal extrapyramidal side effects
- Clonidine is less effective, major side effect is sedation
- Haloperidol, but tardive dyskinesia limits use
- Hypnotherapy
94
Duchenne and Becker MDs
- Progressive, X linked myopathies characterized by myofiber degneration
- DMD is more severe than BMD
- Onset of symptoms is between 2-5 years
95
Pathophysiology of DMD and BMD
- Dystrophin is a high molecular weight cytoskeletal protein that associates with actin and other structural membrane elements
- Absence of dystrophin causes weakness and eventually rupture of the plasma membrane, leading to injury and degeneration of muscle fibers
96
Pathology of DMD and BMD
- Degeneration and regeneration of muscle fibers
- Infiltration of lymphocytes into the injured area and replacement of damaged muscle fibers with fibroblasts and lipid deposits
97
Clinical features of DMD and BMD
- Slow, progressive weakness affecting the legs first
- In DMD, children lose the ability to walk by 10 years but in BMD by 20 or more years
- Pseudohypertrophy of calves is present because of the excess accumulation of lipids, which replace the degenerating muscle fibers
- Gower's sign - due to weakness of pelvic muscles, patients arise from the floor in a characteristic manner by extending each leg and then climbing up each thigh until they reach an upright position
- Cardiac involvement
- Mild cognitive impairment in DMD
