Pediatric Neurology

Question 1

Brain etiologies of floppy baby

Answer 1

1) Hypoxic ischemic encephalopathy
2) Trisomy and other chromosomal alterations
3) Benign congenital hypotonia
4) Cerebral malformation
5) Neonatal adrenoleukodystrophy
6) Pelizaeus-Merzbacher disease
7) Prader-Willi syndrome
8) Zellweger Syndrome

Question 2

Spinal cord etiologies of floppy baby

Answer 2

1) Hypoxic ischemic myelopathy

2) Traumatic spinal cord injury

Question 3

Anterior horn etiologies of floppy baby

Answer 3

1) Spinal muscular atrophy
2) Vaccine related poliomyelitis
3) GM2 gangliosidosis
4) Coxsackie

Question 4

Peripheral nerve etiology of floppy baby

Answer 4

1) Dejerine-Sottas
2) Congenital hypomyelinating polyneuropathy
3) CMT1 and 2
4) AIDP/CIDP
5) MLD
6) Guillen Barre

Question 5

NMJ etiology of floppy baby

Answer 5

1) Familial infantile myasthenia
2) Infantile botulism
3) Transitory myasthenia gravia

Question 6

Muscle etiology of floppy baby

Answer 6

1) Acid maltase deficiency
2) Central core myopathy
3) Congenital myotonic dystrophy
4) cytochrome c oxidase deficiency
5) Fukuyama MD
6) Infantile myositis
7) Merosin deficiency
8) Myotubular myopathy
9) Nemaline rod myopathy
10) Phosphofructokinase deficiency
11) Phosphorylase deficiency
12) Congenital fiber type disproportion myopathy

Look for CPK abnormalities!

Question 7

Signs of brain etiology for floppy baby

Answer 7

Alertness: impaired

CNs: intact

Muscle tone: mixed

Muscle strength: normal

Muscle bulk: normal

DTRs: decreased then increased

Sensation: variable

Question 8

Signs of SC etiology for floppy baby

Answer 8

Alertness: Normal

CNs: Intact

Muscle tone: Mixed

Muscle strength: Mixed

Muscle bulk: Normal

DTRs: Mixed

Sensation: Sensory level

Question 9

Signs of anterior horn body etiology for floppy baby

Answer 9

Alertness: Normal

CNs: Tongue fasciculations

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Low

DTRs: Low or absent

Sensation: Normal

Question 10

Signs of peripheral nerve etiology for floppy baby

Answer 10

Alertness: Normal

CNs: Normal

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Low

DTRs: Absent

Sensation: Diminished

Question 11

Signs of NMJ etiology for floppy baby

Answer 11

Alertness: Normal

CNs: Facial weakness, oculomotor abnormal, bulbar weakness

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Normal

DTRs: Low

Sensation: Normal

Question 12

Signs of muscle etiology for floppy baby

Answer 12

Alertness: Normal

CNs: Facial weakness

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Low to normal

DTRs: Low

Sensation: Normal

Question 13

Spinal muscular atrophy

Answer 13

Autosomal recessive

Carrer frequency of 1 in 50. 1 in 10000 live births.

Caused by mutation in SMN1 gene on chromosome 5. Causes degeneration of the anterior horn motor neurons.

4 clinical subtypes

Question 14

SMA type 1

Answer 14

Most common AKA Werdnig-Hoffman

Most severe form. Onset before 6 months

Death typically by age 2 years.

Pregnancy typically normal, one third note decreased fetal movements.

Normal cerebral function and alertness

Facial muscles normal

Tongue fasciculations in 50%

Poor suck/swallow

Weak cry

Profound hypotonia and flaccid weakness. Frog-legged posture. Distal strength better than proximal.

No head control

Never sit

DTRs usually absent

Sensation normal

Diaphragm spared (paradoxical breathing)

Respiratory distress

Question 15

SMA II

Answer 15

Intermediate severity.

Onset between 7 and 18 months

Eventually sit but never walk on own

Kyphoscoliosis

Weak swallow - poor weight gain - freq aspiration

Respiratory insufficiency is freq cause of death during adolescence

Question 16

SMA III

Answer 16

Mild but broad phenotype

Onset between 7 and 18 months

All walk on own but some may need wheelchair assistance. Others only have mild weakness

Scoliosis is common

Question 17

Diagnosing SMA

Answer 17

SMN1 gene testing

EMG - Abnormal spontaneous activity with fibrillations and positive sharp waves

NCS - usually normal

CK - normal to slightly elevated

Muscle bx - groups of atrophied type 1 and 2 muscle fibers interspersed with hypertrophic type 1 fibers

Question 18

NF1 diagnosis

Answer 18

At least 2 of the following:

1) 6 or more cafe spots greater than 5mm before puberty and 15mm after.
2) 2 or more neurofibromas or 1 plexiform neurofibroma
3) Axillary or inguinal freckling
4) Optic glioma
5) 2 or more Lisch nodules (on fundoscopic exam)
6) osseous lesion such as sphenoid dysplasia or pseudoarthrosis
7) 1st degree relative with NF1 (auto dominant)

Question 19

Malignant Peripheral Nerve Sheath Tumors

Answer 19

If NF1 features plexiform neurofibromas, there is a risk of conversion to this

Lifetime risk 10%

5yr survival 19%. Overall 28%

Presents with rapid growth of a preexisting nodule within a plexiform neurofibroma

Higher incidence of rhabdomyosarcoma

Question 20

Infantile spasm clinical features

Answer 20

Another peds seizure syndrome

includes spasm plus typical EEG pattern of hypsarrhythmia (chaotic) and in early childhood. EEG pattern seen at all times, not just during spasm.

Age range 1day to 4y with peaks at 2-8m. Almost all before 1 y.

“West Syndrome” = IS, hypsarrhythmia, psychomotor regression

Symptomatic in 67%. Due to metabolic conditions, perinatal asphyxia, Down syndrome, cerebral infarct, structural malformations, tuberous sclerosis

Cryptogenic in 33%. We don’t know etiology.

Strong association with mental retardation. 75-93% of affected children

High mortality: 11-33%

Refractory to normal seizure treatments

Sometimes X linked with ARX gene (homeobox)

Question 21

The spasms of IS

Answer 21

Usually involve the muscles of neck, trunk, extremities. Contraction phase is less than 2 seconds then a tonic phase that’s 2-10s. Can have very brief contraction with no tonic phase. Can have periods of lower responsiveness after a spasm up to 90s.

About half have some eye deviation or nystagmoid movements. Often cry after. Most occur in clusters. Tend to occur following arousal. Not triggered by startling stimuli.

Question 22

Hypsarrhythmia

Answer 22

Very high voltage, random, slow spikes and waves, diffusely

Multiple foci

Very disorganized/chaotic

Ictal EEG shows high voltage slow wave followed by attenuation

Question 23

Treatment of IS

Answer 23

ACTH

Vigabatrin

Ketogenic diet

B6

Other AEDs - Topamax, Zonisamide, VPA

Question 24

ACTH as treatment in IS

Answer 24

Mechanism of anti-convulsant effect unknown.

Works better than steroids. 50-86% effectiveness in eliminating spasms.

Side effects: HTN, susceptible to infection, cerebral atrophy, obesity, edema, gastric ulceration and hemorrhage, hyperphagia, glaucoma, irritability**

Must give GI ppx

Follow BPs, DS, Na/K

Mortality can be as high as 5%

Expensive

Question 25

Vigabatrin

Answer 25

Irreversible inhibitor of GABA-transaminase. Increases levels of GABA

May be almost as effective as ACTH esp in patients with tuberous sclerosis

Question 26

Prognosis of IS

Answer 26

Cryptogenic patients do better than symptomatic

50-90% respond to tx

Spasms resolve by 3-5y

Half evolve into Lennox-Gastaul Syndrome

Half have intractable epilepsy

70-90% have moderate to severe learning difficulties. About half have severe cognitive impairment.

20-40% have psych dysfunction

Mortality rate 5-30%

Question 27

Rolandic Syndrome

Answer 27

5-10y old

Seizures with sleep

Focal EEG pattern in central temporal area

Drooling

Can generalize

Kids outgrow it

Some kids have a very active EEG at night (like status)…do you intervene? AEDs or steroids

Normal intellectual function with focal EEG and rare seizures - leave alone