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Flashcards in Pediatric Neurology Deck (27)
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Brain etiologies of floppy baby

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


Spinal cord etiologies of floppy baby

1) Hypoxic ischemic myelopathy

2) Traumatic spinal cord injury


Anterior horn etiologies of floppy baby

1) Spinal muscular atrophy

2) Vaccine related poliomyelitis

3) GM2 gangliosidosis

4) Coxsackie


Peripheral nerve etiology of floppy baby

1) Dejerine-Sottas

2) Congenital hypomyelinating polyneuropathy

3) CMT1 and 2


5) MLD

6) Guillen Barre


NMJ etiology of floppy baby

1) Familial infantile myasthenia

2) Infantile botulism

3) Transitory myasthenia gravia


Muscle etiology of floppy baby

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!


Signs of brain etiology for floppy baby

Alertness: impaired

CNs: intact

Muscle tone: mixed

Muscle strength: normal

Muscle bulk: normal

DTRs: decreased then increased

Sensation: variable


Signs of SC etiology for floppy baby

Alertness: Normal

CNs: Intact

Muscle tone: Mixed

Muscle strength: Mixed

Muscle bulk: Normal

DTRs: Mixed

Sensation: Sensory level


Signs of anterior horn body etiology for floppy baby

Alertness: Normal

CNs: Tongue fasciculations

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Low

DTRs: Low or absent

Sensation: Normal


Signs of peripheral nerve etiology for floppy baby

Alertness: Normal

CNs: Normal

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Low

DTRs: Absent

Sensation: Diminished


Signs of NMJ etiology for floppy baby

Alertness: Normal

CNs: Facial weakness, oculomotor abnormal, bulbar weakness

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Normal

DTRs: Low

Sensation: Normal


Signs of muscle etiology for floppy baby

Alertness: Normal

CNs: Facial weakness

Muscle tone: Low

Muscle strength: Low

Muscle bulk: Low to normal

DTRs: Low

Sensation: Normal


Spinal muscular atrophy

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


SMA type 1

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



Intermediate severity.

Onset between 7 and 18 months

Eventually sit but never walk on own


Weak swallow - poor weight gain - freq aspiration

Respiratory insufficiency is freq cause of death during adolescence



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


Diagnosing SMA

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


NF1 diagnosis

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)


Malignant Peripheral Nerve Sheath Tumors

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


Infantile spasm clinical features

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)


The spasms of IS

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.



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

Multiple foci

Very disorganized/chaotic

Ictal EEG shows high voltage slow wave followed by attenuation


Treatment of IS



Ketogenic diet


Other AEDs - Topamax, Zonisamide, VPA


ACTH as treatment in IS

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%




Irreversible inhibitor of GABA-transaminase. Increases levels of GABA

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


Prognosis of IS

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%


Rolandic Syndrome

5-10y old

Seizures with sleep

Focal EEG pattern in central temporal area


Can generalize

Kids outgrow it

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

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