FLOPPY INFANT

A FLOPPY INFANT is described as an infant with marked hypotonia of all the muscles. Flopppiness is characterized by:
1. Bizarre or unusual postures(Frog legged position)
2. Diminished resistance of joints to passive movement
3. Increased range of joint mobility
4. Paucity of spontaneous movements
5. Motor development delay
This may be associated with frequent respiratory infections, feeding difficulties, facial weakness, ptosis, ophthalmoplegia and dislocated hips. Contracturesmay develop at a later stage.

They may be classified as:


Floppy(peripheral)
disorders involving the lower motor unit.
pathology is at the level of anterior horn cell, peripheral nerve, neuromuscular junction or muscle.
Ex: Werdnig Hoffman SMA, congenital muscular dystrophy, congenital myopathies.



Floppy(central)
Have central neurological(UMN) causes.
Ex: Hypotonic cerebral palsy, Down syndrome.


CAUSES

1.CEREBRAL HYPOTONIA
A> Chromosomal disorders
- Down syndrome
- Prader Willi syndrome

B> Static encephalopathy
- Cerebral malformation
- Intracranial hemorrhage
- Atonic cerebral palsy
- Kernicterus
- Cerebellar ataxia

C> Single gene disorders
- Zellweger syndrome
- Lowe's syndrome
- Tay Sach's disease

2. SPINAL CORD DISORDERS
- Hypotoxic ischaemic myelopathy
- Traumatic myelopathy

3. Anterior horn cell diseases
- Spinal muscular atrophy(SMA)
- Polio myelitis

4. Disorders of the peripheral nerves
- Acute poyneuropathy- GBS
- Familial dysautonomia
- Congenital sensory neuropathy

5. Disorders of myoneural junction
- Neonatal myesthenia gravis
- Infantile botulism
- Congenital defect of neuromuscular junction
- Toxic neuromuscular blockade- Hypermagnesaemia, antibiotics-aminoglycosides

6. Disorders of muscles
- Muscular dystrophies
- Congenital myopathies
-
7. Miscellaneous
- Sepsis
- Hypothyroidism
- Renal tubular acidosis
- Rickets
- Malabsorption syndrome



WHEN TO SUSPECT FLOPPY INFANT???
- Slips from hands
- Less movement of limbs
- Baby is alert, but less motor activity
- Delayed motor development
- Able to walk but frequently falls


HISTORY
- Determine the age of onset, mode of onset, presenting complaints, rapidity of progression.

- History of feeding problems, recurrent pneumonias. (Neuromuscular disorder)

- Antenatal History: Decreased fetal movements and polyhydramnios(due to intrauterine swallowing difficulty) seen in SMA.

- Perinatal history: Birth weight, hypoxia, sepsis.

- Developmental History: Delay of motor milestones with normal intellectual development suggests possible defect in the motor unit.

- Family history: Important to determine the pattern of inheritance.

- Look at the parents' face for evidence of myotonic dystrophy

- If this is suspected, the parent is asked to make a fist and then open hands quickly. This will detect myotonia.

- Look for evidence of myasthenia in the mother(neonatal myasthenia).

Look for pes cavus in the mother(Hereditary neuropathy).

MANEUVERS IN EXAMINATION OF A FLOPPY INFANT
To quantify degree of hypotonicity

Traction response: Initiated by grasping hands and pulling the child to sitting position. It is not elicited in premature infants less than 33 weeks of gestation. After 33 weeks, there is considerable head lag, but neck flexors respond to traction by lifting head. At term, only minimal head lag is present. Presence of more than minimal head lag and failure to counter traction by flexion of limb is abnormal and indicates postural hypotonia in full term newborn.

Vertical suspension: Examiner places both hands in axilla and without grasping thorax, lifts straight up. With weakness, infant needs to be grasped around trunk to prevent falling.

Horizontal suspension: Normal infant suspended horizontally in prone keeps head erect, maintains straight back demonstrates flexion at elbows, hips, knees, and ankles. Hypotonic infant drape over examiners hands with head and limbs hanging limply.

Practical measures of strength in infants and young children.
Head and Trunk

- Upright head stability
- Traction response
- Independent sitting with/without hand popping
- Ability to reach overhead without lateral popping and tilting head back

Proximal arm strength
- Arms over head, reaching to defined height
- Length of ball throw
- Combat crawling

Distal arm strength
- ability to grasp and elevate defined objects of various size and weight

Proximal leg strength
- Movement of leg against gravity while supine
- Kneeling and crawling
- Gower's maneuver
- Gait-Trendelenberg's , waddle

Distal leg strength
- Motion against gravity
- Steppage gait with slapping feet

"Support bacteria. They're the only culture some people have."

Gram Positive

1> Part of the normal flora of the skin, it causes infection of IV lines and catheters; it is a major cause of endocarditis in patients with prosthetic heart valves.

Staphylococcus epidermidis.


2> The second leading cause of urinary tract infection in sexually active women.

Staphylococcus saprophyticus.


3> Infection can lead to the development of acute glomerulonephritis and mitral and aortic stenosis.

Streptococcus pyogenes.

4> The organism is detected as PAS+ rods within the macrophages of the lamina propria of the small intestine.

Tropheryma whippelii ( causative agent of Whipple's disease)

5> As well as being gram positive, this organism is also weakly acid fast and causes a pneumonia predominantly in immunocompromised patients.

Nocardia asteroides.

6> Can cause risus sadonicus, the characteristic grimace of lockjaw.

Clostridium tetani

7> A common cause of nosocomial infections, this organism is often resisitant to many antibiotics, including vancomycin.

Enterococcus spp.

8> Causes a fishy smelling vaginal discharge.

Gardnerella vaginalis. (histologically charaterised by the presence of "clue cells", vaginal epithelial cells covered with bacteria, seen on Pap smear).

9> This cause of late onset neonatal sepsis is a facultative intracellular parasite that spreads from cell to cell via actin rockets.

Listeria monocytogenes. (this organism can be detected as short non-spore-forming rods with a tumbling end-over-end motility).

10> Causes gastroenteritis and is typically associated with the consumption of reheated rice.

Bacillus cereus.

BREAK THROUGH

This section consists of a few pharmacology cases and their respective treatment
Case 1:
A 22 year old male complains of a new lesion on his penis. On examination, you find a single painless ulceration with a firm border. The patient reports that the penile ulcer has been there for over a week. Upon further questioning, you discover that he has been having unprotected sexual contact with several individuals over the last 3 months. Physical exam is also remarkable for enlargement of lymph nodes in the groin, axillary, and supraclavicular regions. Suspecting a specific sexually transmitted disease, you send him to the laboratory for RPR and VDRL test. When he returns from the laboratory, you tell him that you will empirically treat him with a shot and you warn him that rare side effects of this medication include a hemolytic anaemia.






Ans: PENICILLIN


Similar drugs: Penicillin G(i.v), penicillin V(oral)

Mechanism of Action: Bacterial cell walls are composed of a complex configuration of cross linked peptidoglycans. Formation of the peptidoglycan walls are mediated via penicillin-binding proteins(PBPS). Penicillin acts to bind PBPS, thereby blocking peptidoglycan cross-linking and thus inhibiting bacterial cell wall synthesis.

Clinical Uses: Treatment of infections caused by gram positive organisms(strptococci, pneumococci), gram negative cocci(meningococci), enterococci and spirochetes.


Side Effects: Allergic reaction; drug induced Coombs' positive hemolytic anemia.






Case 2:
A 37 year old woman presents to your ophthalmology office for a routine eye examination. In preparation for her retinal exam, you decide to dilate the patient's pupils with a medicated ophthalmic solution. The patient is curious, and she asks you how this ophthalmic solution works. You explain to her that the medication will act to constrict her pupillaary dilator muscle, thereby producing pupillary dilation. You also tell her that this is the same compound that is used to treat nasal decongestion.




Ans: PHENYLEPHRINE

Mechanism of Action: Phenlyephrine is an α1 agonist, thereby leading to systemic vasoconstriction and pupil dilation. When applied topically to the nasal mucosa, it induces vasoconstriction, thereby leading to a decrease in mucosal secretions.

Clinical features: Used to treat nasal decongestion.
Used as an ophthalmic solution to produce mydriasis for retinal examination. Also used in past to treat episodes of supraventricular tachycardia and raise both systolic and diastolic blood pressure.

Side effects: Cardiac arrhythmias; headache.


Case 3:
A 69-year old woman presents to your primary care office, complaining of a 2-week history of back pain. She admits that the pain began after she had been lifting some heavy boxes while cleaning out her husband's study. She denies any neurological symptoms. On physical exam, she has no pain with the straight-leg maneuver, thereby suggesting that she has not herniated her disk: however she does have point tenderness around the T12-L1 region. You send her for imaging studies, which reveal a vertebral compression fracture at L1. A bone scan reveals the presence of significant osteoporosis. You decide to treat her osteoporosis with a medication that acts by decreasing osteoclastic bone resorption.



Ans: ALENDRONATE


Similar Drugs: Other biphosphonates include etidronate, pamidronate, and risedronate.

Mechanism of Action: This class of drugs acts to decrease osteoclastic bone resorption by inhibiting osteoclastic activity and increasing osteoclastic cellular death.

Clinical Uses: Treatment of osteoporosis, Paget's disease of the bone, and hypercalcemia associated with malignancies.

Side Effects: GI upset.