FLOPPY CHILD

Hassan Mohammad Al-Shehri

Objectives

Definition Risk factors Classification History taking and signs of hypotonia Investigations Management and prognosis.

Introduction

Neurological disorders are common in Saudi Arabia.

accounts for 25–30% of all consultations to pediatrics

Definition

Muscle tone is defined as resistance to passive

movement.

Hypotonia means "low tone," and refers to a physiological state in which a muscle has decreased tone, or tension.

AssessmentPrenatal risk factors:• History of drug or teratogen exposure• Presence of polyhydramnios• Maternal diseases (diabetes, epilepsy)• Parental age• Consanguinity• Family history of neuromuscular disease• Other affected siblings

AssessmentBirth/perinatal risk factors (1) History of prematurity: increased risk for cerebral palsy or

central causes. (3) Difficulties sucking/swallowing: may be seen with hypoxic

ischemic injury but if not in context with overall clinical picture, reflects possible neuromuscular cause.

(4) Poor respiratory effort: may be seen with hypoxic ischemic injury but if not in context with overall clinical picture, reflects possible neuromuscular cause.

(5) Encephalopathy: if out of context of birth history, may reflect underlying metabolic disorder or severe cerebral dysgenesis.

(6) Neonatal seizures: may reflect underlying metabolic disorder or cerebral dysgenesis.

(7) Unexplained metabolic “lab” abnormalities: consider metabolic disturbances and inborn errors of metabolism.

Classification Central Spinal Cord Anterior Horn Cell Neuromuscular Junction Muscle Peripheral Nerves Metabolic myopathies

Classification Central Causes

Cerebral palsy Intracranial hemorrhage Cerebral malformations Chromosomal abnormalities Hypoxic ischemic encephalopathy Congenital infection Acquired infections Peroxisomal disorders Drug effects

Classification Spinal cord

Birth trauma (especially Breech delivery) Syringomyelia

Clues to diagnosis History of: - brain insult - seizures - dysmorphic features - lack of interest in surroundings - abnormal head size - spontaneous movements - normal or increased reflexes,

persistence of primitive reflexes

Classification Anterior Horn Cell

Spinal Muscular Atrophy Traumatic myelopathy

Classification Neuromuscular junction

Congenital myasthenia gravis Transient acquired neonatal myasthenia Infantile botulism

Classification Muscle

Muscular dystrophies (congenital myotonic dystrophy)

Congenital myopathies (e.g. central core disease)

Classification

Peripheral nerves

Hereditary sensory motor neuropathies Charcot-Marie-Tooth disease

Classification Metabolic myopathies

Acid maltase deficiency Carnitine deficiency Cytochrome-c-oxidase deficiency

Clues to diagnosis

Decreased fetal movements Alertness and responsiveness Weakness with little spontaneous

movements Absent or decreased reflexes Fasciculation, muscle atrophy Sensory loss.

History TakingAny significant family history?Was the hypotonia present at birth?Pregnancy and delivery history

Drug or teratogen exposure Decreased fetal movements Abnormal presentation Polyhydramnios/ oligohydramnios

Apgar scores Resuscitation requirements Cord gases

Signs of Hypotonia

In supine, Frog position Their heads lag when are held up They slip through at the shoulders Do not stand upright on their legs Form inverted U shape in ventral suspention Lie flat when in prone position.

Signs of Hypotonia

Poor ability to cough and clear airway secretions. Poor swallowing ability Crying character [weak, low pitched] Paradoxical breathing pattern. Intercostal muscles

paralyzed with intact diaphragm.

Signs of HypotoniaVentral suspensionInverted U position The back hangs over the

examiner's hand, and the limbs and head hang loosely

Passive extension of the legs

Pull to sit Head lag

Signs of Hypotonia

The same infant in horizontalsuspension. Note the inverted U posture.

Signs of Hypotonia

A 12-week-old male infant with excessive head-lag evident on ‘pull-to-sit’. Note the hypotonic posture of the legs with external rotation.

Signs of Hypotonia

Vertical suspension: The legs will be extended Decreased tone of the shoulder girdle allows the infant to slip

through the examiner's hands

Signs of Hypotonia

Ptosis and external ophthalmoplegia in a floppy weak child. Suggestive of myasthenia gravis.

Investigations

Required investigations depend upon history and physical examination findings.

Investigations Central Causes

Neuroimaging Ultrasound scan in the first instance MRI for structural abnormality EEG: if seizures suspected

Investigations Central Causes

Genetics review if any dysmorphic features present Karyotype (if dysmorphic features) TORCH screen DNA methylation studies or FISH for Prader-Willi syndrome

(if clinically indicated after a genetics review) Metabolic work up

Investigations Peripheral causes

Neurology services review Molecular genetics – CTG repeats, deletions in SMN gene Creatine kinase: If elevated in an early sample, repeat after

a few days. Nerve conduction studies Muscle biopsy

Depending on clinical situation, may be delayed until around 6 months of age as neonatal results are difficult to interpret

Management

Supportive[respiratory, gastrointestinal] Once the correct diagnosis is confirmed, specific

treatments should be offered if available Physiotherapy:

mainly preventative to avoid contractures and wasting, but will not increase muscle tone

Genetics counseling.

Prognosis

Currently no known treatment or cure for most causes of hypotonia, and objective manifestations can be life long.

The outcome in any particular case of hypotonia depends largely on the nature of the underlying disease.

Prognosis

In some cases, muscle tone improves over time, or the patient may learn mechanisms that enable him to overcome the most disabling aspects of the disorder.

Hypotonia caused by cerebellar dysfunction or motor neuron diseases can be progressive and life-threatening.

Resources

Mohammed M.S. Jan (2007) , “The hypotonic infant: Clinical approach”. Journal of Pediatric Neurology 5 2007

Nelson Essential of Pediatrics 5th edition Pedbase.org

Thank You!