Approach to a child with weakness

Dr. Pushpa Raj Sharma Professor of Child Health Institute of Medicine

Weakness/paresis/paralysis



Upper Motor Neuron.



Lower Motor Neuron



Myopathic

Pattern of weakness

 Sign Atrophy  Fasciculations  Tone +++  Distribution  Tendon reflexes  Babinski’s sign UMN Regional +++ + LMN +++ +++ +/ Segmental -/- Myopathic + Proximal +/-

Important fact:

 When there is a discrepancy between the history and physical findings, it is usually because the patient complains of

weakness

, whereas symptoms are actually due to other causes.



Child Abuse may be the cause.

Motor Neuron Disease

 Asymmetric  Upper and lower motor neurones     Amyotrophic Lateral Sclerosis (ALS) Sporadic ALS Hereditary ALS Superoxide Dismutase ; Chromosome 21; Dominant    Other ALS: Recessive & Dominant Multi-system disorders ALS with Ophthalmoplegia & Extrapyramidal Disorders   Polyglucosan body disease Motor neuronopathy with cataracts and skeletal abnormalities  Multiple system atrophy

Motor Neuron Disease

 Symmetrical and proximal  SMN : Chromosome 5q; Recessive  Androgen Receptor (Bulbo-spinal Muscular Atrophy) : X-linked; Recessive  Hexosaminidase A (Tay-Sachs) : Chromosome 15; Recessive  Hand weakness  Bulbar involvement

Motor Neuron Disease

 Lower motor neurones only • Distal Lower Motor Neuron (LMN) Syndrome  IgM vs GM1 ganglioside   IgM vs GalNAc-GD1a ganglioside Also see: Multifocal motor neuropathy • Proximal Lower Motor Neuron Syndromes  Brachial amyotrophic diplegia  ? Associated with IgM vs asialo-GM1  Rare: Upper > Lower limbs with anti-Hu antibodies

Motor Neuron Disease

 Lower Motor Neuron Syndrome without antibodies (PMA)  ALS variants • • Hereditary Sporadic  Focal motor neuron disease • • • Monomelic Amyotrophy Paraspinous muscle amyotrophy Cervical amyotrophy

Motor Neuron Disease

 Paraneoplastic motor neuro(no)pathy • • Mild weakness: With lymphoma Severe weakness: With breast cancer  Hopkins' syndrome : Acute post-asthmatic amyotrophy  Polio & Post-polio syndrome  SMN2 (SMNC) deletions  Neurofibromatosis, Type 25

Motor Neuron Disease



Symmetric & Proximal

: Hereditary Spinal Muscular Atrophy  SMN : Chromosome 5q; Recessive  Androgen Receptor (Bulbo-spinal Muscular Atrophy) : X-linked; Recessive  Hexosaminidase A (Tay-Sachs) : Chromosome 15; Recessive

Motor Neuron Disease

 Rapid onset  Acute Axonal Motor Neuropathy  (with Campylobacter jejuni or serum IgG vs GM1)  Poliomyelitis  Porphyria  4 types cause neurologic attacks • Acute intermittent • • • Variegate Porphyria Coproporphyria δ-amino-levulinic acid dehydratase deficiency  Urine: All types produce increased δ-amino-levulinic acid during attacks

Motor Neuron Disease

 Painful  Acquired  Others

Motor Neuron Disease



Acquired



Toxic

: Lead ; Dapsone ; Botulism ; Tick Paralysis 

Infections

 Polio  West Nile  Central European encephalitis  Creutzfeld-Jacob • • Amyotrophy Polyneuropathy ( ± Demyelinating )

Weakness/ paresis/ paralysis indicates the lesions in the upper motor nurone or lower motor neurone or myoneural junction or muscles.

Preservation of sensation/ Increased or absent or diminished jerks/ atrophy or hypertrophy indicates the site of lesions.

The major clinical diagnosis associated with AFP (n= 517) *

 Guillain-Barre syndrome (30.2%),  Central nervous system infection (16.2%),  Transverse myelitis (10.6%)  Non-polio enterovirus infection (6.2%),  Hypokalaemic paralysis (5.2%).

* Hussain IH, Ali S, Sinniah M, Kurup D, Khoo TB, Thomas TG, Apandi M, Taha AM

J Paediatr Child Health. 2004 Mar;40(3):127 30

Age distribution of Guillain Barré syndrome.

AIDP=acute inflammatory demyelinating polyradiculoneuropathy; FS=Fisher syndrome

Lyu, R.-K. et al. J Neurol Neurosurg Psychiatry 1997;63:494-500

Seasonal distribution of Guillain Barré syndrome Lyu, R.-K. et al. J Neurol Neurosurg Psychiatry 1997;63:494-500

Recurrent Guillain Barre' Syndrome

 Of the 220 patients of acute idiopathic demyelinating polyneuritis (AIDP/GBS) seen over a seven year period, 15 patients (M:F:11:4) had a relapsing course (6.8%). They had 36 episodes at a variable interval of 3 months to 25 yrs.



Taly AB, Gupta SK, Anisya V, Shankar SK, Rao S, Das KB, Nagaraja D, Swamy HS.

J Assoc Physicians India. 1995 Apr;43(4):249-52.

Follow-up of AGBS

 At a follow-up of 1 year or more, 20 patients recovered and 3 had residua.  Hung PL, Chang WN, Huang LT, Huang SC, Chang YC, Chang CJ, Chang CS, Wang KW, Cheng BC, Chang HW, Lu CH. Pediatr Neurol. 2004 Feb;30(2):86-91.  permanent neurological defects in children under 15 years of age was 1.4/10 million annually  Rantala H, Uhari M, Niemela M. Arch Dis Child. 1991 Jun;66(6):706-8; discussion 708-9.

Subacute Inflammatory Demyelinating Polyneuropathy.

 progressive motor and/or sensory dysfunction consistent with neuropathy in more than one limb with time to nadir between 4 and 8 weeks,  electrophysiologic evidence of demyelination in at least two nerves,  no other etiology of neuropathy, and  no relapse on adequate follow-up.

Complete recovery was achieved in 69% of cases and partial recovery in others.



Oh SJ, Kurokawa K, de Almeida DF, Ryan HF Jr, Claussen GC.

Neurology. 2003 Dec 9;61(11):1507-12.

Chronic Inflammatory Demyelinating Polyradiculoneuropathy

 A low frequency of antecedent events.

 Weakness accompanied by sensory loss and diminished tendon reflexes  Pain and cranial neuropathies are uncommon  Progressive weakness for two months.

 Sladky JT; Ashwal S: Peripheral neuropathies in childre. Pediatric Neurology Principles and Practice. Ed. Swaiman KS; Ashwal S. 3 rd ed.1999. Publisher: Mosby

Causes Inflammatory Polyradiculoneuropathy

 GB Syndrome 58%  Chronic inflammatory demyelinating polyneuropathy 31%  Associated with collagen vascular disease 7%  Other immune/infectous disorders 4%

HOPKINS' SYNDROME: Acute post asthmatic amyotrophy

 Onset  After acute asthmatic attack: Latency 1 to 18 days  Mild pain: Limb, neck or meningismus  Rapid onset weakness

HOPKINS' SYNDROME: Acute post asthmatic amyotrophy

 Weakness  Single limb; Asymmetric; May be Proximal > Distal  Severity: Mild to severe  Arm or leg  Sensory: Normal

HOPKINS' SYNDROME: Acute post asthmatic amyotrophy

 CSF  Pleocytosis  Protein: ± Increased  MRI: May show signal (T2) in spinal cord  Prognosis: Permanent paralysis

Flaccid or hyper tonicity