Rheumatology Made Simple : Differential Diagnosis of difficulty in Walking upstairs and weakness

Main Differentials in this case are :

Muscular Diseases :

Hereditary  

Muscular dystrophies  ( Duchenne, Becker ,Fascioscapulohumeral  , Emery – Dreifuss)

Myotonic dystrophy

Acquired

Polymyositis

Dermatomyositis

Inclusion Body myositis

Rhabdomyolysis

Drud induced myopathy

Endocrine Diseases

Cushing’s Syndrome

Addison”s disease

Neuromuscular junction pathologies

Myasthenia gravis

Botulism

Lambert Eaton Myasthenic syndrome

Neurological Causes

Brain

Stroke

Multiple Sclerosis

Seizures 

Todd"s paralysis

Intra-cranial / space occupying lesions

Spinal cord

Any spinal cord injury / trauma

Transverse myelitis

Arteriovenous malformations

Peripheral Nervous system:

Mononeuropathies

Poly neuropathies

Anterior Horn cell Pathology

Motor Neuron Disease

Poliomyelitis

Miscellaneous causes:

Steroid excess

Malignancy

Polymyalgia rheumatica

Calcium and vitamin D deficiencies

Multiple Myeloma

Malnutrition

Old age

Lack of exercise and healthy diet

Obesity