Neurologic disorders and stroke

Cerebral infarction

Brain-stem infarction

Intracranial hemorrhage

Parkinson's disease

Multiple sclerosis

Amyotrophic lateral sclerosis

Poliomyelitis

Myasthenia gravis

Dementias

Structural lesions

Thyromegaly

Cervical hyperostosis

Congenital web

Zenker's diverticulum

Ingestion of caustic material

Neoplasm

Psychiatric disorder

Psychogenic dysphagia

Connective tissue diseases

Polymyositis

Muscular dystrophy

Iatrogenic causes

Surgical resection

Radiation fibrosis

Medications