Table 2.

World Health Organization diagnostic criteria for HAM/TSP.

Age and sex incidence	Mostly sporadic and adult, but sometimes familial; occasionally seen in childhood; females predominant
Onset	Usually insidious but may be sudden
Main neurological manifestations	Chronic spastic paraparesis, which usually progresses slowly, sometimes remaining static after initial progression
	Weakness of the lower limbs, more marked proximally
	Bladder disturbance usually an early feature; constipation usually occurs later; impotence or decreased libido is common
	Sensory symptoms such as tingling, pins and needles, and burning are more prominent than objective physical signs
	Low lumbar pain with radiation to the legs is common
	Vibration sense is frequently impaired; proprioception is less often affected
	Hyperreflexia of the lower limbs, often with clonus and Babinski’s sign
	Hyperreflexia of the upper limbs, positive Hoffman’s and Tromner signs frequent; weakness may be absent
	Exaggerated jaw jerk in some patients
Less frequent neurological findings	Cerebellar signs, optic atrophy, deafness, nystagmus, other cranial nerve deficits, hand tremor, absent, or decreased ankle jerk. Convulsions, cognitive impairment, dementia, or impaired consciousness are rare
	Muscular atrophy, fasciculations (rare), polymyositis, peripheral neuropathy, polyradiculopathy, cranial neuropathy, meningitis, encephalopathy
Systemic non-neurological manifestations	Pulmonary alveolitis, uveitis, Sjogren’s syndrome, arthropathy, vasculitis, ichthyosis, cryoglobulinemia, monoclonal gammopathy, adult T cell leukemia/lymphoma
Laboratory diagnosis	Presence of HTLV-1 antibodies or antigens in blood and CSF
	CFS may show mild lymphocyte pleiocytosis
	Lobulated lymphocytes may be present in blood and/or CSF
	Mild to moderate increase of protein may present in CSF

CSF, cerebrospinal fluid.