Skip to navigation Skip to content

Symptoms and Diagnosis of HAM


In this article


In response to the infection, the body's immune response may injure nerve tissue, causing a variety of symptoms.

More than 90 percent of affected individuals will experience pain, stiffness and/or weakness in the legs, which can result in a tendency to trip or have trouble with stairs or getting out of a low chair.

More than 90 percent of affected individuals will experience urinary symptoms. Possible bladder abnormalities include:
  • Increased frequency (the number of visits to the toilet to pass urine)
  • Urgency (needing to pass urine with very little warning and often the volume of urine passed is small
  • Nocturia (having to get up at night to pass urine more than once)
  • Incontinence (not being able to get to the toilet in time
  • Urinary retention (the bladder does not fully empty and more than the normal amount of urine remains in the bladder, which can lead to bladder infections and kidney infections)
Bowel function can slow and result in constipation. About 50 percent of people will have loss of feeling in the feet, tingling sensations, unpleasant sensations when the skin is touched, and low back pain.
As many as 20 percent of people may also experience:
  • Deafness
  • Double vision
  • Tendency to incorrectly estimate the amount of motion necessary to accomplish a specific task (dysmetria)
  • Exaggerated reflexes
  • Facial paralysis
  • Tremor
Inflammation of the nerves can also result in impotence or erectile dysfunction in men.


  • Blood test to detect antibodies to HTLV-1. While the presence of antibodies is essential for a diagnosis of HAM/TSP, it is not enough because most people with antibodies do not have HAM/TSP.
  • Blood smears to detect flower cells (also seen in carriers)
  • Spinal tap (lumbar puncture) to detect antibodies to HTLV-1 and to rule out other causes
  • Magnetic resonance imaging (MRI) of the brain and spinal cord
  • Evoked potentials (EPs) to measure the electrical activity of the brain in response to stimulation of specific sensory nerve pathways. EPs are able to detect the slowing of electrical conduction caused by demyelination along these pathways even when the change is too subtle to be noticed by the person or to show up on neurologic examination.
  • Electromyography (EMG) to measures the electrical impulses of muscles
Reviewed by Elias Sotirchos, MD November 2019


© 2022 The National Multiple Sclerosis Society is a tax exempt 501(c)3 nonprofit organization. Its Identification Number (EIN) is 13-5661935.