TREATING PHANTOM-LIMB PAIN

By Zulkiple Ibrahim
KUALA LUMPUR, June 6 (Bernama) -- Ah Keong, a 47-year-old bank officer, had
his right leg amputated below the knee following a road crash in December last year.
A few months after the amputation, the wound healed, but Ah Keong began to
experience frequent bouts of excruciating pain.
The pain was so severe that it forced Ah Keong to resort to painkillers,
like Paracetamol and Voltaren, which failed to work.
"At first, I thought the pain came from the wound, but the doctor said the
wound had healed well. Apparently, the pain emanated from deep within -- from
the nerves. That's why the painkillers did not work," he said, when he was
approached by Bernama at a rehabilitation clinic for amputees at a public
medical centre in Kuala Lumpur.

The pain Keong experienced is different from normal pain and is called
'neuropathic' pain.


DAMAGED NERVES

According to Rehabilitation Medical officer Dr T. Mohan, pain becomes
chronic when nerve fibers get damaged.

"This makes fibers send incorrect signals that are perceived as pain," he
said.

Dr Mohan said that neuropathic pain usually follows a tissue injury and
people affected might experience a pins-and-needles sensation, burning or
electric shocks.

"Neuropathic pain occurs when nerves that typically respond to injury
suddenly become active for no specific reason.

"With such pain, the function of nerves is compromised and nerve activity
increases. If left unchecked, this activity causes other nerves to become
ultra-sensitive and results in further pain," he added.


PHANTOM LIMB SYNDROME

Neuropathic pain could last for a long time and patients are forced to
constantly seek relief.

Dr Mohan pointed out that this type of pain does not respond well to
painkillers.

One example of neuropathic pain is the 'phantom limb syndrome'. It occurs
when an arm or a leg, which has been amputated because of illness or injury,
still gets pain messages from nerves that originally carried impulses from the
missing limb.

"These nerves now misfire and cause pain," he added.

Dr Mohan said that while neuropathic pain often seems to have no obvious
cause, some possible triggers could be alcoholism, amputation, chemotherapy,
diabetes and spinal surgery.

"Symptoms might include shooting or burning pain, as well as tingling and
numbness," he noted.

How is neuropathic pain diagnosed?

Dr Mohan explained that doctors conduct a physical examination, ask patients
to describe the pain, and check for specific triggers.


MANAGEMENT OF NEUROPATHIC PAIN

The International Association for the Study of Pain (IASP) describes
neuropathic pain as pain from a lesion or disease that affects the
somato-sensory system.

Dr Mohan said that 50 percent of such cases involve patients who have had
amputations.

Some studies suggest that the use of non-steroidal anti-inflammatory drugs,
such as Aleve or Motrin, could ease this form of pain.

"Anti-convulsant and anti-depressant drugs seem to work in some cases. If a
patient has diabetes, better management of that disorder could alleviate the
pain," Dr Mohan noted.

"In cases that are difficult to treat, a pain specialist may use invasive or
implantable device therapies to effectively manage the pain. An electrical
stimulation of the nerves involved in neuropathic pain generation can
significantly control the symptoms".

Neuropathic pain often responds poorly to standard pain treatments, and
occasionally could get worse, instead of better, over time. For some people, it
can lead to serious disabilities.

According to doctors, one of the drugs effective in treating neuropathic
pain is Neurontin (Gabapentin).

Gabapentin is an anti-convulsant used to treat seizures associated with
epilepsy. It can also be used to treat pain caused by abnormal nerve stimulation
(neuropathic pain).