番茄社区

Amputees with psychiatric and medical conditions are much more likely to experience phantom limb syndrome (PLS), according to a retrospective cohort study.

After adjusting for factors such as age, sex, and comorbidities, PLS was significantly associated with major depressive disorder (OR 2.36), generalized anxiety disorder (OR 2.35), post-traumatic stress disorder (OR 2.60), and suicidal ideation (OR 2.34; all P<0.0001), reported Alan H. Daniels, MD, of University Orthopedics in Rhode Island, at the American Academy of Orthopaedic Surgeons annual meeting.

There were also significant associations with obesity (OR 1.24), osteoarthritis (OR 1.41), osteoporosis (OR 2.0), low back pain (OR 2.47; all P<0.0001), and hypertension (OR 1.22, P=0.009).

"The symptoms [of PLS] can be incredibly debilitating for the patient. The pain experienced has been described as shooting or stabbing and may accompany other symptoms including numbness and cramping," Daniels told 番茄社区.

"Providers should anticipate and prepare to treat comorbid mental and physical health disorders that may develop in tandem with phantom limb syndrome," he added, noting that PLS itself is not considered a mental illness.

Of note, those with PLS had decreased odds of diabetes (OR 0.74), chronic kidney disease (OR 0.81), and congestive heart failure (OR 0.72; all P<0.0001), the researchers pointed out.

Also surprising was the absence of a link between pain levels from PLS and higher prevalence of mental or physical disorders.

"Further prospective studies should be performed to validate or refute this finding," Daniels said.

In an interview with 番茄社区, Tamar Makin, PhD, a neuroscientist at University College London, said it's important to not assume that mental illness causes PLS.

"The fact that people in this study with PLP [phantom limb pain] also had more depression doesn't mean that having depression will increase your likelihood to develop PLP," she said. "Pain and mental health have a very complicated and bidirectional relationship, and many patients suffering from chronic pain are likely to indeed develop depression due to their debilitating condition."

A retrospective study isn't appropriate to address cause and effect, she added.

PLP "is perhaps better defined as a continuum, with the intensity, frequency, and range of related experiences scaled both within and across most individuals," Makin said.

For this study, Daniels and colleagues examined 64,158 patients from a large insurance database who had undergone one or more extremity amputations. While only 5% were diagnosed and coded in the database as having PLS, "it is likely far under-reported, and may be not overly bothersome in many patients," Daniels noted.

"Unfortunately, treatment for phantom limb pain has limited effectiveness and is focused on symptomatic control through over-the-counter pain medications, narcotics, and antidepressant medications that can relieve pain to damaged nerves," he explained.

Acupuncture is also an option, and another type of therapy uses mirrors to trick patients into thinking that missing limbs are still there. "Research is ongoing, and the treatment outcomes are mixed," he said.

Daniels encouraged physicians to evaluate the mental health of patients before amputation and consider interventions prior to surgery.

"Future studies should be conducted to appreciate if pre-amputation counseling and treatment for psychiatric conditions can prevent the occurrence of phantom limb syndrome and post-amputation depression or anxiety," he said. "One area for our future database research is to answer the question of which comes first, psychiatric comorbidity or phantom limb syndrome."

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