Wednesday, May 8, 2013

Days or Weeks after Stroke, Some Patients Develop Chronic, Debilitating Pain

MAYWOOD, Ill. - Nearly 1 in 10 stroke patients suffer chronic and debilitating pain, typically described as a sharp, stabbing or burning sensation.

It’s called central poststroke pain syndrome (CPSP). It was first described more than 100 years ago, and it is treatable with medications and magnetic or electrical stimulation of the brain. But physicians today often fail to correctly diagnose the condition, Loyola University Medical Center stroke specialists report in the journal Topics in Stroke Rehabilitation.

The article is written by Murray Flaster, MD, PhD; Edwin Meresh, MD; Murali Rao, MD; and José Biller, MD.

CPSP is a form of neuropathic pain caused by damage or dysfunction within the central nervous system. It typically begins days or weeks after a stroke. One study found that among patients who experience CPSP, 63 percent were affected within one month, 18 percent within six months and the remaining 18 percent after six months.

Patients can experience hyperpathia (abnormally painful reaction to a painful stimulus) or allodynia (pain in response to a light touch, contact with clothing or bedsheets, air currents, etc.) Allodynia is reported in two-thirds of CPSP patients.
The prevalence of CPSP among stroke patients is 8 percent, but can range from 1 percent to 12 percent. It is among several types of poststroke pain, which also include headache and musculoskeletal pain, especially pain related to abnormal shoulder movement.

“There are many causes of poststroke pain and these frequently coexist in our patients,” the authors write. “It is crucial to recognize CPSP and differentiate it from musculoskeletal pain or spasticity-associated pain."

First-line drug treatments for CPSP include amitriptyline (an antidepressant) and lamotrigine (an anticonvulsant). Second-line treatment includes the anticonvulsant gabapentin.

If medications don’t work, a non-invasive therapy called transcranial magnetic stimulation (TMS) should be considered. TMS sends short pulses of magnetic fields to the brain.

If drugs and TMS both fail, invasive therapies that electrically stimulate the brain should be considered in carefully selected patients. The treatments involve inserting electrodes into the membrane covering the brain (motor cortex stimulation) or into the brain itself (deep brain stimulation).

CPSP was first described in a medical journal in 1906. (It was then called “thalamic syndrome.”) More than a century later, CPSP still is frequently misdiagnosed.
“CPSP is treatable,” Flaster, Meresh, Rao and Biller write. “Recognition of the syndrome in and of itself can be reassuring to the patient."

Flaster is an associate professor in the departments of Neurology and Neurological Surgery of Loyola University Chicago Stritch School of Medicine. Meresh is an assistant professor and Rao is a professor and chair of the Department of Psychiatry and Behavioral Neurosciences. Biller is professor and chair of the Department of Neurology.

The title of their article is “Central Poststroke Pain: Current Diagnosis and Treatment.”

About Loyola University Health System

Loyola University Health System (LUHS) is a member of Trinity Health. Based in the western suburbs of Chicago, LUHS is a quaternary care system that includes Loyola University Medical Center (LUMC), located on a 61-acre campus in Maywood, Gottlieb Memorial Hospital (GMH), on a 36-acre campus in Melrose Park, and convenient locations offering primary and specialty care services throughout Cook, Will and DuPage counties. At the heart of LUMC is a 547-licensed-bed hospital that houses the Center for Heart & Vascular Medicine, the Cardinal Bernardin Cancer Center, a Level 1 trauma center, a burn center, a children's hospital, Loyola Outpatient Center, and Loyola Oral Health Center. The campus also is home to Loyola University Chicago Stritch School of Medicine, Loyola University Chicago Marcella Niehoff School of Nursing and the Loyola Center for Fitness. The GMH campus includes a 254-licensed-bed community hospital, a Professional Office Building with 150 private practice clinics, an adult day care program, the Gottlieb Center for Fitness, the Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park.

Trinity Health is one of the largest multi-institutional Catholic health care delivery systems in the nation. It serves people and communities in 22 states from coast to coast with 93 hospitals, and 120 continuing care locations — including home care, hospice, PACE and senior living facilities — that provide nearly 2.5 million visits annually.