Subscribe:

Ads 468x60px

a

Pages

Sunday, June 27, 2010

Ankylosing Spondilitis

A 22-year-old man is evaluated in the office for a 12-month history of gradually worsening low back stiffness that is present for 2 hours after awakening in the morning. He has significant fatigue but no fever, chills, night sweats, or weight loss. He does not have pains in the peripheral joints but does have bilateral buttock pains throughout the day on sitting. One year ago, he also had a 2-week episode of uveitis of the right eye, which responded to corticosteroid eye drops.

On physical examination, vital signs are normal. He appears healthy but walks with a mild forward bending of his spine. Deep pressure and palpation of the lumbar spine in the midline and both sacroiliac joints elicits tenderness. Chest expansion in the fourth intercostal space is 2 cm (normal ≥5 cm), and he can only reach the midcalf region when attempting to touch his fingers to the floor.

On laboratory studies, hemoglobin is 12.5 g/dL, erythrocyte sedimentation rate is 85 mm/h, and C-reactive protein is 5 mg/dL. Anteroposterior radiograph of the pelvis and sacroiliac joints is shown




Which of the following is the most likely diagnosis?
A Ankylosing spondylitis
B Metastatic cancer
C Osteoarthritis
D Sacral fracture

ANSWER

This patient most likely has ankylosing spondylitis, a systemic inflammatory disorder that most commonly occurs in men and primarily involves the spine and sacroiliac joints. Ankylosing spondylitis should be considered in the following : patients <40 years of age, patients with insidious onset of chronic low-back pain and stiffness of >3 months' duration; and those with low-back pain and stiffness that worsen at night or after prolonged rest or physical inactivity and are alleviated with physical activity or a hot shower. Within 6 to 12 months after disease onset, sacroiliac joint damage occurs and is manifested by narrowing and erosions, as seen on this patient's radiograph. The earliest finding is fuzziness and irregularity of the sacroiliac articular surface. Ankylosing spondylitis is later associated with subchondral sclerosis. These findings are first detected and are more marked on the iliac side of the joint. The erosion of the joint surface can cause erosions in and irregularity (serration) of the subchondral bone. The concomitant pseudo-widening of the joint space later leads to gradual joint space narrowing. The inflammatory process results in healing and bone formation that ultimately bring about fusion of the sacroiliac joints. Inflammatory changes also begin in the T12–L1 region of the spine and eventually lead to ossification of the outer fibers of the annulus fibrosis and the development of syndesmophytes. In the most severe cases of ankylosing spondylitis, “bamboo spine” develops, which is associated with soft tissue and bony changes that reflect this condition's inflammatory and calcifying nature.

Sacral fracture usually occurs in patients with osteoporosis and is triggered by seemingly minor episodes of trauma. Osteoarthritis of the spine or sacroiliac joints is common in older patients and is manifested by spur formation originating in the corners of the vertebrae and disk-space narrowing. In addition, pain in osteoarthritis, as well as mechanical back pain, is alleviated by a night of rest and worsens as the day progresses; conversely, low back pain in ankylosing spondylitis occurs because of inflammation and is therefore worse in the morning and is alleviated as the day progresses. Cancer of the spine or pelvis most often occurs in older patients because of metastatic disease and would be unusual in an otherwise healthy 22-year-old man. Furthermore, metastatic disease is associated with severe pain during the day and night. Imaging studies in this setting typically reveal lytic or blastic lesions.


Key Point
Consider ankylosing spondylitis in patients <40 years with insidious onset of chronic low-back pain and stiffness of >3 months' duration and low-back pain and stiffness that worsen at night or after prolonged rest or physical inactivity.

Spinal cord compression due to epidural metastasis

A 64-year-old woman is evaluated in the emergency department for a 4-day history of progressive bilateral leg weakness and numbness and a 1-day history of urinary incontinence. She has also had increasingly severe midback pain for the past 2 months. She has a history of breast cancer diagnosed 2 years ago and treated with surgery and local radiation therapy. Her only current medication is tamoxifen.

Physical examination shows normal mental status and cranial nerves. Strength in the arms is normal. The legs are diffusely weak, 3/5 proximally and 4/5 distally. Sensory examination shows diminished pinprick sensation from the nipples downward; vibratory sense is severely diminished in the feet. Reflexes are 2+ in the biceps and triceps and 3+ in the knees and ankles. An extensor plantar response is present bilaterally. Anal sphincter tone is diminished.

Which of the following is the most appropriate diagnostic study at this time?
A CT scan of the lumbar spine
B Electromyography and nerve conduction studies
C MRI of the brain
D MRI of the entire spine
E Plain radiographs of the entire spine


ANSWER

This patient has bilateral weakness and upper motor neuron signs in the legs, sensory loss below the T4 level, and sphincter dysfunction; there are no signs or symptoms of brain or brainstem dysfunction. These findings are consistent with a spinal cord process. Given her history of breast cancer, metastatic spinal cord compression from an epidural metastasis is most likely and represents a neurologic emergency that must be excluded by urgent imaging. Although the distribution of pain and the sensory level suggest that the lesion is at the thoracic level, MRI of her entire spine is most appropriate because sensory levels can be unreliable for localizing the site of an epidural tumor. In addition, patients with a metastatic epidural tumor can have multiple sites of disease in the spine. MRI gives excellent images of both the spinal cord and the vertebrae, whereas CT does not adequately show the substance of the spinal cord and epidural region, making MRI the modality of choice in this patient.

CT scan of the lumbar spine is not an appropriate imaging choice in this patient. Because the spinal cord ends at around the L1 vertebral body, the spinal cord would not be visualized if imaging of the lumbar spine alone is performed. Plain radiographs of the spine can visualize some bony metastases and fractures but are not sensitive for the site of cord compression and do not image the spinal cord. Electromyography and nerve conduction studies are helpful in diagnosing peripheral nerve and muscle diseases but have no role in the evaluation of spinal cord disorders. MRI of the brain may be needed to assess for asymptomatic brain metastases but is not as urgent as spine imaging.


Key Point
Spinal cord compression due to epidural metastasis is a neurologic emergency for which urgent MRI of the entire spine is appropriate.

Omega 3

Acute nonspecific low back pain

A 48-year-old man is evaluated in the office for back pain of 1 month's duration. He describes the pain as an ache that has been slowly worsening and is only partially relieved with acetaminophen. He is most comfortable lying down and least comfortable sitting or moving. He has not had any recent trauma or previous back pain. He has not had weight loss, fever, chills, numbness or weakness in his legs, or problems with bowel or bladder function. His only other medical problems are hypertension and osteoarthritis of the knees, for which he takes hydrochlorothiazide and acetaminophen, with occasional ibuprofen.

On physical examination, vital signs, including temperature, are normal. He has mild lumbar paravertebral tenderness and spasm. Neurologic examination, including muscle strength, deep tendon reflexes, and sensation, is normal. The straight-leg-raising test is normal.

Complete blood count and metabolic panel performed in the office 3 months ago were normal.

Which of the following is the best initial management plan for this patient?
A Analgesics and strict bed rest
B CT scan of the lumbosacral spine
C MRI of the lumbosacral spine
D Physical therapy
E Symptomatic treatment


ANSWER

This patient should do well with symptomatic treatment alone. Most acute nonspecific pain resolves over time without the need for treatment, and controlling pain while symptoms diminish on their own is the goal for most persons. A patient with back pain but at low risk for serious disease by history and physical examination does not need anything other than simple analgesics and continued activity. Some patients may benefit from the addition of moist heat.

Strict bed rest is associated with prolongation of symptoms and higher morbidity. A systematic review of bed rest for low back pain and sciatica showed that advice to continue normal activities was more beneficial than bed rest. The need for obtaining plain radiographs of the spine can be determined on the basis of the history and physical examination. More sophisticated imaging is most useful when the pretest probability of underlying serious disease is high. Diagnostic imaging techniques are indicated in individuals with “red flags” for serious underlying disease, including fever, chills, weight loss, history of malignancy, injection drug use, trauma, or indolent course. Some authorities recommend radiographic imaging of patients >50 years of age with low back pain because of the increased incidence of malignancy, compression fractures, and spinal stenosis in this age group. Physical therapy is an appropriate adjuvant but is not an appropriate initial treatment. Clinical trial evidence has shown that beginning back exercises immediately actually delays recovery.


Key Points

* Most acute nonspecific low back pain resolves over time without the need for treatment.
* Diagnostic imaging is indicated for individuals with “red flag” signs or symptoms for serious disease, including fever, chills, weight loss, history of malignancy, injection drug use, trauma, or indolent course.

omega 3

Thursday, June 24, 2010

Vitamin C and Gout, A study

Vitamin C and Gout, A study

Men with a higher intake of vitamin C from food or supplements have a lower risk of developing gout, say researchers.

"Vitamin C intake may provide a useful option in the prevention of gout," Dr Hyon Choi and colleagues at the University of British Columbia in Vancouver say in a paper published in the Archives of Internal Medicine.

Gout is a form of arthritis from uric acid build-up that causes inflamed joints, typically in extremities such as toes, ankles and hands.

Sufferers are typically men age 40 and older, although it is known to also strike women.

Gout can lead to permanent joint damage and is linked to alcohol abuse, obesity, high blood pressure and a diet heavy in meat.

The research team found vitamin C appears to lower the levels of uric acid in the blood.

Lower risk

The study followed nearly 47,000 US men from 1986 to 2006 for a variety of health issues. Every four years, the men completed a dietary questionnaire, and their vitamin C intake through food and supplements was computed. During the study period 1317 men developed gout.

The researchers found that every 500 milligram increase of daily vitamin C intake produced a 17% decrease in the risk for gout.

Among the men studied those with daily intake of 1500 supplemental milligrams a day had a 45% lower risk of gout than those who took in less than 250 milligrams a day, says Choi.

An orange has about 70 milligrams of vitamin C - higher concentrations come in pill form.

Vitamin C may affect reabsorption of uric acid by the kidneys, increase the speed at which the kidneys work or protect against inflammation, all of which may reduce gout risk, the authors note.

But before stocking up on vitamin C, gout sufferers are reminded not to over do it.

The Australian National Health and Medical Research Council suggest adults should not consume more than 1000 milligrams of vitamin C each day.

Previous research has also linked fructose with an increased risk of gout. A 2008 study in the British Medical Journal found that two glasses of fruit juice a day, was a stronger risk factor than alcohol, and similar to meat and obesity.

Sunday, June 20, 2010

Is human brain lost in space

Is human brain lost in space

The limitations of the human brain mean some of the biggest mysteries of the universe may never be solved, a top scientist has claimed.

According to the President of the Royal Society Lord Martin Rees, questions about the big bang and the existence of parallel universes may be never resolved because of the built-in limitations of mankind. He said that a true fundamental theory of the universe may exist, but could be just too hard for human brains to grasp.

Just as a fish may be barely aware of the medium in which it lives and swims, so the microstructure of empty space could be far too complex for unaided human brains.

His prediction was prompted by the failure of scientists to reconcile the forces that govern the behaviour of the cosmos with those that rule the micro world of atoms and particles.

While Einstein used mathematical calculations to build his 1915 theory of general relativity and 20th-century physicists devised quantum theory, no scientists has since found the tools to unify the two.

"Some aspects of reality, a unified theory of physics or a full understanding of consciousness, might elude us simply because they are beyond human brains, just as surely as Einstein ideas would baffle a chimp, "Rees said.

The royal astronomer said, "There are powerful reasons to suspect that space has a grainy structure, but on a scale a trillion trillion times smaller than atoms. Solving how this might work is crucial for 21st-century science."

Friday, June 18, 2010

Why Girls Can't Stop Stressing

Girls Can't Stop Stressing

Women may be more prone to emotional stress than men because of heir brain chemistry. US researchers found females were more sensitive to low levels of a key stress hormone called corticotropine-releasing factor.

A study of rats undergoing a swim stress test showed female animals had neurons that were more sensitive to CRF.

It was also found that stressed male rats adapted by making themselves less responsive to the hormone, but females didn't. The same signaling pathway is known to play a role in humans.

This may help to explain why women are twice as vulnerable as men to stress-related disorders.